Antibacterial collagen-guar gum hydrogels with zeolitic imidazolate framework-67 (ZIF-67): an innovative platform for advanced wound healing

The current challenge in developing wound healing dressings lies in achieving antibacterial effects while avoiding cytotoxicity to cells that are crucial for the healing process. Addressing this challenge, Zeolitic Imidazolate Framework-67 (ZIF-67), a cobalt-containing metal-organic framework (MOF), has emerged as a promising additive due to cobalt's broad-spectrum antimicrobial effects. This study developed semi-interpenetrating polymer network (semi-IPN) hydrogels by incorporating 1-3 wt.% ZIF-67 into collagen-guar gum matrices, resulting in biocomposites with tunable structural and functional properties. These biocomposites exhibit a fibrillar-granular morphology, uniform cobalt ion distribution on a semi-crystalline surface, and strong antibacterial activity against Escherichia coli (E. coli). At 3 wt.%, ZIF-67 accelerates gelation, strengthens crosslinking interactions, and enhances the storage modulus, thermal stability, and hydrolytic resistance of the hydrogels. Furthermore, biocomposites with 1 wt.% ZIF-67 also function as in-situ curcumin delivery systems, offering controlled release under physiological conditions and significant biodegradation in the presence of collagenase. In vitro tests demonstrate that the chemical composition of these hydrogels, regardless of ZIF-67 content, effectively supports monocyte and fibroblast metabolic activity, promotes cell proliferation, and increases interleukin-10 (IL-10) secretion by human monocytes. Additionally, the absence of hemolytic effects in human blood further underscores the safety and suitability of these hydrogel biocomposites for advanced wound treatment applications.