Tumor Specific Delivery and Therapy by Double-Targeted Nanostructured Lipid Carriers with Anti-VEGFR-2 Antibody

Vascular endothelial growth factor receptors (VEGFRs) are overexpressed on the surface of a variety of tumor cells and on tumor :neovasculature in situ, which are potential targets for "double targeting" (tumor- and vascular-targeting) tumor therapy. This study aimed to develop a VEGFR-mediated drug delivery system to target chemotherapeutic agents to VEGFR-overexpressed tumor cells and tumor neovasculature endothelial cells in vitro and in vivo. An antibody modified docetaxel (DTX)-loaded targeted nanostructured lipid carrier (tNLC) was designed and prepared with DSPE-PEG-NH2 as linker. The cellular cytotoxicity, cellular uptake, in vivo therapeutic effect and biodistribution of tNLC were investigated. The tNLC showed a particle size about 168 am with encapsulation efficiency >95%, drug loading 5.55 +/- 0.06% (w/w) and an average ligand coupling efficiency of 3.34 +/- 2.63%. Cytotoxicity of tNLC against three human cell lines and one murine malignant melanoma was superior to that of Duopafei and nontargeted NLC (nNLC). The tNLC also showed better tolerance and antitumor efficacy in a murine model bearing B16 compared with Duopafei or nNLC. The studies on cellular uptake and biodistribution indicated that the better antitumor efficacy of tNLC was attributed to the increased accumulation of drug in both tumor and tumor vasculature. These findings suggested that tNLC designed to bind specifically to VEGFR-2 can be used to deliver DTX to the tumor vasculature and tumor and may inhibit tumor growth.