[Tissue reactions during the degradation of polylactide implants in the body].

Tissue reactions, accompanying the degradation processes of polylactide (PLA) implants after their placement into the subcutaneous tissue, were studied by the methods of light microscopy in 6 month-old Wag rats (n=24) weighing 180-200 g. It was found that PLA implants became encapsulated by connective tissue. If the implant or its fragment had sharp margins that damaged the tissues, a thick capsule was formed with a distinct inflammatory infiltration and the sclerosis of the surrounding tissues. If the implant had no sharp margins, the capsule was thin, and the activity of inflammation was minimal. In all cases, the giant cells of foreign body type were present in the capsule and next to it. Gradually, during 6 months, the activity of inflammatory process subsided. Inflammation sharply increased 12 months after the implantation, when, as a result of effect of enzymes released by phagocytes and deformation by a capsule, PLA implants were either fragmented or is liquified. PLA-based materials are not totally biodegradable, and may persist in the body for a long time.

Peculiarities of using stem cells for regeneration of the bone and cartilage tissue.

Scientific literature about the use of MSC contains clinical and experimental data on the efficiency of cell technologies for restoration of the osteoarticular apparatus. The use of MSC immobilized in the appropriate carriers and differentiation of these cells towards the bone cells and chondrocytes are of crucial importance. However, the use of MSC, both individual and in combination with other preparations and substances has a number of drawbacks and advantages. The absence of published reports on contraindications and complications of cell therapy is worthy of note, because the analysis of unsuccessful application of MSC will help to determine the indication for this treatment, and hence, to improve the efficiency of cell technologies in the future. Wider use of MSC in clinical practice and experimental studies for acceleration of reparative processes in the bone and cartilage tissue seems to be promising.