Metal-polyphenol network coated photothermal nanocarriers for pH-activated drug delivery

The combination of photothermal and chemotherapy is a promising strategy for the synergistic inhibition of tumor cells. By exploiting the tumor microenvironment, chemotherapeutic drugs can target the tumor site, thereby enhancing their efficacy. This study focused on the development of nanodrugs, aiming to harness the synergistic photothermal and chemotherapy capabilities for enhanced anti-tumor effects. The core material was made of copper sulfide (CuS), which possesses photothermal conversion properties, while doxorubicin (DOX) was loaded on mesoporous polydopamine (MPDA). The drug-loaded nanoparticles were then encapsulated in acid-sensitive tannic acid and an Fe complex (TA-Fe). The photothermal conversion properties, drug loading, and release of DOX from CuS-MPDA-DOX@TA-Fe were then investigated. The results showed that DOX had an encapsulation ratio of 82.2 % and a release ratio of 43.49 % in an acidic environment (pH 5.2). In vitro studies showed that CuS-MPDA-DOX@TA-Fe triggered by NIR effectively inhibited tumor cell proliferation and that the tumor cells showed suitable levels of nanoparticle uptake. The results thus show that CuS-MPDA-DOX@TA-Fe nanodrugs could be utilized as a promising therapeutic strategy for cancer treatment with synergistic photothermal/chemotherapeutic anti-tumor effects.