Evaluating the cytocompatibility and differentiation of bone progenitors on electrospun zein scaffolds

Bone fractures often result in complications that require surgical intervention to promote fracture healing. Tissue engineering seeks to alleviate the need for autologous bone grafting by utilizing scaffolds that can promote bone fracture healing. Plant-derived materials are desirable biomaterials because of their biodegradability, availability, and low immunogenicity. Among various plant-derived proteins, zein, which is a corn protein, has shown promise for bone repair. However, when processed, zein is often blended with synthetic materials to improve mechanical properties and overall hydrolytic stability. In this study, pure zein was electrospun to create fibrous scaffolds and cross-linked with trimethylolpropane triglycidyl ether to improve hydrolytic stability. Scaffolds were characterized and evaluated in vitro for promoting the osteogenic differentiation of MC3T3-E1 cells, which are bone progenitor cells. Cross-linked zein scaffolds retained their uniform fiber morphologies after hydration. MC3T3-E1 cells grew and differentiated on the zein scaffolds even in the absence of induction factors, as demonstrated by increased alkaline phosphatase activity, mineralization, and early upregulation of Runx2 gene expression, a transcription factor associated with osteoblast differentiation. These studies demonstrate that stable, zein fibrous scaffolds could have potential for use in bone repair applications.