Compositions and methods for prevention and treatment of uncontrolled formation of intravascular fibrin clots are provided wherein fibrinolytic or anticoagulant drugs are biocompatibly coupled to red blood cell carriers.

Occlusions of blood vessels by intravascular clots cause or/and contribute to the pathogenesis of a variety of disease conditions including myocardial infarction, stroke and pulmonary embolism and thus represent a significant medical problem. Although fibrinolytics, such as plasminogen activators, have recently been used in the treatment of some of these diseases or conditions, their effectiveness and safety are still of a great concern, especially under specific prothrombotic conditions such as deep vein thrombosis and pulmonary embolism.
Pulmonary thromboembolism, a leading cause of mortality, is most often a complication of deep venous thrombosis. Statistics show that more than 95% of pulmonary emboli result from thrombi in the deep venous system of the lower extremities. Despite advances in medicine, the incidence and/or recognition of embolism and deep vein thrombosis appears to be increasing. This increase has been attributed to higher survival of trauma patients, an increase in orthopedic surgeries for joint replacement, and the widespread use of indwelling catheters, as well as the overall increase in medical and surgical procedures, particularly in older patients. As a result, methods of preventing and treating deep vein thrombosis are required to reduce the incidence of pulmonary embolisms.
Factors which promote deep vein thrombosis were defined as early as the nineteenth century and include stasis, abnormalities of the blood vessel wall, and alterations in the blood coagulation system. The highest risk groups for deep vein thrombosis are surgical patients requiring 30 minutes or more of general anesthesia, postpartum patients, patients with right and left ventricular failure, patients with fractures or injuries involving the lower extremities, patients with chronic deep venous insufficiency of the legs, patients on prolonged bed rest, cancer patients, obese individuals, and patients using estrogens. Treatment of deep vein thrombosis most often involves use of an anticoagulant such as heparin. Even with this well-known drug, however, there is no consensus regarding the optimum regimen of anticoagulant therapy that affords both safety and efficacy. In addition to anticoagulant therapy, thrombolytic agents, such as streptokinase and urokinase, have been used in the management of acute deep vein thrombosis.
Streptokinase, staphylokinase, tissue-type plasminogen activator or tPA, and urokinase are members of a family of agents known as plasminogen activators. These compounds act to dissolve intravascular clots by activating plasmin, a protease that digests fibrin. Plasminogen, the inactive precursor of plasmin, is converted to plasmin by cleavage of a single peptide bond. Plasmin itself is a nonspecific protease that digests fibrin clots as well as other plasma proteins, including several coagulation factors.
Fibrinolytic therapy with plasminogen activators have been shown to be useful in the treatment of myocardial infarction and stroke. However, application of these agents to dissolution of clots formed or lodged in other vascular areas such as deep venous areas is limited by extremely rapid elimination and inactivation after bolus dosing (Plow, E. et al. 1995. FASEB J. 9:939-945; Narita, M. et al. 1995. J. Clin. Invest. 96:1164-1168). Both tPA and urokinase undergo rapid inactivation by a circulating plasminogen activator inhibitor and plasmin itself is inactivated by a circulating glycoprotein, xcex1-2-antiplasmin (Collen, D. 1996. Circulation 93:857-865; Reilly, C. et al. 1991. Arterioscl. Thromb. 11:1276-1286). xcex1-2-antiplasmin inactivates staphylokinase, while streptokinase is more resistant to this endogenous glycoprotein inhibitor (Collen, B. et al. 1993. Eur. J. Biochem. 216:307-314). Although therapeutic doses of plasminogen activators can overwhelm the potential inhibitory activity of plasminogen activator inhibitor and xcex1-2-antiplasmin, other inhibitors of plasminogen activators also are present (C1-inhibitor, xcex12-macroglobulin, anti-trypsin) and contribute to the decrease over time in the fibrinolytic response upon treatment with plasminogen activators (Collen, D. 1996. Circulation 93:857-865). Such inactivation, or degradation of plasminogen activators and plasmin reduce the effectiveness of thrombolytic therapy and thus fail to prevent re-occlusion of blood vessels.
To overcome this problem, attempts have been made to infuse plasminogen activators intravenously for prolonged periods of time with little success; failure was attributed to the harmful side effects such as bleeding and uncontrolled tissue proteolysis that occurred, likely after extra vascular deposition of plasminogen activators.
Accordingly, several different approaches have been attempted to improve efficacy of these agents in deep vein thrombosis including: prolongation of the half-life of plasminogen activators in blood; protection of plasminogen activators from inactivation by inhibitors; and targeting plasminogen activators to fibrin and thrombi. For example, chemical modifications and incorporation of plasminogen activators into liposomes have been used to prolong the half-life of plasminogen activators in the circulation (Kajihara, J. et al. 1994. Biochim. Biophys. Acta 1199:202-208; Heeremans, J. et al. 1995. J. Drug Targeting. 73:488-494). However, these studies have shown that the activity of liposome-encapsulated plasminogen activators is strongly compromised by steric limitations. Genetically engineered tPA compounds have also been produced which possess altered pharmacokinetic properties, enhanced resistance to inhibitors, and higher fibrinolytic potency (Collen, D. 1996. Circulation 93:857-865; Collen, D. 1993. Lancet 342:34-36; Krishnamurti, C. et al. 1996. Blood 87:14-19; Lijnen, R. and D. Collen. 1992. Ann. N.Y. Acad. Sci. 667:357-364). Several laboratories have explored conjugation of plasminogen activators with antibodies recognizing fibrin or activated platelets in order to localize plasmin generation to the clot (Holvoet, P. et al. 1993. Circulation 87:1007-1016; Runge, M. et al. 1996. Circulation 94:1412-1422; Fears, R. and G. Poste. 1994. Fibrinolysis 8:203-213). However, such conjugated plasminogen activators with affinity for clot components only bind to the superficial layer of the clot and do not enter into the clot interior (Sakharov, D. and D. Rijken. 1995. Circulation 92:1883-1890). In addition, clots bind only a small fraction of injected xe2x80x9cfibrin-specificxe2x80x9d plasminogen activator because of limited surface area of the formed clots.
Further, to date, none of these methods for modifying plasminogen activators prevents deposition of plasminogen activators in tissues, which can lead to an increase in harmful side effects; they all represent molecules or molecular complexes with sizes that do not exceed that of blood proteins. Such deposition leads to plasmin activation in tissues. Activated plasmin degrades the extracellular matrix, thus causing vascular remodeling, abnormal elevation of vascular permeability and even partial denudation of subendothelium (Plow et al. 1995. FASEB J. 9:939-945; Shreiber et al. 1995. J. Cell. Physiol. 165:107-118).
Accordingly, there is a need for methods of modifying plasminogen activators which not only decrease the rate of elimination and degradation of the plasminogen activators, but also prevent deposition of the plasminogen activator in the tissues.
Red blood cells (RBCs) normally have a life span of 120 days and thus can serve as natural carriers for drugs and biomolecules. Autologous RBCs can be easily obtained from the patient""s blood, loaded with drug, and re-injected. RBCs have been used as carriers for drugs loaded into the inner volume of RBCs (Poznansky, M. and R. Juliano. 1984. Pharmacol. Rev. 36:277-324; Kirch, M. et al. 1994. Biotechnol. App. Biochem. 19:331-363; Kinoshita, K. and T. Tsong. 1978. Nature 272:258-260). In addition, methods for conjugation of proteins to RBCs have been developed, including methods using a streptavidin-biotin pair as a cross-linker.
