Wound-Healing with Mechanically Robust and Biodegradable Hydrogel Fibers Loaded with Silver Nanoparticles

The objective of this study is to provide a novel synthetic approach for the manufacture of wound-healing materials using covalently cross-linked alginate fibers loaded with silver nanoparticles. Alginate fibers are prepared by wet-spinning in a CaCl2 precipitation bath. Using this same approach, calcium cross-links in alginate fibers are replaced by chemical cross-links that involve hydroxyl groups for subsequent cross-linking by glutaraldehyde. The cross-linked fibers become highly swollen in aqueous solution due to the presence of carboxyl functional groups, and retain their mechanical stability in physiological fluids owing to the stabilized network of covalent bonds. Alginate fibers can then be loaded with silver ions via the ion-exchange reaction. Silver ions are reduced to yield 11 nm silver nanoparticles incorporated in the polymer gel. This method provides a convenient platform to incorporate silver nanoparticles into alginate fibers in controlled concentrations while retaining the mechanical and swelling properties of the alginate fibers. Our study suggests that the silver nanoparticles loaded fibers may be easily applied in a wound healing paradigm and promote the repair process though the promotion of fibroblast migration to the wound area, reduction of the inflammatory phase, and the increased epidermal thickness in the repaired wound area, thereby improving the overall quality and speed of healing.