Multifunctional and Tunable Coacervate Powders to Enable Rapid Hemostasis and Promote Infected Wound Healing

Clotting Blood into an Adhesive Gel by Hemostatic Powder Based on Cationic/Anionic Polysaccharides and Laponite

Hemostatic powder is widely employed for emergency bleeding control due to its ability to conform to irregularly shaped wounds, ease of use, and stable storage. However, current powders exhibit limited tissue adhesion and insufficient support for thrombus formation, making them easily washed away by blood. In this study, a hybrid powder (QAL) was produced by mixing quaternized chitosan (QCS) powder, catechol-modified alginate (Cat-SA) powder, and laponite (Lap) powder. Upon addition of QAL, the blood quickly transformed to a robust and adhesive blood gel. The adhesion strength of the blood gel was up to 31.33 ± 1.56 kPa. When compared with Celox, QAL showed superior performance in promoting hemostasis. Additionally, QAL exhibited effectiveness in eliminating bacteria while also demonstrating outstanding biocompatibility with cells and blood. These favorable properties, including strong coagulation, adhesion to wet tissue, antibacterial activity, biosafety, ease of use, and stable storage, make QAL a promising emergency hemostatic agent.

Coagulating blood into adhesive gel by hybrid powder based on oppositely charged polysaccharide/tannic acid-modified mesoporous bioactive glass

Hemostatic powder is widely utilized in emergency situations to control bleeding due to its ability to work well on wounds with irregular shapes, ease of application, and long-term stability. However, traditional powder often suffers from limited tissue adhesion and insufficient support for blood clot formation, leaving it susceptible to displacement by the flow of blood. This study introduces a hemostatic powder composed of tannic modified mesoporous bioactive glass (TMBG), cationic quaternized chitosan (QCS), and anionic hyaluronic acid modified with catechol group (HADA). The resulting TMBG/QCS/HADA based hemostatic powder (TMQH) rapidly absorbs plasma, concentrating blood coagulation factors. Simultaneously, the water-soluble QCS and HADA interact to form a 3D network structure, which can be strengthened by crosslinking with TMBG. This network effectively captures clustered blood coagulation factors, leading to a strong and adhesive thrombus that resists disruption from blood flow. TMQH exhibits superior efficacy in promoting hemostasis compared to Celox™ both in rat arterial injuries and non-compressible liver puncture wounds. TMQH demonstrates excellent antibacterial activity, cytocompatibility, and blood compatibility. These outstanding superiorities in blood clotting capability, wet tissue adhesion, antibacterial activity, safety for living organisms, ease of application, and long-term stability, make TMQH highly suitable for emergency hemostasis.

Gluing blood into adhesive gel by oppositely charged polysaccharide dry powder inspired by fibrin fibers coagulation mediator

Hemostatic powders that adapt to irregularly shaped wounds, allowing for easy application and stable storage, have gained popularity for first-aid hemorrhage control. However, traditional powders often provide weak thrombus support and exhibit limited tissue adhesion, making them susceptible to dislodgment by the bloodstream. Inspired by fibrin fibers coagulation mediator, we have developed a bi-component hemostatic powder composed of positively charged quaternized chitosan (QCS) and negatively charged catechol-modified alginate (Cat-SA). Upon application to the wound, the bi-component powders (QCS/Cat-SA) rapidly absorb plasma and dissolve into chains. These chains interact with each other to form a network, which can effectively bind and entraps clustered red blood cells and platelets, ultimately leading to the creation of a durable and robust thrombus. Significantly, these interconnected polymers adhere to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from these synthetic properties, QCS/Cat-SA demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox™ in both arterial injuries and non-compressible liver puncture wounds. Importantly, QCS/Cat-SA exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of QCS/Cat-SA, including strong blood clotting, wet tissue adherence, antibacterial activity, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.

