Developing bio-multifunctional patches with natural extracellular matrixlike structures, excellent high adhesion in the wet state, self-healing ability, antibacterial activity, and favorable cell responses for accelerating tissue healing is highly desirable in clinical applications. Herein, bio-multifunctional composite hydrogels are developed by coupling carboxymethyl chitosan and 4-arm poly (ethylene glycol) aldehyde for full-thickness abdominal wall defect repair. The prepared hydrogels exhibit excellent self-healing and mechanical properties, high adhesion in the wet state, and significant antibacterial ability. In vitro cellular experiments show that the hydrogels combined with recombinant bovine basic fibroblast growth factor remarkably promote cell proliferation and then accelerate full-thickness abdominal wall defect repair in a rat model. The histomorphological evaluation shows that compared to the commercial polypropylene mesh used clinically, the designed hydrogel patches facilitate an increase in the thickness and integrity of the abdominal wall tissue by upregulating the production of Ki67, enhancing the formation of collagen, inducing neovascularization, and inhibiting inflammation by reducing the expression of IL-6, TNF-α, and IL-1β. The results demonstrate that this novel bio-multifunctional hydrogel patch holds great potential for the treatment of full-thickness abdominal wall defects.

When skin trauma occurs, rapid achievement of the post‐wound closure is required to prevent microbial invasion, inhibit scar formation and promote wound healing. To develop a wound dressing for accelerating post‐wound‐closure and wound healing, a thermo‐responsive and tissue‐adhesive hydrogel with interpenetrating polymer networks (IPN) is fabricated based on N‐dimethylbisacrylamide (NIPAM) and glutaraldehyde (GTA) cross‐linked hyaluronic acid (HA). Results not only confirm the thermo‐stimulated self‐contraction and tissue adhesiveness of the HA‐based IPN (PNI‐HA), which effectively aids wound closure via mechanical stretch, but also verify the hemocompatibility and cytocompatibility of PNI‐HA that tend to accelerate wound healing. In vivo, a mouse model of total skin defect demonstrates that PNI‐HA acting as hydrogel sealant significantly achieves the sutureless post‐wound‐closure at the early stage of wound healing, and then promotes wound healing by reducing inflammatory cells infiltration, promoting angiogenesis as well as reducing collagen deposition. These results indicate that the developed thermo‐responsive and tissue‐adhesive hydrogel dressing offers a candidate to serve as a tissue sealant for wound healing.

Background Clinical tissue adhesives remain some critical drawbacks for managing emergency injuries, such as inadequate adhesive strength and insufficient anti-infection ability. Herein, a novel, self-healing, and antibacterial carboxymethyl chitosan/polyaldehyde dextran (CMCS/PD) hydrogel is designed as the first-aid tissue adhesive for effective trauma emergency management. Methods We examined the gel-forming time, porosity, self-healing, antibacterial properties, cytotoxicity, adhesive strength, and hemocompatibility. Liver hemorrhage, tail severance, and skin wound infection models of rats are constructed in vivo, respectively. Results Results demonstrate that the CMCS/PD hydrogel has the rapid gel-forming (~ 5 s), good self-healing, and effective antibacterial abilities, and could adhere to tissue firmly (adhesive strength of ~ 10 kPa and burst pressure of 327.5 mmHg) with excellent hemocompatibility and cytocompatibility. This suggests the great prospect of CMCS/PD hydrogel in acting as a first-aid tissue adhesive for trauma emergency management. The CMCS/PD hydrogel is observed to not only achieve rapid hemostasis for curing liver hemorrhage and tail severance in comparison to commercial hemostatic gel (Surgiflo ®) but also exhibit superior anti-infection for treating acute skin trauma compared with clinical disinfectant gel (Prontosan ®). Conclusions Overall, the CMCS/PD hydrogel offers a promising candidate for first-aid tissue adhesives to manage the trauma emergency. Because of the rapid gel-forming time, it could also be applied as a liquid first-aid bandage for mini-invasive surgical treatment. Graphical Abstract