Streptavidin is a 60 kDa protein that possesses four high affinity biotin binding sites and the streptavidin-biotin pair is widely used in biomedicine as a cross-linking agent (Wilchek, M. and E. Bayer. 1988. Anal. Biochem. 171:1-32). Several groups have reported application of streptavidin-biotin technology in vivo for gamma-immunoscintigraphy (Kalofonos, H. et al. 1990. J. Nucl. Med. 31:1791-1796) and drug targeting (Pardridge, W. et al. 1995. Proc. Natl. Acad. Sci. USA 92:5592-5596; Muzykantov, V. et al. 1996. Proc. Natl. Acad. Sci. USA 93:5213-5218). Moreover, streptavidin induces no known harmful reactions in animals or humans (Kalofonos, H. et al. 1990. J. Nucl. Med. 31:1791-1796). Biotinylation of RBCs can be accomplished in manner which has no effect on the life span and biocompatibility of these cells in vivo in animals (Suzuki, T. and G. Dale. 1987. Blood 70:791-795; Muzykantov, V. et al. 1991. Blood 78:2611-2618).
Biotinylation of proteins, including plasminogen activators, without significant reduction of functional activity of the plasminogen activator has been described (Muzykantov, V. et al. 1986. Biochem. Biophys. Acta, 884:355-363; Muzykantov, V. et al. 1995. Anal. Biochem., 226:279-287; Muzykantov, V. et al. 1996. J. Pharm. Exp. Ther., 279:1026-1034). In in vitro studies, polyvalent conjugation of various biotinylated proteins such as antibodies, enzyme peroxidase and fibrinolytic streptokinase with streptavidin conjugated-biotinylated RBCs (SA/b-RBC) was performed and high functional activity of these proteins bound to SA/b-RBC in vitro was reported (Muzykantov, V. et al. 1985. FEBS Lett. 182:62-66; Muzykantov, V. et al. 1986. Biochim. Biophys. Acta 884:355-363; Muzykantov, V. et al. 1987. Am. J. Pathol. 128:226-234).
However, polyvalent conjugation of biotinylated proteins to b-RBCs via streptavidin cross-linker profoundly compromises the biocompatibility of the carrier RBC. Binding of streptavidin to b-RBC leads to elimination of homologous restriction of both classical and alternative pathways of the complement thereby causing lysis of SA/b-RBC in the plasma (Muzykantov, V. et al. 1991. Blood 78:2611-2618; Muzykantov, V. et al. 1992. Int. J. Artif. Organs 15:620-627; Muzykantov, V. et al. 1993. FEBS Lett. 318:108-112). Streptavidin-induced cross-linking and membrane redistribution of the complement inhibitors, DAF and CD59, in biotinylated RBC membrane represents the likely mechanism for complement activation and lysis (Muzykantov, V. et al. 1992. Biochim. Biophys. Acta 1107:119-125; Zaltzman, A. et al. 1995. Biochem. J. 307:651-656). In addition, fixation of C3b complement component has been shown to lead to an increased rate of elimination of SA/b-RBC from the bloodstream via hepatic and splenic uptake (Muzykantov, V. et al. 1992. Int. J. Artif. Organs 15:620-627; Muzykantov, V. et al. 1996. Anal. Biochem. 214:109-119). Accordingly, drugs polyvalently conjugated to an RBC carrier via streptavidin can not be delivered to their targets in vivo.
This lack of biocompatibility of SA/b-RBC carrier can be overcome through modifications of the conjugation method. For example, monovalent coupling of streptavidin to b-RBCs has been demonstrated to produce a serum-stable carrier SA/b-RBC capable of binding up to 105 molecules of a biotinylated model protein per RBC (Muzykantov, V. et al. 1991. Biochem. J. 273:393-397; Muzykantov, V. et al. 1992. Biochim. Biophys. Acta 1107:119-125; Muzykantov, V. et al. 1993. Anal. Biochem. 208:338-342; Muzykantov, V. and R. Taylor. 1994. Anal. Biochem. 223:142-148; Muzykantov, V. et al. 1996. Anal. Biochem. 214:109-119;). B-RBC carrier, monovalently conjugated with a model biotinylated protein (b-IgG) via streptavidin, circulated for at least a day as a stable complex after intravenous injection in animals, with no evidence of lysis or hepatic uptake (Muzykantov, V. et al. 1996. Anal. Biochem. 214:109-119). In these studies, it was also found that the half-life b-IgG monovalently conjugated with SA/b-RBCs significantly exceeded that of non-conjugated b-IgG (Muzykantov, V. et al. 1996. Anal. Biochem. 214:109-119).
It has now been found that monovalent conjugation of a biotinylated plasminogen activator to a SA/b-RBC carrier results in prolonged circulation of the plasminogen activator in the bloodstream and decreased deposition of the plasminogen activator in the tissues. It has also now been found that monovalent conjugation of biotinylated soluble receptor for urokinase plasminogen activator, (b-suPAr), and monovalent conjugation of biotinylated tissue plasminogen activator, (tPA), to a SA/b-RBC carrier results in prolonged circulation of these biotinylated plasminogen activators in the bloodstream in a form of the receptor/RBC complex (b-suPAr/SA/b-RBC complex) and the tPA/RBC complex, respectively. Moreover, it has now been found that the b-suPAr/SA/b-RBC complex retains its ability to bind single chain urokinase plasminogen activator (scuPA) even after prolonged circulation in the bloodstream and that non-covalent binding of this fibrinolytic precursor (scuPA) to the receptor conjugated to RBC carrier (i.e., to b-suPAr/SA/b-RBC complex) leads to scuPA activation and greater resistance to plasma inhibitors and thus provides increased fibrinolytic activity on the clot itself. It has also been found that pulmonary vascular uptake of tPA is increased by crosslinking tPA to biotinylated RBC to form a tPA/RBC complex, with the increase seen to a level that exceeds the level of tPA/RBC complex in larger blood vessels. Finally, it has now been found that conjugation of tPA and suPAr with a monoclonal antibody against human CR1 promotes specific coupling of fibrinolytically active anti-thrombotic agents to red blood cells, limiting the non-specific binding and tissue uptake of the complexes. Accordingly, the present invention relates to compositions comprising a fibrinolytic or anticoagulant drug biocompatibly coupled to a carrier red blood cell molecule and methods of using these compositions in the treatment of uncontrolled intravascular clot formation including deep vein thrombosis.
An object of the present invention is to provide compositions which comprise a fibrinolytic or anticoagulant drug biocompatibly coupled to the surface of red blood cell carrier. In one embodiment, this coupling is accomplished by crosslinking biotinylated tissue plasminogen activator to biotinylated red blood cells via streptavidin. In another embodiment, biotinylated tissue plasminogen activator is crosslinked via streptavidin to biotinylated molecules such as monoclonal antibodies which then couple specifically with red blood cells as carriers. An example of a monoclonal antibody specific for red blood cells is a monoclonal antibody against human CR1.
Another object of the present invention is to provide a method for decreasing the rate of elimination of a fibrinolytic or anticoagulant drug from blood and decreasing deposition of the drug in tissues by biocompatibly coupling the drug to red blood cell carriers.
Another object of the present invention is to provide a method for activating a precursor of fibrinolytic, single chain urokinase plasminogen activator (scuPA) in blood which comprises binding of scuPA to its receptor which is biocompatibly coupled to red blood cell carriers.
Another object of the present invention is to provide a method for increasing pulmonary vascular uptake of tissue plasminogen activator which comprises coupling tissue plasminogen activator to red blood cells and administering the tissue plasminogen activator coupled to the red blood cell to an animal.
Another object of the present invention is to provide a method for increasing degradation of existing intravascular fibrin clots by a fibrinolytic drug in blood of a patient which comprises administering to a patient a composition comprising a fibrinolytic drug biocompatibly coupled to red blood cell carriers.
Yet another object of the present invention is to provide a method of preventing and treating uncontrolled formation of intravascular clots in a patient which comprises administering to a patient suffering from uncontrolled formation of intravascular clots a composition comprising a fibrinolytic or anticoagulant drug biocompatibly coupled to red blood cell carriers.
