Electrospinning of gelatin nanofiber scaffolds with mild neutral cosolvents for use in tissue engineering

Abstract

Electrospun gelatin nanofibers are effective tissue engineering scaffolds with high biocompatibility and cell adhesion activity. In gelatin electrospinning, fluorinated alcohols, which are irritants, and acidic organic solvents are used as solvents to prevent gelation. This study established a technique to embed protein reagents into the nanofibers using mild solvents. From 22 mixtures of 50% organic solvent–50% H2O, less denaturing neutral dipolar aprotic solvents (specifically N,N-dimethylacetamide, N,N-dimethylformamide and N-methyl-2-pyrrolidone), were screened to assess their suitability for use in electrospinning of gelatin nanofiber scaffolds by their ability to maintain gelatin in a sol state at room temperature. By selecting the solvents and their concentrations, gelatin nanofibers were electrospun with different structures from a thick, wide, porous nanofibrous structure to a thin, fine, nanofibrous mesh structure. Swiss 3T3 fibroblasts grew well on the gelatin nanofibers. In particular, some cells showed in vivo-like spindle morphologies on the thick porous nanofibers using N,N-dimethylacetamide. Additionally, as a model protein reagent, alkaline phosphatase was embedded in the gelatin nanofibers while maintaining high activity. Considering these results, the gelatin nanofibers in this study are expected to provide effective structural and chemical cues and will be useful for tissue engineering and regenerative medicine. Gelatin nanofibers were electrospun using mild N,N-dimethylacetamide, N,N-dimethylformamide and N-methyl-2-pyrrolidone. Various gelatin nanofibers were fabricated, ranging from a thick, wide, porous nanofibrous structure to a thin, fine, nanofibrous mesh structure, depending on the solvents and their concentrations. In particular, Swiss 3T3 fibroblasts exhibited in vivo-like spindle morphologies on the thick nanofibers. A model protein, alkaline phosphatase, embedded in the gelatin nanofibers maintained high activity.