Janus asymmetric galactomannan-based hydrogel with programmable deformation for accelerating wound healing.

The development of an asymmetrical engineering dressing that accelerates wound closure is crucial for clinical applications. The hydrogel with a Janus structure that integrates thermo-responsive contraction and adhesive properties was fabricated through a robust cross-linked network of isopropylacrylamide and polyacrylamide, while a functional surface layer was created by cross-linking zwitterionic monomers and hyaluronic acid. The hydrogel exhibited superior tensile stress (80 Kpa), fracture strain (3000 %), tissue adhesiveness (35 Kpa) and high antibacterial activity (with a 99.9 % reduction in bacterial growth). The Janus hydrogel demonstrated significant thermal responsiveness and self-contraction properties, contributing to accelerated wound closure. In vivo experiments showed that the Janus hydrogel facilitated sutureless wound closure and enhanced wound healing through mechanical inward force, significantly improving wound contraction and promoting granulation tissue formation, as well as collagen deposition, resulting in 99 % wound healing efficiency by day 14. These results underscore the novel design of the Janus hydrogel as a multifunctional wound dressing, offering a unique combination of thermo-responsive and adhesive properties, along with excellent antibacterial and healing-promoting effects, making it a promising candidate for clinical wound repair.