Copper–Zinc‐Doped Bilayer Bioactive Glasses Loaded Hydrogel with Spatiotemporal Immunomodulation Supports MRSA‐Infected Wound Healing

Abstract Developing biomaterials with antimicrobial and wound‐healing activities for the treatment of wound infections remains challenging. Macrophages play non‐negligible roles in healing infection‐related wounds. In this study, a new sequential immunomodulatory approach is proposed to promote effective and rapid wound healing using a novel hybrid hydrogel dressing based on the immune characteristics of bacteria‐associated wounds. The hydrogel dressing substrate is derived from a porcine dermal extracellular matrix (PADM) and loaded with a new class of bioactive glass nanoparticles (BGns) doped with copper (Cu) and zinc (Zn) ions (Cu–Zn BGns). This hybrid hydrogel demonstrates a controlled release of Cu2+ and Zn2+ and sequentially regulates the phenotypic transition of macrophages from M1 to M2 by alternately activating nucleotide‐binding oligomerization domain (NOD) and inhibiting mitogen‐activated protein kinases (MAPK) signaling pathways. Additionally, its dual‐temporal bidirectional immunomodulatory function facilitates enhanced antibacterial activity and wound healing. Hence, this novel hydrogel is capable of safely and efficiently accelerating wound healing during infections. As such, the design strategy provides a new direction for exploring novel immunomodulatory biomaterials to address current clinical challenges related to the treatment of wound infections.


Figure S4 .
Figure S4.(a) Representative images of the bacterial colonies formed by the bacteria cultured

Figure S6 .
Figure S6.Results of transcriptome sequencing.(a, d) Correlation analysis of gene expression levels between samples in cells co-cultured with PACM@CZ samples on days 5 (a) and days 11 (d) for 24 h.(b, e) PCA of the global genes in cells co-cultured with PACM@CZ samples on days 5 (b) and days 11 (e) for 24 h.(c, f) Volcano plot displaying the differentially expressed genes (fold change ≥ 2 and p < 0.05) in cells co-cultured with PACM@CZ samples on days 5 (c) and days 11 (f) for 24 h.

Figure S7 .
Figure S7.In vitro indirect antimicrobial SPM results for Days 5 and 11 samples.(a) Representative images of the bacterial colonies formed by the MRSA phagocytosed by macrophages cultured with Day 5 samples (upper panel); Representative images of the bacterial colonies formed by the MRSA survived the macrophage phagocytosis cultured with Day 5 samples (lower panel).(b) Representative images of the bacterial colonies formed by the MRSA phagocytosed by macrophages cultured with Day 11 samples (upper panel); Representative images of the bacterial colonies formed by the MRSA survived the macrophage phagocytosis cultured with Day 11 samples (lower panel).

Figure S9 .
Figure S9.The bacterial burden of wound skin tissues after 4 (upper panel) and 10 days (lower panel) after surgery.

Figure S11 .
Figure S11.The immunohistochemical staining of IL-6 and TNF-α in the skin tissues of the wounded area after 4-and 14-days.Scale bar 200 μm.

Figure S12 .
Figure S12.Impact of the PADM@CZ hydrogel on immune regulation in vivo.(a, b) Flow cytometry analysis of CD4 + and CD8 + T cells (a), and CD8 + /CD4 + ratios (b) in the spleens of mice subjected to diverse treatments over varying time intervals.(c, d) Representative flow cytometric analysis and quantification of Th1 (CD4 + CCR5 + ) proportion in the spleens of mice.

Table S1
Primers used in this study.