Biological properties of sulfanilamide-loaded alginate hydrogel fibers based on ionic and chemical crosslinking for wound dressings

In this work, alginate hydrogel fibers loading sulfanilamide were proposed using a combination of Ca2+ ions and glutaraldehyde crosslinking to develop an efficient wound dressing. The structure, mechanical properties, absorbency, in vitro drug release and cytotoxicity of the proposed alginate hydrogel fibers were investigated systematically. The results indicated that crosslinking with glutaraldehyde can efficiently enhance the mechanical properties of the alginate hydrogel fibers, and reduce their swelling degree which is beneficial for hydrogel fibers to obtain adjustable fluid adsorption capacity, sustained drug release feature over hydrogel fibers crosslinked only by Ca2+ ions. Antibacterial activity assay demonstrated the bactericidal ability of the alginate hydrogel fibers towards S. aureus and E. coli with the highest antibacterial rate of 99.9%. Furthermore, a preliminary trial of papermaking process for producing alginate hydrogel mats showed the workability and the applicability of the mechanically tough hydrogel fibers. Cytotoxicity assay indicated the enhancement of cell adhesion and proliferation, revealing the non-cytotoxicity and biocompatibility of the alginate hydrogel mats. Based on the excellent mechanical strength, adjustable fluid adsorption capacity, sustained drug release, and biocompatibility, the bi-crosslinked alginate hydrogel fibers had a promising application as ideal wound dressings in clinic.