The present invention provides compositions and methods for prevention and treatment of deep vein thrombosis, pulmonary embolism and other diseases or syndromes characterized by uncontrolled formation of intravascular fibrin clots. The invention is based on the biocompatible coupling of a drug, preferably a fibrinolytic or anticoagulant drug, more preferably a plasminogen activator, to RBCs which serve as carriers providing prolonged circulation and restricted tissue uptake of the drug. The monovalent conjugation of plasminogen activators to biotinylated RBCs via streptavidin (referred to herein as SA/b-RBC) serves as an example in the present invention of a biocompatible coupling method. Biotinylated plasminogen activators are referred to herein as b-PAs. Another example of biocompatible coupling is the crosslinking of plasminogen activators to biotinylated molecules such as monoclonal antibodies which then couple specifically with red blood cells in whole blood. An example of an antibody useful in this coupling method is a monoclonal antibody against human CR1.
Experiments were performed to examine the conjugation of b-PAs to biotinylated RBCs via streptavidin. Results of in vitro tests showed that streptavidin provided specific and effective conjugation of the b-PAs to the biotinylated RBC (Table 1)
When tested in a fibrin plate lysis assay and in an assay of release of radio labeled iodine from a fibrin clot (formed from 125I-fibrinogen), the b-PA/SA/b-RBC conjugates were shown to be stable and to display high fibrinolytic activity. When the b-PA/SA/b-RBC conjugates were added to solution of 125I-fibrinogen before formation of fibrin clot, the subsequent fibrinolysis attained 71xc2x112%. Non-conjugated PAs induced 96xc2x15.5% lysis of fibrin clot. Thus, conjugation of b-PA to SA/b-RBC does not compromise significantly fibrinolytic activity of PA.
The half-life (i.e., rate of degradation and elimination from blood) of RBC-conjugated plasminogen activators was also examined in vivo in rats. The kinetics of blood clearance of 125I-scuPA, 125I-urokinase, 125I-streptokinase, or 125I-tPA were determined following intravenous injection of scuPA or tPA at a dose of 5 xcexcg/kg. Within one hour of injection, the blood level of scuPA dropped to less than 5% of the injected dose. In contrast, the blood level of SA/b-RBC-conjugated scuPA was 10-fold higher at the one hour time point, and remained at high levels (20% of injected dose) for up to 24 hours. Similar results were seen with tPA, urokinase and streptokinase. Pharmacokinetic analysis of the areas below the curves of blood level of plasminogen activators versus those biocompatibly coupled to RBC during 24 hours after intravenous injection revealed that the half-life of RBC-conjugated PAs exceeded that of non-conjugated PAs by several orders of magnitude.
Further, conjugation of the biotinylated plasminogen activators with SA/b-RBC carrier did not cause intravascular lysis of the carrier RBC labeled with 51Cr and did not change the biodistribution of RBC in any tissues except the spleen. Splenic uptake of the b-PA/SA/b-RBC was elevated about 4-fold. However, such increases in splenic uptake of chemically modified RBCs are well known in the literature. Importantly, after injection of b-PA/SA/b-RBC conjugates, tissue uptake of plasminogen activators was markedly reduced. For example, level of 125I-tPA in the brain tissue (expressed as percentage of that in the blood) was 18.3xc2x11.1%, whereas that parameter for 125I-b-tPA/SA/b-RBC was 1.8xc2x10.5%. Thus conjugation with RBC carrier provides ten fold reduction of the uptake in the brain.
In the case of tPA, the tissue distribution data revealed that conjugation of tPA to RBC not only prolonged its bioavailability in the circulation, but also dramatically increased its pulmonary vascular uptake. One hour after injection, 20% of the radiolabeled tPA was found in the lungs of rats injected with 125I-tPA/RBC, a value that is 100-fold higher than what is seen following injection of soluble 125I-tPA. Yet, the pulmonary uptake of tPA/51Cr-RBC was only marginally higher than that of non-modified RBC (3.8% versus 1.2%). Thus, the lungs of rats injected with tPA/RBC contained five-fold more radiolabeled tPA than radiolabeled RBC, whereas the ratio of radiolabeled tPA to radiolabeled RBC equaled one in all other tissues, including blood. This indicates that there was a significant transfer of tPA to the lung, the pulmonary vasculature, a result that was not seen in other organs (an organ-specific effect). This transfer of tPA from the carrier RBC occurred rapidly and lasted for several hours. In addition, the lung to blood ratio of 125I-tPA/RBC was 20 times higher than that of radiolabeled tPA whereas in the kidney, brain and heart, these organ to blood ratios were ten times lower, data indicating that coupling of tPA to RBC strongly restricted uptake by organs other than the lung.
Experiments were also performed to determine strategies for activating inactive plasminogen activators in blood. The soluble form of urokinase receptor (suPAr) has been reported to bind scuPA and convert inactive scuPA to an active uPA, as well as protect it from inhibition by plasma inhibitors (Higazi, A. et al. 1995. J. Biol. Chem. 270:17375-17380; Higazi, A. et al. 1996. Blood 87:3545-3549). The half-life of suPAr in blood, however, is short, in the range of minutes following intravenous injection. Accordingly biotinylated suPAr was coupled to SA/biotinylated RBCs to prolong the half-life of suPAr in vivo. This coupling yielded a complex designated as b-suPAr/SA/b-RBC that possessed up to 1.3xc3x97105 molecules of suPAr per SA/b-RBC molecule. Without streptavidin conjugated to the biotinylated RBCs, the binding of suPAr to the RBC carrier was an order of magnitude lower (1.2xc3x97104 suPAr molecules/RBC).
The ability of b-suPAr/SA/b-RBC complex to bind single chain urokinase plasminogen activator (scuPA) was examined in vitro by incubating 125I-labeled scuPA with b-suPAr/SA/b-RBC or intact RBCs (used as a control of non-specific binding of scuPA). It was found that 1.5+0.1xc3x97104 molecules of 125I-scuPA per b-suPAr/SA/b-RBC bound while only 0.06+0.01xc3x97104 125I-scuPA per RBC bound. Thus, the b-suPAr/SA/b-RBC complex binds scuPA effectively and specifically.
The fibrinolytic activity of the scuPA associated with b-suPAr/SA/b-RBC complex (scuPA/b-suPAr/SA/b-RBC) was then examined. Fibrin clots were prepared that contained 125I-fibrin and either phosphate-buffered saline (control clots), RBC carrier alone, b-scuPA/SA/b-RBC complexes, scuPA/b-suPAr/SA/b-RBC complexes, or scuPA alone. In control clots, less than 5% of the radiolabel was released to the supernatant after 120 minutes incubation at 37xc2x0 C. Neither RBC carrier alone nor b-scuPA/SA/b-RBC complexes (b-scuPA conjugated to SA/b-RBC directly) caused detectable fibrinolysis. Free scuPA caused about 10% fibrinolysis. However, similar doses of scuPA/b-suPAr/SA/b-RBC complexes caused 95xc2x14% fibrinolysis. These results indicate that binding of scuPA to b-suPAr conjugated with SA/b-RBC indeed stimulates fibrinolytic activity of scuPA and that b-suPAr/SA/b-RBC complex is active as a fibrinolytic agent.
To determine the fate of the b-suPAr/SA/b-RBC complex in vivo, rats were injected intravenously with 125I-suPAr/SA/51Cr-b-RBC and the blood levels and biodistribution of the complex were studied. Conjugation of suPAr to the carrier RBC significantly increased the half-life of suPAr in the bloodstream. The blood level of non-conjugated suPAr was undetectable within 3 hours, while 20% of the b-suPAr/SA/b-RBC complex was measurable out to 24 hours after injection.
Biodistribution studies showed that conjugation of suPAr did not lead to hemolysis or to reticuloendothelial uptake of the carrier RBC. In fact, distribution of the conjugated b-suPAr/SA/51Cr-b-RBC was similar to that of the control 51Cr-RBC distribution. One hour after injection of rats with b-suPAr/SA/51Cr-b-RBC, blood samples were obtained for determination of binding of 125I-scuPA to blood cells. Blood obtained from rats injected with the b-suPAr/SA/b-RBC complexes bound three times more scuPA than blood obtained from control animals. These data indicate that b-suPAr/SA/b-RBC is functionally active in the circulation and is capable of binding scuPA. Quantitation of the binding revealed that, after circulating for one hour in the bloodstream, each b-suPAr/SA/b-RBC complex binds approximately 104 molecules of scuPA. This value is similar to the initial levels of scuPA binding of b-suPAr/SA/RBC before injection in rats. Therefore, circulation in the bloodstream did not alter the binding ability of this complex.
