fig9

Figure 9. Ultrasound-responsive metal nanozyme-hydrogel systems for enhanced antibacterial therapy and infected wound healing. (A) An ultrasound-activated PPCN@Pt-AMPs/HGel dressing alleviates H₂O₂-mediated oxidative stress and hypoxia while enhancing sonodynamic therapy to promote healing of diabetic-infected wounds. Reproduced with permission from Ref.^[136]. Copyright 2025, Elsevier; (B) Representative wound photographs at multiple time points and corresponding healing curves, illustrating residual wound area over time under different treatments (n = 3). US: with the ultrasound irradiation at 0.8 W/cm² for 5 min. WO: without ultrasound irradiation. ^*P < 0.05, ^***P < 0.001. Reproduced with permission from Ref.^[136]. Copyright 2025, Elsevier; (C) Schematic depiction of the preparation of GelMA + PNAs and their ultrasound-assisted wound healing mechanism. Reproduced with permission from Ref.^[137]. Copyright 2023, Royal Society of Chemistry; (D) Comparative analysis of wound healing-related mechanisms under different treatments, including (i) ROS levels, (ii) HIF-1α expression, (iii) EGF expression, and (iv) VEGF expression on day 6. Reproduced with permission from Ref.^[137]. Copyright 2023, Royal Society of Chemistry; (E) Schematic illustration of PNAs’ GR-like activity. Reproduced with permission from Ref.^[137]. Copyright 2023, Royal Society of Chemistry; (F) Quantitative assessment of ROS levels and HIF-1α, EGF, and VEGF expression on day 9 following different treatments. (n = 3 independent mice). ^**P < 0.01, ^***P < 0.001, ^****P < 0.0001. Reproduced with permission from Ref.^[137]. Copyright 2023, Royal Society of Chemistry. PPCN@Pt-AMPs/HGel: Polydopamine-Prussian blue nanocage loaded with platinum-antimicrobial peptides/hydrogel; AMPs: antimicrobial peptides; HGel: hydrogel; GelMA: gelatin methacryloyl; PNAs: platinum nanoparticle assemblies; ROS: reactive oxygen species; HIF: hypoxia-inducible factor; EGF: epidermal growth factor; VEGF: vascular endothelial growth factor; GR: glutathione reductase; PCN: porous coordination network; DA: dopamine; SDT: sonodynamic therapy; MRSA: methicillin-resistant Staphylococcus aureus; BHGel: biological hydrogel; US: ultrasound; WO: without ultrasound; POD: peroxidase; GSSG: oxidized glutathione; GSH: reduced glutathione; M1: M1 macrophage; M2: M2 macrophage; NADPH: nicotinamide adenine dinucleotide phosphate; NADP⁺: nicotinamide adenine dinucleotide phosphate (oxidized form); NPs: nanoparticles.