Application and outlook of topical hemostatic materials: a narrative review

Recent progress in polysaccharide microsphere-based hemostatic material for intravascular and extravascular hemostasis: A review

Hemorrhage, a common consequence of diseases, surgical procedures, and traffic accidents, poses a significant threat to public health. Effective hemostasis is crucial for patient survival and prognosis, particular in case of internal bleeding. While polysaccharide microsphere-based hemostatic materials have gained clinical acceptance due to their effectiveness, good biocompatibility, and versatility in both intravascular and extravascular hemostasis, they are limited by their single function and insufficient hemostatic properties. Recently, booming developments have been witnessed in microsphere-based biomaterials to achieve a combination therapy for hemostasis. This review first examines the fundamentals of coagulation process, hemostatic mechanisms, and microsphere fabrication techniques. We then discuss the latest investigations in functionalized microsphere-based hemostatic materials for controlling intravascular and extravascular hemorrhage, focusing on design strategies, hemostatic properties, and clinical implementation. Finally, we also propose some limitations and challenges of these hemostatic materials, aiming to provide valuable insights for future research in novel polysaccharide microsphere-based biomaterial.

Development of self-gelling powder combining chitosan/ bentonite nanoclay/ sodium polyacrylate for rapid hemostasis: In vitro and in vivo study

Although hemostatic powders are commonly used in clinical and emergency settings, they frequently show poor absorption, raise cytotoxicity issues, and are not effective for fatal non-compressible bleeding. The purpose of this research is to create a self-gelling hemostatic powder based on chitosan, bentonite, and sodium polyacrylate (CBS) to improve the hemostatic effect. When liquid comes into contact with CBS powders, they can fuse and form a stable hydrogel in less than 30s. Here, the concentration of the superabsorbent polymer is the primary determinant of the self-gel's creation. CBS groups exhibited excellent in vitro biocompatibility and hemocompatibility. In terms of bleeding and hemostatic time, the in vivo hemostatic results demonstrate the superiority of CBS-3 powder (∼57 s in rat liver avulsion model) and (∼64 s in rat tail amputation model) over a commercial product group called ARISTA. Additionally, the fabricated CBS powders can quickly absorb large amounts of blood, which can also aggregate platelets and blood cells. After four weeks of rat liver implantation, CBS-3 significantly accelerated the angiogenesis and wound healing processes. Thus, the hemostatic CBS self-gelling powder could be an effective solution for treating blood loss and liver wounds.

Comparative analyses of the hemostatic efficacy and surgical device performance of powdered oxidized regenerated cellulose and starch-based powder formulations

Background

Hemostatic powders offer unique therapeutic advantages over other formulations, including ease of application and rapid distribution over large bleeding surfaces. The efficacy of powder-based hemostats is dependent on device performance, which is rarely investigated independently from efficacy.

Objectives

The current study aimed to compare the hemostatic efficacy of an oxidized regenerated cellulose agent (Surgicel, Ethicon, Inc) and 3 starch-based biopolymers (Arista, Becton Dickinson; PerClot, Baxter International; and 4DryField, PlantTec Medical GmbH) and the performance of their delivery device applicators.

Methods

Efficacy was evaluated in a porcine model of bleeding using 2 study designs where the powder was delivered with (experiment 1) and without (experiment 2) device applicators. Device performance (powder expression) was examined in vitro at 3 device positions/angles: 90° (vertical, downward), 45° (slanted, downward), and 180° (horizontal).

Results

Surgicel efficacy rate was noninferior (P ≤ .0002) and superior (P ≤ .004) to that of any of the 3 starch-based agents regardless of whether the powder was delivered with their devices (experiment 1) or directly applied onto the bleeding sites (experiment 2). Surgicel required fewer applications (P ≤ .0002) and less powder (P < .0001) to achieve hemostasis. The Surgicel device was the only one that consistently delivered precise amounts of powder over a critical range of applications in the 3 positions tested.

