Abstract: The ability of biodegradation and the expression of biological activity in vitro are among the most important characteristics of polymers for medical purposes, which will make it possible to predict the behavior of polymers in vivo. Therefore, this article is devoted to the study of the biodegradability of composite materials based on PUU filled with silver-containing silica nanocomposites of various compositions (02AgCu, AgCu, 01Ag) in different amounts (0.1, 0.5, and 1.0 wt.%) under the influence of biological medium 199 (BM 199) for 1, 3 and 6 months as potential biopolymers and the study of their antibacterial properties. The biodegradation ability was assessed by changes in structure, physical-mechanical, thermophysical and thermogravimetric characteristics. The results of IR spectroscopic studies demonstrate the absence of changes in the absorption bands of functional groups before and after incubation in BM 199, which indicates the stability of polymer materials under the influence of BM 199. According to physical-mechanical studies after 6 months of incubation in BM 199 the strength values are greater than the control values, and the values of relative elongation at break does not undergo significant changes compared to the control values. It also allows us to conclude about the biostability of composite materials for 6 months. According to the results of tests by the DSC method, after 6 months of incubation in BM 199 the values of Tg and ΔCp at the glass-transition temperature do not undergo significant changes, which also indicates the biostability of the studied materials. Using the TGA method, it was established that after incubation in BM 199 composite materials in vitro remain heat-resistant materials. According to the results of microbiological studies, all filled film materials have antibacterial properties against the most common gram-positive and gram-negative bacteria, which are manifested by the formation of zones of bacterial growth retardation with a diameter of 14-31 mm. Thus, composite materials filled with silver-containing silica nanocomposites are biostable for 6 months without significant changes in their structure and properties under the influence of biological medium for a long period of time and exhibit antibacterial activity. This makes it possible to use them as biologically active polymer materials of long-term use in various branches of medicine.Abstract: The ability of biodegradation and the expression of biological activity in vitro are among the most important characteristics of polymers for medical purposes, which will make it possible to predict the behavior of polymers in vivo. Therefore, this article is devoted to the study of the biodegradability of composite materials based on PUU filled wi...Show More