A simple green route to obtain poly(vinyl alcohol) electrospun mats with improved water stability for use as potential carriers of drugs

Abstract

Poly(vinyl alcohol) (PVA) is a hydrophilic, biocompatible and nontoxic polymer. However, because of its low water-resistance, some applications for PVA-based materials are limited (e.g., drug delivery systems and wound dressings). In the current work, PVA mats containing tetracycline hydrochloride (TC) were successfully developed by electrospinning. In order to improve the water stability of the systems, the cross-linking of the PVA matrix was induced by citric acid (CA) addition together with heating treatments (150°C or 190°C for 3min). TC presence led to a strong increase in the electrical conductivity of the blends and as a result, fibers with about 44% lower diameter (270nm) than that of the corresponding unloaded mats (485nm) were obtained. Laser scanning confocal microscopy images indicated that TC was well distributed along the PVA nanofibers. The mats were evaluated by FTIR, which revealed chemical interactions between PVA hydroxyl groups and CA carboxylic ones. The treatment at 150°C for 3min proved to be the more suitable for the preparation of TC-containing mats with improved water resistance, maintaining the TC antimicrobial activity against both Escherichia coli and Staphylococcus aureus almost unaltered. These mats showed a burst release of TC, giving around 95% of the drug within the first hour of immersion in water.