Calcium Phosphate Glass (CPG): Potential as Biomaterial for Hard-Tissue Repair

Abstract: The purpose of this study was to evaluate the cell affinity of calcium phosphate glass scaffold in the system of CaO-CaF2-P2O5-MgO-ZnO, which is already reported that promoted the bone-like tissue formation in vitro and formed new bone in Sprague-Dawley rats. We prepared calcium phosphate glass saffolds with three-dimensionally interconnected pores of 200~500 µm. Commercial HA scaffold was employed as a control in this study. Bone marrow cells were collected from the healthy human donors and cultured within the prepared scaffolds. After 2, 4, 6, and 8 weeks, hMSCs/scaffold were fixed and stained with hematoxylin and eosin. hMSCs were continuously proliferated both in the experimental and control groups at every incubation period. The number of cells was higher in the experimental group than that of the control group, however, there was no significant difference (p>0.05). Extracellular matrices could be observed at the 2nd and 4th days in the experimental and control groups, respectively. The extracellular matrices were more abundant in the experimental group at all periods. The prepared calcium phosphate glass scaffolds are expected effective in bone tissue engineering.

Abstract: Calcium phosphate bioceramics and bovine bone xenograft with or without sintering are more or less used in orthopaedics or in maxillofacial surgery. In this study we compare in a rat femoral epiphysis model after 3 weeks of implantation the bone in growth at the expense of granules of same size of micro macro porous biphasic calcium phosphate MBCP, sintered bovine bone and unsintered BioOss.

Abstract: The purpose of this study is to explore the osteoinductivity of the composite materials (calcium phosphate ceramics/PLA or collagen composites) with similar physical character of osteoinductive calcium phosphate ceramics and the influence of the chemical composition of the composite materials on osteoinductivity, and also to provide an experimental evidence for optimizing the design of the composite materials. Two kinds of composite materials were prepared. One (BCP/PLA) is fabricated with different ratio of BCP (biphasic calcium phosphate) ceramics powder and PDLLA powder through the particulateleaching technique. The other (BCP/collagen) is that BCP ceramics sintered at 1250oC and modified with collagen. The porous materials cylinders with Φ 5×8 mm were prepared. SEM was used to observe the microstructure and physical morphology of the composite materials. The two groups of composite materials cylinders were implanted in the dorsal muscles of four dogs. Six samples of each group were implanted in each dog respectively. The specimens were harvested at 2, 4, 12 and 24 weeks post operation, and thin decalcified sections were prepared for light microscopy (LM) analysis to evaluate their osteoinductivity and compare the capability of osteoinduction. The fibro-tissue and bone-like tissue were observed in the two composites, but no obvious bone formation was found in the tested periods. The results indicated that the composite materials could modify the mechanical property of ceramics. However, if the composite materials were biodegraded soon, new bone could not form into the scaffold, and the calcium phosphate should be the major component of osteoinductive materials.