Magnesium-Substituted Hydroxyapatite /Spider Silk fibroin /N-Carboxymethyl Chitosan Based Microsphere: A potential template for bone regeneration

Abstract

Ageing, sedentary lifestyle and bone trauma have contributed to a sequel of clinical manifestation and risk factors associated with bone health. However, there are constant efforts made by researchers on both invasive and non-invasive strategies for a revival of bone architecture. In recent years, biomaterials, primarily biocomposites, have improved the facet of bone repair and regeneration. In the present work, a biocomposite of spider silk fibroin (SSF), N-caboxymethyl chitosan (N-CMCh) and magnesium (Mg2+) incorporated hydroxyapatite (HA), i.e. SSF/N-CMCh/Mg-HA was prepared to fabricate microspheres for bone regenerative applications. Initially, synthetic stoichiometric HA doped with Mg was synthesized by wet chemical method. The crystallographic property of Mg2+ incorporation in HA was investigated by XRD analysis. SEM-EDX and FTIR confirmed even distribution of the element and stoichiometric ratio of Ca:P along with Mg2+ in the biocomposite. A comparative analysis of the polarized SSF/N-CMCh/Mg-HA and SSF/N-CMCh was carried out to analyse the porosity and swelling of the fabricated microspheres. In vitro evaluation confirms the cellular metabolic viability of the microspheres. Further, Mg-HA-incorporated microspheres showed better protein absorption with enhanced ALP activity. Improved biocompatibility of the microspheres could be confirmed with high expression of osteogenic gene markers such as ALP, OCN, RUNX2, and COL-1. The studies confirmed that the fabricated SSF/N-CMCh/Mg-HA microspheres could be used as a potential template for bone regeneration.