Incorporation of chitosan whisker and hydroxyapatite: A synergistic approach to reinforce chitosan/Poly(ethylene glycol) gel

Optimizing mechanical properties of scaffolds is important to control cell behaviors. Chitosan (CS) is a potential biomaterial for scaffolds due to the rich functionality and cationic property. However, the conventional fabrication of CS-based scaffolds requires more or less toxic cross-linking reagents, and the control of the mechanical property is achieved by the dose of such reagents. In this study, CS scaffolds embedding CS whiskers (CSWK) and hydroxyapatite (HA) are developed via thiol-maleimide Click reaction, of which no by-products generated, followed by alternate soaking of calcium chloride (CaCl2) and disodium phosphate (Na2HPO4). Incorporation of CSWK favors the densed networks and improves the compressive strength. The subsequent HA deposition is not only for gel reinforcement but also osteo-compatibility and osteoinductive properties after transforming to scaffold via freeze-drying. In addition, CSWK promotes the HA deposition onfin the gel. The use of Sarcoma osteogenic (SAOS2) cell model confirms cell compatibility as well as cell penetration of CS-CSWK-HA scaffolds. As the mechanical strength of the osteoblast cell compatible CS-CSWK-HA scaffolds can be tuned based on the contents of CSWK, HA, and the degree of crosslinking (via thiol-ene), the CS-CSWK-HA scaffolds are potential material for bone tissue engineering. (C) 2019 Elsevier Ltd. All rights reserved.