Multifunctional nanoparticles of biodegradable copolymer blend for cancer diagnosis and treatment

A multifunctional nanoparticle (NP) system is developed to provide a sustained, controlled and targeted co-delivery of quantum dots (QDs) as a model imaging agent and docetaxel as a model anticancer drug. The NPs are made of a polymeric blend of poly(lactic-co-glycolic acid), which forms a biodegradable NP matrix, and the novel copolymer D-alpha-tocopheryl polyethylene glycol 1000 succinate-COOH, which facilitates ligand conjugation on the NP surface. Materials & methods: The NPs were prepared by nanoprecipitation and characterized for their size and size distribution, surface morphology, surface charge, QD/drug encapsulation and loading efficiency, and in vitro drug release profile. The targeting effects of such NPs were evaluated both quantitatively and qualitatively through the cellular uptake of the QDs as well as the cytotoxicity of the drug using MCF-7 cells, which overexpress folate receptors and NIH 313 cells, which have no folate receptors overexpression. Results & conclusions: NPs with folate conjugated on their surface achieved much higher cellular uptake than those with no folate conjugation in MCF-7 cells while no significant targeting effect could be observed for NIH 313 cells. The drug formulated in the folate-conjugated NPs were more efficious compared with NPs with no folate conjugation as well as the current clinical formulation Taxotere (R).