Influence of the hydrophobic polyhydroxyethyl methacrylate branches grafted with high amylose corn starch on the properties of its electrospun drug-loaded membranes

Abstract

The nanofiber membranes based on native starch are prone to swelling or dissolution after contact with water, and the fragile starch membranes, due to the aging of molecular chains, are unsuitable for medical dressings. Herein, the hydrophobic polyhydroxyethyl methacrylate (PHEMA) branches in different ratios were grafted onto high amylose corn starch (HACS) using a redox system. Furthermore, electrospun aspirin-loaded nanofiber membranes were prepared and investigated in terms of porosity, swelling capacity, water vapor transmittance rate (WVTR), cumulative release rate, and cytotoxicity. The results confirmed that with increasing grafting ratio, the porosity and WVTR of the HACS-g-PHEMA drug-loaded membrane gradually increased, while swelling capacity slightly decreased from 746.2% to 619.9%, and the cumulative release rate decreased from 56.21% to 32.54% in 2 h. The Ritger-Peppas mathematical model fitting found that the diffusion coefficients of drug-loaded membranes were less than 0.45, which belonged to the Fick diffusion behavior. After the grafting of PHEMA branches, the hydrophobic interaction between starch molecular chains and aspirin was enhanced, and the nanofiber membrane defects were alleviated while still maintaining good biocompatibility. This study provides a foundation for the sustained release of hydrophobic drugs in starch-based medical dressings.