Bioorthogonal Janus microparticles for photothermal and chemo‐therapy

Bioorthogonal chemistry, recognized as a highly efficient tool in chemical biology, has shown significant value in cancer treatment. The primary objective is to develop efficient delivery strategies to achieve enhanced bioorthogonal drug treatment for tumors. Here, Janus microparticles (JMs) loaded with cyclooctene-modified doxorubicin prodrug (TCO-DOX) and tetrazine-modified indocyanine green (Tz-ICG) triggers are reported. Besides activating TCO-DOX, Tz-ICG is also a photothermal agent used in photothermal therapy (PTT), enabling the simultaneous use of biorthogonal chemotherapy and PTT. Additionally, the DOX could be significantly reduced in systemic toxicity with the modification of cyclooctene. Thus, the developed drug-carrying JMs system exhibits effective tumor cell killing in vitro and effectively inhibits tumor local progress and distant lung metastasis after postoperative treatment with good safety. These results demonstrate that the prepared JMs provide a paradigm for bioorthogonal prodrug activation and localized delivery, and hold great promise for cancer therapy as well as other related applications.