Conclusion

The oxidized regenerated cellulose powder was the most efficacious hemostat, and the Surgicel applicator exhibited the highest performance compared with any of the 3 starch-based devices investigated. The current study highlights the relevance of combining high-efficacy powder hemostats with innovative, high-performance applicators to effectively manage bleeding control in surgical settings.

Self-expanding cellulose sponge with enhanced hemostatic ability by tannic acid/metal ion composite coating for highly effective hemostasis of difficult-to-control bleeding wounds

Refractory bleeding presents a critical, life-threatening challenge, and the goal of medical professionals and researchers has always been to achieve safe and effective hemostasis for bleeding wounds. In this study, we utilized the benefits of a self-expanding cellulose sponge to control incompressible bleeding, which is achieved this by creating a tannic acid/metal ion coating on the surface and within the pores of the sponge to improve its hemostatic effectiveness. The effects of various types and concentrations of metal ions (calcium, magnesium, iron, and zinc) on hemostatic efficiency and biosafety is systematically investigated. The results from bacteriostasis and in vitro coagulation experiments identified 0.3 wt% Fe3+ as the optimal metal ion coating. Scanning electron microscope energy spectrum analysis confirmed the uniform distribution of Fe3+ within the cellulose sponge. Furthermore, the in vivo and in vitro results demonstrated that the prepared tannic acid/Fe3+ coated composite hemostatic sponge exhibits excellent coagulation ability and biocompatibility. Both the bleeding time and theblood loss in two bleeding models are significantly reduced, showing promising potential for treating extensive surface bleeding and deep penetrating wounds. Furthermore, the straightforward preparation method for this composite hemostatic sponge facilitates additional research towards market application.

A Study of Safety and Effectiveness of Evicel Fibrin Sealant as an Adjunctive Hemostat in Pediatric Surgery

INTRODUCTION

 Data on the use of fibrin sealants to control intraoperative bleeding in children are scarce. Evicel Fibrin Sealant (Ethicon Inc., Raritan, New Jersey, United States) was found safe and effective in clinical trials of adults undergoing various surgery types. We evaluated the safety and efficacy of Evicel versus Surgicel Absorbable Hemostat (Ethicon Inc.) as adjunctive topical hemostats for mild/moderate raw-surface bleeding in pediatric surgery.

METHODS

 A phase III randomized clinical trial was designed as required by the European Medicines Agency's Evicel Pediatric Investigation Plan: 40 pediatric subjects undergoing abdominal, retroperitoneal, pelvic, or thoracic surgery were randomized to Evicel or Surgicel, to treat intraoperative mild-to-moderate bleeding. Descriptive analyses included time-to-hemostasis and rates of treatment success (4, 7, 10 minutes), intraoperative treatment failure, rebleeding, and thromboembolic events.

RESULTS

 Forty of 130 screened subjects aged 0.9 to 17 years were randomized 1:1 to Evicel or Surgicel. Surgeries were predominantly open abdominal procedures. The median bleeding area was 4.0 cm2 for Evicel and 1.0 cm2 for Surgicel. The median time-to-hemostasis was 4.0 minutes for both groups. The 4-, 7-, and 10-minute treatment success rates were 80.0% versus 65.0%, 100.0% versus 80.0%, and 95.0% versus 90.0%, whereas treatment failure rates were 5.0% versus 25.0%, for Evicel and Surgicel, respectively. No deaths or thrombotic events occurred. Re-bleeding occurred in 5.0% of Evicel and 10.0% of Surgicel subjects.

CONCLUSIONS

 In accordance with adult clinical trials, this randomized study supports the safety and efficacy of Evicel for controlling mild-to-moderate surgical bleeding in a broad range of pediatric surgical procedures.

Comparison of gauze packing, sponge-based, and hemostatic surgicel wound stasis dressings to treat hemorrhages from grade IV liver injuries: An experimental study

Background

Uncontrolled bleeding is still the major factor leading to preventable deaths following trauma. This study sought to assess the effectiveness of mini sponge-based wound stasis, cellulose-based local hemostatic, and traditional gauze dressings for the control of hemorrhages resulting from grade 4 liver injuries in rats.

