Nanozymes-recent development and biomedical applications

Abstract

Nanozyme is a series of nanomaterials with enzyme-mimetic activities that can proceed with the catalytic reactions of natural enzymes. In the field of biomedicine, nanozymes are capturing tremendous attention due to their high stability and low cost. Enzyme-mimetic activities of nanozymes can be regulated by multiple factors, such as the chemical state of metal ion, pH, hydrogen peroxide (H2O2), and glutathione (GSH) level, presenting great promise for biomedical applications. Over the past decade, multi-functional nanozymes have been developed for various biomedical applications. To promote the understandings of nanozymes and the development of novel and multifunctional nanozymes, we herein provide a comprehensive review of the nanozymes and their applications in the biomedical field. Nanozymes with versatile enzyme-like properties are briefly overviewed, and their mechanism and application are discussed to provide understandings for future research. Finally, underlying challenges and prospects of nanozymes in the biomedical frontier are discussed in this review. Graphical Abstract

What are inorganic nanozymes? Artificial or inorganic enzymes

“…The term ''nanozyme'' is becoming increasingly popular as more and more research occurs on this class of biocatalysts [3][4][5]116,[217][218][219][220] due to their low cost, high stability, and durability and the ease of manufacture. There have been more than 900 nanozymes discovered so far by 386 laboratories in 31 countries, and these enzyme-like activities include oxidoreductase, hydrolase, lyase, and isomerase.…”

“…There have been more than 900 nanozymes discovered so far by 386 laboratories in 31 countries, and these enzyme-like activities include oxidoreductase, hydrolase, lyase, and isomerase. 220 With the explosion of new discoveries of nanozymes, many scientists now consider these inorganic nanozymes as ''artificial enzymes'' [3][4][5][217][218][219][220] or ''enzyme mimics'' 221 even for inorganic nanomaterials devoid of surface modification. It was noted that the term ''nanozyme'' first emerged in the article on triazacyclonane/Zn 2+ -functionalized gold nanoparticles as RNase mimics in 2004.…”

“…They are not designed or predicated upon the natural protein ''sphere'' as claimed by many scientists. [3][4][5][217][218][219][220] ''Artificial'' enzymes are based on the concept of the protein as a natural enzyme and thus focus on the entire architecture of the catalyst. 2 The inorganic nanomaterials with intrinsic enzyme-like activities do not contain amino acids to build the scaffold of the protein, and they are not the ''small molecules in which much (or all) of the protein scaffold has been removed while preserving the essential features of the original active site (often including one or more metal ions)''.…”

Application of nanosonosensitizer materials in cancer sono-dynamic therapy

“…124 Compared with native enzymes, nanozymes are considered as promising theranostic adjuvants due to their tunable enzymatic activity, higher stability, and lower production cost. 125 Similarly, Qiao et al fabricated a Pd/H-TiO 2 nanosheet (NSs) (Fig. 12B).…”

Aspergillus tamarii mediated green synthesis of magnetic chitosan beads for sustainable remediation of wastewater contaminants

“…Water has been deemed as one major constituent for the life sustainability on the earth 1 – 3 . The water deficiency problem is a hot issue facing both developing and developed countries.…”