A novel lignin-based nanofibrous dressing containing arginine for wound-healing applications

Nanofiber-based wound dressings have attracted much attention in wound care owing to their unique properties such as high aspect ratio and three-dimensional structure. Arginine is a precursor of nitric oxide that plays an important role in the wound-healing process. Therefore, in this study, we have developed a gel which contains lignin nanofibers (Lig-NFs) that were surface modified by arginine molecules via electrostatic interaction (Arg-Lig-NF gel). The effect of pH on the amount of arginine attached on Lig-NF surface was evaluated at three different pH values—5, 6, and 7. Fourier transform infrared spectroscopy and zeta potential of Lig-NFs before and after surface modification confirmed the surface modification of Lig-NFs with arginine molecules. The optimum gel composed of uniform Arg-Lig-NFs with diameter ranging from 100 to 250 nm. There was 184.60 ± 4.85 mg arginine in each gram of optimum gel. The release of arginine from Arg-Lig-NF gel showed a sustained release manner, and about 86.28 ± 3.50% of attached arginine were released after 24 h. Moreover, the optimum gel presented suitable viscosity and spreadability for topical application. The in vivo full thickness wound-healing assay carried out in rats demonstrated that the optimum Arg-Lig-NF gel can accelerate wound closure and increase re-epithelialization, collagen deposition, and angiogenesis significantly in Arg-Lig-NF gel-treated wounds compared to Lig-NF gel and arginine solution. Overall, these findings demonstrate that Arg-Lig-NF gel can be a promising material for the future development of effective hydrocolloid wound dressings used in the treatment of acute and chronic wounds.