Photodynamic therapy

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-MG(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.