Uptake Mechanism and Endosomal Fate of Drug-Phospholipid Lipid Nanoparticles in Subcutaneous and In Situ Hepatoma

Drug-phospholipid lipid nanoparticles (DPLNs) can effectively enhance the properties of traditional solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), as previously demonstrated by our research group and others. To date, however, very few studies have focused on the cellular uptake mechanism and fate of DPLNs in hepatoma. Therefore, we systematically studied the cellular uptake mechanism and endosomal fate of DPLNs through in vitro and in vivo experiments. Confocal laser scanning microscopy (CLSM) and flow cytometry demonstrated that the Raw264.7 cell line (macrophage Raw264.7 cells), Chang cells (a human liver cell line) and HepG2 cells (a human hepatoma cell line) exhibited distinct uptake mechanisms. The Raw264.7 cells served as a model for examining liver-targeting ability. The results from mice with subcutaneous hepatomas and in situ hepatomas confirmed that the liver tumor-targeting property of the DPLNs was associated with the liver drug reservoir function. These findings further improve our understanding of DPLNs for clinical applications.