Antibacterial polyurethane foams with quaternized-chitosan as a chain extender for nasal packing and hemostasis

Endoscopic surgery is an effective and common clinical practice for chronic sinusitis. Nasal packing materials are applied in nasal surgery to prevent hemorrhage and promote wound healing. In this study, a degradable polyurethane foam dressing is successfully developed as a promising nasal packing material with good biocompatibility and antibacterial capability. Specifically, quaternized chitosan (QCS) serves as the crosslinker instead of polyols to offer polyurethane foam (PUF-QCS) antibacterial capability. The PUF-QCS2.0 % (with 2.0 wt% QCS) exhibits satisfactory liquid absorption capacity (19.4 g/g), high compressive strengths at both wet (14.5 kPa) and dry states (7.7 kPa), and a good degradation rate (8.3 %) within 7 days. Meanwhile, PUF-QCS2.0 % retains long-term antibacterial activity for 7 days and kills 97.3 % of S. aureus and 91.8 % of E. coli within 6 hours in antibacterial testing. Furthermore, PUF-QCS2.0 % demonstrates a positive hemostatic response in the rabbit nasal septum mucosa trauma model by reducing hemostatic time over 50.0 % and decreasing blood loss up to 76.1 % compared to the commercial PVA nasal packing sponge. Importantly, PUF-QCS also exhibits a significant antibacterial activity in nasal cavity. This nasal packing material has advantages in post-surgery bleeding control and infection prevention. STATEMENT OF SIGNIFICANCE: The performance of a nasal packing sponge requires good mechanical properties, fast and high liquid absorption rate, effective degradability and strong antibacterial activity. These features are helpful for improving the postoperative recovery and patient healing. However, integrating these into a single polyurethane foam is a challenge. In this study, quaternized chitosan (QCS) is synthesized and used as a chain extender and antibacterial agent in preparing a degradable polyurethane foam (PUF-QCS) dressing. PUF-QCS undergoes partial degradation and exhibits effective broad-spectrum antibacterial activity in 7 days. The reduction of postoperative bleeding and infection observed in the animal experiment further demonstrates that the PUF-QCS developed here outperforms the existing commercial nasal packing materials.

Swift Covalent Gelation Coupled with Robust Wet Adhesive Powder: A Novel Approach for Acute Massive Hemorrhage Control in Dynamic and High-Pressure Wound Environments

The quest for efficient hemostatic agents in emergency medicine is critical, particularly for managing massive hemorrhages in dynamic and high-pressure wound environments. Traditional self-gelling powders, while beneficial due to their ease of application and rapid action, fall short in such challenging conditions. To bridge this gap, the research introduces a novel self-gelling powder that combines ultrafast covalent gelation and robust wet adhesion, presenting a significant advancement in acute hemorrhage control. This ternary system comprises ε-polylysine (ε-PLL) and 4-arm polyethylene glycol succinyl succinate (4-arm-PEG-NHS) forming the hydrogel framework. Na2HPO4 functions as the "H+ sucker" to expedite the amidation reaction, slashing gelation time to under 10 s, crucial for immediate blood loss restriction. Moreover, PEG chains' hydrophilicity facilitates efficient absorption of interfacial blood, increasing the generated hydrogel's cross-linking density and strengthens its tissue bonding, thereby resulting in excellent mechanical and wet adhesion properties. In vitro experiments reveal the optimized formulation's exceptional tissue compliance, procoagulant activity, biocompatibility and antibacterial efficacy. In porcine models of heart injuries and arterial punctures, it outperforms commercial hemostatic agent Celox, confirming its rapid and effective hemostasis. Conclusively, this study presents a transformative approach to hemostasis, offering a reliable and potent solution for the emergency management of massive hemorrhage.

Sprayable Zwitterionic Antibacterial Hydrogel With High Mechanical Resilience and Robust Adhesion for Joint Wound Treatment