The fibrinolytic activity of crosslinked plasminogen activators was examined in vivo in rats. Rats were injected intravenously with either 250 xcexcg of unconjugated tPA or 50 xcexcg of tPA conjugated to carrier RBC and blood was collected after 10, 60 and 180 minutes. 125I-fibrinogen was added to all samples and blood was allowed to coagulate at room temperature. Neither tPA nor tPA/RBC suppressed clot formation at the test concentrations, an important consideration in terms of safety of the present invention. The clots were then incubated at 37xc2x0 C. and the rate of clot lysis was examined. Spontaneous fibrinolysis did not exceed 10% at either 10 minutes or 60 minutes in rats injected with saline. Fibrinolysis was augmented 10 minutes after injection of unconjugated tPA. However, the rate of fibrinolysis in blood obtained 60 minutes after tPA injection only marginally exceeded that of the control animals, as was expected in light of the rapid elimination of tPA from blood. Remarkably, blood obtained even 3 hours after tPA/RBC injection retained significant fibrinolytic activity (40% clot lysis), even though the injected dose of tPA was 5-fold lower. These data show that conjugation of tPA to the carrier RBC significantly increased the circulation of enzymatically active plasminogen activator in vivo and prolonged the in vivo half-life of the plasminogen activator in blood to a level that would overcome any steric limitations that might be imposed by conjugation to RBC.
Experiments were also performed with mouse RBCs. In these experiments, tPA was conjugated to washed murine RBC in Krebs-Ringer buffer containing glucose and 3% bovine serum albumin to minimize energy depletion and mechanical damage. Using methods as described for rat RBCs, 3 to 4xc3x97104 molecules of biotinylated tPA or suPAr per biotinylated murine RBC were coupled without detectable hemolysis as shown below in Table 2. In these tests, the murine RBC were biotinylated with 10 xcexcM BxNHS in Krebs-Ringer glucose (pH 7.4). The radiolabeled activators were coupled to b-RBC via streptavidin in BSA-containing Krebs-Ringer glucose. Therefore, murine RBC were conjugated in the same way as human and rat RBCs.
Experiments were also performed to determine whether conjugation of soluble uPA receptor (suPAr) to RBCs prolongs its half-life in mice as was observed in rats. Radiolabeled suPAr or RBC/suPAr complexes were generated with b-RBC and then injected intravenously in mice. Conjugation of suPAr did not accelerate splenic or hepatic uptake of the carrier murine RBC. Moreover, coupling to the carrier murine RBC prolonged the circulation of suPAr by several orders of magnitude from several minutes to several hours.
Experiments were also performed with monoclonal antibodies as the RBC carrier molecules. In these experiments, the human monoclonal antibody CR1 was used. b-tPA and b-suPAr were conjugated to biotinylated monoclonal antibody 1B4 directed against human CR1 using a streptavidin crosslinker. Using methods similar to those with the ex vivo carrier, the anti-CR1/125I-tPA and anti-CR1/125I-suPAr heteropolymers were shown to bind specifically to naive human RBC in whole blood (Table 3). The amount of tPA and suPAr coupled (2-3xc3x97103 molecules per RBC) was equivalent to what was produced for other anti-CR1 conjugated proteins (Muzykantov and Taylor 1994. Anal. Biochem. 223:142-148). The conjugation of b-tPA via the antibody suppressed the non-specific adhesiveness by an order of magnitude ( less than 100 molecules of IgG/125I-tPA bound per naive RBC versus 4,000 molecules 125I-tPA bound per naive RBC, see column 3 of Table 2). These data demonstrated that immunotargeting of anti-CR1/tPA in vivo was likely specific and restricted predominantly to RBC.
To examine the fibrinolytic activity of the resultant human anti-CR1/tPA-RBC complex, radiolabeled fibrin clots were used as described before. Anti-CR1/tPA-RBC lysed fibrin and blood clots demonstrating that tPA coupled to RBC via the anti-CR1 antibody retains its functional activity. Lysis of clots by IgG/tPA-RBC used as controls was approximately ten times less effective (Table 3, column 5, bottom row) and did not differ significantly from the background level of fibrinolysis mediated by naive RBC.
Studies were then performed to examine the transfer of tPA from its carrier RBC to tissue, specifically vascular tissue. As a model for pulmonary vasculature transfer, human umbilical vein endothelial cells (HUVEC) cells were used in culture. RBC carriers were constructed by the method of the present invention. The RBCs carried either no protein (naive RBC), tPA (tPA/RBC, suPAr (suPAr/RBC), scuPA conjugated to suPAr molecules (scuPA-suPAr/RBC), scuPA (scuPA/RBC), or anti-TM/RBC. RBC carrying the protein molecules (3xc3x97104 molecules/RBC) were incubated with HUVEC (2xc3x97107 RBC per well, 160 minutes at 37xc2x0 C.). Non-bound cells were eliminated by gentle washing with a phenol-free medium and 1 ml of water was added to lyse bound RBC. The number of HUVEC-bound RBC was determined by measuring the absorbance at 405 nm emitted by hemoglobin released into the cell lysates and expressed as 1,000 RBC/well. The results are shown in Table 4.
Neither tPA/RBC, suPAr/RBC, nor scuPA-suPAr/RBC were adhesive to HUVEC, as evidenced by binding levels comparable to naive RBC. In contrast, scuPA/RBC complex or RBC conjugated with antibody against endothelial surface glycoprotein, thrombomodulin (used as a positive control) were highly adhesive. Accordingly, complexes comprising a soluble form of urokinase receptor biocompatibly coupled to a red blood cell carrier minimize the potential hazardous interactions of urokinase with endothelial cells.
Next, 125I-tPA/RBC were incubated with HUVEC , the unbound RBC removed by washing and 125I in the wells measured. HUVEC bound 8.1+0.2xc3x97109 molecules tPA/well after incubation with 125I-tPA/RBC. The results shown in Table 4 indicate that only 5% of this amount of cell-bound 125I-tPA was attributable to RBC-associated tPA in the wells (3xc3x97104 molecules 125I-tPA/RBCxc3x971.7xc3x97103 RBC/well=5.1xc3x97108 molecules RBC/125-tPA/well). Therefore, tPA transfers from RBC to HUVEC, demonstrating the successful use of the RBC carrier of the instant invention. Accordingly, the present invention provides novel compositions for prolonging the half-life of drugs including fibrinolytics such as plasminogen activators and anticoagulants in the bloodstream of animals including humans by decreasing the degradation and elimination of the drugs in the bloodstream. The present invention also provides a method for increasing dissolution of fibrin clots by plasminogen activators in blood of a patient which comprises administering to a patient a composition comprising plasminogen activators biocompatibly coupled to red blood cell carriers. Thus, the compositions of the present invention are useful in preventing and treating uncontrolled formation of intravascular clots in a patient by administering to a patient suffering from uncontrolled formation of intravascular clots a composition comprising a fibrinolytic or anticoagulant drug biocompatibly coupled to red blood cell carriers.
Preparation of compositions comprising biocompatible red blood cell carriers is performed in accordance with known methods of conjugation and is exemplified by monovalent crosslinkage via biotin, streptavidin, and monoclonal antibodies. However, as will be obvious to those of skill in the art upon this disclosure, other methods of biocompatible coupling, i.e., chemical conjugation, noncovalent binding via a conjugated receptor, or other means of attachment which does not lead to poor biocompatibility of the RBC carrier exemplified by lysis and increased phagocytosis could also be used. In a preferred embodiment, the compositions of the present invention further comprise pharmaceutically acceptable vehicles for intravenous administration to patients with a disease or condition characterized by uncontrolled intravascular fibrin clot formation including deep venous thrombosis. In addition to plasminogen activators, it is believed that this delivery system will also be useful in delivering other drugs, such as anticoagulants. Compositions of the present invention are preferably administered systemically as a bolus intravenous injection of a single therapeutic dose of the drug (for example, 0.1-1.0 mg/kg for plasminogen activators).
The following nonlimiting examples are provided to further illustrate the present invention.

