• fibroblasts: 3T3, 1,2 L929, SNL, human dermal, • osteoblasts MC3T3, • human fetal osteoblasts hFOB 1.19, • human umbilical artery smooth muscle cells (HUASMC), • human umbilical vein endothelial cells (HUVEC), • Schwann cells, • human mesenchymal stem cells (hMSC). In vivo tests were also conducted using the following organisms: mice (BALB/c, YFP+ ), rats (Wistar, , Fisher, , Lewis (CD® (Sprague-Dawley) IGS, Sprague-Dawley, ), rabbits. No tissue necrosis or degradation was noted in these studies, but mild and transient inflammation occurred. This is a typical effect after the implantation of biodegradable polyesters. The cytotoxicity of PGS strongly depends on the degree of polymer cross-linking. If the cross-linking process is too short or not effective, the material is toxic. This effect is caused by free carboxylic acid groups, which acidify the cell medium and self-catalysing polymer degradation, which also deepens this effect. All these performed tests made PGS known as a promising material for tissue engineering, drug delivery systems, surgical sealant and other biomedical uses. In addition to its use in tissue engineering and drug delivery systems, PGS is also used as a culture substrate. This material has been successfully used in root culture media for the production of deoxyshikonin. Unfortunately, prepolymer synthesis and its subsequent cross-linking are usually time-consuming processes carried out at high temperatures (Table ). This is not beneficial from an economic and ecological point of view and, therefore, poses a threat to attempts at implementation and industrial production of PGS-based biomaterials. In the case of enzymatic syntheses, most works focus on prepolymer synthesis without studying cross-linking. This is the result of the lack of work on modernizing synthesis and cross-linking. Scientists mostly focus on testing the biocompatible properties of PGS in recent years. Most of the processes are very similar to the method published in 2002. In our opinion, there is a strong need to study the manufacturing processes to improve the fabrication of PGS and make it possible to further industry transfer. G/SA = 0,33 -2; 150℃; 24 h; reflux 150℃; 24 h; with or without water removal 40 G/SA -glycerol/sebacic acid ratio This work aims to develop rapid synthesis which allows to obtain prepolymer for further easy thermal cross-linking. First of all, based on polymerization theories, it is known that the stoichiometric functional groups ratio (G/SA = 2:3) is the most effective for obtaining cross-linked structures. The gel point should be 71 -83% of the functional group conversion, depending on which theory was used for calculations. To achieve conversion near to the 71% in short reaction time, catalyst and water removal are used to increase polycondensation's effectiveness in this work. Unfortunately, such a procedure is contrary to the assumptions of the previously used polycondensation theories. It is known, however, that esterification using the Fischer mechanism is an effective process and is successfully used in industry. This work describes a study of PGS prepolymer synthesis with the use of an acid catalyst in the Fischer mechanism (Scheme 1). Mathematical methods were used to optimize and develop a fast and stable synthesis method, which allowed the obtaining of prepolymer in a short time without risk of gelation in the reactor.