Water-insoluble, nanocrystalline, and hydrogel fibrillar scaffolds for biomedical applications

Recently, micro/nanofibrillar materials have been widely utilized for a variety of applications in many different fields of research due to their relatively large surface-to-volume ratios, high porosity, and three-dimensional connectivity, along with their cost-effective fabrication processes. Herein, we present a review of recent progress in the development of micro/ nanofibrillar scaffolds with a specific focus on their biomedical applications. From the perspective of controlling polymer-polymer and polymer-water molecular interactions, we categorized the fibrillar scaffolds into insoluble, nanocrystalline, and hydrogel fibers. Based on our recent studies related to this research topic, we provide the significance and essential information on four different micro/nanofibrillar scaffolds: (1) solid micro/nanofibrillar scaffolds based on water-insoluble polymers, (2) hydrogel nanofibrillar network scaffolds based on crystalline bacterial cellulose, (3) hydrogel micro/nanofiber scaffolds based on partially precipitated PVA, and (4) hydrogel micro/nanofiber scaffolds based on chemically cross-linked PVA. The present discussion should provide guidance to researchers in selecting a micro/ nanofibrillar scaffold suitable for their own purposes and should help inspire them to develop more sophisticated fibrillar scaffolds in the future.