Electrospun Nanofibers as a Green Approach for the Development of Advanced Biomedical, Pharmaceutical, and Filter Materials

The present Thesis focuses on the fabrication of polysaccharide – based nanofibrous mats via electrospinning technique primarily for, but not limited to, the development of wound healing patches with enhanced tissue regeneration capabilities. Specifically, this project arose to overcome the lack of methodologies concerning the proficient electrospinning of polysaccharides due to their poor processability, the requirement of hazardous and/or toxic solvents, and nanofiber inadequate stability in aqueous environments. To tackle this task, this Thesis proposes the use of poly(ethylene oxide), a biocompatible and water – soluble synthetic polymer able to increase the polysaccharide – based formulation spinnability, along with a simple washing – physical crosslinking treatment to fabricate pure polysaccharide nanofibers with boosted water resistance and marked biocompatibility. In the first Chapters, after a general discussion concerning the technological relevance and versatility of electrospinning technique together with its main applications, this Thesis concentrates on briefly presenting the properties of polysaccharide materials and their advantages with respect to synthetic polymers, as well as the experimental methodologies and characterization approaches used to achieve the investigated purpose. Then, either alginate or chitosan polysaccharides are employed for the fabrication of nanofibrous mats, whose physical – chemical properties, drug delivery capabilities, and biological responses are fully characterized. As a matter of fact, the developed systems effectively display a significant capacity to promote cell adhesion and proliferation along with proper mechanical, water – related, and drug release features, hence representing promising materials to be used in several biomedical and pharmaceutical products. Finally, the preparation of a multilayer nanofibrous patch comprised of an external hydrophobic stratum and an internal bioactive one is explored and discussed. To this end, combining a polyurethane nanofibrous layer with an alginate nanofibrous layer enriched with ZnO nanoparticles allows the fabrication of potential wound healing patches endowed with superior support and protective performances. These results are an important first step in making straightforward the electrospinning of polysaccharide materials granting the possibility to easily prepare nanofibrous meshes with potential uses in various application fields, with particular relevance in the biomedical and pharmaceutical industries where the bioactivity of these materials with respect to synthetic polymers plays a topical role.