Polysaccharides composite materials for rapid hemostasis

Dual Functionalized Absorbable Hairy Cellulose-Based Fabric for Efficient Hemostasis and Antibacterial Property

Uncontrolled hemorrhage and subsequent infection at the injury sites are major causes of trauma-related mortality. Herein, we present a novel approach to creating a multifunctional biodegradable textile fabric with hemostatic and antibacterial properties, synthesized through chemical modification, including etherification, oxidation (aldehyde), and amination via a Schiff-based reaction between octadecyl ammonium and oxidized cellulose, followed by calcium ion cross-linking. The fabric demonstrated significant antibacterial efficay against both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, validated through assays such as colony counting, minimum inhibitory concentration (MIC), scanning electron microscopy, and fluorescent staining using Acridine Orange and Propidium Iodide. In vitro assessments demonstrated superior performance compared to commercial alternatives in red blood cell attachment (90%), blood clotting index (6%), platelet adhesion, and clotting time (20s) (P-value < 0.001). In vivo studies using a Wistar rat liver injury model confirmed the fabric's effectiveness, reducing bleeding time (3.1 and 6.2-fold) and blood loss (1.2 and 5.48-fold) compared to available commercial hemostatic agents. Pathological, hematological, and biochemical analyses demonstrated the biocompatibility and biodegradability of our developed material with no evidence of systemic toxicity, significant localized inflammatory reactions in the liver, renal, or skin tissues, or vascular thrombosis stimulation.

An Antibacterial, Antioxidant Adherent Sponge Constructed for Control of Arterial Bleeding Via Gallic Acid-Mediated Robust Assembly of Fibrous Clay in Collagen

Acute hemorrhage death on battlefields, during clinical surgeries, and in major accidents is a widespread worldwide problem. Clay-based hemostatic materials have received considerable attention for their low cost and reliable clotting activity, especially in cases of severe bleeding, such as QuikClot, which is a kaolin-based hemostatic gauze that is preferred for battlefield resuscitation. However, the easy detachment of clay particles and the associated risk of thrombosis have seriously hindered the development of clay-based hemostatic materials. Here, inexpensive palygorskite (Pal) nanoclay was integrated into the collagen (COL) matrix by loading Ca2+ in the clay and further using gallic acid (GA) to mediate the robust assembly of clay on the COL matrix. This targeted interfacial design is a simple and gentle method that effectively improves the dispersion of the Pal particles and reduces the risk of shedding. Unlike QuikClot where the aqueous solution was significantly turbid after 2 min of ultrasonic washing, the aqueous solution of the composite sponge (Ca-Pal-GA-COL) remained clear and was accompanied by 82.71% of the mass residue after 10 min of ultrasonic washing. The composite sponge also exhibited excellent antibacterial (87.93% inhibition rate of Escherichia coli), antioxidant, and tissue adhesion properties. Importantly, the Ca-Pal-GA-COL sponge exhibited less blood loss (632 mg) and a shorter hemostasis time (151 s) in a rat femoral artery hemorrhage model than the medical gauze (3850 mg and 299 s), pure COL sponge (1627 mg and 201 s), and Pal-COL sponge (1494 mg and 193 s) in a co-mingled mode, which are comparable to those of QuikClot (559 mg and 142 s). Furthermore, certain tissue adhesion properties render the Ca-Pal-GA-COL sponge more suitable than QuikClot for severe femoral artery active bleeding scenarios. Cellular experiments confirmed that the composite dressing has a certain biosafety.

Preparation and Biochemical Activity of Copper-Coated Cellulose Nonwoven Fabric via Magnetron Sputtering and Alginate-Calcium Ion Complexation

Alginate-based materials have gained significant recognition in the medical industry due to their favorable biochemical properties. As a continuation of our previous studies, we have introduced a new composite consisting of cellulose nonwoven fabric charged with a metallic copper core (CNW-Cu0) covered with a calcium alginate (ALG-Ca2+) layer. The preparation process for these materials involved three main steps: coating the cellulose nonwoven fabric with copper via magnetron sputtering (CNW → CNW-Cu0), subsequent deposition with sodium alginate (CNW-Cu0 → CNW-Cu0/ALG-Na+), followed by cross-linking the alginate chains with calcium ions (CNW-Cu0/ALG-Na+ → CNW-Cu0/ALG-Ca2+). The primary objective of the work was to supply these composites with such biological attributes as antibacterial and hemostatic activity. Namely, equipping the antibacterial materials (copper action on representative Gram-positive and Gram-negative bacteria and fungal strains) with induction of blood plasma clotting processes (activated partial thromboplastin time (aPTT) and prothrombin time (PT)). We determined the effect of CNW-Cu0/ALG-Ca2+ materials on the viability of Peripheral blood mononuclear (PBM) cells. Moreover, we studied the interactions of CNW-Cu0/ALG-Ca2+ materials with DNA using the relaxation plasmid assay. However, results showed CNW-Cu0/ALG-Ca2+'s cytotoxic properties against PBM cells in a time-dependent manner. Furthermore, the CNW-Cu0/ALG-Ca2+ composite exhibited the potential to interact directly with DNA. The results demonstrated that the CNW-Cu0/ALG-Ca2+ composites synthesized show promising potential for wound dressing applications.