Trustees of the University of Pennsylvania


Therapeutic composition having anti-infective activity. The therapeutic composition is a formulation comprising an antibiotic, preferably a tetracycline, most preferably doxycycline, which has not been chemically modified to eliminate antimicrobial efficacy. The antibiotic is preferably in a liquid vehicle, most preferably one that contains at least 20% alcohol by volume. The therapeutic composition is preferably in local delivery form and is self-administered orally or via the nasal cavity. Administration of the therapeutic composition of the present invention treats diseases that originate from the oral cavity or that do not originate in the oral cavity, but are affected by contaminants, such as viruses or bacteria, in the oral cavity entering the bloodstream including but not limited to periodontal disease, sinusitis, gingivitis, the common cold, sore throat, influenza, allergies (particularly to tree pollen), resistant pneumonia, diseases of the gastrointestinal tract, inflammatory diseases such as rheumatoid arthritis, cancer, ulcers, heart disease, etc.

The accumulation bacteria in the oral cavity, such as on the teeth or tongue has been identified as a contributor or cause of various inflammatory conditions, including gingivitis, periodontitis and other gum diseases. Treatment of the oral cavity with antibiotics to reduce or eliminate the effects of bacteria is known. For example, broad spectrum antibiotics such as tetracyclines and metronidazole have been used in the treatment of periodontal disease to reduce oral cavity microflora. Typically such use has been systemic, which can result in various undesirable side effects, including the threat or danger or building allergies or immunity to the antibiotic, overgrowth of opportunistic yeast and fungi and intestinal disturbances.
Many other common inflammatory diseases, such as sinusitis, diseases of the gastrointestinal tract (including those that manifest themselves in stomach and bowel problems), the common cold, influenza, allergies, halitosis, pneumonia, etc., also may be caused by viruses and/or bacteria. Often the source of the bacteria and viruses is the oral cavity, especially the ear, nose and throat passages, and the sinuses. Once the bacteria and/or viruses are resident in the oral cavities or sinuses (e.g., the maxillary, frontal and ethmoid), they can continually cause infection through circulation in the blood stream. Continual reduction or elimination of these bacteria and viruses would reduce chronic infection in the body.
The problems of the prior art have been overcome by the present invention, which provides a therapeutic composition having anti-infective activity. In a preferred embodiment, the therapeutic composition is a formulation comprising an antibiotic, preferably a tetracycline, most preferably doxycycline, which has not been chemically modified to eliminate antimicrobial efficacy. The antibiotic is preferably in a liquid vehicle, most preferably one that contains at least 20% alcohol by volume. The therapeutic composition is preferably in local delivery form and is preferably self-administered orally or via-the nasal cavity. The therapeutic composition most preferably is a self-delivered formulation in local delivery form that consists essentially of a tetracycline, most preferably doxycline, which has not been chemically modified to eliminate antimicrobial efficacy, and a liquid vehicle, more preferably one which contains at least 20% alcohol by volume, and most preferably one which consists essentially of sterile water or Listerine or the like, which tetracyline is preferably present in the formulation in the amount of between 50 to 100 mgs per ounce of liquid vehicle.
Administration of the therapeutic composition of the present invention treats diseases that originate from the oral cavity or that do not originate in the oral cavity, but are affected by contaminants, such as viruses or bacteria, in the oral cavity entering the bloodstream including but not limited to periodontal disease, sinusitis, gingivitis, the common cold, sore throat, influenza, allergies (particularly to tree pollen), resistant pneumonia, diseases of the gastrointestinal tract, inflammatory diseases such as rheumatoid arthritis, cancer, ulcers, heart disease, etc.
The therapeutic compositions of the present invention are local delivery compositions that have anti-infective activity and comprise an antibiotic, preferably a tetracycline which has not been chemically modified to eliminate antimicrobial efficacy. The compositions are effective to prevent pollutants from passing from oral passages into the blood stream.
The tetracyclines useful in the compositions of the present invention include apicycline, chlortetracycline, clomocycline, demeclocycline, doxycycline, guamecycline, lymecycline, meclocycline, methacycline, minocycline, oxytetracycline, penimepicycline, pipacycline, rolitetracycline, sancycline, senociclin, and tetracycline. Doxycycline is particularly preferred.
The therapeutic composition of the invention also includes a carrier which is any compatible, nontoxic substance suitable to deliver the antibiotic. Carriers can include sterile water, alcohol, fats, waxes, inert solids and even liposomes. Preferably, the antibiotic is in a liquid vehicle. Water is a preferred liquid for the liquid vehicle and the vehicle even more preferably comprises at least about 20% alcohol by volume, more preferably 20-40% alcohol and most preferably about 20-28% alcohol. Preferably, the therapeutic composition does not include a morpholinoamino alcohol or pharmaceutically-acceptable salt thereof. One particularly preferred formulation includes a mixture of doxycline with Listerine(copyright), which is 0.064% thymol, 0.092% eucalyptol, 0.060% methylsalicylate, 0.042% menthol, 26.9% alcohol, poloxamer 407, water, sodium benzoate and caramel. Other suitable formulations include a mixture of doxycline with other commercially available mouthwashes, oral rinses or anti-plaque formulations. Pharmaceutically acceptable adjuvants may also be incorporated into the therapeutic composition. In certain therapeutic compositions of the invention, antiphlogisitic agents are not preferred. The compositions of the present invention also may contain various inactive ingredients, such as sweeteners (natural and artificial), flavorings (natural or artificial), colorants, preservatives, etc.
The amount of antibiotic used in the formulation depends upon the frequency of the dose, the particular infection and the severity of the infection being treated, the method of local administration of the composition and the effect desired (including whether the treatment is a prophylactic or therapeutic application). Actual methods for preparing administrable compositions will be known or apparent to those skilled in the art and are described in more detail in, for example, Remington""s Pharmaceutical Science, 17th Ed., Mack Publishing Co., Easton, Pa. (1985), which is incorporated herein by reference. Preferably the formulation contains from about 50 to about 100 mgs tetracycline, preferably doxycline, per ounce of total liquid in the formulation. The formulation is prepared by mixing the tetracycline with the liquid vehicle and shaking the mixture.
Alternative forms of the therapeutic composition of the present invention include lozenges, chewing gum, toothpaste, salve, ointments and gels. The compositions also can be provided in the form of a kit, including the tetracycline and the liquid vehicle.
In the preferred form of the present invention, the therapeutic composition is a mouthwash or a rinse, nose drops or ear drops, and is self-administered. For example, the mouthwash or rinse can be introduced into the mouth and held in the mouth for at least 30 seconds and preferably at least 1 minute. During the holding period, the mouthwash or rinse is preferably swirled around the mouth in order to bathe the teeth and gums in the composition. Gargling with the mouthwash and rinse during this holding period can also be carried out. The mouthwash or rinse is then expelled from the mouth into a waste receptacle. This procedure can be carried out at least once daily, preferably 2-6 times daily. If the mouthwash or rinse is being given for preventative purposes, then the rinse is preferably used twice a day, preferably in the AM and in the PM on a long-term basis and preferably consists of 50 mgs of antibiotic, preferably doxycline per 1 ounce of liquid vehicle. The rinse can be used continually for many years without diminishing its benefits, and with no adverse side effects. The rinse can be use on an acute basis or for continual periods as long as 3 months, 6 months, 1 year, 2 years, 5 years or greater. Long term use of more than 5 years with no reported adverse side effects is documented. If the mouthwash or rinse is being used to treat an acute infection, the dosage of antibiotic, preferably doxycline, is doubled to 100 mgs per ounce of liquid vehicle and the rinse is preferably used between 4 to 6 times a day during the period of acute infection. Nosedrops are particularly useful for treating or preventing sinusitis. If nosedrops comprising the therapeutic composition of the invention are used, between 3 to 10, preferably 4 to 7, and more preferably 5 drops should be placed in each nostril between 3 to 5 times per day, based on the severity of the infection. This should be done for approximately one week. Administration of the composition of the present invention to the oral cavity cleanses the oral cavity of bacteria and/or viruses, and reduces or eliminates inflammation and concomitant diseases and conditions associated therewith. Additionally, reduction or elimination of bacteria and/or viruses in the oral cavity reduces the concentration of bacteria and/or viruses that are absorbed into the bloodstream, and therefore reduces their effect throughout the body.
Without intending to be bound to any mechanism of action, it is believed that cleansing the oral cavity with a therapeutic composition of the invention prevents the blood from being contaminated and therefore prevents and aids in treating diseases such as heart disease, cancer and ulcers caused in part or in whole by toxins or contaminants which have entered the bloodstream through the oral cavity and have attached themselves to the walls of small blood vessels in the heart, pancreas, breast, stomach, bowel, etc. and serve as irritants to cause ulcers, intestinal irritations, and growths and plaque in blood vessels.
The terms xe2x80x9ctreatmentxe2x80x9d or xe2x80x9ctreatingxe2x80x9d or xe2x80x9ctreat(s)xe2x80x9d as used herein in reference to diseases include 1) preventing such diseases from occurring in a subject who may be predisposed to such disease or diseases but who has not yet been diagnosed as having it or them; 2) inhibiting these diseases, i.e. arresting their development; or 3) ameliorating or relieving the symptoms of these diseases, i.e., causing regression of the disease state. xe2x80x9cTherapeuticxe2x80x9d as used herein includes compositions for prophylactic treatment of diseases.
The amount of antibiotic, e.g. doxycycline, used in the therapeutic compositions and the dosage selection is an amount and dosage effective to achieve anti-infective activity, i.e. the amount necessary to effectively treat the infection. Dosage regimens will depend on the dosage and effectiveness thereof, the intended use, the route of administration, the severity of the disease, the body weight of the mammal or human being treated and the patient""s general state of health. Although suitable amounts of antibiotic in-the therapeutic composition are within the range of 50 to 100 mg per ounce of liquid vehicle, those skilled in the art will determine optimum concentrations and dosages from clinical experience in order to carry out the method of the invention. For example, the physician or dentist treating the patient may begin the patient on a normal strength mouth rinse of 50 mg per ounce of liquid vehicle and then increase the strength of the dose and potentially add nose drops where indicated. Blood cultures and growth cultures can be done after the rinse is used in order to define the optimum dosage more precisely. The amount of therapeutic composition used to treat the patient is defined herein as a therapeutically effective dose.

