Optimization, characterization, and in vitro assessment of alginate-pectin ionic cross-linked hydrogel film for wound dressing applications

Natural polymer-based hydrogel films have great potential for biomedical applications and are good candidates for wound dressings. In this study, we aimed to develop simvastatin-loaded crosslinked alginate-pectin hydrogel films by ionic crosslinking to improve the mechanical characteristics, wound fluid uptake and drug release behavior. Alginate-pectin hydrocolloid films were chemically crosslinked by immersing in different concentrations of CaCl2 (0.5–3% w/v) for 2–20 min. The degree of crosslinking was influenced by both contact time and CaCl2 concentration. The optimized conditions for crosslinking were 0.5% and 1% (CaCl2) for 2 min. The optimized hydrogel films were then characterized for their physical, mechanical, morphological, thermal, in vitro drug release, and cytocompatibility profiles. Crosslinking improved the mechanical profile and wound fluid uptake capacity of dressings. The hydrogel films were able to maintain their physical integrity during use, and the best results were obtained with the film in which the extent of crosslinking was low (0.5%). Thermal analysis confirmed that the crosslinking process enhanced the thermal stability of hydrogel films. Sustained, slow release of simvastatin was obtained from the crosslinked films and in vitro cytotoxicity assay demonstrated that the hydrogel films were non-toxic.