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Aim.A study of biocompatible and matrix properties of polylactide scaffolds as a materials for medical implanted articles as well as scaffolds for cell and tissue engineering constructions.Materials and methods. Biocompatibility of polylactide scaffolds in the form of porous disks obtained by freeze drying method was estimated in vitro: by UV spectroscopy, pH measurements and cytotoxicity to NIH/3T3 mice fi broblasts in static conditions. Biocompatibility of scaffolds in vivo was investigated by its implantation under mice skin. Matrix properties of polylactide scaffolds (cell adhesion and proliferation) were studied in dynamic conditions with mesenchymal stromal cells of human adipose tissue (MSC ADh) in perfusion bioreactor.Results.As a result of in vitro investigations it was shown that polylactide scaffolds obtained by freeze drying are satisfi ed to demands presenting biocompatible medical articles with respect to pH measurements, extraction tests and cyto toxicity to mice fi broblasts NIH/3T3. Cultivation of MSC ADh in perfusion bioreactor in hepatogenic media is accompanying by good adhesion and proliferation both on the surface and in the bulk of porous disks. However implantation of polylactide scaffolds under mice skin is accompanying by resorption and leads to the infl ammation reaction of adjacent tissues.Conclusions.Positive results obtained only by in vitro testing of biocompatibility and matrix properties are not enough to recommend the material to be used as a scaffolds for cell and tissue engineering constructions. The preliminary study of biomechanical characteristics of the implant is recommended.

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Correcting the pleural cavity space or filling large residual cavities (up to 500-700 cm3), arising as a result of extensive combined resections of the lung or extrapleural pneumolysis in tuberculosis and other lung diseases, still remains a challenging issue. The surgical methods used to correct the pleural cavity space are traumatic in nature. Moreover, various biological and synthetic materials used are not effective enough. Objective: to conduct an in vivo study of the biocompatible properties of laboratory samples of porous materials based on polylactide (PLA) and polycaprolactone (PCL) as potential materials for pleural implants development, as part of the general problem of developing a resorbable porous implant for intra- and extrapleural implantation and in situ formation of a «biological filling» to correct the volume of the pleural cavity. Materials and methods. In vivo subcutaneous implantation was performed in Wistar rats. The experiment involved the following samples: No. 1 - 3.0%; No. 2 - 4.0%; No. 3 - 1.7%. The ratio of the polymers in the solution was, respectively: 3/1, 1/3 and 1/1 PLA/PCL. Highly porous implants were obtained by lyophilization. The porosity of the samples ranged from 96.0% to 98.3%. The Young's modulus was from 100 to 1800 kPa. In the control group, a Mentor silicone implant shell was used. The explantation time was 1, 2, 3, 4, 5, 8, 12, 14 weeks. Histological, histochemical and immunohistochemical studies of explants and surrounding local tissues were conducted. Results. Reaction of local tissues to the implantation of three types of samples of different composition from PLA/PCL, accompanied by material resorption processes, replacement by fibrous tissue, vascularization and encapsulation, without perifocal inflammation and reactive changes, indicates the biocompatibility of the materials studied. In control samples with silicone implant, a long-lasting perifocal reaction from eosinophilic leukocytes was revealed, which prevents us from excluding the possibility of an allergic reaction to the implant material in the surrounding tissues. Conclusion. In vivo experiments on the small animals show the biosafety and high biocompatibility of laboratory samples of bioresorbable highly porous matrices based on polylactide and polycaprolatcon as potential materials for development of pleural implants. Further studies with scaling of laboratory samples and a detailed study of the dynamics of biodegradation of porous matrices in vivo in large animals are required. The need for further improvement in laboratory samples of bioresorbable pleural implants is associated with giving the porous matrices antibacterial, bioactive and X-ray contrast properties.

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