Methods

Thirty Sprague-Dawley rats were divided into three equal groups. In the first group, a liver laceration was treated with gauze packing. The second group received XStat minisponge dressing (MDS), and the third group was administered a combination of MDS dressing and Surgicel hemostatic agent. After gaining access to the intra-abdominal cavity, a liver laceration measuring 10 mm in length, 5 mm in depth, and extending to the middle lobe was created. The dressings were removed after 2 and 10 min to assess the amount of bleeding, and any bleeding was documented again after 48 h. Intraperitoneal adhesions were evaluated during euthanasia.

Results

At 2 min post-injury, the gauze packing group had an average bleeding volume of 0.97 ± 0.15 mL, compared to 1.08 ± 0.25 mL in the MDS group (P = 0.26) and 1.02 ± 0.18 mL in the MDS + Surgicel group (P = 0.69). At 10 min, the bleeding volumes were 0.13 ± 0.05 mL, 0.22 ± 0.01 mL (P = 0.09), and 0.14 ± 0.05 mL (P = 0.19), respectively. At 48 h, significant differences were observed in bleeding volumes (gauze: 0.55 ± 0.18 mL, MDS: 1.15 ± 0.21 mL, MDS + Surgicel: 0.82 ± 0.06 mL, P < 0.001). Mortality rates after 14 days were 0 % in the gauze packing group, 60 % in the MDS group (P = 0.001), and 60 % in the MDS + Surgicel group (P = 0.001). The gauze packing group displayed no adhesions, while the other groups exhibited adhesions in the liver, bowel, omentum, and abdominal wall.

Conclusion

Our results indicate that, when it comes to managing bleeding in severe liver injuries, traditional gauze packing remains the tried-and-true method, showing superior effectiveness in terms of blood loss and mortality when compared to XStat minisponge dressings and the fibrillar Surgicel hemostatic agents.

Epidermal growth factor-incorporated hydrogen bond crosslinked hemostatic microparticles capable of timely response to accidental bleeding for prehospital rescue

Prehospital rescue of accidental massive bleeding is crucial for saving lives. However, currently available hemostatic materials are still in infancy in treating accidental bleeding due to the challenges in fully satisfying the complex outdoor hemostatic requirements. Herein, we designed an epidermal growth factor (EGF)- incorporated, microparticle-formed, high-strength, dynamic environment-stable hemostatic gel system for prehospital rescue. Carboxyl and dimethylamide were employed as the hydrogen bond (H-bond) groups and were carefully engineered into the microparticles (DHMs). We demonstrated that the unique H-bond crosslinked micronized structure enabled the DHM-based gelling system to adequately meet the outdoor hemostatic requirements. The stable H-bond groups allow the DHMs to be stored at room temperature and be easily carried around. The small sizes (150-250 μm) of the DHMs enabled the filling of irregular defects, and upon encountering water, these DHMs integrated into hydrogels (DHMs-gels) with high mechanical strength (1.61 MPa), strong tissue adhesiveness (66.5 kPa) and stable performance under dynamic environments. In vivo results showed that the EGF-incorporated DHMs-gels (DHMs-EGF gel) achieved a 100 % survival rate in a simulated rescue process and promoted wound healing. Simultaneously possessing multiple prehospital rescue-required properties, the hemostatic DHMs-EGF may become an effective tool for emergency rescue.

Local and Systemic Hemostatic Agents: A Comprehensive Review

Traumatic hemorrhage is the leading preventable cause of death worldwide. Systemic administration of hemostatic agents requires trained personnel and preparation, limiting their use in combat environments and prehospital settings. However, local administration of hemostatic agents may ameliorate these challenges. Currently available hemostatic products are limited by risk of infection, immunogenicity, tissue damage, limited usage and efficacy, high costs, short shelf life, and storage requirements under specific conditions. Future studies should be considered to overcome these limitations and develop effective, multifunctional hemostatic materials for widespread usage. In this review, we will provide an overview of the most commonly used systemic and local hemostatic agents in hemorrhage control.

