Electrospun polyurethane fiber mats coated with fish collagen layer to improve cellular affinity for skin repair

The poor wettability of polyurethane (PU) nanofiber mats hinders their use as a wound dressing. We employed a hydrothermal precipitation approach to coat the extracted and purified fish collagen molecules onto polyurethane fibers. The surface precipitation with 5% and 10% of collagen to the as-spun fibers significantly increased the fiber diameter by about two folds (1.025 ± 0.425 μm to 2.575 ± 0.340 μm). In contrast, the pore size of the composite mat decreased by about 30% at 15% and vanished at 20% of collagen loading. The water contact angle decreased from 84° ± 2.36° to 28.2° ± 2.56°. At the same time, the concentration of the coating solution in the reactor increased from 0% to 20%, demonstrating a significant improvement in the hydrophilicity of PU fiber mats. The proliferation of HdFa reached a maximum of 189.7 ± 4.7% in PU mats coated with 10% collagen. However, mats coated with 15% collagen could provide a better niche for the differentiation of these cells. Higher collagen concentration (20%) resulted in distorted fibroblast morphology. The rate of migration of fibroblasts toward the wound area in the scratch assay was higher on the composite than over unmodified mats and the tissue culture plate. The proposed strategy can be considered a straightforward process to coat the nanofibers of a hydrophobic nature with heat-labile materials like collagen, which have great potential as wound dressing material.