Gemcitabine-loaded niosomes: Optimization, characterization, and in vitro efficacy against invasive malignancies

Gemcitabine (dFdC) is a widely used prodrug against pancreatic cancer and has been investigated against pancreatic, glioblastoma and breast cancer. However, the nature of gemcitabine hinders its incorporation into nanocarriers at high loading levels. This work focuses for the first time on optimizing gemcitabine-loaded stearic acid-based niosomes for enhanced anti-tumor efficacy. The antitumor effect of the optimized formula (dFdC -9 mM subset of Nio) was studied against three undruggable cancer cell lines: pancreatic cancer (PANC-1), glioblastoma (U-87), and triple negative breast cancer (MDA-MB-231), and against normal fibroblasts (HDF). The size of dFdC -9 mM subset of Nio formula was 151.3 +/- 3.3 nm, the encapsulation efficiency was 68.83 +/- 0.08%, and the drug loading capacity was 16.5 +/- 0.7%. Cellular uptake of dFdC -9 mM subset of Nio by PANC-1 was found to increase 3fold relative to the untreated cancer cell lines. A positive correlation between cellular uptake and increased cytotoxicity was observed, along with a significant reduction in IC50 values compared to the free form gemcitabine in all three cell lines. Moreover, the overall apoptotic populations in each of the cancer cell lines revealed a statistical difference in PANC-1 (p-value: 0.0451), U-87 (p-value: 0.0497), and MDA-MB-231 (p-value: 0.048) between dFdc and dFdC -9 mM subset of Nio treated groups. These results propose stearic acid-based niosomes as a biocompatible drug delivery system for gemcitabine, with a promising potential in enhancing its anti-tumor outcome, especially against pancreatic cancer and glioblastoma.