Carbon-dots crosslinked collagen- fucoidan hydrogel with anti-bacterial and immunomodulatory activities promotes...

Skin defects caused by inflammation, burns, or infections typically require functional wound dressings to promote healing. Hydrogels with three-dimensional hydrophilic porous structures provide a favorable microenvironment for the migration and proliferation of cells involved in wound healing. As a key biomolecular component of the extracellular matrix (ECM), collagen can self-assemble into collagen-based hydrogels. Herein, glutaraldehyde-derived carbon dots (GACDs) and fucoidan (FC), a sulfated fucose-containing marine polysaccharide were innovatively incorporated into collagen, constructing a mechanically strengthened, antibacterial, and immunomodulatory ECM-like hydrogel and was used as a multifunctional wound dressing. Experimental results demonstrated that the incorporation of GACDs did not disrupt the self-assembly of collagen fibrils and significantly enhanced the mechanical strength of the hydrogel. The composite hydrogel exhibited good cytocompatibility and hemocompatibility. FC was added to the hydrogel to significantly down-regulate the expression of TNF-α and IL-β, and promote the expression of TGF-β1 to achieve anti-inflammatory effects. Additionally, FC worked synergistically with the carbon dots to exert antibacterial effects. Results from animal experiments showed that this ECM-like hydrogel promoted the deposition and rearrangement of collagen fibers. This composite hydrogel demonstrates significant efficacy in anti-inflammatory activity, antibacterial action, and tissue-repair promotion. Critically, the integration of immunomodulatory capability within the collagen-based scaffold addresses the multifactorial challenges of healing in inflammatory or infected wounds, representing a substantial advance over conventional single-function dressings and presenting a promising, clinically applicable strategy for wound management.