Biodegradable Composite Material for Bone Reconstruction: Medical and Biological Research

Modern and promising concepts in bone reconstruction surgery are related to the achievements in tissue engineering, the key element of which is artificially created tissue equivalents (matrices) in which the cells can attach, proliferate and differentiate with subsequent new tissue formation. Recently there has been an increasing interest in the development of new biodegradable matrices used in reconstructive surgery. The biological properties of bioresorbable PURASORB PL-38 polylactic acid-based polymers formed by the method of aerodynamic molding in a turbulent gas flow were studied. To enhance the biological activity of the implants, two types of filler were used: dicalcium phosphate dihydrate and hydroxyapatite, which were included in the structure of the material using laser ablation method. The osteointegrative properties of the implants were tested on 48 male Wistar rats weighting 180-200 g. The rats were divided into 3 groups depending on the test sample. The follow-up ranged from 15 to 90 days. Microscopic study revealed inflammatory giant cell infiltrate with the presence of histiocytes and fibroblasts around the implants. The inflammatory infiltrate persisted for 60 days and gradually replaced the resorbable implant material, providing its biodegradability. On day 90 after implantation, decreased inflammatory infiltrate (a decrease in the number of giant cells) was observed in all groups of the studied samples. Osteogenesis occurred only in cases of the damage to bone tissue, when the implant was in close contact with both the cranial bones and the pelvic bones. The results obtained demonstrated that the biodegradable implant made of PURASORB PL polylactic acid polymer and organic mineral tiller obtained by the method of laser ablation of a solid target made from dicalcium phosphate dihydrate showed the best integration properties.