Composite Hydrogel Scaffolds with Eggshell Particles as a Novel Bone Regeneration Material

Abstract

The development of bone regeneration materials to support new bone formation is an active field of research. This report describes the development and characterization of a novel composite scaffold made of a chitosan-alginate co-polymer hydrogel matrix and eggshell (ES) particles. Scaffolds with ES particles or with nanotextured ES (NTES) particles following treatment with phosphoric acid were compared to scaffolds without particles. The scaffolds with particles exhibited a higher porosity and a larger median pore size. Their mechanical strength remained low, but both scaffold types were more resistant to deformation following compression than the scaffolds without particles. The osteogenic potential of the scaffolds was then evaluated with human bone-marrow derived mesenchymal stem cells (MSCs) from four different donors. Results showed that the inclusion of ES or NTES particles significantly increased MSC adherence and viability, as well as alkaline phosphatase activity in the scaffolds. A change of cell morphology and a small, although not statistically significant, increase of osteogenic protein expression (RUNX2 and osteopontin) were also observed at later time points (days 14 and 21). Overall, this research highlights the potential of ES for bone regeneration applications, opening the door for a high-value repurposing of a current industrial waste product.