Engineering Single‐Atom Nanozymes for Catalytic Biomedical Applications

Abstract

Nanomaterials with enzyme‐mimicking properties, coined as nanozymes, are a promising alternative to natural enzymes owing to their remarkable advantages, such as high stability, easy preparation, and favorable catalytic performance. Recently, with the rapid development of nanotechnology and characterization techniques, single atom nanozymes (SAzymes) with atomically dispersed active sites, well‐defined electronic and geometric structures, tunable coordination environment, and maximum metal atom utilization are developed and exploited. With superior catalytic performance and selectivity, SAzymes have made impressive progress in biomedical applications and are expected to bridge the gap between artificial nanozymes and natural enzymes. Herein, the recent advances in SAzyme preparation methods, catalytic mechanisms, and biomedical applications are systematically summarized. Their biomedical applications in cancer therapy, oxidative stress cytoprotection, antibacterial therapy, and biosensing are discussed in depth. Furthermore, to appreciate these advances, the main challenges, and prospects for the future development of SAzymes are also outlined and highlighted in this review.

Single-atom nanozymes: classification, regulation strategy, and safety concerns

“…Therefore, the utilization of surface engineering can enhance the performance of SAzymes in specific physiological environments by improving water dispersion, targeting ability, catalytic efficiency, immunogenicity, and prolonging circulation time. 136…”

“…In contrast, natural OXD can activate O 2 molecules to produce ROS without the need for additional H 2 O 2 , making them more versatile catalysts for oxidation reactions. 178,179 Recently, some SAzymes have been found to exhibit oxidase-like activity. 180–183…”

“…Recently, there have been publications discussing the essential properties, synthesis methods, and potential applications of SAzymes in protecting cells from oxidative stress and breaking down organic pollutants. 61,62…”

Single atom nanozymes for bacterial infection therapy

“…18,19 Owing to the adjustable coordination environment and electronic structure of the metal site, single-atom nanozymes (SAzymes) exhibit a diverse range of enzyme-like catalytic activities, including peroxidase (POD), oxidase (OXD), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx). 20 Thus far, SAzymes have been successfully applied in the treatment of cancer, bacterial infections, and oxidative stress-related diseases. 21,22 Although several outstanding reviews have summarized the development of SAzymes in the field of biomedicine, 23,24 no specific review pertaining to antibacterial treatment has been reported.…”

Nanozymes Based on MXene Nanosheets Decorated with Pt Nanoparticles for Hyperthermal-Enhanced Cascade Catalytic Therapy of Tumors

“…Realizing efficient and less toxic treatments for cancer is always the focus of research . Together with the development of nanomedicine, nanocatalytic therapy provides new perspectives for the treatment of cancer. , Catalytic therapy mainly involves a chemical reaction in situ within the tumor with catalytically active nanomaterials to produce toxic substances to kill tumor cells. , Nanozymes are attracting widespread attention in the field of catalytic medicine since they contain the catalytic activity of natural enzymes and the physicochemical properties of nanomaterials. − In recent years, multiple nanozymes are emerging, including carbon-based nanozymes, iron-based nanozymes, manganese-based nanozymes, , and single-atom nanozymes, − which are widely used for detection, disease therapy, and especially nanozyme-mediated tumor catalytic therapy. − …”