Anti-inflammatory composition comprising tetracycline


This application concerns the use of the combination of a volatile oil and a phenylated silicone oil in a composition containing a fatty phase.

The present invention concerns a composition, in particular a cosmetic composition capable of being applied on the skin and/or lips, and, in particular, an anhydrous composition for the care and/or make-up of the skin, and/or lips, especially a lipstick in stick form or a make-up foundation.
Lipstick and make-up foundation compositions normally contain fatty substances such as oils, viscous compounds and waxes, as well as particulate phase usually composed of fillers and pigments. When applied to the skin or lips, these compounds have the disadvantage of being transferred, that is, of forming a deposit, at least in part, while leaving a trace on objects with which they come into contact, in particular, a glass, a cup, a piece of clothing or the skin. Consequently, there remains on the skin or lips a reduced film which requires the periodic re-application of the make-up foundation or lipstick composition.
Furthermore, the appearance of unacceptable traces on clothing and, most especially, on the necks of blouses, may dissuade some women from using this type of make-up.
Another disadvantage of these compositions lies in the problem of migration. Indeed, it has been observed that some foundation compositions tended to spread inside wrinkles in the skin, that some lipstick compositions traveled in the small wrinkles surrounding the lips, while eye-shadows tended to spread in the folds of the eyelids. In the case of eye-shadows, the appearance of lines in the make-up, caused by movements of the eyelids, were also noted. All of these phenomena produced an unaesthetic effect which the consumer quite obviously wished to avoid.
For several years, many cosmeticians have been interested in lipsticks, and, more recently, make-up foundation compositions, that xe2x80x9cdid not transfer.xe2x80x9d Thus, Patent Application No. JP-A-61-65809 disclosed xe2x80x9ctransferlessxe2x80x9d lipstick compositions containing 1 to 70% by weight of a liquid silicone resin incorporating repeating silicate patterns (or having a three-dimensional lattice) comprising alkylated suspended chains of 1 to 6 atoms of carbon or phenylated chains, 10 to 98% by weight of a volatile silicone oil having a cyclic Sixe2x80x94O chain and containing methyl radicals, and pulverulent fillers. These compositions, although highly satisfactory as regards the lack of transference, had the disadvantage of being in liquid form and thus inconvenient to use, or, at the very least, of being far removed from the conventional idea of a lipstick, thereby limiting the number of women prepared to use this type of lipstick. In addition, the film produced on the lips after evaporation of the silicone oil had the disadvantage of becoming uncomfortable over time (sensation of drying and tugging, thus dissuading still other women from using this type of lipstick). To enhance the comfort given by this type of composition, non-volatile oils, whether or not they contained silicone, could be added; however, in this case the xe2x80x9ctransferlessxe2x80x9d property is lost. Moreover, these compositions take a long time to dry: that is, the lack of transfer appears only after several minutes.
More recently, Patent Application No. EP-A-602905 disclosed xe2x80x9ctransferlessxe2x80x9d lipsticks containing a volatile cyclic or linear silicone containing suspended methylated chains and a silicone resin incorporating a suspended esterified chain having at least 12 atoms of carbon. The lipstick film still possesses the problem of being uncomfortable when applied and, most notably, of being too dry.
The invention in question is intended to propose a composition, in particular an anhydrous composition, for skin care or make-up making it possible to remedy these difficulties, while, in particular, allowing the production of a film that does not transfer or migrate and that does not stain an object with which it comes into in contact, while exhibiting improved cosmetic properties as compared with the properties of xe2x80x9ctransferlessxe2x80x9d products according to prior art, in particular smooth sliding, the absence of tugging, and the lack of drying of the lips.
Accordingly, the object of the invention is the use of the combination of a volatile oil and a silicone-containing phenylated oil in a composition containing a fatty phase, in order to reduce transfer and/or migration and/or to improve the holding power of this composition.
Another object of the invention is a composition containing, in a fatty phase, a volatile oil, a silicone-containing phenylated oil, and less than 20% by weight of a non-volatile hydrocarbonic oil, e.g., a foundation product.
The invention encompasses compositions to be applied to the skin, the semi-mucous membranes, e.g., the lips, and/or the mucous membranes, e.g., the internal areas of the eyelids, and, in particular, not only to lip make-up but also to lip-care products and to skin and rouge make-up and care products such as foundations. In fact, facial make-up products possess the same problems of xe2x80x9ctransferxe2x80x9d to an object as do lipsticks.
The composition according to the invention may exist in solid form, e.g., as a stick. Furthermore, it yields a homogeneous film that is easily applied and spreads smoothly and uniformly. The film produced also has a light texture and remains comfortable and moist, and can be worn throughout the day.
The invention composition thus comprises a volatile oil which can be chosen, in particular, from hydrocarbonic or silicone-containing oils, whether cyclic or linear, either alone or in mixtures. The term xe2x80x9cvolatile oilxe2x80x9d in this description signifies any oil that can evaporate on contact with the skin. Preferably, use is made of oils whose flash point is sufficiently high to allow the use of these oils in formulations, and low enough to obtain the desired evanescent effect. Oils having a flash point of approximately 40-100xc2x0 C. are preferably used.
Usable volatile silicone oils include cyclotetradimethylsiloxane, cyclopentadimethylsiloxane, cyclohexadimethylsiloxane, and methylhexyldimethylsiloxane. Among the volatile hydrocarbonic oils, isoparaffins may be mentioned.
The composition according to the invention may contain 8-70% by weight, and preferably 30-60%, volatile oils in relation to the total weight of the composition.
The composition according to the invention also contains at least one phenylated silicone oil. This oil may be a polyphenylmethylsiloxane or a phenyltrimethicone, or a mixture of different phenylated silicone oils, and, in particular, it may correspond to the following formula:
where:
R is an alkyl radical at C1-C30, an aryl radical, or an aralkyl radical
n is a whole number between 0 and 100,
m is a whole number between 0 and 100, provided that the sum m+n is between 1 and 100.
Preferably, R is a methyl, ethyl, propyl, isopropyl, decyl, dodecyl, or octadecyl radical, or a phenyl, tolyl, benzyl, or phenethyl radical.
Among these phenylated oils, mention may be made of Belsil PDM1000 oil from Wacker, DC556 and SF558 oils made by Dow Corning, Abil AV8853 oil made by Goldschmidt, and Silbione 70633V30 oil manufactured by Rhxc3x4ne Poulenc.
The composition according to the invention may contain 1-35% by weight, and preferably 20-30% by weight, phenylated silicone oils.
In addition to the oils cited above, the fatty phase may contain the fatty substances normally used in the contemplated scope of application. These substances include silicone-containing fatty substances such as oils, viscous fatty substances, silicone waxes, and non-silicone-containing fatty substances such as oils, viscous substances, and vegetable, mineral, animal, and/or synthetic waxes.
Silicone-containing fatty substances include polydimethylsiloxanes (PDMS) and alkyldimethicones, as well as silicones modified by potentially fluorinated aliphatic and/or aromatic groups or by functional groups, such as hydroxyl groups, thiols, and amines.
Among non-silicone-containing fatty substances, mention may be made of paraffin, vaseline, perhydrosqualene, arara oil, sweet almond oil, calophyllum oil, palm oil, castor oil, avocado oil, jojoba oil, olive oil, or cereal gerin oil; esters of fatty acids; alcohols; acetylglycerides; the octanoates, decanoates, and ricinoleates of alcohols and polyalcohols; fatty acid triglycerides; glycerides; concrete hydrogenated oil at 25xc2x0 C.; lanolines; concrete fatty esters at 25xc2x0 C.; beeswaxes; vegetable waxes such as carnauba, candellila, urricury, and Japan waxes or cork or sugar cane fiber waxes; mineral waxes, e.g., paraffin and lignite waxes and microcrystalline waxes and ozokerites; synthetic waxes, including polyethylene waxes and waxes produced by Fischer-Tropsch synthesis.
The choice of these fatty substances made by the specialist may be varied, in order to prepare a composition having the desired properties, e.g., consistency and texture.
In particular, the composition according to the invention may contain at least one wax, in order to ensure mechanical strength when the composition is produced in stick form.
When it exists as a flexible paste or molded product, the composition according to the invention contains a smaller quantity of wax, e.g., of approximately 2 to 15% by weight.
In general, the composition may contain 0.5 to 30% by weight of at least one hydrocarbonic and/or silicone wax, and, preferably, 10-20% by weight of hydrocarbonic wax and 0 to 10% by weight silicone wax.
Furthermore, it has been found that the improved staying power of the composition according to the invention and the absence of migration and/or transfer thereof could prove particularly advantageous when the composition contains less than 20% by weight of a non-volatile hydrocarbonic oil, preferably less than 5% by weight, and, in fact, it might contain no non-volatile hydrocarbonic oils at all.
The composition according to the invention may contain a particulate phase normally accounting for 0 to 35% by weight and preferably 5-25% by weight, and this phase may contain the pigments and/or nacres and/or fillers normally used in cosmetic compositions.
The term pigments refers to white or colored mineral or organic particles which are insoluble in wax and volatile silicone and which are intended to color the composition and/or render it opaque. The term fillers refers to colorless or white mineral or synthetic particles, whether lamellate or non-lamellate, intended to impart body or stiffness to the composition. The term nacres refers to iridescent particles rich in lime and produced by certain mollusks in their shell.
The pigments may make up 0 to 15% by weight of the final composition, and preferably from 8 to 10%. They may be white or colored, mineral and/or organic. Among the mineral pigments, mention may be made of titanium, zirconium, or cerium dioxides, as well as zinc, iron, or chrome oxides and ferric blue. Organic pigments include carbon black and barium, strontium, calcium, and aluminum lacquers.
The nacres may make up 0 to 20% by weight of the composition, preferably in a high proportion of approximately 8 to 15% by weight. Usable nacres include mica coated with titanium oxide, iron oxide, natural pigment or bismuth oxychloride, as well as colored mica titanium.
The fillers, which may compose 0 to 30% by weight, and preferably 5 to 15%, of the composition may be mineral or synthetic, lamellate or non-lamellate. Mention may be made of talc, mica, silica, kaolin, nylon and polyethylene powders, teflon, starch, micatitanium, natural nacre, boron nitrate, microspheres such as Expancel (Nobel Industrie), polytrap (Dow Corning), and silicone resin microballs (e.g., Tospearls made by Toshiba).
The composition may further contain any additive normally employed in the cosmetic field, such as antioxidants, perfumes, essential oils, preservatives, cosmetic active ingredients, vitamins, essential fatty acids, sphingolipids, self-tanning compounds such as DHA, sunscreens, surfactants, liposoluble polymers, in particular hydrocarbonic polymers, such as polybutene, polyalkylenes, polyacrylates, and silicone polymers compatible with fatty substances. These additives may be present in the composition in a proportion of 0 to 10% by weight.
Of course, those skilled in the art will take care to select any additional compounds and/or quantities thereof, so as ensure that the advantageous properties of the composition according to the invention will not, or substantially not, be altered by the contemplated addition.
The procedures for manufacture of the compositions according to the invention do not differ in any way form the procedures conventionally used in the cosmetics field and are entirely known to the specialist. These procedures consist in mixing the different constituents of the composition, preferably after heating, then in pouring them to produce the desired shape.
The compositions according to the invention may take the form of sticks or of flexible or poured pastes, or even of an oily, potentially gelled liquid.
The compositions according to the invention may take the form of a cosmetic product, and, in particular, as a skin make-up product, especially a make-up foundation, a blusher or eyeshadow, or a lipstick.
They may also exist as uncolored products, potentially containing cosmetic active ingredients. In that case, they may be used as a lip-care base or as a fixing base to be applied on a conventional lipstick. The fixing base then forms a protective film on the lipstick film, restricts the transfer and migration thereof, and thus increases its staying power.
The compositions may also be produced as a dermatological or skin-care composition or as a sun or self-tanning composition.
The invention is illustrated in greater detail in the following examples.

