Fabrication and Characterization of Nisin‐Loaded Polycaprolactone/Sericin Nanofibers: Assessment of Their Anticancer Activity Against Melanoma Cells

In this study, we developed nisin-loaded polycaprolactone/sericin nanofibers using electrospinning. The structural properties of the nanofibrous scaffolds were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction analysis. Furthermore, in vitro evaluations assessed swelling ability, biocompatibility, biodegradability, cytotoxicity, and controlled release of nisin. The nanofiber with the optimal combination of properties, including the smallest average fiber diameter and a uniform and bead-free morphology, was selected for nisin loading. The anticancer potency of the nisin-loaded nanofiber against melanoma cells was evaluated using molecular and biochemical assays. Biochemical analyses examined oxidative stress and inflammatory markers (TNF-α, IL-1α, and IL-6) in the cell lysates. In molecular analyses, gene expression levels of p53, caspase-3, TRAIL-1, TRAIL-2, NF-κB, Bcl-2, Bax, Bcl-xL, and Cyclin D1 were measured to elucidate apoptotic and proliferative mechanisms in melanoma cells. Peaks at 3000-650 cm^-1 in the nanofibers' FTIR spectrum were characteristic. Thermal gravimetric analysis revealed a two-stage decomposition process for the nanofibers. XRD results showed peaks at 21.74°, 22.39°, and 24.04° for the nanofiber and at 21.59°, 22.17°, 23.94°, 34.80°, and 30.09° for the nisin-loaded nanofiber. In vitro swelling tests demonstrated that the nisin-loaded nanofiber absorbed more water than the unloaded nanofiber. Moreover, the nisin-loaded nanofiber degraded faster than the unloaded nanofiber. Nisin release increased over time. IC₅₀ values for nisin, sericin, and polycaprolactone were 29.58, 75.15, and 11.85 mg/mL, respectively. The expression levels of p53, caspase-3, TRAIL-1, TRAIL-2, NF-κB, Bcl-2, Bax, Bcl-xL, and Cyclin D1 genes in G361 cells were evaluated in comparison to the control group. It was observed that gene expression was stimulated in all regions treated with nisin-loaded PCL/sericin nanofibers, except for the p53 gene. Molecular and biochemical analyses revealed that the nisin-loaded nanofiber induced apoptosis, reduced inflammation and oxidative stress levels, and enhanced antioxidant activity. These findings suggest the anticancer potential of the nisin-loaded nanofiber.