Research of the biocompatibility of composite materials based on hydroxyapatitis and copolymer lactide-glycolide on laboratory mice Laboratory

Summary. In this study, the biocompatibility of composite materials based on hydroxyapatite and the copolymer lactide and glycolide with different ratios of components was studied on mice: composite material No. 1 – 95: 5 wt%, composite material No. 2 – 93: 7 wt%. During the experiments, 30 outbred male mice weighing 30–40 g were used, which before the operation were randomly divided into six groups depending on what material was implanted into the body: hydroxyapatite, lactide-glycolide copolymer, composite material No. 1, composite material no. 2; in the group of sham-operated animals, access to the pectoralis major muscle was performed without placing the material. Operations were performed to introduce the tested materials for the large pectoral muscle. The experi-ment lasted 22 days. On the 21st day after the operation, blood was collected from the retroorbital sinus to determine the level of white blood cells. After euthanasia in a CO2 box, macroscopic and histological examination of the pectoralis major muscle was performed. Staining of histological preparations was performed using hematoxylin-eosin and van gieson staining on connective tissue. The follow-ing parameters were evaluated: inflammation, fibrosis, and vascularization. It has been shown that isolated use of hydroxyapatite is accompanied by moderate fibrosis and local inflammation. In response to the implantation of a pure copolymer of lactide and glycolide, no reaction was observed on the part of the body. Among composite materials from the point of view of biocompatibility, the optimal material for implantation among the studied was a composite material with a ratio of hydroxyapatite to the copolymer of lactide and glycolide equal to 93:7 wt.% (composite material # 2), the use of which is characterized by a lower degree of inflammation and fibrosis in the implantation zone compared to hydroxyapatite. The greater biocompatibility of composite material No. 2 in comparison with hydroxyapatite and composite material No. 1 can probably be associated with an increase in the content of the copolymer of lactide and glycolide in its composition.