Platelet-Rich Plasma-Embedded Porous Polycaprolactone Film with a Large Surface Area for Effective Hemostasis

BACKGROUND

Uncontrollable and widespread bleeding caused by surgery or sudden accidents can lead to death if not treated with appropriate hemostasis. To prevent excessive life-threatening bleeding, various hemostatic agents based on polymeric biomaterials with various additives for accelerated blood coagulation have been adopted in clinical fields. In particular, platelet-rich plasma (PRP), which contains many blood coagulation factors that can accelerate blood clot formation, is considered as one of the most effective hemostatic additives.

METHODS

We investigated a PRP-embedded porous film using discarded (expired) PRP and a film with a leaf-stacked structure (FLSS), as a hemostatic agent to induce rapid hemostasis. The film, which contained an LSS on one side (PCL-FLSS), was fabricated by a simple heating-cooling technique using tetraglycol and polycaprolactone (PCL) film. Activated PRP was obtained by the thawing of frozen PRP at the end of its expiration date (the platelet cell membrane is disrupted during the freezing and thawing of PRP, thus releasing various coagulation factors) and embedded in the PCL-FLSS (PRP-FLSS).

RESULTS

From in vitro and in vivo experiments using a rat hepatic bleeding model, it was recognized that PRP-FLSS is not only biocompatible but also significantly accelerates blood clotting and thus prevents rapid bleeding, probably due to a synergistic effect of the sufficient supply of various blood coagulants from activated PRP embedded in the LSS layer and the large surface area of the LSS itself.

CONCLUSION

The study suggests that PRP-FLSS, a combination of a porous polymer matrix with a unique morphology and discarded biofunctional resources, can be an advanced hemostatic agent as well as an upcycling platform to avoid the waste of biofunctional resources.

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.

Amphiphilic Janus cotton gauze with enhanced moisture management and blood coagulation for rapid hemostasis and wound healing

Cotton gauze is commonly used in initial emergency care. However, its high hydrophilicity and limited clotting capacity can lead to the excessive absorption of blood, resulting in unnecessary blood loss. Herein, an amphiphilic Janus cotton gauze with excellent moisture management and enhanced blood coagulation has been developed via in situ generating bioactive glass (BG) onto the cotton gauze (CG), and then attaching cardanol (CA) onto one side of the BG-loaded CG (CG@BG) via click reaction. The Janus gauze (CA-CG@BG) has asymmetric wetting properties with a hydrophilic side (CA-CG@BGHL) and a hydrophobic side (HBCA-CG@BG). When applied to hemostatic, the porous and active BG on CA-CG@BGHL can rapidly initiate coagulation cascade to form a robust thrombus. CA on HBCA-CG@BG can entangled with each other, creating a hydrophobic barrier that prevents blood from flowing out. The hemostatic performance of CA-CG@BG is superior to that of CG in both rats and pigs. Interestingly, CA-CG@BG possesses unidirectional exudate removal. When applied to wound healing, the exudate can penetrate the hydrophobic HBCA-CG@BG to the hydrophilic CA-CG@BGHL, resulting in faster wound healing than CG. CA-CG@BG exhibits excellent cytocompatibility and hemocompatibility. This unique Janus dressing shows promise as a potential material for clinical applications in the future.

Electrospun Polymeric Fiber Systems Inoculated with Cyanoacrylate Tissue Adhesive: A Novel Hemostatic Alternative during Open Surgery

