Tumor Response and NIR‐II Photonic Thermal Co‐Enhanced Catalytic Therapy Based on Single‐Atom Manganese Nanozyme

Abstract

Single‐atom nanozymes (SAzymes) can effectively mimic the metal active centers of natural enzymes at the atomic level owing to their atomically dispersed active sites, thereby maximizing atom utilization efficiency and density of active sites. Hence, SAzymes can be considered the most promising candidates to replace natural enzymes. Herein, a PEGylated mesoporous Mn‐based single‐atom nanozyme (PmMn/SAE) employing a coordination‐assisted polymerization pyrolysis strategy that uses polydopamine for photothermal‐augmented nanocatalytic therapy is designed. PmMn/SAE exhibits excellent multiple enzymatic performance, including catalase‐like, oxidase‐like, and peroxidase (POD)‐like performance, due to the atomically dispersed Mn active species. As a result, PmMn/SAE not only catalyzes the decomposition of endogenous H2O2 to generate O2 for relieving hypoxia inside the tumor but also transfers electrons to O2 to produce superoxide radicals to kill tumor cells. Meanwhile, PmMn/SAE is able to trigger Fenton‐like reactions to generate highly toxic hydroxyl radicals to induce cancer cell apoptosis. The POD‐like catalytic mechanism of mMn/SAE is revealed using experimental results and density functional theory. Furthermor, PmMn/SAE shows good photothermal conversion efficiency (η = 22.1%) in the second near‐infrared region (1064 nm). Both the in vitro and in vivo experimental results indicate that PmMn/SAE can effectively kill cancer cells through photothermal‐enhanced catalytic therapy.

Simultaneous Detection of Ovarian Cancer-Concerned HE4 and CA125 Markers Based on Cu Single-Atom-Triggered CdS QDs and Eu MOF@Isoluminol ECL

“…MB could be oxidized to colorless (oxMB) by • OH, and its concentration could be detected by the absorption peak of 665 nm. 27 As illustrated in Figure 3A 3C) and O 2 production (Figure 3D) confirmed that Cu SAC/NC could significantly catalyze the decomposition of H 2 O 2 to produce • OH and O 2 . 28 In addition, it was found that at pH 7.4, O 2 production was the fastest and most stable (Figure 3E).…”

“…To evaluate the catalytic activity of Cu SAC/NC, the catalytic reduction of H 2 O 2 to • OH was monitored by measuring the consumption of substrate methylene blue (MB). MB could be oxidized to colorless (oxMB) by • OH, and its concentration could be detected by the absorption peak of 665 nm . As illustrated in Figure A (inset), Cu SAC/NC + H 2 O 2 made the color of MB change significantly, accompanied by the production of dense bubbles.…”

Optimized core–shell lanthanide nanoparticles with ultrabright Ce3+-modulated second near-infrared emission for “lighting” plants

“…41 Besides, doped Yb 3+ ions in the shell have high inherent absorption of NIR photons and intensive energy transfer rate to the luminescent center Er 3+ ions, which can also boost the DC pathway. 42,43 It is reported that the presence of more Yb 3+ ions in the lattice will shorten the distance between Yb 3+ and Er 3+ ions, resulting in energy back-transfer Paper Nanoscale from Er 3+ to Yb 3+ ions. When the Yb 3+ ion content is 20%, the energy transfer efficiency reaches the maximum.…”

Activity Regulating Strategies of Nanozymes for Biomedical Applications

“…The PEGylated mesoporous Mn‐based single‐atom nanozyme (P m Mn/SAE) is prepared by the coordination assisted polymerization strategy of polydopamine with highly active Mn atoms disperse. [ 53 ] The nanozyme possesses CAT‐, OXD‐, and POD‐like activity. In this regard, P m Mn/SAE nanozymes can not only decompose H 2 O 2 to produce O 2 for easing the hypoxia in the cancer, it can also transfer electrons to O 2 for generate superoxide radicals (•O 2− ) and hydroxyl radicals (•OH) stimulated by Fenton‐like reactions to effective prompt apoptosis of tumor cells.…”