 provide vaccine passport options.
Minister Copping said the QR codes remain available, as do the readers, for the interim.
As an alternative, businesses could require a printed copy of the QR code for a visual check, Copping said.
So tired of the Alberta Government’s flip-flopping, lies, and self-serving corrupt actions, not to mention caving to the “Trucker’s Protest”. Which is neither organized/funded by the truckers (too much money coming in too quickly), or a recognizable protest (we just had an election and they want to collapse the government).
Caving to this type of protest tells us that the UCP is overly “friendly” to them, and is quite willing to sacrifice our democracy so the UCP leader can try to stay in power.In Vitro Evaluation of PCL and P(3HB) as Coating Materials for Selective Laser Melted Porous Titanium Implants

Titanium is widely used as a bone implant material due to its biocompatibility and high resilience. Since its Young’s modulus differs from bone tissue, the resulting “stress shielding” could lead to scaffold loosening. However, by using a scaffold-shaped geometry, the Young’s modulus can be adjusted. Also, a porous geometry enables vascularisation and bone ingrowth inside the implant itself. Additionally, growth factors can improve these effects. In order to create a deposit and release system for these factors, the titanium scaffolds could be coated with degradable polymers. Therefore, in the present study, synthetic poly-ε-caprolactone (PCL) and the biopolymer poly(3-hydroxybutyrate) (P(3HB)) were tested for coating efficiency, cell adhesion, and biocompatibility to find a suitable coating material. The underlying scaffold was created from titanium by Selective Laser Melting (SLM) and coated with PCL or P(3HB) via dip coating. To test the biocompatibility, Live Cell Imaging (LCI) as well as vitality and proliferation assays were performed. In addition, cell adhesion forces were detected via Single Cell Force Spectroscopy, while the coating efficiency was observed using environmental scanning electron microscopy (ESEM) and energy-dispersive X-ray (EDX) analyses. Regarding the coating efficiency, PCL showed higher values in comparison to P(3HB). Vitality assays revealed decent vitality values for both polymers, while values for PCL were significantly lower than those for blank titanium. No significant differences could be observed between PCL and P(3HB) in proliferation and cell adhesion studies. Although LCI observations revealed decreasing values in cell number and populated area over time on both polymer-coated scaffolds, these outcomes could be explained by the possibility of coating diluent residues accumulating in the culture medium. Overall, both polymers fulfill the requirements regarding biocompatibility. Nonetheless, since only PCL coating ensured the maintenance of the porous implant structure, it is preferable to be used as a coating material for creating a deposit and release system for growth factors.

The overall aim of this study was to find an implant coating material that fulfills several properties like high biocompatibility, strong cell adhesion, and the absence of coating-related pore occlusion at once. Against this background, this material may be further tested in future investigations to consider its suitability to act as a deposit and release system for drug delivery.

Osteoblast Isolation and Cultivation
As previously described, adult C57Bl6 mice or GFP*C57Bl6 mice were used for osteoblast isolation [19]. After mincing the calvarias of ten mice, these were dissolved in 5 mL Hank's medium (HBSS, PAA Laboratories GmbH, Pasching, Austria) containing 200 U/mL collagenase II (Cell Systems, Troisdorf, Germany) and incubated five times for 10 min at 37 • C for proper digestion. Between every incubation step, the supernatant containing detached cells was collected and the remaining calvarial material was dissolved in new collagenase solution. Collected supernatants from all five incubation steps were pooled and centrifuged for 7 min at 1200 rpm before washing the resulting cell pellet twice with Dulbecco's modified Eagle Medium (DMEM) (Biochrom, Berlin, Germany). For cultivation, the osteoblasts were seeded into T25 tissue culture flasks (TPP, Trasadingen, Switzerland) filled with 5 mL DMEM containing 10% foetal calf serum (FCS) (Biochrom, Berlin, Germany). The medium was changed twice a week and cells were split after reaching 80% confluency.

