Single-stage synthesis of electrospun polyurethane scaffold impregnated with zinc nitrate nanofibers for wound healing applications

Abstract

In this study, a wound dressing scaffold was developed based on polyurethane (PU, 9 wt %) incorporated with zinc nitrate nanofibers (9 wt %) using an electrospinning technique. The morphological studies revealed that the electrospun nanocomposites showed smaller fiber (568 ± 136.69 nm) and pore diameters (703 ± 60.76 nm) than the pure PU (fiber diameter 1159 ± 147.48 nm and pore diameter 1087 ± 62.51 nm). Energy-dispersive X-ray spectroscopy confirmed the presence of zinc nitrate in the PU matrix. The formation of hydrogen bonds and the enhanced weight residue found by Fourier transform infrared spectroscopy and thermogravimetric analysis revealed the interaction of PU with zinc nitrate. Moreover, the contact angle measurements revealed the hydrophilic nature of the electrospun nanocomposite (84° ± 4.041°) compared to the control (100° ± 0.5774°). Mechanical testing and atomic force microscopy showed an improvement in the tensile strength (15.98 MPa) and surface roughness (277 nm) of the fabricated nanocomposites compared to the PU membrane (tensile strength 7.12 MPa and surface roughness 216 nm). Further, incorporation of zinc nitrate into PU improved the blood compatibility, as demonstrated by the prolonged blood clotting time (APTT 188 ± 4 s and PT 102.7 ± 3.786 s) compared to the pure PU (APTT 147.7 ± 3.512 s and PT 84.67 ± 2.517 s), as revealed in coagulation assays. Moreover, the electrospun nanocomposites showed a low hemolytic index and enhanced fibroblast proliferation rates, as indicated in the hemolysis and cytocompatibility studies. The newly developed wound dressing displayed better physicochemical characteristics, prolonged blood clotting time, and enhanced fibroblast proliferation rates, indicating that it might be utilized as an alternate candidate for wound dressings.