Shapable bulk agarose–gelatine–hydroxyapatite–minocycline nanocomposite fabricated using a mineralizing system aided with electrophoresis for bone tissue regeneration

Abstract

Abstract To develop a shapable bulk antibacterial nanocomposite biomaterial for bone regeneration. A bulk agarose–gelatine hydrogel was mineralized using a hydrogel mineralizing system aided with electrophoresis, and the mineralized hydrogel was loaded with minocycline to obtain the agarose–gelatine–hydroxyapatite–minocycline nanocomposite. The nanocomposite had a large Brunauer–Emmett–Teller surface area of 44.4518 m2 g−1 and a high porosity of 76.9%. Hydroxyapatite crystals were well developed in the hydrogel matrix and exhibited a hybrid structure of microscale and nanoscale motifs. The addition of minocycline resulted in a continuous antibiotic release, inhibiting the growth of Staphylococcus aureus over 2 weeks in vitro. Exposed to rabbit bone marrow mesenchymal stem cells, the nanocomposite revealed good cytocompatibility in vitro. Furthermore, the biomaterial could effectively enhance the bone regeneration in a critical-size rabbit cranial defect model in vivo. These findings depicted that the nanocomposite, with good biocompatibility and good antibacterial property, is a promising candidate for future clinical application in bone tissue engineering or as a prospective bone replacement biomaterial.