A Phase-change Material Packaged within Hollow Copper Sulfide Nanoparticles Carrying Doxorubicin and Chlorin e6 for Fluorescence-guided Trimodal Therapy of Cancer.

Environmental stimuli, including pH, light and temperature, have been utilized for activating controlled drug delivery to achieve efficient antitumor therapeutics while minimizing undesirable side effects. In this study, a multifunctional nanoplatform based on hollow mesoporous copper sulfide nanoparticles (H-CuS NPs) was developed by loading the interior cavity of the NPs with a drug-loaded phase change material (PCM, 1-tetradecanol). Doxorubicin (DOX) and chlorin e6 (Ce6) were selected as the model chemotherapeutic drug and photosensitizer, respectively, which were encapsulated in H-CuS NPs via the PCM to form H-CuS@PCM/DOX/Ce6 (HPDC) NPs. When exposed to near infrared (NIR) laser irradiation, this nanocomplex could produce a strong photothermic effect and thus induce the controlled release of DOX and Ce6 from the melting PCM. Subsequently, the DOX-mediated chemotherapeutic effect and Ce6-mediated photodynamic effect further contributed to enhanced tumor eradication. The efficacy of this multimodal cancer treatment combining chemo-, photothermal and photodynamic therapies was systematically evaluated both in vitro and in vivo using a 4T1 mouse mammary tumor cell line and a mouse model bearing breast cancer. Moreover, this nanoplatform exhibited minimal systemic toxicity and good hemocompatibility and may provide an effective strategy for the delivery of multiple therapeutic agents and the application of multimodal cancer treatments.