Pluronic-based graphene oxide-methylene blue nanocomposite for photodynamic/photothermal combined therapy of cancer cells.

Abstract

A nanocomposite containing methylene blue (MB), graphene oxide (GO) and Pluronic F127 (PF127) had been developed for combined photothermal therapy (PTT) and photodynamic therapy (PDT). In this study, GO was firstly loaded with MB to form GO-MB by a self-assembly method, and then the surface was modified with PF127 to form GO-MB/PF127 nanocomposite (GO-MB/PF127) by a thin-film hydration method. The structure and properties of the nanocomposite were characterized by Ultraviolet-Visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS) and zeta potential. The results showed that the as-prepared nanocomposite exhibited high stability in aqueous solution, high release rate of MB from the nanocomposite under acidic conditions. In addition, when excited by 808 nm near infrared (NIR) light and 660 nm light emitting diode (LED) source, GO in GO-MB/PF127 caused photothermal ablation of cancer cells while MB produced singlet oxygen (1O2) to kill cancer cells through oxidative stress in PDT. The combined therapy had a synergistic effect and can achieve a strong killing effect on SiHa cells at a low dose of GO-MB/PF127 containing GO (10 μg mL-1) and MB (5 μg mL-1). And PF127 did not affect the photothermal heating of GO and the 1O2 generation of MB. Moreover, light-induced GO-MB/PF127 nanocomposite killed SiHa cells by apoptosis pathway. The results indicated that the nanocomposite had the potential to effectively treat cancer via noninvasive phototherapy, and could be served as a multifunctional therapeutic agent for photodynamic/photothermal cancer therapy.