Emerging antibacterial nanozymes for wound healing

Abstract

Wound infections continuously impose a huge economic and social burden on public healthcare. Despite the effective treatment of bacteria-infected wounds after using traditional antibiotics, the misuse of antibiotics usually causes the spread of bacterial resistance and decreases therapeutic outcomes. Therefore, the development of efficient antibacterial agents is urgently needed. Nanozymes, as a new generation of artificial enzymes, combine the intrinsic abilities of nanomaterials and natural enzymes. Recently, nanozymes has been widely developed to kill bacteria and treat wound infections by catalyzing the generation of various reactive oxygen species. Thus, this new concept of "antibacterial nanozymes" will promote the further advances of connecting nanozymes and bacterial elimination. To highlight these achievements, we summarize different types of antibacterial nanozymes for wound healing. It is believed that such a promising therapeutic strategy of developing antibacterial nanozymes will make a great contribution in the field of skin regeneration. We expect that antibacterial nanozymes will play the significant roles in both basic research and clinical applications.

Keywords: bacteria; nanozymes; reactive oxygen species; skin regeneration; wound.

FIGURE 1

Illustration of antibacterial nanozymes in wound healing applications. MOF, metal organic framework; ROS, reactive oxygen species. Source: Images reprinted with permission from Refs., , , , , , Copyright 2021, Elsevier B.V. on behalf of KeAi Communications Co. Ltd. Copyright 2018, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. Copyright 2018, American Chemical Society. Copyright 2019, American Chemical Society. Copyright 2016, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. Copyright 2022, Wiley‐VCH GmbH. Copyright 2021, Wiley‐VCH GmbH.

FIGURE 2

(A) Scheme of Zn‐based SAzyme with POD‐mimicking property for wound treatment. (B) Photographs of Pseudomonas aeruginosa colonies and infected wounds treated by different groups. Source: Images reprinted with permission from Ref. Copyright 2019, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. (C) Cu‐based SAzyme with enzyme‐like and photothermal properties for eradicating bacteria (a) and treating MRSA‐infected wounds (b). (D) Photographs of infected wounds and bacterial colonies from the tissues treated by different groups. Source: Images reprinted with permission from Ref. Copyright 2021, Elsevier B.V. on behalf of KeAi Communications Co. Ltd. NIR, near‐infrared; ROS, reactive oxygen species

FIGURE 3

(A) Morphology and composition characterization of Pt hollow nanodendrites without Pd atoms. (B) Photographs of wound, wound healing condition, and bacterial colony forming unit in wound tissue treated by different groups. Source: Images reprinted with permission from Ref. Copyright 2018, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. (C) Copper‐doped nanozymes with POD‐like activity for treating wound infection. (D) Photographs of S. aureus‐infected wounds treated by copper‐doped nanozymes. Source: Images reprinted with permission from Ref. Copyright 2021, American Chemical Society.

FIGURE 4

(A) Scheme of POD‐like MoS₂ NFs with photothermal performance for killing bacteria. (B) Photographs of wounds and bacterial CFU in wound tissue treated by different groups. Source: Images reprinted with permission from Ref. Copyright 2016, American Chemical Society. (C) Scheme of MoS₂‐hydrogel with POD‐like and photothermal performance for treating wound infection. (D) Photographs of wound and bacterial CFU in wound tissue treated by (1) phosphate buffer saline (PBS), (2) H₂O₂, (3) MoS₂‐cysteine, (4) MoS₂‐cysteine + H₂O₂, (5) hydrogel, (6) hydrogel + H₂O₂, (7) MoS₂‐hydrogel, and (8) MoS₂‐hydrogel + H₂O₂, respectively. Source: Images reprinted with permission from Ref. Copyright 2019, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. CFU, colony forming unit; NIR, near‐infrared

FIGURE 5

(A) Scheme of the synthesis process and antibacterial performance of Cu‐MoS₂ nanozymes. (B) Photographs of wounds treated by different groups. Source: Images reprinted with permission from Ref. Copyright 2019, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. (C) Scheme of synthesis process and antibacterial performance of Cu₂WS₄ NPs (CWS) with dual enzyme‐like properties. (D) Photographs of wound treated by CWS and vancomycin (Van), respectively. Source: Images reprinted with permission from Ref. Copyright 2019, American Chemical Society. ROS, reactive oxygen species

FIGURE 6

(A) Scheme of MOF‐derived multifunctional porphyrin‐like metal center NPs (PMCS) integrated microneedles (PMCS‐MNs) with the POD‐like activity for antibacterial treatment. (B) Scheme of PMCS‐MNs for wound treatment (i) and the near‐infrared (NIR) thermal images of wounds (ii). Source: Images reprinted with permission from Ref. Copyright 2021, Wiley‐VCH GmbH.

FIGURE 7

(A) Scheme of 2D MOF (Cu‐TCPP(Fe)) nanosheet absorbing glucose oxidase (GOx) as a hybrid nanozyme for antibacterial treatment. (B) Photographs of S. aureus‐infected wound treated by different groups. Source: Images reprinted with permission from Ref. Copyright 2019, American Chemical Society. (C) Scheme of the preparation process and antibacterial application of Au NPs/MOFs hybrid nanozyme. (D) Photographs of S. aureus‐infected wound treated by (1) phosphate buffer saline (PBS), (2) Au NPs/MOFs, (3) H₂O₂, (4) MOFs + H₂O₂, and (5) Au NPs/MOFs + H₂O₂, respectively. Source: Images reprinted with permission from Ref. Copyright 2020, WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. MOF, metal organic framework

FIGURE 8

(A) Scheme of oxygenated carbon nanotubes with the enzyme‐like activity. Source: Images reprinted with permission from Ref. Copyright 2018, American Chemical Society. (B) Scheme of the synthesis process (i) and anti‐infection treatment (ii) for APGH. Source: Images reprinted with permission from Ref. Copyright 2021, Wiley‐VCH GmbH. (C) Scheme of FNDs‐MNs preparation process (i) and anti‐infection treatment (ii). (D) Scheme of the therapeutic process (i), MNs colorimetric photographs for different wounds (ii), FNDs‐MNs for treating MRSA‐infected wounds (iii), and wound healing conditions (iv). Source: Images reprinted with permission from Ref. Copyright 2022, Elsevier.