羟基磷灰石生物陶瓷支架的多级结构决定骨诱导性

In this paper, the previously developed porous bioceramics scaffolds by accumulating hydroxyapatite (HA) spherulites which has a hierarchical structure with large dimension of 2.5~3cm in length and 1.5cm in diameter were implanted into dorsal muscle and abdominal cavity of dogs, which were deliberately created spaces within the body used as "autologous bioreactor" to grow engineered bone grafts based on the natural physiological environment. After 6 months, the dogs were sacrificed and histological analysis of explants was performed on thin paraffin sections. Lively osteogenesis was observed in pores between spherulites and in the ceramic cylinder foam, even in the micropores of HA spherulites. Bone formation by means of creeping substitution was evidently observed, in which the woven bone matrix was surrounded by osteoblasts and subsequently matured into mineralized bone while the HA bioceramics were resorbed by osteoclasts on the resorption line. Bone marrow recanalization inside the explants was obviously found. It is confirmed that an engineered bone graft similar to natural bone can been reconstructed through the novel porous bioceramics scaffold by accumulating HA spherulites in which the osteogenesis occurred in autologous bioreactors. Furthermore, the results also suggest the hierarchical structure depended osteoinduction/osteogenesis of the accumulating scaffolds.