Fabrication and cell viability of injectable n-HA/chitosan composite microspheres for bone tissue engineering

摘要

Composite microspheres based on nano-hydroxyapatite (n-HA)/chitosan (CS) with different weight ratios were fabricated by an emulsion method and using natural vanillin as a cross-linking agent. FT-IR, XRD, TGA, SEM and laser particle size analysis were used to characterize their physico-chemical properties. Live-dead cell staining and MTT assay were used to evaluate cell viability and cytocompatibility. The results showed that the rod-like n-HA crystals could be incorporated into the CS matrix in a relatively high level up to 29.57 wt%. The encapsulation efficiency of n-HA in the composite microspheres was between 29.50-73.93%. The composite microspheres with a diameter of 10.9-55.0 mm and good swelling properties should be easy to inject into irregular bone defects. The studies of in vitro biodegradation and cell culture using MG63 cells demonstrated that the vanillin-crosslinked n-HA/CS microspheres could be degraded in a sustained and controlled behavior while supporting cell growth, thus acting as worthy candidates for a multifunctional injectable matrix in bone tissue engineering.