Quality by design (QbD) assisted Fabrication & evaluation of Simvastatin loaded Nano-Enabled thermogel for melanoma therapy

Melanoma is a form of skin cancer that starts in melanocytes. Rampant chemo-resistance, metastasis, and inability to cross the skin barriers and accumulate within the tumor microenvironment render the conventional chemotherapeutic approaches ineffective. Simvastatin (SIM), a cholesterol synthesis inhibitor, has shown tremendous anticancer potential. Due to the lack of therapeutic alternatives, repositioning SIM in melanoma could be beneficial. Incorporating SIM within the nanoparticles promoted increased melanoma cell internalization, apoptosis, and sustained release profile. Further, the incorporation of nanoparticles into the thermogel facilitated depot formation over the upper dermal layers. Sol-to-gel transition at 34 degrees C was observed with a 14.03-fold increase in viscosity. This could be fruitful in limiting systemic exposure and preventing adverse effects. Entrapment of SIM in the PLGA NPs enhanced the cytotoxicity by 9.38-fold (p less than 0.05). Nuclear staining with DAPI showed blebbing, membrane shrinkage, and apoptosis confirmed by DCFDA and acridine orange/ethidium bromide staining. Ex vivo diffusion studies revealed the accumulation of C-6 loaded nanoparticles incorporated within the thermogel onto the upper dermal layer and depot formation up to 6 h. Thus, we conclude that SIM-loaded nanoparticulate thermogel could be an efficacious therapeutic alternative for melanoma.