MF59-based lipid nanocarriers for paclitaxel delivery: optimization and anticancer evaluation

Breast cancer is the most common invasive cancer in women worldwide, necessitating innovative therapeutic strategies to enhance treatment efficacy and safety. This study focuses on the development and optimization of novel paclitaxel (PTX)-loaded nanostructured lipid carriers (NLCs) that incorporate components of MF59, an oil-in-water emulsion adjuvant approved for use in influenza vaccines and known for its safety in humans. The formulation of these NLCs is designed to overcome significant challenges in PTX delivery, particularly its poor solubility and the side effects associated with traditional formulations containing Cremophor EL. We prepared two sets of NLC formulations using different liquid-to-solid lipid ratios through hot melt ultrasonication. Characterization of the selected formulations, NLC_Pre and NLC_Lec, was conducted using dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, and ultraviolet-visible (UV-Vis) spectroscopy. The mean diameters were 120.6 ± 36.4 nm and 112 ± 41.7 nm, with encapsulation efficiencies (EE) of 85% and 82%, and drug loading (DL) of 4.25% and 4.1%, respectively for NLC_Pre and NLC_Lec. In vitro cytotoxicity assays demonstrated that these MF59-based NLCs effectively target MCF-7 (Michigan Cancer Foundation) breast cancer cells while minimizing toxicity to normal HDF (human dermal fibroblasts) cells, thus enhancing the therapeutic index of PTX and offering promising clinical implications for breast cancer treatment.