Sergey A. Shein, Natalia V. Nukolova, Anna A. Korchagina, Vladimir P. Baklaushev, Olga I. Gurina and Vladimir P. Chekhonin

Department of Medicinal Nanobiotechnologies, N.I. Pirogov Russian National Research Medical University, Moscow, Russia

Abstract:

The usage of monoclonal antibodies conjugated with drug-loaded liposomes is a promising strategy for improvement the efficacy of the cancer therapy. Well-known that many types of solid tumors overexpress VEGF (Vascular endothelial growth factor), including high-grade gliomas. Therefore, VEGF can be considered as a prime target for site directed delivery of therapeutic.

The aim of the study was to investigate the effectiveness of anti-VEGF-modified, poly(ethylene glycol)-modified (PEGylated) liposomes for delivery therapeutic agents to glioma cells, using monoclonal anti-VEGF antibodies as a vector.

We produced high affinity anti-VEGF antibodies against native dimer form of VEGF with an affinity constant of Kd=1.37±108 M-1. Then antibodies against VEGF were covalently conjugated with phosphatidylcholine PEGylated liposomes (d= 210±10 nm). Covalent conjugation immunoliposomes with monoclonal antibodies was significantly improving accumulation in the tumor tissue of glioma cells.

For the first time we have demonstrated selective delivery of anti-VEGF-coated liposomes into intracranial brain tumor in vivo. In addition, we have shown that intravenously injecting of anti-VEGF-coated liposomes to animals with model C6 intracranial glioma was a significant increase in specific cellular uptake of these immunoliposomes by glioma cells and reactive astrocytes. These findings suggest that liposomes conjugated with antibodies against VEGF visualize accumulation in brain tumor.

Fig. (1). Immunofluorescent analysis of the accumulation of anti-VEGF-coated liposomes in the C6 glioma after 48 hours. Red fluorescence reveals liposomes conjugated with anti-VEGF antibodies, cell nuclei have been stained with DAPI.