Dual-network methacrylated collagen-magnesium hydrogels for enhanced biocompatibility and precision in DLP 3D bioprinting.

The advancement of 3D bioprinting for tissue and organ engineering necessitates the development of bioinks with superior biocompatibility, printability, and mechanical properties. Collagen, renowned for its biocompatibility and bioactivity, remains underutilized due to its inadequate mechanical strength and slow gelation rates. To address these limitations, we present a novel dual-network methacrylated collagen‑magnesium (CMAMg) hydrogel fabricated via digital light processing (DLP) 3D printing. This bioink leverages methacrylation to improve photocrosslinking capabilities and incorporates magnesium ion (Mg) coordination crosslinking to significantly enhance mechanical stability, printability, and enzymatic degradation resistance. The CMA-Mg hydrogel demonstrated excellent biological activity, promoting cell proliferation, migration, and differentiation. In a rat full-thickness skin wound model, the CMA-Mg hydrogel accelerated epidermal regeneration, enhanced collagen deposition, and achieved superior wound healing efficacy. These findings highlight the CMA-Mg bioink as a promising candidate for high-precision DLP bioprinting in tissue engineering and regenerative medicine.