Gradient Modulus Tissue Adhesive Composite for Dynamic Wound Closure

Wound closure in fluid-rich and dynamic environments is challenging. Wound closed by suturing or stapling is prone to tear, causing fluid leakage and inflection. Despite recent advances in tissue adhesive for wound sealing, existing tissue adhesive hydrogels are too soft and stretchable to keep wound edges together under dynamic loading. Here a biodegradable gradient modulus tissue adhesive composite (GmTAC), consisting of three functional components including a tissue adhesive matrix, a gradient modulus micro-mesh, and an oil-infused anti-adhesion surface is presented. The 100 µm thick GmTAC patch can rapidly adhere on wet tissue surface to seal the wound, protect the wound from dynamic tear, prevent adhesion with surrounding tissue, and gradually degrade without the need of patch retrieval. Moreover, an optimally designed GmTAC patch can make the wounded intestine deform like its intact counterpart without visible tear or stress concentration even under large tension or inflation. Efficacy of the GmTAC for wound closure and tear prevention in dynamic and fluid-rich environments is verified in vitro and in vivo with simulation. This study thereby demonstrates that this strategy has the great potential for the management of challenging wounds.