Blood Coagulation Activities and Influence on DNA Condition of Alginate-Calcium Composites Prepared by Freeze-Drying Technique

The aim of this research was to synthesize and characterize alginate-calcium composites using a freeze-drying method, with a focus on their potential applications in biomedicine. This study specifically explored the biochemical properties of these composites, emphasizing their role in blood coagulation and their capacity to interact with DNA. Additionally, the research aimed to assess how the cross-linking process influences the structural and chemical characteristics of the composites. Detailed analyses, including microscopic examination, surface area assessment, and atomic absorption spectrometry, yielded significant results. The objective of this study was to examine the impact of calcium chloride concentration on the calcium content in alginate composites. Specifically, the study assessed how varying concentrations of the cross-linking solution (ranging from 0.5% to 2%) influence the calcium ion saturation within the composites. This investigation is essential for understanding the physicochemical properties of the materials, including calcium content, porosity, and specific surface area. The results are intended to identify the optimal cross-linking conditions that maximize calcium enrichment efficiency while preserving the material's structural integrity. The study found that higher calcium chloride concentrations in alginate cross-linking improve the formation of a porous structure, enhanced by two-stage freeze-drying. Increased calcium levels led to a larger surface area and pore volume, and significantly higher calcium content. Furthermore, assays of activated partial thromboplastin time (aPTT) showed a reduction in clotting time for alginate composites containing calcium ions, indicating their potential as hemostatic agents. The aPTT test showed shorter clotting times with higher calcium ion concentrations, without enhanced activation of the extrinsic clotting pathway. The developed alginate material with calcium effectively supports hemostasis and reduces the risk of infection. The study also explored the capacity of these composites to interact with and modify the structure of plasmid DNA, underscoring their potential for future biomedical applications.

A macromolecular cross-linked alginate aerogel with excellent concentrating effect for rapid hemostasis

Alginate-based materials present promising potential for emergency hemostasis due to their excellent properties, such as procoagulant capability, biocompatibility, low immunogenicity, and cost-effectiveness. However, the inherent deficiencies in water solubility and mechanical strength pose a threat to hemostatic efficiency. Here, we innovatively developed a macromolecular cross-linked alginate aerogel based on norbornene- and thiol-functionalized alginates through a combined thiol-ene cross-linking/freeze-drying process. The resulting aerogel features an interconnected macroporous structure with remarkable water-uptake capacity (approximately 9000 % in weight ratio), contributing to efficient blood absorption, while the enhanced mechanical strength of the aerogel ensures stability and durability during the hemostatic process. Comprehensive hemostasis-relevant assays demonstrated that the aerogel possessed outstanding coagulation capability, which is attributed to the synergistic impacts on concentrating effect, platelet enrichment, and intrinsic coagulation pathway. Upon application to in vivo uncontrolled hemorrhage models of tail amputation and hepatic injury, the aerogel demonstrated significantly superior performance compared to commercial alginate hemostatic agent, yielding reductions in clotting time and blood loss of up to 80 % and 85 %, respectively. Collectively, our work illustrated that the alginate porous aerogel overcomes the deficiencies of alginate materials while exhibiting exceptional performance in hemorrhage, rendering it an appealing candidate for rapid hemostasis.

Conductive Hyaluronic Acid/Deep Eutectic Solvent Composite Hydrogel as a Wound Dressing for Promoting Skin Burn Healing Under Electrical Stimulation

Burns can cause severe damage to the skin due to bacterial infection and severe inflammation. Although conductive hydrogels as electroactive burn-wound dressings achieve remarkable effects on accelerating wound healing, issues such as imbalance between their high conductivity and mechanical properties, easy dehydration, and low transparency must be addressed. Herein, a double-network conductive eutectogel is fabricated by integrating polymerizable deep eutectic solvents (PDESs)including acrylamide/choline chloride/glycerol (acrylamide-polymerization crosslink) and thiolated hyaluronic acid (disulfide-bonding crosslink). The introduction of PDESs provides the eutectogel with a conductivity (up to 0.25 S·m-1) and mechanical strength (tensile strain of 59-77%) simulating those of natural human skin, as well as satisfactory tissue adhesiveness, self-healing ability, and antibacterial properties. When combined with exogenous electrical stimulation, the conductive eutectogel exhibits the ability to reduce inflammation, stimulate cell proliferation and migration, promote collagen deposition and angiogenesis, and facilitate skin tissue remodeling. This conductive eutectogel shows great potential as a dressing for healing major burn wounds.

