Oxygen‐Independent Photocleavage of Radical Nanogenerator for Near‐IR‐Gated and H2O‐Mediated Free‐Radical Nanotherapy

• Published in: Advanced materials (Weinheim) Vol. 33; no. 36
• Main Authors: Chen, Yixin, Xiang, Huijing, Zhuang, Shangwen, Shen, Yujia, Chen, Yu, Zhang, Jun
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.09.2021
• Subjects: Apoptosis; Cancer; cancer treatment; Contrast agents; free‐radicals burst; Gadolinium; Hydroxyl radicals; Hypoxia; Irradiation; Light; Magnetic resonance imaging; Nanogenerators; Nanoparticles; near‐IR light; Oxygen; oxygen‐independent photocleavage; photoactivated chemotherapy; Photodynamic therapy; Silicon dioxide; Tumors
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202100129

The oxygen‐dependent nature and limited penetration capacity of visible light render the low efficiency of photodynamic therapy in hypoxic and deep‐seated tumors. Therefore, the development of oxygen‐free photoactivated chemotherapy (PACT) to generate cytotoxic reactive oxygen species by near‐IR (NIR) light‐cleavable photocages is in high demand. Here, an oxygen‐irrelevant PACT strategy based on NIR light‐triggered hydroxyl radicals (•OH) generation is developed for free‐radical nanotherapy. Blebbistatin‐loaded upconversion of mesoporous silica nanoparticles (UCSNs‐B) is established to facilitate the high loading efficiency of blebbistatin and implement the efficient transformation of NIR light into blue light for unprecedented direct photorelease of oxygen‐independent •OH. Under NIR laser irradiation, UCSNs‐B converted NIR light into blue light, thus enabling the photocleavage of blebbistatin to induce the burst of •OH. The •OH burst under NIR laser irradiation further induces cancer cell apoptosis and significant suppression of hypoxic tumors. In addition, the gadolinium ion (Gd3+)‐doped UCSNs‐B are used as contrast agents in magnetic resonance imaging to facilitate real‐time monitoring of the therapeutic processes. This study effectively demonstrates that the UCSNs‐B act as NIR light‐triggered photocages to facilitate oxygen‐irrelevant •OH bursts, thus providing insights into the development of efficient PACT nanoagents for cancer treatment. An interesting paradigm of oxygen‐irrelevant photoactivated chemotherapy (PACT) via near‐IR‐gated and H2O‐mediated photocleavage based on engineered yolk–shell upconversion of mesoporous silica nanoparticle nanomedicines to augment the therapeutic efficacy of PACT nanoagents for cancer treatment is reported.