Synthetic Biphasic Calcium Phosphate Research Articles

Comparison of Osteoinduction by Autologous Bone and Biphasic Calcium Phosphate Ceramic in Goats

Autologous bone chips are widely used in orthopedic surgery to fill large defects due to osteoinductive property but are limited in quantity. Several groups have reported the formation of mineralized bone after implantation of bioceramics in ectopic sites of different animals. However, osteoinduction by bioceramics has not yet proved to be equivalent to those of autologous bone. In this study, we compare the bone inducing capability of autologous bone chips and synthetic biphasic calcium phosphate (BCP) ceramics granules sintered at various temperatures. Both materials were implanted in muscles and femurs of goats inside hollow containers for 6, 12 and 24 weeks and analyzed by histology. This study showed that bone tissue formed in contact with micro porous ceramics sintered at low temperature as well as autologous bone chips both in ectopic and intrafemoral sites of goats.

Biodegradation of synthetic biphasic calcium phosphate by human monocytes in vitro: a morphological study

Biodegradation processes (both intra- and extracellular) occur immediately after implantation of calcium phosphate (CaP) ceramics. Monocytes and macrophages, among the first cells to appear in wound healing, are largely implicated in phagocytosis and may be involved in CaP degradation because of their sensitivity to secreted cytokines. We tested the behaviour of human monocytes placed on the surface of hydroxyapatite (HA) and biphasic calcium phosphate (BCP) tablets in the presence of vitamin D3 (VD3) and interferon gamma (INF gamma). After short-term culture (6 days), morphological events were observed in histological and scanning electron microscopy studies, and degradation lacunae were characterized. There were cell prints but no pits on the HA surface, but pits appeared near cells on the BCP surface. Preincubation of biomaterial in culture medium was essential. Variations in cell morphology were observed in different culture types. In the presence of VD3, degradation was greater than in the control, and cells were more polarized and rounded. With INF gamma, cells were extensively spread out on the sample surface, and the biomaterial seemed to be extracted from the surface by cells. Thus, monocytes are clearly influenced by soluble factors (vitamins, cytokines) and could be key cells in initiating the degradation of biomaterial.