Preparation of Stimulus-Responsive Copolymer-Decorated Gold Nanorods and Their Anti-Tumor Effect

A triblock copolymer with mussel-inspired adhesive ability, poly(acryl hydrazide)-b-poly(N-(3, 4-dihydroxyphenylethyl) acrylamide)-b-poly(monomethoxypolyethylene glycol acrylate) (PAH-b-PAD-b-PmPEGA, abbreviated as HDP), was designed and synthesized via reversible addition fragmentation chain transfer polymerization process from three monomers, including 1-tert-butcarbonyl-2-acrylhydrazide(Boc-AH), N-(3, 4-dihydroxyphenylethyl) acrylamide(DA) and poly(ethylene glycol) methyl ether methacrylate (mPEGA). The copolymer was used for decorating gold nanorod (GNR) to obtain GNR-based nanocarrier. Chemotherapeutic drug doxorubicin (DOX) was conjugated onto the nanocarrier by an acid-labile hydrazone linkage, resulting in HDP-GNR-DOX nanodrug. The physicochemical properties of the nanocarrier, such as structure, stability, photothermal performance, and pH-responsive drug release, were characterized. Moreover, the in vitro anti-tumor effect of the nanodrug towards breast cancer cells (MCF-7) was evaluated. Results showed that the DOX content of the nanodrug was as high as 8.1% and the nanodrug exhibited excellent photothermal conversion ability, favorable stability and pH-responsive drug release behavior. Importantly, the results of cellular experiments demonstrated that the nanodrug could be effectively internalized by MCF-7. In the case of near infrared irradiation, the nanodrug showed high apoptosis-inducing ability on MCF-7, achieving highly efficient photothermal-chemotherapy of breast cancer.