MBene as a Theranostic Nanoplatform for Photocontrolled Intratumoral Retention and Drug Release

Abstract Tumor‐targeted drug delivery by nanomaterials is important to improve tumor therapy efficacy and reduce toxic side effects, but its efficiency is quite limited. In this work, a new type of MBene, zirconium boride nanosheet (ZBN), as a versatile nanoplatform to realize near‐infrared (NIR)‐controlled intratumoral retention and drug release is developed. ZBN exhibits high NIR‐photothermal conversion efficiency (76.8%), surface modification with hyaluronic acid (HA) by polyol−borate esterfication endows ZBN‐HA with good dispersion, and the photopyrolysis of borate ester causes HA detachment and ZBN aggregation, enabling NIR‐controlled intratumoral retention to achieve high intratumoral accumulation. By virtue of surface borate esterfication, polyol chemotherapeutic drug (doxorubicin, DOX), and NO prodrug (β‐galactosyl‐diazeniumdiolate, Gal‐NO) can be efficiently and stably conjugated on the surface of ZBN‐HA (1.21 g DOX or 0.57 g Gal‐NO per gram ZBN) without visible drug leakage, and the photopyrolysis of borate ester enables NIR‐controlled drug release with high responsiveness and controllability. Combined chemothermal/gasothermal therapies based on ZBN‐HA/DOX and ZBN‐HA/NO nanomedicines eradicate primary tumors and interdict tumor metastasis by changing the tumor microenvironment and killing cancer cells in primary tumors. The developed NIR‐photothermal MBene is confirmed as a versatile nanoplatform capable of high‐efficacy tumor‐targeted drug delivery and controlled drug release.