Electrospun thymol-loaded porous cellulose acetate fibers with potential biomedical applications

Drug toxicity induced by burst release has become a great challenge in clinical therapeutics. In most studies of drug delivery, great attention has been given to achieving sustained drug release by enhancing the surface hydrophobicity of drug carriers. However, many of them improved surface hydrophobicity through chemical methods, which could be toxic and time-consuming. This paper aims at providing a facile way to improve surface hydrophobicity of drug carriers. Here, a kind of porous cellulose acetate (CA) fibrous membranes containing different amount of thymol (THY) for sustained drug release were prepared, by co-electrospinning technique. The ellipse-shaped nanopores were generated on the surfaces of electrospun fibers in situ, which trapped a part of air at the interface and thus enhanced the hydrophobicity of fibrous membranes. The in vitro drug release results showed that the porous THY-loaded fibrous membranes had slower initial drug release and extended drug release time, compared with nonporous THY-loaded fibrous membranes. In addition, the higher specific surface area of porous THY-loaded CA fibrous membranes contributed to a higher drug utilization ratio. Antibacterial results demonstrated that porous THY-loaded CA fibrous membranes possessed more effective inhibition against S. aureus and E. coli, with only 0.07% and 0.09% of bacterial survival rate, respectively. Furthermore, the combination of porous surface structure with a controllable drug release improved the proliferation of L929 cells, indicating a better cytocompatibility. Taken together, the porous THY-loaded CA fibrous membrane offer significant promise as novel wound healing materials.