Reparative processes in allo- and xenoimplantation of extracellular bone matrix

Abstract

The need for bone-plastic material is presently rapidly increasing, particularly for reconstructive and restorative surgeries on bone tissue in traumatology and orthopedics, maxillofacial surgery, bone oncology, and other cases of surgical practice. Among the implantation materials based on bone tissue the leading place is occupied by auto- and allogeneic implants. Autogenic implants are the best from the biological point of view but xenobone materials are their worthy alternative due to their availability and biocompatibility. The aim of this research was to study reparative processes in the regeneration zone during allo- and xenoimplantation of a material obtained from bone tissue into a semicircular defect in the rat femoral diaphysis. The materials were prepared using the same technology. Methods. Biochemical and morphological studies were performed on 18 male Wistar rats aged 6—8 months. The rats were divided into 3 groups. The first group (n = 6), xenoimplantation; the second group (n = 6), alloimplantation, and the third group, healthy control (n = 6). On the 60th day of experiment, biochemical indexes of blood serum were studied, including activities of total alkaline phosphatase (TCA) and tartrate-resistant isoenzyme of acid phosphatase (TrAP), calcium, phosphate, total protein (TP), C-reactive protein, protein fractions, and morphological studies. Results. Measuring serum protein fractions and C-reactive protein showed the absence of a significant inflammatory reaction to allo- and xenoimplantation of extracellular bone matrix into the defect of femoral metaphysis. Activation of reparative process was noted in both experimental groups. Histological analysis found osteointegration of both allogeneic and xenogenic fragments of the spongy bone implanted into the semicircular defect of rat femur. When alloimplants were used a high rate of their biodegradation and organotypic remodeling of the operated recipient’s bone were observed. However, in all cases, there was no evidence of a rejection reaction, encapsulation of the implant or inflammation in tissues of the maternal bed. The study produced biochemical and histological evidence supporting for a possible use of extracellular matrix of xenogeneic nature for replacement of bone tissue defects.