Development of a pH/NIR/temperature-responsive drug delivery system using AuNRs@ZnO@mPDA nanoparticles for synergistic cancer therapy

In recent years, there has been a notable focus on the development and design of multifunctional drug delivery systems tailored for photothermal, photodynamic, and chemotherapy triple-modality cancer treatment. The paper presents the utilization of gold nanorods (AuNRs) for photothermal effect, zinc oxide (ZnO) for photodynamic effect, mesoporous polydopamine (mPDA) loaded with curcumin (Cur), and 1-tetradecanol (TD) as a temperature-sensitive gating switch to achieve integration of functional organic/inorganic nanomaterials. The core-shell structural nanocarriers (AuNRs@ZnO@mPDA-Cur/TD) achieved a drug loading rate of 178 mg/g. It is important to note that the pH-responsive release properties of Cur have been observed due to the acid response of mPDA. Furthermore, the photothermal effect of AuNRs and mPDA facilitates the thermal-induced melting of TD and subsequent release of Cur upon near-infrared (NIR) irradiation, thereby achieving an effective integration of photothermal therapy and chemotherapy. Simultaneously, under NIR excitation, AuNRs inject thermal electrons into the conduction band of ZnO, leading to the generation of singlet oxygen species that confer remarkable photodynamic healing capabilities to the as-prepared carriers. The combined treatment involving photothermal, photodynamic, and chemotherapy demonstrated synergistic effects and superior efficacy compared to individual treatments. The core-shell nanodrug carrier AuNRs@ZnO@mPDA developed in this study exhibits pH-, NIR-, and temperature-responsive drug release properties, highlighting the synergistic impact of photothermal, photodynamic, and chemotherapy on tumor therapy. This research provides a novel concept and preparation strategy for a multifunctional smart drug delivery platform with integrated therapeutic efficacy.