IMMUNOHISTOCHEMICAL EVALUATION OF OSTEOCONDUCTIVE PROPERTIES OF FIBER POLYMER MATRIX АT BONE DEFECT RECONSTRUCTION ON DIFFERENT TERMS IN EXPERIMENT

Abstract

The challenge for reconstructive surgery and tissue engineering is to optimize cell isolation, proliferation, and differentiation, to construct matrices or delivery systems, and to support, coordinate, tissue regeneration in three dimensions. Today in surgical dental practice the role of matrices is performed by granular matrix based on tricalcium-phosphate and hydroxyapatite, but still the inability to restore a complete bone structure remains a significant problem. One of the promising ways are the use of microfiber frames for bone tissue regeneration. The purpose of our study is to experimentally evaluate the nature of bone regeneration of the defect during implantation of a biopolymer nonwoven microfiber matrix. The study was performed on 50 laboratory animals (rabbits), which were divided into 2 groups. The first comparison group: 25 animals underwent surgery, which included the formation of a defect in the bone tissue. The second group: 25 animals developed a bone defect with subsequent implantation of a biopolymer matrix. The fibrous matrix made of 100% pure polycaprolactone granules developed by our method, which was made by phase separation of the polymer, was used for the research. The fiber diameter ranged from 0.7 μm to 10 μm. These matrices were subjected to gamma sterilization. Material collection was performed on the 1st, 2nd, 3rd, 4th and 5th months. The sections were incubated with primary antibodies for 12 hours at 4°C with a titer of 1:800 for osteocalcin and 1:400 for osteopontin. On the basis of immunohistochemical studies, increased reparative osteogenesis was established in the early stages (2-3 months) of the bone generation, which was confirmed by the increase in densitometric optical density of osteoinductive markers. The experimental group exceeds the control data, accompanied by increased strength (probable strength) of tissues in the area of defect and accelerate the processes of its subsequent compaction. This indicates a pronounced framework function of the polymeric microfiber matrix synthesized by us. Thus, a group of polymer fibers creates a kind of substrate for the construction of tissues on it, in particular bone tissue.

Keywords

• biopolymer
• matrix
• osteocalcin
• osteopontin.