Features of Cell Reactions during Implantation of Biodegradable Polymer and Polypropylene in the Experiment

Quantitative and qualitative characteristics of cell infiltrates in male Wistar rats were studied from 14 days to 12 months after implantation of polypropylene and a biodegradable polymer obtained by electrospinning and consisting of 65% polycaprolactone and 35% polytrimethylene carbonate. It was found that a predominantly macrophage-giant cell reaction developed around the biodegradable polymer; it spread into the matrix and the number of cells in the infiltrate decreased, as the degradation progressed. Around polypropylene, mainly lymphocytic and leukocytic reaction was seen; it also decreased with time, but was characterized by a reverse increase in the number of lymphocytes. Immunohistochemical analysis showed that the proportion of CD38⁺ cells 12 months after implantation increased around polypropylene to a greater extent than around the biodegradable polymer, while the proportion of CD68⁺ cells decreased. These findings suggest that implantation of a biodegradable polymer caused no prolonged lymphocytic and plasma cell reaction in animals as in the case of polypropylene, which indicates that biodegradable polymer is a promising material for tissue engineering.