Fabrication of pH/photothermal-responsive ZIF-8 nanocarriers loaded with baicalein for effective drug delivery and synergistic chem-photothermal effects

Synergistic therapy has been confirmed to be a promising strategy for cancer treatment. Herein, we designed a pH-responsive, chemotherapeutic and photothermal synergistic drug delivery-nanocomposites (BA@ZIF-8-PDA-PEG, BZPP) based on ZIF-8. The synthesized nanocarriers had a loading capacity of 790 μg mg−1 for baicalein (BA) and performed excellent pH-triggered drug release behavior under the acidic condition of pH 5.0. Polydopamine (PDA) coating endowed the drug delivery system (DDS) with good photothermal performance, and the photothermal conversion efficiency (η) was 39.48% under 808 nm laser irradiation for 10 min. Then, PEGylation was performed using amino-terminated PEG (PEG-NH2) to provide high biocompatibility and stability. In addition, PEGylation and PDA-coating assisted in improving the hemolytic toxicity and cytotoxicity of bare nanocarriers. Furthermore, in vitro cellular studies showed that DDS of BZPP had excellent cellular internalization in A549 cells and enhanced synergistic anti-tumor ability to cancer cells compared to monotherapy. Therefore, BZPP can be used as a powerful chemo-photothermal synergistic therapy strategy to improve the insufficiency of mono-chemotherapy and has unexceptionable prospects for the therapy of tumor.