3D-printed fish-skin-derived composite dECM hydrogel patch for immunomodulatory and pro-angiogenic diabetic wound...

Diabetic wounds are sustained by persistent inflammation, oxidative stress, infection susceptibility, and impaired angiogenesis, highlighting the need for bioactive dressings with manufacturable architectures. Here, we developed a methacrylation-free and photopolymerization-free fish-derived composite decellularized extracellular matrix (dECM) hydrogel scaffold by blending tilapia skin-derived dECM (TdECM) with carp skin-derived dECM (CdECM). Rheology-guided screening identified TdECM/CdECM-2, a 1:2 (v/v) blend of TdECM and CdECM, as a printable formulation that combined shear-thinning behavior, thermally induced collagen fibrillogenesis, and extrusion printability. Post-print stabilization with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) preserved lattice architecture and generated highly porous scaffolds with a porosity of 90.3 ± 3.9%. In vitro, the composite scaffold (TdECM/CdECM-2) supported fibroblast, keratinocyte, and endothelial cell growth; promoted keratinocyte migration and endothelial network formation; and reduced Staphylococcus aureus and Pseudomonas aeruginosa survival to 10.5 ± 1.3% and 13.3 ± 3.3%, respectively, in direct-contact assays. Macrophage studies indicated attenuated pro-inflammatory gene expression, increased pro-regenerative macrophage-associated markers, and reduced oxidative stress-associated reactive oxygen species accumulation. In mice with streptozotocin-induced diabetes, TdECM/CdECM-2 increased wound closure to 91.2 ± 3.9% at day 14, compared with 73.2 ± 9.7% in the untreated control and 79.3 ± 12.5% in the porcine skin-derived dECM (PdECM) group, together with improved re-epithelialization, collagen deposition, and cluster of differentiation 31 (CD31)-positive neovascularization, and reduced inflammatory myeloid cell accumulation and macrophage activation. Exploratory single-cell transcriptomic profiling suggested treatment-associated modulation of immune and stromal/endothelial gene programs related to inflammation and angiogenesis. These findings support fish-derived composite dECM scaffolds as printable bioactive wound dressing platforms for diabetic wound repair.