Targeted delivery of doxorubicin into tumor cells by nanostructured lipid carriers conjugated to anti-EGFRvIII monoclonal antibody.

Epidermal growth factor receptor variant III (EGFRvIII) is the most common variant of the EGF receptor in many human tumors. This variant is tumor specific and highly immunogenic, thus, it can be used as a target for targeted drug delivery toward tumor cells. The major aim of this study was to develop an EGFRvIII-mediated drug delivery system by anti-EGFRvIII monoclonal antibody (MAb) conjugated to doxorubicin (Dox)-loaded nanostructured lipid carriers (NLC) to enhance the targeting specificity and cytotoxic effect of Dox on EGFRvIII-overexpressing cell line. In our study, Dox was chosen as a hydrophobic cytotoxic drug and drug-loaded nanostructured lipid carriers (Dox-NLC) was prepared by solvent emulsification/evaporation method. In order to conjugate anti-EGFRvIII MAb to Dox-NLC, DSPE-PEG2000-NHS (1,2-distearoylphosphatidylethanolamine-polyethylene glycol 2000-NHS) was used as a linker. Physicochemical characteristics of antibody conjugated Dox-NLC (MAb-Dox-NLC), including particle size, zeta potential, entrapment efficiency and in vitro Dox release were investigated. Cytotoxicity of MAb-Dox-NLC against NIH-3T3 and HC2 20d2/c (EGFRvIII-transfected NIH-3T3) cell lines was evaluated. The MAb-Dox-NLC appeared to enhance the cytotoxic activity of targeted NLC against HC2 20d2/c cells. The cellular uptake percentage of targeted NLC by HC2 20d2/c cells was higher than that of NIH-3T3 cells, indicating that EGFRvIII can specifically target HC2 20d2/c cells. In conclusion, anti-EGFRvIII MAb-targeted NLC may be considered as an effective nanocarrier for targeted drug delivery.

Evaluation of targeted curcumin (CUR) loaded PLGA nanoparticles for in vitro photodynamic therapy on human glioblastoma cell line.

In this study, antibody-conjugated biodegradable polymeric nanoparticles were developed to enhance the photodaynamic efficiency of curcumin (CUR) on glioblastoma tumor cells. Poly (D, l-lactic-co-glycolic acid) nanoparticles (PLGA NPs) were synthesized and stabilized by polyvinyl alcohol (PVA). Poly(ethylene-alt-maleic anhydride) (PEMA) was used to provide carboxyl groups on the surface of NPs. The CUR or FITC (fluorescein isothiocyanate) was encapsulated in PLGA NPs using the nanoprecipitation method. The carboxylic groups on the surface of the PLGA NPs were covalently conjugated to the amino groups of a monoclonal antibody against EGFRvIII (A-EGFRvIII-f). The prepared NPs were fully characterized by Zetasizer, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR), and then entrapment efficiency (EE), drug loading efficiency (DLE), CUR release, cell internalization, intrinsic cytotoxicity, and phototoxicity were evaluated. Furthermore, the effect of monoclonal antibody (MAb) on the tyrosine phosphorylation of EGFRvIII after photodynamic therapy (PDT) was assessed. The immunoreactivity of the antibody in MAb-PLGA NPs was preserved during the process of conjugation. The selective cellular internalization of MAb-PLGA NPs (FITC or CUR loaded) into the DKMG/EGFRvIII cells (EGFRvIII overexpressed human glioblastoma cell line) in comparison with DK-MGlow (human glioblastoma cell line with low level of EGFRvIII) was also confirmed. MAb-CUR-PLGA NPs were able to show more effective photodynamic toxicity (56% vs. 24%) on the DKMG/EGFRvIII cells compared to CUR-PLGA NPs. These results suggest that the anti-EGFRvIII MAb-CUR-PLGA NPs have potential of targeted drug delivery system for PDT in the overexpressed EGFRvIII tumor cells.