Electrospinning of alginate/soy protein isolated nanofibers and their release characteristics for biomedical applications

Natural polymer-based nanofibers with functions of loading and releasing bioactive cues or drugs have recently gained interest for biomedical applications. Nanotopography and large surface area to volume ratio of hydrophilic polymer fibers promote their use as carriers of hydrophilic drugs. Here, sodium alginate (SA) and soy protein isolated (SPI) blended fibers encapsulated with vancomycin were fabricated via electrospinning with the assistance of poly(ethylene oxide) (PEO). Morphological results showed submicron-sized, smooth and uniform as-spun SA/PEO/SPI fibers with an average diameter of 200 nm. Beads on the fiber mats were formed with increasing SPI content in the blending system. The optimal polymer composition of the electrospinning solution was determined as 5.6/2.4/2 SA/PEO/SPI. Polymer blends were maintained after ionic “cross-linking”, as indicated by the FTIR result. Investigation of release characteristic of vancomycin-loaded SA/PEO/SPI electrospun fibers exhibited initial burst release followed by a controlled release after 2 days of immersion in a phosphate buffered saline. The release rate of SA/PEO/SPI fibers was significantly slower than that of SA/PEO fibers, and drug-loaded fibers inhibited bacterial growth against Staphylococcus aureus after 24 h of incubation. Non-toxicity and biocompatibility of the fibers were confirmed by an indirect cytotoxicity test using human dermal fibroblasts. These results suggest that the vancomycin-loaded SA/PEO/SPI blended fibers are a promising nanomaterial for use in biomedical fields such as scaffolds for tissue engineering and drug delivery systems.