Effect of solvent and additives on the electrospinnability of BSA solutions

Electrospun nanofibrous membranes have attracted the interest of the scientific community over the past decades due to their unique properties (e.g., high surface area, enzyme encapsulation high efficiency in filtering). Among the most promising membranes are those derived from natural polymers, which are not based on fossil fuels and most of them are highly biocompatible. In this regard, this study is focused on the development and characterization of electrospun nanofibrous membranes of bovine serum albumin (BSA) with potential applications in several fields, from tissue engineering to advanced filtering. Although the globular structure of BSA hinders the generation of nanofibers, some previous studies have succeeded in its electrospinning. However, they made use of either toxic reagents or co-electrospinning with synthetic polymers, which resulted in poorer biocompatibility. To prevent this, the present study explores the impact of non-hazardous reagents on the formation of BSA nanofibers. As a result, it was observed that the addition of ethanol (EtOH) in the solvent mixture and the thermal denaturation of BSA favored the electrospraying of nanoparticles (∼ 300 nm). It was also noticed that the presence of hydroxypropyl methylcellulose (HPMC) favors the formation of nanofibers (∼ 60 nm). However, bead formation was found in these membranes. This work contributes to clarifying the influence of solvents and surfactants when proteins are electrospun, enabling the manufacture of bio-based nanofibrous mats with applications in different fields (e.g., filtering, biomaterials, active packaging).