Effect of thermal treatments and UV radiation on green soy protein isolated crosslinked electrospun mats

Abstract

Plant-derived proteins continue to draw great interest due to their high availability,biodegradability, and biological properties. Among them, soy protein isolate (SPI) has beenexplored for the development of different sustainable and biodegradable materials in manybionanotechnological fields. In addition, the electrospinning technique has gained interest asa versatile platform for designing synthetic/biopolymer-based nanofibrous mats for a hugevariety of bionanotechnological fields. However, the water stability of SPI mats is low, andthe sterilization procedures and conditions are not well established. In this work, oxidizedsucrose (OS) was used as a green and inexpensive crosslinker for electrospun SPI mats. Thesugar oxidation process was optimized by varying hydrogen peroxide concentration andreaction temperature. SPI-OS solutions were electrospun using acetic acid as a benign solventand the resulting mats were thermally treated at mild temperatures and different times. Thecrosslinked structures were fully characterized in terms of fiber morphology, andphysicochemical and thermal properties. Interestingly, uniform bead-free nanofibrous SPIOSmembranes that retained their fibrous morphology after 7 days of immersion inphosphate-buffered saline were successfully obtained. In addition, bilayered SPIOS/polycaprolactone mats were also produced by green electrospinning and sterilized by UVradiation for different exposure times. Finally, the effect of sterilization on the relevantproperties was presented and discussed. UV radiation demonstrated to be an effective methodfor sterilizing crosslinked SPI-based nanofibrous structures.