Preparation and characterization of alginate/HACC/oyster shell powder biocomposite scaffolds for potential bone tissue engineering applications

Abstract

Tissue engineering scaffolds combining biominerals and natural polymers are prospective candidates for bone repair materials. In this work, biocompatible and antibacterial scaffolds were prepared by blending alginate, hydroxypropyl trimethyl ammonium chloride chitosan (HACC) and oyster shell powder (OSP) by freeze drying. SEM, FTIR, mechanical testing and BET surface area analysis were applied to characterize the prepared scaffolds. The swelling behavior, biomineralization, in vitro biodegradation, protein adsorption, antibacterial test, cytotoxicity, and alkaline phosphatase (ALP) activity test were also investigated. The prepared scaffolds have a highly porous and interconnected pore structure with a pore size of around 20 to 200 μm suitable for cells to grow in. The addition of oyster shell powder in the scaffolds improved their compressive strength, specific surface area, and protein adsorption capacity, and also controlled the swelling behavior. Both of the scaffolds were biodegradable; the degradation was decreased on increasing the OSP content in the scaffolds, while the biomineralization ability was improved. Meanwhile the prepared scaffolds exhibited antibacterial activity toward E. coli and S. aureus. There was no significant cytotoxicity effect of the prepared scaffolds towards MC3T3-E1, HOS, and MG-63 cells and they have a good ALP activity. Therefore, these results suggest that the Alg/HACC/OSP scaffold is a prospective candidate for bone repair materials.