Wound healing in movable parts, including the joints and neck, remains a critical challenge due to frequent motions and poor flexibility of dressings, which may lead to mismatching of mechanical properties and poor fitting between dressings and wounds; thus, increasing the risk of bacterial infection. This study proposes a sprayable zwitterionic antibacterial hydrogel with outstanding flexibility and desirable adhesion. This hydrogel precursor is fabricated by combining zwitterionic sulfobetaine methacrylate (SBMA) with poly(sulfobetaine methacrylate-co-dopamine methacrylamide)-modified silver nanoparticles (PSBDA@AgNPs) through robust electrostatic interactions. About 150 s of exposure to UV light, the SBMA monomer polymerizes to form PSB chains entangled with PSBDA@AgNPs, transformed into a stable and adhesion PSB-PSB@Ag hydrogel at the wound site. The resulting hydrogel has adhesive strength (15-38 kPa), large tensile strain (>400%), suitable shape adaptation, and excellent mechanical resilience. Moreover, the hydrogel displays pH-responsive behavior; the acidic microenvironment at the infected wound sites prompts the hydrogel to rapidly release AgNPs and kill bacteria. Further, the healing effect of the hydrogel is demonstrated on the rat neck skin wound, showing improved wound closing rate due to reduced inflammation and enhanced angiogenesis. Overall, the sprayable zwitterionic antibacterial hydrogel has significant potential to promote joint skin wound healing.

Cohering Plasma into Adhesive Gel by Natural Biopolymer-Nanoparticle Hybrid Powder for Efficient Hemostasis and Wound Healing

Hemostatic powder is commonly used in emergency bleeding control due to its suitability for irregularly shaped wounds, ease of use, and stable storage. However, traditional powder often has limited tissue adhesion and weak thrombus support, which makes it vulnerable to displacement by blood flow. Herein, we have developed a tricomponent hemostatic powder (MQS) composed of mesoporous bioactive glass nanoparticle (MBG), positively charged quaternized chitosan (QCS), and negatively charged catechol-modified alginate (SADA). Upon application to the wound, MBG with its high specific surface area quickly absorbs plasma, concentrating the blood coagulation factor. Simultaneously, the water-soluble QCS and SADA interact with each other and form a net, which can be further cross-linked by MBG. This network efficiently binds and entraps clustered blood coagulation factors, ultimately resulting in the formation of a durable and robust thrombus. Furthermore, the formed net adheres to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from the synergistic effect of these three components, MQS demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox in both arterial injuries and noncompressible liver puncture wounds. Furthermore, MQS can effectively accelerate wound healing. In addition, MQS exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of MQS, including strong blood clotting, wet tissue adherence, antibacterial activity, wound healing ability, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.

Metallic-Polyphenolic Nanoparticles Reinforced Cationic Guar Gum Hydrogel for Effectively Treating Burn Wound

The development of injectable hydrogel dressings which are long-term moisturizing, easy-to-apply, and effectively inhibiting infection and inflammatory is essential to promote burn wound repairing. Herein, an injectable hydrogel with moisturizing, antibacterial, and anti-inflammation abilities via multiple reversible interactions between cation guar gum (CG) and metallic-polyphenolic nanoparticles (PA-ZnII NPs) is developed. Specifically, PA-ZnII NPs is formed by synergistic complexation of protocatechualdehyde (PA) and zinc ion (Zn2+ ), provides CGPZ hydrogel with plentiful reversible interactions to inhibit the loss of moist. By interacting with PA-ZnII NPs, the CGPZ hydrogel can provide enhanced moisturization for more than 3 days. Moreover, the CGPZ hydrogel can maintain good adhesion for a period of time with injection and self-healing capabilities due to reversible interactions between CG and PA-ZnII NPs. In addition, CGPZ hydrogel exhibits outstanding broad spectrum antibacterial performance, as its killing efficiency against Escherichia coli and Staphylococcus aureus is all greater than 99.99%. Importantly, compared with commercial dressing, the CGPZ hydrogel can promote wound healing faster by inhibiting tissue damage from dysregulated inflammation and accelerating neovascularization. It is believed that the moisturizing CGPZ hydrogel with antibacterial and anti-inflammation performance can serve as a promising dressing for the effective treatment of burn wound.

