Polydopamine-embedded Nonstoichiometric Copper Chalcogenide Nanoparticles for Chemotherapy-Photothermal Synergistic Therapy against Cancer Cells

Developing multifunctional nanomaterials is a hot topic for the combination therapy of tumor cells. In this work, a distinctive multifunctional composite (FA-Cu2-xSySe1-y@pDA-BTZ) was fabricated by assembling folic acid (FA) and the anticancer drug bortezomib (BTZ) to the surface of the nonstoichiometric copper chalcogenide nanoparticle (Cu2-xSySe1-y NPs) with typical localized surface plasmon resonance (LSPR) in the near-infrared region coated by polydopamine (Cu2-xSySe1-y@pDA). The FA-Cu2-xSySe1-y@pDA-BTZ showed a good light harvest in the second near-infrared window for bio-application and the photothermal conversion efficiency could reach 30.8%. FA was attached to the surface of the Cu2-xSySe1-y@pDA, so that the nanocomplex could be specifically delivered into cancer cells with overexpressed folate receptor. Meanwhile, BTZ could easily bind with Cu2-xSySe1-y@pDA through the formation of pH-responsive boronate ester bond between boronic acid and catechol groups in polydopamine under weakly alkaline conditions. Under 1064 nm laser irradiation in weakly acidic phosphate buffer, the controlled release of drugs was obtained. Under the laser irradiation (1064 nm), the relative survival rate of the cells was lower than 10%, which could realize the synergistic treatment of photothermal therapy and chemotherapy for tumor cells. The FA-Cu2-xSySe1-y@ pDA-BTZ could be used as a new probe in the dark-field imaging for monitoring the therapy. The above results showed that the synthesized FA-Cu2-xSySe1-y@pDA-BTZ multifunctional composite had a good application prospect in the diagnosis and treatment of cancer.

Automated summary

A multifunctional composite material consisting of folate acid and the anticancer drug bortezomib was successfully developed, allowing for synergistic treatment of tumor cells through photothermal therapy and chemotherapy.