Effect of sterilization methods on electrospun cellulose acetate butyrate nanofibers for SH-SY5Y cultivation

Abstract

In the biomedical field, the sterilization of nanofibers is of particular importance because it can significantly affect their morphology, physicochemical properties and cytocompatibility. Here, we studied the effect of conventional sterilization with 70% ethanol or ultraviolet (UV) radiation on cellulose acetate butyrate (CAB) nanofibers. Scanning electron microscopy (SEM) revealed that short-term (30 min) UV sterilization had no influence on nanofiber morphology while 70% ethanol led to swelling and, thus, reduced porosity. Water contact angle (WCA) measurements confirmed an increase in wettability after sterilization with ethanol. Fourier transform spectroscopy (FTIR) and electrokinetic analyses indicated only slight changes in the chemical composition of the CAB nanofibers for both sterilization types. However, longer sterilization time (2 h) led to notable changes in the chemical structure of the scaffolds. In turn, X-ray photoelectron spectroscopy (XPS) revealed changes in the chemical composition, even after short-term sterilization. In combination with FTIR and XPS, differential scanning calorimetry (DSC) identified the hydrolysis of the ethanol-sterilized scaffold and degradation of UV-sterilized one. Human neuroblastoma cell (SH-SY5Y) cultivation on the CAB scaffolds demonstrated significant changes in cell morphology and viability depending on sterilization type. Sterilization of CAB with 70% ethanol was preferable for SH-SY5Y attachment, growth and migration.