A novel gold nanorods-based pH-sensitive thiol-ended triblock copolymer for chemo-photothermo therapy of cancer cells.

Currently an effective strategy in nanomedicine for cancer therapy is the combination of photothermal therapy with chemotherapy. Because combination cancer therapy improve the therapy efficiency by synergistic effects and overcoming drug resistance as compared to monotherapy possesses. According to these facts, gold nanorods-cored biodegradable micelles were prepared by coating gold nanorods (AuNRs) with synthesized pH-sensitive thiol-ended amphiphilic triblock copolymer (PAA-b-PDMAEMAQ-b-PCL-SH). The synthesized AuNRs@polymer was loaded with methotrexate (MTX) as an anticancer drug through electrostatic interactions to afford AuNRs@polymer-MTX. The success of the coating was investigated by means of atomic force microscopy (AFM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, as well as dynamic light scattering (DLS), and zeta potential measurements. MTX-loading capacity, and pH triggered in vitro drug release behavior of the synthesized nanocomposites were also investigated. In vitro cytotoxic effects was comprehensively evaluated among free MTX, AuNRs@polymer, and AuNRs@polymer-MTX, with or without NIR light irradiation (1064 nm, 125 mJ/pulse, and 4 min) to improve curative effect of AuNRs@polymer-MTX led by the combination of photothermal therapy and chemotherapy.