Construction of poly-(γ-benzyl‐l‐glutamate) composite microcarriers with osteogenic and angiogenic properties for the restoration of alveolar bone defects

The repair of alveolar bone defects is one of the urgent clinical problems to be solved. Injectable microcarriers show great potential for bone repair due to their ability to fill irregular bone defects. In this study, the ICA@nCP/nHA-g-PBLG composite microcarriers with osteogenic and angiogenic properties were fabricated via double emulsion (W/O/W) method. Firstly, poly-(γ-benzyl‐l‐glutamate) (PBLG) was linkaged onto the surface of nano copper hydroxyphosphate (nCP) and nano hydroxyapatite (nHA) to construct nCP-g-PBLG and nHA-g-PBLG nanohybrids by chemical grafting, respectively. Then, nCP/nHA-g-PBLG porous microcarriers were fabricated via double emulsion (W/O/W) method and immersed in icariin (ICA) solution to obtain ICA@nCP/nHA-g-PBLG composite microcarriers. The composite microcarriers were more conducive to the proliferation of bone marrow mesenchymal stem cells (BMSCs) when the content of nCP and ICA in the composite microcarriers were 0.5 wt% and 0.1 wt%, respectively. The release of Cu2+ in nCP could promote angiogenesis, while the release of ICA could promote the osteogenic differentiation of BMSCs. The ability of ICA@nCP/nHA-g-PBLG microcarriers to restore alveolar bone defects was proved in a rabbit model. In conclusion, the ICA@nCP/nHA-g-PBLG microcarriers exhibited two functions: osteogenesis and angiogenesis, which could be served as a promising implant for alveolar bone defects repair.