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Hydrogel is a kind of hemostatic agent with good application prospect. However, the water molecules on the wound made the hydrogel less adhesive to wet wound tissue. Herein, the carboxymethyl chitosan (CMCS)/oxidized dextran (OD)/γ-polyglutamic acid (γ-PGA) hydrogel was prepared using a double-barreled syringe for hemostasis of diffuse and incompressible wound bleeding. The hydrogel formation was based on the intramolecular lactam bonds, intermolecular amide bonds, and Schiff base bonds. In the hydrogel, the super hydrophilic γ-PGA could drain the surface moisture of the wound and create a local dry environment for enhanced surface adhesion. In vivo study showed that the CMCS/ODex/γ-PGA hydrogel possesses a good biosafety and biodegradability. Interestingly, the CMCS/ODex/γ-PGA hydrogel exhibited excellent hemostatic abilities in dynamic humid environment and resisted a high blood pressure of 238 mmHg, which exceeds the threshold systolic blood pressure of healthy adults (i.e. , 120 mmHg). Together with the antibacterial and reactive nitrogen species scavenging activities, this study is expected to provide a new method to design the wet-surface adhesives for the efficient hemostatic application. [Display omitted] [ABSTRACT FROM AUTHOR]

Currently, hydrogels are widely studied for wound dressings. However, wound healing is often hindered by bacterial infection. In this study, in situ cross-linked carboxymethyl chitosan (CMCS)/oxidized dextran (OD)/poly-γ-glutamic acid (γ-PGA) (COP) hydrogel was prepared for antimicrobial and hemostasis of diffuse wounds. In the COP hydrogel, γ-PGA was able to drain the surface moisture of the wound to enhance the surface adhesion. Moreover, γ-PGA could concentrate blood by absorbing plasma, and CMCS could electrostatically adsorb negative RBCs. The antibacterial properties of CMCS and OD endowed the COP hydrogel with certain antibacterial effects. In the inhibition zone experiment, an obvious inhibition zone appeared around the COP hydrogel. In vivo studies showed that the COP hydrogel significantly inhibited bacterial growth and promoted wound healing. In the rat tail diffuse hemorrhage wound model, the COP hydrogel showed superior hemostasis ability. Therefore, the multifunctional COP hydrogel is expected to find different applications in wound hemostasis and healing. [ABSTRACT FROM AUTHOR]

Massive bleeding is a great threat to the life safety of patients, which is a challenging clinical problem. Therefore, it is urgent to develop a kind of multifunctional dressing material with hemostatic ability and antibacterial performance to promote wound healing and repair. To resolve this issue, in this study, a carboxymethyl chitosan (CMCS)/sodium alginate (SA)/oxidized dextran (ODE) (CSO) multifunctional hydrogel was developed. The hydrogel could rapidly gel through Schiff base reaction and amide reaction and firmly adhere to the skin at the wound, to realize the fast hemostasis. Importantly, it was verified that the hydrogel could prevent the Staphylococcus aureus -caused wound infection, owing to the antibacterial effect of CMCS and ODE. In addition, the CSO hydrogel had good water retention capacity and was able to mimic the three-dimensional structure of the natural extracellular matrix, thereby promoting wound repair in mice. In vitro whole-blood clotting assay demonstrated that red blood cells could be adhered to the surface of hydrogel, showing good hemostasis in rat liver injury and tail amputation models. Together with the biocompatible feature, CSO hydrogel holds a great application prospect in hemostasis and wound healing. • Carboxymethyl chitosan/sodium alginate/oxidized dextran hydrogel was prepared. • The hydrogel had excellent adhesion, mechanical properties and biodegradability. • The hydrogel could firmly adhere to the skin at the wound. • The hydrogel reduced the blood loss on rat liver injury and tail bleeding models. [ABSTRACT FROM AUTHOR]

Hydrogels have been widely used as wound dressings to accelerate wound healing. However, due to the impaired skin barrier at the wound site, external bacteria can easily invade the wound and cause infection. In this study, we designed a dopamine-modified sodium alginate/carboxymethyl chitosan/polyvinylpyrrolidone (CPD) hydrogel, which was able to promote wound healing while preventing wound infection. Due to the high content of catechol groups, the CPD hydrogel exhibited good tissue adhesion ability and a significant scavenging ability for DPPH• and PTIO• radicals. Under near-infrared laser irradiation, the temperature of CPD hydrogel increased significantly, which significantly killed the Staphylococcus aureus and Escherichia coli. The cell migration test confirmed that CPD hydrogel could promote the cell migration ratio. In the in vivo wound healing test for infected full-thickness skin defect, CPD hydrogel significantly inhibited bacterial proliferation and enhanced wound healing rate. Therefore, the multifunctional hydrogel is expected to be applied to wound healing. [ABSTRACT FROM AUTHOR]

[Display omitted] • MXene-based nanofibrous membrane for the multi-modal antibacterial applications. • The nanofibrous membranes can control the release of antibiotics. • Hyperthermia can destroy bacteria and further promote AMX release. • The nanofibrous membrane as a physical barrier promotes the wound healing. Featured with a three-dimensional network structure, electrostatic spinning nanofibrous membranes can maintain the hygroscopic balance in the wound place and promote the wound healing, thus have been extensively studied as a promising wound healing dressing. In this study, amoxicillin (AMX), MXene, and polyvinyl alcohol (PVA) were mixed and electrospun into an antibacterial nanofibrous membrane (MXene-AMX-PVA nanofibrous membrane). In the composite nanofibrous membrane, the PVA matrix could control the release of AMX to combat bacterial infection, while the MXene could transform the near-infrared laser into heat, leading to local hyperthermia to promote the AMX release. Meanwhile, the local hyperthermia could also destroy the noncellular components of bacteria and synergistically cause the bacterial inactivation. The bacteriostatic activity and wound healing ability of the composite nanofibrous membrane were systematically verified on the S. aureus in vitro and the S. aureus -infected mouse skin defect model in vivo. This membrane not only functioned as a physical barrier to co-load the AMX and MXene, but also exhibited the high antibacterial and accelerated wound healing capacity, which will advance the design of novel wound healing dressings and antibacterial strategies. [ABSTRACT FROM AUTHOR]

An in-situ formed hemostatic hydrogel (GelMA/OD/Borax) was prepared for the emergency wound hemostasis and anti-inflammation applications. Gelatin was chosen as the backbone and modified with methacrylic anhydride (MA) to synthesize GelMA, which showed the admirable UV light activatable polymerizing ability. Aldehyde groups, which cross-linked with the -NH 2 on the tissue surface and afforded the tissue adhesion, were produced by oxidizing the o-hydroxyl groups of dextran. Further, the sodium tetraborate formed dynamic boric acid ester bonds with the oxidized dextran (OD). With this triple-network structure, the as-prepared hydrogel presented excellent hemostatic capacity and surmounted a high blood pressure of 165 mmHg, which is higher than the threshold systolic blood pressure of healthy adults (i.e., 120 mmHg). The mechanical property, morphology, biocompatibility and degradation of the hydrogel were character Borax, the hydrogel successfully blocked the bleeding and accelerated the wound healing. This research provides a new modality for the design of a multifunctional hemostatic hydrogel for effective hemostasis and wound healing. • GelMA/OD/Borax hydrogel is reported for the wound hemostasis and anti-inflammation. • The hemostatic hydrogel can surmount a high blood pressure of 165 mmHg. • The hydrogel is biocompatible, degradable, and has a good antibacterial capacity. • The hydrogel can accelerate the wound healing. [ABSTRACT FROM AUTHOR]