Ultrafast self-gelling, sprayable, and adhesive carboxymethyl chitosan/poly-γ-glutamic acid/oxidized dextran powder for effective gastric perforation hemostasis and wound healing

The rapid and effective hemostasis of gastrointestinal bleeding sites remains an urgent clinical challenge. In this study, an ultrafast self-gelling, sprayable, and adhesive carboxymethyl chitosan/poly-γ-glutamic acid/oxidized dextran (CPO) powder was designed for gastric perforation hemostasis and healing. When the CPO powder was sprayed to the gastric perforation site, the CPO powder absorbed water from the blood and concentrate blood cells and clotting factors to achieve the purpose of rapid hemostasis. During the hemostasis, the CPO powder formed a hydrogel in situ through the formation of amide bonds and Schiff base bonds within 15 s, forming a physical barrier to cover the wound surface. Concurrently, the aldehyde group (-CHO) of oxidized dextran formed additional Schiff base bonds with the amino group (-NH2) of the tissue, enabling the CPO powder with wound surface adhesion. Moreover, the CPO powder was shown to have excellent in vitro and in vivo antibacterial properties and it was able to promote the healing of infected wounds in a mouse model. In summary, CPO powder provides a promising idea for the rational design of gastrointestinal hemostatic agents.

Preparation and Hemostatic Effect of Micro-Nanograded Porous Particles Doped with Dopamine-Based Water-Triggered Intelligent Composite Adhesives

The wet environment of water or tissue in bleeding wounds poses significant challenges to the adhesion performance of existing hemostatic adhesives. An intelligent composite adhesive prepared by doping starch-based silicate micro-nanograded porous particles (MBC@CMS) with dopamine-hyperbranched polymers (HPD, 7800 Mw) synthesized by the Michael addition reaction could be triggered by water to form a glue (MBC@CMS-HPD). The results indicated that MBC@CMS-HPD could still have adhesion properties under running water washing and water immersion and could effectively seal the water outlet. The results of the glue-forming mechanism showed that MBC@CMS-HPD had better wettability than water, which could eliminate water molecules at the wet adhesive surface. When contacted with water, the agglomeration of the HPD hydrophobic chain increases the exposure of the catechol group, and the relative atomic mass of the N element on the surface increases from 2.8 to 4.8%. The adhesion of MBC@CMS-HPD was enhanced and stable. MBC@CMS-HPD showed significant hemostasis effects in five injury bleeding models of Sprague-Dawley (SD) rats and New Zealand rabbits. Especially in the fatal femoral artery bleeding model of New Zealand rabbits, MBC@CMS-HPD reduced the amount of bleeding by 75% and shortened the bleeding time by 78% compared with the a-cyanoacrylate adhesives. The results of the coagulation mechanism showed that compared with HPD, MBC@CMS-HPD could activate both endogenous and exogenous coagulation pathways. Among them, after contact with blood, HPD formed a gel to close the blood outlet, and MBC@CMS entered the wound to activate the internal and external coagulation pathways. In addition, HPD and MBC@CMS had good histocompatibility and degradability, which has the potential to be applied to different wounds.

Multifunctional Sodium Hyaluronate/Chitosan Foam Used as an Absorbable Hemostatic Material

Absorbable hemostatic materials have great potential in clinical hemostasis. However, their single coagulation mechanism, long degradation cycles, and limited functionality mean that they have restricted applications. Here, we prepared a sodium hyaluronate/carboxymethyl chitosan absorbable hemostatic foam (SHCF) by combining high-molecular-weight polysaccharide sodium hyaluronate with carboxymethyl chitosan via hydrogen bonding. SHCFs have rapid liquid absorption performance and can enrich blood cells. They transform into a gel when it they come into contact with blood, and are more easily degraded in this state. Meanwhile, SHCFs have multiple coagulation effects and promote hemostasis. In a rabbit liver bleeding model, SHCFs reduced the hemostatic time by 85% and blood loss by 80%. In three severe and complex bleeding models of porcine liver injury, uterine wall injury, and bone injury, bleeding was well-controlled and anti-tissue adhesion effects were observed. In addition, degradation metabolism studies show that SHCFs are 93% degraded within one day and almost completely metabolized within three weeks. The absorbable hemostatic foam developed in this study is multifunctional; with rapid hemostasis, anti-adhesion, and rapid degradation properties, it has great clinical potential for in vivo hemostasis.

