Regenerative osteogenesis at the interface of tissue–osteoplastic material

Abstract

BACKGROUND: About a half a century ago, the concept of physiological regeneration of bone tissue was introduced, which is based on the functioning of basic multicellular units (BMUs). Later, such an approach can also be used to understand the regularities of reparative regeneration. Bone grafting using gene-activated synthetic replacement materials introduces additional features into the reparative process because the material becomes an active participant in the process. Bone grafts sequentially undergo resorption and metabolism and become a matrix on the basis of which the BMUs implement regenerative osteogenesis. AIM: To reveal the function of BMUs in a human bone wound during implantation of a gene-activated osteoplastic material from octacalcium phosphate. MATERIALS AND METHODS: Microfocal computed tomography, histological and immunohistochemical studies, histomorphometry were analyzed and processed statistically. RESULTS: When using an ordinary product and a gene-activated material based on octacalcium phosphate, the bone regenerate was represented by a multi-tissue structure formed by bone beams surrounding non-resorbed fragments of bone replacement products. In the histomorphometric analysis of gene-activated material, the median area of the unresorbed granules was 0.039 [0.013; 0.079] mm2, and the median area of the osteoclasts was 67 [22; 235] cells/mm2. In the group using an ordinary product, the values were 0.029 [0.009; 0.068] mm2 and 15 [0; 79] cells/mm2, respectively. CONCLUSION: BMUs that are in various phases of functional activity (resorption, reversion, formation, and rest) can be detected at the gene-activated material–bone interface. The last phase appears only in cases when the components of the material do not induce osteogenesis.