Make-up compositions containing phenylated silicone oils, which are resistant to transfer and migration

Abstract: The invention also relates to a composition containing, in a fatty phase, a volatile oil, a phenylated silicone oil, and less than 20% by weight of a non-volatile hydrocarbonic oil.


A smart film or material which automatically controls its porous properties in relation to changes in its local environment thus allowing fluids to pass through the film or material in a controlled fashion.

The present invention relates to smart films and materials particularly those which can modify their porous properties and can be used in clothing.
When covering objects with a protective film or material it is often desirable for the film or material to be capable of allowing fluids, such as liquids and gases, to pass from the object through the film or material to the surrounding environment.
Examples of this requirement can be found particularly in clothing where a variety of Moisture Vapour Permeable (MVP) materials are known which allow water vapour to pass through the garment thus removing a proportion of the sweat generated by a wearer. These materials are also widely used in the medical field in the form of bandages and dressings. Also known are materials such as Stomatex (RTM) which is a rubber material having a number of perforations spread throughout the material. The material has pockets below each perforation configured so as to allow a local build up of vapour pressure before allowing the gases through. In both the clothing and medical uses these materials perform their specific function but are limited in that they can only remove gases and vapours and have a limited performance which is constant and does not change in response to environmental changes. Thus under extreme conditions the material will not be able to function satisfactorily. Clothing includes gloves, hats and footwear.
An aim of the present invention is to provide a smart porous film or material which automatically controls its porous properties in relation to changes in its local environment thus allowing fluids to pass through the film or material in a controlled fashion.
Accordingly, the present invention provides a smart film or material comprising at least two layers having different fluid absorption properties wherein all the layers are cut so as to provide a plurality of close fitting flaps through the film or material such that any strain differences between the layers caused by their different fluid absorption properties will cause the flaps to bend providing a plurality of openings in the layer.
As an alternative, the present invention also provides a smart film or material comprising a layer, a surface of which has discrete areas which have fluid absorption properties different to the rest of the layer wherein the discrete areas and the layer which they cover are cut so as to provide a plurality of close fitting flaps through the film or material such that any strain difference between the discrete areas and the layer which they cover, caused by their different fluid absorption properties, will cause the flaps to bend thus providing an opening in the layer.
The bending of the flaps is a result of the layers having different affinities for a fluid in the local atmosphere or the discrete areas having a different affinity for a fluid than layer which they cover.
One example of this effect is where a discrete area has different hydrophilic properties to the layer it covers or the layers have different hydrophilic properties to each other.
In a more specific example a discrete area could be arranged to take in more water or water vapour from the local atmosphere than the layer which it covers it then expands causing a strain difference between it and the layer which it covers. This strain difference causes the flaps to bend in the most energetically favourable direction.
The advantage of the above is that a film or material whose porosity can change in a controlled manner in response to changes in its local environment is provided.
In use the layer or one of the layers can be substantially impermeable such that fluids cannot pass through the film or material except via the openings caused through the film or material. Alternatively the layer or one of the layers can be permeable, in such an embodiment the amount of fluid which can pass through the film or material is increased or decreased by the opening or closing of the flaps through the film or material.
Advantageously one of the layers can be made of a polymer fibre with increased fluid absorption properties such as a polyethylene oxide macromolecular polymer covered by nylon such as Hygra(trademark).
The discrete areas can be produced in the form of materials individually deposited on a surface of the layer, possibly using some form of chemical bond, by a printing process such as dot printing, by transfer coating or spread coating or by any other means which is capable of accurately depositing small amounts of a material on a surface. Alternatively the discrete areas can be produced by an etching process whereby a further layer is attached to the surface of the layer and areas of the further layer are etched away to leave the discrete areas.
The discrete areas deposited on a surface of the layer can be a hydrophilic gel or gel mixture or other suitable material. Such materials may contain, singly or in combination, polyvinyl alcohol, partially hydrolysed polyvinyl acetate, poly(vinylpyrrolidone), polyethylene glycol, ethoxylated polyethylene glycol, polysiloxane, ethoxylated polysiloxane, poly(acrylic acid),copolymers of acrylic acid, poly(N-isopropylacrylamide), poly(2-acrylamide-2-methylpropanesulphonic acid), collagen, gelatin, pectin, starch, in each case optionally cross-linked by incorporation of an appropriate physical cross-linking agent, e.g. borax, or chemical cross-linking agent, e.g. ethylene-bis-acrylamide, and suitable catalysts, e.g. lactic acid, or free radical initiators, e.g. azo-bis-isobutyronitrile, and compatible vegetable or mineral fillers, as has all been described in literature regarding such materials.
The discrete areas can also be formed by locally modifying the layer""s fluid absorption properties thus avoiding the need to bond the discrete areas to the layer this can be done by plasma treating a surface of the layer or by treating a surface of the layer with chemicals or radiation. For example, exposing a material composed of an uncrosslinked polymer to a source of high energy radiation (such as UV light or gamma rays) or ionic particles (such as a plasma) it is possible to form crosslinks between the polymer molecules. If the initial starting material is hydrophilic it will be made more hydrophobic by this treatment and the material may also become stiffer.
Advantageously the discrete areas can be only a few millimeters in diameter and can be dispersed over the entire layer, or in specific locations of the layer, in a density defined by the level of porosity required of the film or material. The size of the discrete areas will in practice be limited by manufacturing techniques and the ability to make accurate, small cuts through the film or material.
Obviously larger discrete areas can be provided should large openings be required such as would be needed to allow liquids instead of gases to pass through the film or material.
The cutting of the flaps is preferably done so as to form a plurality of flaps which are located in a close fitting arrangement, i.e. the amount of material removed during cutting should be kept to a minimum. This is advantageous as it aims to maintain as much of the properties of the uncut film or material as is possible. Usefully this can be done using laser, water jet or punching techniques.
Any number of close fitting flaps can be provided at a single location in the film or material however a minimum of 3 flaps will allow the flaps to bend easily providing an opening. Further flaps would increase the size of opening produced at each location, however, the cutting procedure increases in complexity, and the amount of material removed will be increased, as more cuts are needed. The removal of more material will increasingly affect the overall properties of the film or material when the flaps are closed.
An additional improvement of the invention can be obtained by causing a further discrete area which has fluid absorption properties different to the rest of the layer to be formed, which individually surrounds some or all of the discrete areas and is disposed from the discrete area it surrounds. This can be done in the form of a hoop. When the environment adjacent to a further discrete area changes the strain differences between the layer and the further discrete area, as a result of their different fluid absorption properties, causes a pocket or bulge to form in the film or material. Provision of a pocket or bulge beneath the opening formed by the flaps may improve the efficiency of the proposed system. For example, when the pocket or bulge is formed the concentration of a gas, such as water vapour, could be allowed to build up to high levels before the flaps formed in the discrete area are caused, as a result of strain differences between the layers of the flap, to bend thus forming an opening. Once the opening has formed gas exchange between the pocket or bulge and the environment can occur by a process of diffusion. Diffusion is driven by concentration gradients and as such this process of gas exchange is increased by the high concentration of gas in the pocket or bulge and would quickly reduce the level of gas inside the chamber thus allowing the flaps to close. This also reduces the amount of time that the flaps are required to be open.
A film or material according to the present invention can be used in a variety of applications. These applications include use in clothing, medical applications, food wrappings and structures such as tents and garden cloches.
When in use as a clothing material the material can be arranged to have a predetermined porosity which will be capable of being increased by the opening of the flaps in response to changes in the local environment caused by the actions of the wearer. This could possibly be as a result of an increase in the workload of the wearer causing the wearer to become hotter thus requiring an increased amount of fluid, either in the form of moisture vapour or sweat, to be removed from the body. This opening of the flaps could be arranged to occur as a response to an average level of fluid absorption in the film or material or only to occur at extreme levels to reduce heat stress under heavy exertion.
Medical uses of a film or material according to the present invention include uses in bandages or dressings for wounds where it is desirable to either keep the covered area dry or allow gases to escape from the covered area. Again a film or material could be arranged such that the flaps open under average conditions or the flaps could be arranged to open only under extreme conditions.
Uses as food wraps are similar to the medical uses where food needs either to be kept dry or free from a build up of gases. Particular uses in food wraps are where the film or material absorbs gases naturally emitted from the food causing pores to open and thus allowing the gases to be released.
When used in structures such as tents or garden cloches the film or material can prevent the build up of condensation on the inside of the structure or it can allow gases given off from within the structure to escape.
As stated the film or material will be made more porous by the cuts made in it, even when the resulting flaps are closed, unless these cuts can be made to be so close fitting so as to render them impermeable or the cuts are made under tension such that when released the flaps are in close contact with each other. As such the smart film or material may be required to be combined with further materials, possibly using moisture vapour permeable materials or tufted, embedded or woven hairs or fibres, to provide the required overall properties. Another material which could be used is a fur-mimetic material acting as an outer layer to provide protection from rain.
Various materials can be used to produce smart porous textiles according to the present invention. Materials which absorb water and could be coated onto or extruded with a non-absorbing layer include Polyurethanes, Polyether block amides (PEBA), Hydrogels and Water Soluble polymers such as polyvinylpyrrolidone, carboxyl methyl cellulose and polyvinyl alcohol.
The following are, by way of example only, four examples of methods of manufacturing materials in accordance with the present invention:
A 2xc3x972 200 gsm polyester plainweave fabric is passed through a solution of primer and after drying is stippled with a jet printer dot paste coating and immediately contacted with a powder comprising a 1:1 dry blend of polyvinyl alcohol and polyacrylic acid, pressure being applied by a heated roll at 170 deg C.
The resulting 5 mm diameter adhered disks are present at a surface density of two per square centimeter in a regular grid pattern.
The fabric is subsequently passed intermittently through the work zone of a focused and collimated indexing Carbon Dioxide laser which irradiates each disk area in turn producing cruciform slots each 0.3 mm in width and 3 mm in length through the disk area.
A previously degreased 300 gsm polyester cored cotton plainweave fabric is passed through the Nitrogen atmosphere work zone of an indexed scanning electron beam (300 KeV, 15 mA) traversing the full width of fabric at a lateral sweep velocity of 25 m/min.
Acrylic Acid is sprayed onto one side of the fabric in striated zones and the fabric passed through a drying oven at 100 deg C. with a residence time of 10 minutes followed by cooling to room temperature over a further 10 minutes with fan assist.
The add on weight of polyacrylic acid is 200 gsm in the areas treated.
The fabric is subsequently punched with a cruciform pattern in the region of the striations only to give a pore density of one pore per square centimeter, the pores being 5 mm long in each orthogonal direction.
A previously degreased 300 gsm polyester cored cotton plainweave fabric is activated by electron beam exposure in selected zones and is then fully coated with N-vinylpyrrolidone containing 0.5% by weight of N.N-mythylene-bis-acrylamide. The fabric could also be activated chemically by treatment with any of peroxydisulphuric acid, chromic acid, ferric chloride/hydrogen peroxide or peroxyacetic acid.
The fabric is passed through a ventilated drying oven at 70 degrees C. with residence time of 10 minutes followed by a further 10 minutes cooling with fan assist.
The fabric is then passed through a water bath with agitation to dissolves away the unfixed coating leaving a fabric having poly(N-vinylpyrrolidone) coating (200 gsm) in irradiated zones only.
The fabric is then punched to form cruciform cuts.
An A4 specimen of 60 gsm microfibre polyester woven fabric is laid on foil and the exposed surface treated for 10 minutes in a cold plasma barrel reactor with a maintained rarefied atmosphere of nitrogen containing 20% v/v N-vinylpyrrolidone (0.05 Torr) excited by a 100W microwave field (433 MHz).
The polyester fabric is then exposed to a scanning and indexing CO2 laser to receive cruciform cuts.
The textile has become hydrophilic on one side, while remaining hydrophobic on the other.


The present invention relates to a method and a device for selective laser sintering in which powder is introduced in layers into a jacketed design space, forming a powder cake which is consolidated layerwise by laser radiation. The design space is encircled and heated by a jacket heating device.

