Enhancing the bioactivity of hydroxyapatite bioceramic via encapsulating with silica-based bioactive glass sol.

Although hydroxyapatite (HA) bioceramic has excellent biocompatibility and osteoconductivity, its high chemical stability results in slow degradation which affects osteogenesis, angiogenesis and clinical applications. Silica-based bioglass (BG) with superior biological performance has been introduced into HA bioceramic to overcome this insufficiency; however, the composite bioceramics are usually prepared by traditional mechanical mixture of HA and BG powders, which tremendously weakens their mechanical performance. In this research, BG-modified HA bioceramics were prepared by the use of BG sol encapsulated HA powders. The results showed that introducing 1 and 3 wt% BG allowed the HA-based bioceramics to maintain the high compressive strength (>300 MPa), improved the apatite mineralization activity, and played an important role in cellular response. The bioceramic modified with 1 wt% BG (1BG/HA) remarkably enhanced in vitro cell proliferation, osteogenic and angiogenic activities. This present work provides a new strategy to improve the biological performance of bioceramics and the HA-based bioceramics with 1 wt% BG can be as a promising candidate material for bone repair.