Pro-angiogenic dual-crosslinked collagen bioinks for precise cell-laden DLP 3D printing and rapid vascularized...

Robust vascularization is essential for advancing tissue engineering and regenerative medicine. However, engineering bioinks that integrate mechanical integrity, cellular compatibility, and proangiogenic functionality remains a significant challenge for fabricating vascularized constructs via bioprinting. Here, we present a dual-crosslinked methacrylated collagen (CMA) bioink (PCMA-Fe) tailored for high-resolution digital light processing (DLP) bioprinting and enhanced vascular regeneration in angiogenesis-impaired diabetic wounds. This bioink utilizes Fe³⁺-mediated coordination to enable rapid photo-crosslinking, improved mechanical stability, suppressed swelling, and increased resistance to biodegradation. Functionalization with the QHREDGS peptide promotes upregulation of key angiogenic genes (VEGF, CDH5, PECAM1), enhancing endothelial migration, capillary network formation, and tube maturation. DLP bioprinting with PCMA-Fe supports sustained viability and proliferation of encapsulated fibroblasts and endothelial cells, allowing fabrication of multicellular skin constructs with micron-scale resolution and precise architectural fidelity. In a diabetic wound model, both acellular and cell-laden PCMA-Fe scaffolds significantly accelerate re-epithelialization, collagen remodeling, M2 macrophage polarization, and functional neovascularization, culminating in scarless wound closure within 18 days. This study establishes a clinically translatable collagen-based DLP bioprinting platform for vascularized tissue engineering.