Tumor Acidity and Near‐Infrared Light Responsive Dual Drug Delivery Polydopamine‐Based Nanoparticles for Chemo‐Photothermal Therapy

Abstract Photothermal therapy (PTT) combined with chemotherapy, a promising strategy for breast cancer treatment, has a high potential to control drug release, reduce multidrug resistance, and improve therapeutic efficacy. The challenge is how to realize tumor ablation in deeper tissue and NIR‐controlled drug delivery. Herein, tumor acidity and near‐infrared light (NIR) responsive folic acid (FA) functionalized polydopamine (DPA) nanoparticles (NPs) are developed for doxorubicin (DOX) and epigallocatechin‐3‐gallate (EGCG) dual delivery. With the assistance of NIR, the cellular uptake of DOX‐EGCG/DPA‐FA NPs is about three‐ to sixfold higher when compared with the free DOX group and the control group without NIR irradiation. Moreover, biodistribution study in vivo indicates that DPA‐FA NPs can enhance tumoral accumulation, penetration, retention of drugs, and display a ≈ 4‐ and 19‐fold higher intra‐tumoral distribution than that of the DPA NPs and free drug groups at 24 h postinjection. Furthermore, 60% of breast cancer‐bearing mice survive over 70 days in the DOX‐EGCG/DPA‐FA NPs group. Additionally, DOX‐EGCG/DPA‐FA NPs can effectively boost therapeutic efficacy by inducing significant suppression of tumor growth and angiogenesis, and enhancement of apoptosis and necrosis of breast cancer cells. Taken together, DOX‐EGCG/DPA‐FA NPs may have potential applications as a useful nanoscale vector for enhanced cancer therapy.