Biocompatibility of synthetic ultraviolet radiation cross-linked polymers - Subcutaneous implantation study

Photo-cross-linked polymers have attracted a lot of attention in the biomedical field. The main benefits of these materials are related to the fact that they are most of the time viscous liquids or pastes that adapt a custom and fixed shape on demand of the user. Present study deals specifically with the biological response upon subcutaneous implantation of four different materials in rabbits. In the study 20 rabbits were divided into four groups (each five rabbits): Groups 1-3 were implanted with tested new obtained by us macromonomers (P1838-DMA; P1838-UR; PDEGA-UR - respectively), while group 4 (control) was implanted with the mesh (PLA) routinely used for surgical treatment of a hernia. The new compounds were polarized earlier using ultraviolet radiation to obtain cross-linked networks. The polymers in the form of discs were then implanted subcutaneously in dorsal region of rabbits. After 28 days polymers were explanted and examined. Microscopic observation evaluated: thickness of the connective tissue capsule around the discs, cells of inflammatory response, disc surface erosion, spectroscopic analysis. The examined materials cause no chronic inflammation, abscesses or tissue necrosis, and the biological response is similar to observed in control group. Therefore, new synthetic materials could be considered as biocompatible and safe. Materials undergo slow degradation of ester bonds and surface erosion and degradation products could be eliminated probably by phagocytosis. On the basis on the afore mentioned knowledge, we formulated hypothesis, that the new polymers are well tolerated by the adjacent tissues. The aim of the following study was to examine reaction of the tissue on new types of prepolymerized material implanted subcutaneously. The obtained results suggest, that the new UV cross-linked polymers do not affect negatively on the connective tissue that is in the contact with the implants. Furthermore, the used materials are in the liquid form, thus they could be easily performed in in minimally invasive laparoscopic treatment of abdominal hernias. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1889-1897, 2019.