Selective Laser Melting of Titanium Scaffolds
An SLM ® 280 HL Selective Laser Melting machine system (SLM Solutions GmbH, Lübeck, Germany) was used to create three-layered porous titanium scaffolds out of TiAl6V4 alloy with a length and width of 3.5 mm, height of 1.25 mm, and with a pore size as well as a strut width of 250 µm [5] (Figure 1). All scaffolds were post-treated using a chemical deburring process in order to create a smooth scaffold surface [18]. The overall aim of this study was to find an implant coating material that fulfills several properties like high biocompatibility, strong cell adhesion, and the absence of coating-related pore occlusion at once. Against this background, this material may be further tested in future investigations to consider its suitability to act as a deposit and release system for drug delivery.

Osteoblast Isolation and Cultivation
As previously described, adult C57Bl6 mice or GFP*C57Bl6 mice were used for osteoblast isolation [19]. After mincing the calvarias of ten mice, these were dissolved in 5 mL Hank's medium (HBSS, PAA Laboratories GmbH, Pasching, Austria) containing 200 U/mL collagenase II (Cell Systems, Troisdorf, Germany) and incubated five times for 10 min at 37 °C for proper digestion. Between every incubation step, the supernatant containing detached cells was collected and the remaining calvarial material was dissolved in new collagenase solution. Collected supernatants from all five incubation steps were pooled and centrifuged for 7 min at 1200 rpm before washing the resulting cell pellet twice with Dulbecco's modified Eagle Medium (DMEM) (Biochrom, Berlin, Germany). For cultivation, the osteoblasts were seeded into T25 tissue culture flasks (TPP, Trasadingen, Switzerland) filled with 5 mL DMEM containing 10% foetal calf serum (FCS) (Biochrom, Berlin, Germany). The medium was changed twice a week and cells were split after reaching 80% confluency.

Selective Laser Melting of Titanium Scaffolds
An SLM ® 280 HL Selective Laser Melting machine system (SLM Solutions GmbH, Lübeck, Germany) was used to create three-layered porous titanium scaffolds out of TiAl6V4 alloy with a length and width of 3.5 mm, height of 1.25 mm, and with a pore size as well as a strut width of 250 µm [5] (Figure 1). All scaffolds were post-treated using a chemical deburring process in order to create a smooth scaffold surface [18].

Viscosimetry of PCL and P(3HB) Coating Solutions
To determine the dynamic viscosity, an Ubbelohde viscosimeter (CT52 with Visco Clock, Schott Instruments GmbH, Mainz, Germany) was used with different capillary sizes, according to the viscosity of the solvent. Temperature was regulated at 20.0 ± 0.01 • C. Mass density of the solvent was calculated by defined volume in a graduated flask, and mass analyses were performed using a Kern 770 analytical precision balance (Gottlieb Kern & Sohn GmbH, Balingen-Frommern, Germany). The dynamic viscosity was determined via η = ν × ρ and ν = K × t with ν = kinematic viscosity, ρ = density of the coating solution, t = efflux time, and K = capillary constant. The measurement was repeated three times.

PCL and P(3HB) Coating of Titanium Scaffolds
In order to apply polymeric coatings to the porous titanium scaffolds, a manual dip-coating process was established using a constructed sample holder [17]. The scaffolds were immersed six times in 0.4 wt. % chloroformic solutions of either PCL or P(3HB), with an intermediate drying step being performed after each dipping process for 10 min at 23 ± 2 • C. After the final drying step, the scaffolds were dried in a vacuum cabinet drier at 40 • C and 40 mbar for seven days.

Characterisation of PCL and P(3HB) Coatings via ESEM and EDX Analysis
In order to gain an overview of the coated implant surface and to verify the coating, environmental scanning electron microscopy (ESEM) and energy-dispersive X-ray (EDX) analyses were performed using a scanning electron microscope (Quanta FEG 250, FEI, Eindhoven, The Netherlands) equipped with an EDX analysis unit [18]. After fixing PCL-and P(3HB)-coated scaffolds as well as uncoated ones (positive control), electron micrographic examinations were performed at 50 Pa and 10 kV in a moisturised atmosphere. For analysing of the pore diameter, the arithmetical means and the standard deviation were calculated from the maximum width of each pore (n = 35 per scaffold). Thereby occluded pores were also taken into account with a value of 0 µm. Additionally, EDX measurements were taken to determine the atomic composition of Ti and C elements on the scaffold's surface.

Cross-Sections of PCL-Coated Titanium Scaffolds