A bioinspired, ice-templated multifunctional 3D cryogel composite crosslinked through in situ reduction of GO displayed improved mechanical, osteogenic and antimicrobial properties

Highlights

• Current scaffolds used for bone tissue engineering use chemical crosslinkers, which may be toxic.

• Aim is to develop crosslinker free 3D gelatin scaffolds based on ice templating.

• In situ reduction of GO in the gelatin matrix provided improved mechanical and physical properties.

• Gel-RGO and Gel-RGO_Ag@Hap cryogels demonstrated good biocompatibility and cellular adhesion.

• Gel-RGO_Ag@Hap cryogels showed superior osteoinductive and osteoconductive properties, with prolonged antimicrobial activity.

Abstract

3D biopolymeric scaffolds often lack the biochemical cues and mechanical strength to encourage bone tissue regeneration. Chemical crosslinkers have been extensively used to impart strength, but have been found to be toxic at the site of implantation and possess a lacuna in physical strength. We attempted to address this by engineering a self-crosslinked polymer through the in-situ reduction of Graphene oxide (GO) in a gelatin cryogel (Gel-RGO) using ice as a template to create pores. Superior osteoinductive and antimicrobial properties were further endowed on the cryogel by incorporating silver nanoparticles decorated nanohydroxyapatite in the Gel-RGO_Ag@Hap(2%) cryogel. The optimized biocompatible cryogel favoured bone cell adhesion and its proliferation. The osteoconductive and osteoinductive potential of the cryogel was confirmed through biomineralization and differentiation of bone cells. In addition, these cryogels showed prolonged antimicrobial activity against S. aureus. This investigation exhibits the achievability/prospect of building up an ideal gelatin platform without the utilization of an outside crosslinking agent via manipulating the conditions of gelation. The superior crosslinking achieved between gelatin and GO, in addition to its ability to support bone formation and prevent infection make this cryogel an attractive candidate for bone tissue engineering applications.