Formulation, characterization, and In vitro evaluation of lenvatinib-loaded solid lipid nanoparticles functionalized with Twenty-Polyglycerol vitamin E succinate for liver cancer treatment.

Objective: Lenvatinib (LEN), a first-line treatment for advanced hepatocellular carcinoma (HCC), faces limitations due to adverse effects and drug resistance. This study aimed to develop LEN-loaded solid lipid nanoparticles (SLNs) modified with Twenty-polyglycerol vitamin E succinate (PG20-VES@LEN-SLNs) to enhance therapeutic efficacy and compare them with Tween80-modified SLNs (Tween80@LEN-SLNs).

Methods: The formulation of LEN-SLNs was optimized based on particle size and polydispersity index (PDI) by screening lipid matrices (GMS, GMP, SA, CP, GB, GMD), surfactant types (Tween80, PG20-VES, TPGS1000, F68), and GMS:SPC ratios. Physicochemical properties were characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR). Encapsulation efficiency (EE), drug loading (DL), and drug release profiles were evaluated. Cytotoxicity against HepG2, Huh-7, and L02 cells was assessed MTT assay, while cellular uptake in HepG2 was visualized using Nile Red-labeled SLNs.

Results: Optimized PG20-VES@LEN-SLNs exhibited a smaller particle size (294.6 ± 10.4 nm vs. 308.6 ± 29.5 nm for Tween80@LEN-SLNs) and higher EE (80.7 ± 5.1% vs. 72.7 ± 4.0%). Both formulations showed sustained drug release over 48 h, significantly slower than free LEN (97.4% released in 24 h). PG20-VES@LEN-SLNs demonstrated superior cytotoxicity against HepG2 cells (IC50 = 36.47 μM) compared to Tween80@LEN-SLNs (IC50 = 42.49 μM) and free LEN (IC50 = 116.8 μM), with enhanced cellular uptake observed confocal microscopy. In Huh-7 cells, PG20-VES@LEN-SLNs and Tween80@LEN-SLNs reduced the IC50 of lenvatinib from 189.21 μM (free LEN) to 18.04 μM and 18.41 μM, respectively.

Conclusion: PG20-VES@LEN-SLNs effectively improved LEN's therapeutic index through sustained release, enhanced tumor cell targeting, and synergistic cytotoxicity. This study highlights PG20-VES as a multifunctional surfactant for advanced HCC nanotherapy, offering a promising strategy to overcome clinical limitations of LEN.