Development of Manganese Carbonyl Loaded Upconversion Nanoparticles for Near‐Infrared‐Triggered Carbon Monoxide and Mn²⁺ Delivery

Photoactivatable carbon monoxide‐releasing molecules (CORMs), typically based on transition‐metal carbonyl complexes, have reliance on activation by UV or visible light that restricts their biomedical applications. To address this limitation, a near‐infrared (NIR)‐responsive nanoplatform is presented based on upconversion nanoparticles (UCNPs) loading with manganese carbonyl complex Mn 2 (CO) 10 that concurrently releases CO and manganese ion (Mn 2+ ). With the UCNPs, the more tissue‐penetrable NIR is used to locally generate UV light for photodecomposition of Mn 2 (CO) 10 into CO and manganese oxide (MnO X ), after which MnO X is reduced to Mn 2+ by the overexpressed glutathione in cancer cells. Moreover, the released Mn 2+ can serve as a magnetic resonance imaging contrast agent to monitor the NIR‐controlled corelease of CO and Mn 2+ in real time. Therefore, this nanoplatform can provide a potential strategy for NIR‐enabled spatiotemporally release of CO and Mn 2+ , enhancing the controlled delivery and biomedical application of CORMs.