Priority to German Patent Application No. 101 08 612.1-24, filed Feb. 22, 2001 and hereby incorporated by reference herein, is claimed.
The present invention relates to a method and a device for selective laser sintering in which powder is introduced in layers into a jacketed design space, forming a powder cake which is consolidated layerwise using laser radiation.
Selective laser sintering (SLS) is a rapid prototyping method in which a platform (design space bottom) which can be lowered into a design space carries a powder layer which is heated by a laser beam in selected regions so that the powder particles fuse to form a first layer. Subsequently, the platform is lowered downward into the design space by approximately 50 to 200 xcexcm (depending on the particle size and type), and a new powder layer is applied. The laser beam draws its path again, fusing together the powder particles of the second layer as well as the second with the first layer. In this manner, a multilayer powder cake and, inside of it, a component such as an injection mold are formed little by little.
Inside of the design space, specific regions undergo a heating by the laser beam for a longer or shorter period of time, depending on the geometry of the component to be manufactured, whereas others are not heated at all. Moreover, in each case only the uppermost powder layer is heated by the laser; the lower layers give off the absorbed heat to their surroundings and cool off. The consequences include inhomogeneous temperature distributions and thermal stress within the powder cake which may result in component distortion.
To minimize this problem, it was already proposed in European Patent Document EP 5 56 291 to adjust a uniform base temperature of the respective surface layer, using a ring-shaped radiant heater mounted parallel to and above it. The intended result is a more uniform cooling of the individual layers and, consequently, less component distortion. This European Patent Document is related to U.S. Pat. No. 5,155,321, which is hereby incorporated by reference herein.
However, several tests have shown that temperature gradients still occur within and between the individual layers of which, in particular, those mentioned first result in component distortion which is not tolerable at least in the case of high-quality components.
An object of the present invention is to provide a method and a device for selective laser sintering in which the temperature within a layer of the deposited powder cake is as homogenous as possible and decreases as uniformly as possible, starting from the sintered regions of the surface down to the bottom of the design space.
The present invention provides a method for selective laser sintering of a powder in which the powder is introduced in layers into a jacketed design space, forming a powder cake, wherein the jacket is heated in such a manner that a temperature distribution develops in the jacket, the temperature in the jacket decreasing in the direction of the design space bottom, starting from the jacket regions bordering the powder cake surface which was sintered last.
The selective laser sintering carried out according to the present invention reduces component distortion since the temperature distribution within a layer of the deposited powder cake is homogenized better and decreases more uniformly, starting from the sintered regions of the surface down to the bottom of the design space.
This homogenization of the temperature distribution within a layer and of the temperature decrease is attained in that an additional temperature distribution featuring a decreasing temperature in the direction of the design space bottom is superposed via the jacket heating upon the temperature distribution generated by the laser radiation and, possibly, upon that generated by a ring-shaped radiant heater. This additional temperature distribution must, of course, not reach temperatures which would give rise to an independent sintering of the powder articles. It rather predetermines an essentially uniform base temperature of the individual powder layers so as to minimize the temperature dissipation of the sintered regions within a layer and to promote a temperature flow from the sintered regions into the depth, that is in a direction perpendicular to the powder layers. A suitable temperature distribution is, for example, a linear one.
The powder cake continuously grows by adding new powder layers and is at the same time lowered into the design space. In the process, the surface of the powder cake always borders the top edge of the design space. However, the platform of the design space bottom moves further and further away from the powder surface and borders regions of the design space wall which have lower and lower temperatures as the depth increases.
Therefore, it is advantageous for the jacket heating to include a design space bottom heating which is controlled in such a manner that the temperature of the design space bottom is, at each instant, adapted to the temperature of the design space wall region which it borders at this point in time.
It is particular advantageous to select an arbitrary, for example, also a non-linear and time-variant temperature distribution of the jacket heating which was optimized with regard to reduced component distortion with the assistance of a simulation of the laser sintering process. Simulations of the energy input of the laser into the powder layers have already been proposed, for example, in German Patent Document DE 10050280; the resulting temperature distributions within the powder cake can also be determined using known methods, for example, by solving the equation of heat conduction and, also, the influence on this temperature distribution by superposition of a jacket heating. Optimization methods are also known to one skilled in the art. Individual steps of the simulation can be experimentally verified or substituted.
The present invention also provides a device for selective laser sintering of a powder which features a jacketed design space for receiving the powder and which has a jacket heating device encircling the design space, wherein the jacket heating is able to heat different regions of the jacket separately.
The jacket heating device presets an essentially uniform base temperature of the individual powder layers so as to minimize the temperature dissipation of the sintered regions within a layer and to promote a temperature flow from the sintered regions into the depth, that is in a direction perpendicular to the powder layers. In this manner, thermal stress and, also, a resulting component distortion are minimized.
Advantageously, the jacket heating device is designed in such a manner that it can heat different regions of the jacket separately. For instance, in the case of a design space having a cylindrical configuration, this can easily be effected using heating rings which are disposed in parallel one over another and arranged concentrically around the design space. In addition to such an active heating, an active cooling via cooling circuits (e.g., piping) containing a coolant (e.g., water) can be advantageous as well.
In this context, it turns out to be particularly advantageous if the individual heating rings can also be separately controlled via at least one control device, and if this at least one control device features an input unit into which a temperature distribution can be entered. This temperature distribution can, for example, be one that is optimized via simulation of the laser sintering process with regard to homogeneity and/or reduced component distortion.

Method and device for selective laser sintering


A method of inserting z-axis reinforcing fibers into a multi-layer composite laminate. Layers of material made up of z-axis fiber and y-axis fibers are automatically transported into a z-fiber deposition machine having a housing with upper and lower surfaces. Z-axis apertures are formed in the respective upper and lower surfaces. An elongated solid rod having a tapered front tip is aligned in close proximity to the aperture n the bottom surface. The rod is first rotated by a motor and then actuated upwardly completely through the thickness of the layer of x-y material by an actuator. A first hollow tube having a z-axis is axially aligned with the aperture in the top surface and a fiber bundle is threaded downwardly through a first hollow tube to a position adjacent its bottom end. The z-fiber deposition machine has structure to feed a predetermined length of the fiber bundle downwardly through the first hollow tube so that it follows the pathway in the x-y material formed by the rod which is now withdrawn downwardly through the aperture in the bottom wall. The z-axis fiber is thus deposited into the x-y material. The top end of the z-fiber is then severed and the x-y material is then advanced a predetermined distance to complete the cycle and is thus set to be repeated.

The invention relates to a method of producing a composite material and more specifically a process for incorporating z-axis fiber reinforcement into x-y axis composite material.
Traditional composite materials are made up of resin matrix material and a quantity of 2-dimensional fibers, continuous in the x-y axis directions, but laminated in layers to produce a material thickness. Composite material construction, wherein a fiber material such as glass fiber, carbon fiber, or aramid fiber is combined with a matrix material, such as thermoplastic or thermoset resins, is an example of a traditional 2-dimensional structure. The resulting structure is produced from xe2x80x9clayeringxe2x80x9d of the 2-dimensional material (known as plies). Because the matrix is weaker in strength than the fiber (in may cases by at least an order of magnitude), the failure mechanism of these composites when test loaded toward their ultimate strength is a cracking or buckling or separation of the matrix material. When this occurs, the composite is known to have delaminated, or the layers of fiber material have separated.
Attempts have been made to lace or tie multiple layers of 2-dimensional composite materials together with z-axis directional fibers which tie all of the layers together. By doing this, delamination can be delayed or eliminated. Some techniques that have been used include 3-D braiding, 3-D weaving, and z-axis pinning. All of these methods have deficiencies, drawbacks and are expensive and labor intensive.
The Fusco et al U.S. Pat. No. 5,589,015 is directed to a method and system for inserting reinforcing pins in composite structure. Ultra sound energy is applied to the pins and pressure is applied simultaneously to insert the pins into the composite structure to join two laminates or reinforce a single composite structure.
The Childress U.S. Pat. No. 5,935,680 is directed to an interlaced z-axis pin sandwich structure that utilizes a plurality of z-axis pins that extend through the core and into each of the face sheets. The pins are arranged in an interlaced configuration off-normal to provide crack resistance around fasteners for connecting the composite structure to other structural elements in aerospace applications.
The Boyce et al U.S. Pat. No. 4,808,461 discloses a translaminar reinforcement structure that utilizes z-axis reinforcing elements and the method for driving these reinforcing elements into the composite structure as it is subjected to an elevated temperature and decomposes.
The Campbell et al U.S. Pat. No. 5,789,061 discloses a stiffener reinforced assembly and its method of manufacturing. The Boyce et al U.S. Pat. No. 5,667,859 also discloses the use of joining composite parts by including reinforcing elements that pass through the thickness of two composite adherents to be joined. The Campbell et al U.S. Pat. No. 5,827,383 also discloses a stiffener reinforcement assembly and its method of manufacturing.
Other patents that teach the use of tow members that are encapsulated within the foam core and which extend between the opposing face sheets to form a combined composite structure are the Boyce et al U.S. Pat. No. 5,624,622 and the Boyce et al U.S. Pat. No. 5,741,574. The Boyce et al U.S. Pat. No. 5,186,776 teaches a technique for translaminar reinforcement and the method includes heating and softening the composite laminates by ultrasonic energy and then inserting reinforcing fibers therein.
It is an object of the invention to provide a novel method of inserting an unstable reinforcing fiber into a composite laminate for z-axis reinforcement.
It is also an object of the invention to provide novel machinery for inserting an unstable z-axis reinforcing fiber into a composite laminate.
It is another object of the invention to provide a new type of composite material with substantial z-axis fiber reinforcement.
It is a further object of the invention to provide a novel method for producing layer quantities of 3-D bar stock, sheet and composite sandwich structure in a continuous, automated fashion.
The method of inserting an unstable reinforcing fiber into a composite laminate for z-axis reinforcement of the laminate requires a z-axis fiber deposition material. The side plates of the chamber formed between top and bottom plates into which is fed x-y axis material. The side plates of the chamber restrict the edges of x-y axis material. There would be multiple laterally spaced z-axis fiber deposition machines so that multiple z-axis fibers could be deposited into the x-y axis material at the same time. Each would have its own respective aperture in the top plate and the bottom plate and these would be aligned. Below each aperture in the bottom plate is an elongated solid rod having a tapered front tip. This rod is known as the xe2x80x9cpathway deposition Probexe2x80x9d (PDP). The PDP is rotated by a motor and then actuated upwardly through the aperture in the bottom plate, the x-y axis material and the aperture in the top plate. Mounted above each aperture in the top plate is a movable hollow tube whose initial position has its bottom end slightly inserted into the aperture in the top plate. Z-axis fiber bundles are contained on stationary rolls and are free to be drawn from the rolls continuously. The front end of each z-axis fiber bundle is threaded downwardly through one of the movable hollow tubes to a position adjacent its bottom end. There would be structure to resupply a predetermined length of z-axis fiber bundle to each movable hollow tube as a new length is needed.
After the PDP has been actuated upwardly to its upper most position, it is then retracted downwardly to its initial position and simultaneously, the movable hollow tube would travel downwardly through the hole created in the x-y axis material. While this is happening, the tip of the PDP would remain inserted into the bottom end of the movable hollow tube to insure a smooth entry of the hollow tube through the aperture in the x-y axis material created by the PDP. Each z-axis fiber deposition unit has a mechanism for preventing withdraw of z-axis fiber from the x-y axis material when the movable hollow tube is withdrawn upwardly. Once the movable hollow tube has been raised to its upper position, the top end of z-axis fiber that has been inserted into the x-axis material is severed. This would complete a whole cycle. Simultaneously, across the width of the housing each of the other z-axis fiber deposition units would have completed their cycle. The next x-y axis material is stepped forwardly to provide a new position for the z-axis fibers to be deposited. Alternatively, the method could provide structure for stepping the housing rearwardly instead of stepping forwardly the x-y axis composite material.
After the x-y axis material has had the z-axis fibers deposited therein, it travels forwardly to a pultrusion die. Here the heated die cures the composite material of the plies and it exits the dies as a cured 3-D fiber composite material. The material is pulled from the die continuously by the alternate gripping edges of multiple grippers that are attached to motion control hydraulic cylinders.

Method of inserting z-axis reinforcing fibers into a composite laminate