Chitosan-based hemostatic sponges as new generation hemostatic materials for uncontrolled bleeding emergency: Modification, composition, and applications

The choice of hemostatic technique is a curial concern for surgery and as first-aid treatment in combat. To treat uncontrolled bleeding in complex wound environments, chitosan-based hemostatic sponges have attracted significant attention in recent years because of the excellent biocompatibility, degradability, hemostasis and antibacterial properties of chitosan and their unique sponge-like morphology for high fluid absorption rate and priority aggregation of blood cells/platelets to achieve rapid hemostasis. In this review, we provide a historical perspective on the use of chitosan hemostatic sponges as the new generation of hemostatic materials for uncontrolled bleeding emergencies in complex wounds. We summarize the modification of chitosan, review the current status of preparation protocols of chitosan sponges based on various composite systems, and highlight the recent achievements on the detailed breakdown of the existing chitosan sponges to present the relationship between their composition, physical properties, and hemostatic capacity. Finally, the future opportunities and challenges of chitosan hemostatic sponges are also proposed.

Biomass-derived ultrafast cross-linked hydrogels with double dynamic bonds for hemostasis and wound healing

Developing novel hemostatic materials with accelerating wound healing functions has raised widespread attention recently. To adapt to irregular and incompressible wounds, we fabricated a series of biomass-derived ultrafast cross-linked adhesive hydrogels with adjustable gelation time and injectable properties through Schiff-base and ionic coordinate bonds among catechol-conjugated gelatin (GelDA), dialdehyde cellulose nanocrystals (DACNCs), calcium ions (Ca²⁺) and ferric iron (Fe³⁺). The fast-gelling hydrogels possess adjustable gelation time and mechanical properties by altering the contents of DACNCs and Fe³⁺. With double-dynamic-bond crosslinking, the hydrogels are endowed with the desired self-healing and injectable performance compared to gelatin-based hydrogels without DACNCs. Additionally, the hydrogels present enhanced adhesiveness, NIR responsiveness and antibacterial activity with the introduction of catechol groups and the formation of catechol-Fe complexes. Both in vitro and in vivo hemostatic assays and degradation experiments confirm that the hydrogels achieve rapid hemostasis and display fantastic biodegradability. As demonstrated by a rat full-thickness skin defect model, the hydrogels with multifunctionality remarkably accelerate the regeneration of wound tissues. Thus, the ultrafast cross-linked hydrogels are potentially valuable as hemostatic materials for wound healing applications in the biomedical field.

Polysaccharide-based nanocomposites for biomedical applications: a critical review

Polysaccharides (PSA) have taken specific position among biomaterials for advanced applications in medicine. Nevertheless, poor mechanical properties are known as the main drawback of PSA, which highlights the need for PSA modification. Nanocomposites PSA (NPSA) are a class of biomaterials widely used as biomedical platforms, but despite their importance and worldwide use, they have not been reviewed. Herein, we critically reviewed the application of NPSA by categorizing them into generic and advanced application realms. First, the application of NPSA as drug and gene delivery systems, along with their role in the field as an antibacterial platform and hemostasis agent is discussed. Then, applications of NPSA for skin, bone, nerve, and cartilage tissue engineering are highlighted, followed by cell encapsulation and more critically cancer diagnosis and treatment potentials. In particular, three features of investigations are devoted to cancer therapy, i.e., radiotherapy, immunotherapy, and photothermal therapy, are comprehensively reviewed and discussed. Since this field is at an early stage of maturity, some other aspects such as bioimaging and biosensing are reviewed in order to give an idea of potential applications of NPSA for future developments, providing support for clinical applications. It is well-documented that using nanoparticles/nanomaterials above a critical concentration brings about concerns of toxicity; thus, their effect on cellular interactions would become critical. We compared nanoparticles used in the fabrication of NPSA in terms of toxicity mechanism to shed more light on future challenging aspects of NPSA development. Indeed, the neutralization mechanisms underlying the cytotoxicity of nanomaterials, which are expected to be induced by PSA introduction, should be taken into account for future investigations.

Recent Progress in Electrospun Polyacrylonitrile Nanofiber-Based Wound Dressing

Bleeding control plays a very important role in worldwide healthcare, which also promotes research and development of wound dressings. The wound healing process involves four stages of hemostasis, inflammation, proliferation and remodeling, which is a complex process, and wound dressings play a huge role in it. Electrospinning technology is simple to operate. Electrospun nanofibers have a high specific surface area, high porosity, high oxygen permeability, and excellent mechanical properties, which show great utilization value in the manufacture of wound dressings. As one of the most popular reactive and functional synthetic polymers, polyacrylonitrile (PAN) is frequently explored to create nanofibers for a wide variety of applications. In recent years, researchers have invested in the application of PAN nanofibers in wound dressings. Research on spun nanofibers is reviewed, and future development directions and prospects of electrospun PAN nanofibers for wound dressings are proposed.