Natural polymer-based bioadhesives as hemostatic platforms for wound healing

Medical adhesives are advanced but challenging alternatives to wound closure and repair, especially in mitigating uncontrolled hemorrhage. Ideal hemostatic adhesives need to meet good biocompatibility and biodegradability, adequate mechanical strength, and strong tissue adhesion functionality under wet and dynamic conditions. Considering these requirements, natural polymers such as polysaccharide, protein and DNA, attract great attention as candidates for making bioadhesives because of their distinctive physicochemical performances and biological properties. This review systematically summarizes the advances of bioadhesives based on natural polysaccharide, protein and DNA. Various physical and chemical cross-linking strategies have been introduced for adhesive synthesis and their hemostatic applications are introduced from the aspect of versatility. Furthermore, the possible challenges and future opportunities of bioadhesives are discussed, providing insights into the development of high-performance hemostatic materials.

Biomimetic Hemostatic Powder Derived from Coacervate-Immobilized Thermogelling Copolymers

Intrinsic hemostasis is an innate body response to prevent bleeding based on the sol-gel transition of blood. However, it is often inadequate for exceptional situations, such as acute injury and coagulation disorders, which typically require immediate medical intervention. Herein, we report the preparation of an efficient hemostatic powder, composed of tannic acid (TA), poly(ethylene glycol) (PEG), and poly(d,l-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(d,l-lactide-co-glycolide) triblock copolymer (TB), for biomimetic hemostasis at the bleeding sites. TA has a high affinity for biomolecules and cells and can form coacervates with PEG driven by hydrogen bonding. TB enhances the mechanical strength and provides thermoresponsiveness. The hemostatic powder can rapidly transit into a physical and biodegradable seal on wet substrates under physiological conditions, demonstrating its promise for the generation of instant artificial clots. Importantly, this process is independent of the innate blood clotting process, which could benefit those with blood clotting disorders. This biomimetic hemostatic powder is an adaptive topical sealing agent for noncompressible and irregular wounds, which is promising for biomedical applications.

Gelatin Sponges with a Uniform Interoperable Pore Structure and Biodegradability for Liver Injury Hemostasis and Tissue Regeneration

Developing a hemostatic sponge that can effectively control bleeding from visceral injuries while guiding in situ tissue regeneration in incompressible wounds remains a challenge. Most of the existing hemostatic sponges degrade slowly, are relatively single-functioning, and cannot cope with complex environments. Herein, a biodegradable rapidly hemostatic sponge (GPZ) was created by dual-dynamic-bond cross-linking among Zn2+, protocatechualdehyde (PA)-containing catechol and aldehyde groups, and gelatin. GPZ had a uniformly distributed interconnected pore structure with excellent fluid absorption. It could effectively absorb the oozing blood and increase the blood concentration while stimulating platelet activation and accelerating blood coagulation. Compared to commercial hemostats, GPZ treatment significantly accelerated hemostasis in the rat liver defect model (∼0.33 min, ≥50% reduction in the hemostatic time) and in the rabbit liver defect model (∼1.02 min, ≥60% reduction in the hemostatic time). Additionally, GPZ had excellent antibacterial and antioxidant properties that effectively protected the wound from infection and excessive inflammation. In the liver regeneration model, GPZ significantly increased the rate of hepatic tissue repair and promoted rapid functional recovery without complications and adverse reactions. Overall, we designed a simple and effective biodegradable rapid hemostatic sponge with good clinical translational potential for treating lethal incompressible bleeding and promoting wound healing.

Biologically Derived Nanoarchitectonic Coatings for the Engineering of Hemostatic Needles

Bleeding after venipuncture could cause blood loss, hematoma, bruising, hemorrhagic shock, and even death. Herein, a hemostatic needle with antibacterial property is developed via coating of biologically derived carboxymethyl chitosan (CMCS) and Cirsium setosum extract (CsE). The rapid transition from films of the coatings to hydrogels under a wet environment provides an opportunity to detach the coatings from needles and subsequently seal the punctured site. The hydrogels do not significantly influence the healing process of the puncture site. After hemostasis, the coatings on hemostatic needles degrade in 72 h without inducing a systemic immune response. The composition of CMCS can inhibit bacteria of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus by destroying the membrane of bacteria. The hemostatic needle with good hemostasis efficacy, antibacterial property, and safety is promising for the prevention of bleeding-associated complications in practical applications.