Natural-based and synthetic tissue adhesives have attracted extensive attention in the last two decades for their ability to stabilize uncontrolled bleeding instances. However; these materials present several drawbacks during use that scientists have tried to minimize in order to optimize their usage. This study comprises the development of a novel wound dressing, combining the excellent properties of polylactic acid (PLA) non-woven textile, as substrate, obtained through electrospinning, and a cyanoacrylate-based (CA) tissue adhesive, for rapid hemostatic action. Thus, the fabrication of electrospun PLA membranes at three different PLA concentrations, the design and manufacturing of the support system and the production of surgical patches were carried out. SEM and FT-IR methods were employed for analyzing the morphology as well as the indicative markers for the shelf life evolution of the obtained patches. PLA fibers with well-defined structures and a mean diameter varying between 4.6 and 7.24 μm were obtained with the increase of the concentration of the PLA solutions. In vivo tests on a rat model as well as peeling tests for good patch adhesion on liver fragments harvested from the test animals, with a limit for the strength of the liver tissue of 1.5 N, were carried out. The devices exhibited excellent adhesion to the parenchymal tissue and a long enough shelf life to be used with success in surgical procedures, also facilitating prompt hemostatic action.

An Injectable Hydrogel with Ultrahigh Burst Pressure and Innate Antibacterial Activity for Emergency Hemostasis and Wound Repair

Uncontrolled bleeding and wound infections following severe trauma pose significant challenges for existing tissue adhesives, primarily due to their weak wet adhesion, slow adhesion formation, cytotoxicity concerns, and lack of antibacterial properties. Herein, an injectable hydrogel (denoted as ES gel) with rapid, robust adhesive sealing and inherent antibacterial activity based on ε-polylysine and a poly(ethylene glycol) derivative is developed. The engineered hydrogel exhibits rapid gelation behavior, high mechanical strength, strong adhesion to various tissues, and can sustain an ultrahigh burst pressure of 450 mmHg. It also presents excellent biocompatibility, biodegradability, antibacterial properties, and on-demand removability. Significantly improved hemostatic efficacy of ES gel compared to fibrin glue is demonstrated using various injury models in rats and rabbits. Remarkably, the adhesive hydrogel can effectively halt lethal non-compressible hemorrhages in visceral organs (liver, spleen, and heart) and femoral artery injury models in fully anticoagulated pigs. Furthermore, the hydrogel outperforms commercial products in sutureless wound closure and repair in the rat liver defect, skin incision, and infected full-thickness skin wound models. Overall, this study highlights the promising clinical applications of ES gel for managing uncontrolled hemorrhage, sutureless wound closure, and infected wound repair.

Alginate based hemostatic materials for bleeding management: A review

Severe bleeding has caused significant financial losses as well as a major risk to the lives and health of military and civilian populations. Under some situations, the natural coagulation mechanism of the body is unable to achieve fast hemostasis without the use of hemostatic drugs. Thus, the development of hemostatic materials and techniques is essential. Improving the quality of life and survival rate of patients and minimizing bodily damage requires fast, efficient hemostasis and prevention of bleeding. Alginate is regarded as an outstanding hemostatic polymer because of its non-immunogenicity, biodegradability, good biocompatibility, simple gelation, non-toxicity, and easy availability. This review summarizes the basics of hemostasis and emphasizes the recent developments regarding alginate-based hemostatic systems. Structural modifications and mixing with other materials have widely been used for the improvement of hemostatic characteristics of alginate and for making multifunctional medical devices that not only prevent uncontrolled bleeding but also have antibacterial characteristics, drug delivery abilities, and curing effects. This review is hoped to prepare critical insights into alginate modifications for better hemostatic properties.

Development of Polyphosphate/Nanokaolin-Modified Alginate Sponge by Gas-Foaming and Plasma Glow Discharge Methods for Ultrarapid Hemostasis in Noncompressible Bleeding

Effective bleeding management strategies in uncontrollable and noncompressible massive hemorrhage are becoming important in both clinical and combat situations. Here, a novel approach was developed to create a superporous and highly absorbable hemostatic sponge through a facile chemical gas-foaming method by cross-linking long-chain polyphosphate along with nanokaolin and Ca2+ in an alginate structure to synergistically activate the coagulation pathway. Natural kaolin obtained from the Marand mine in East Azarbaijan was converted into pseudohexagonal-shaped kaolin nanoparticles (30 to 150 nm) using ball milling followed by a newly developed glow discharge plasma treatment method. The obtained ultralight sponges (>90% porosity) exhibit ultrarapid water/blood absorption capacity (∼4000%) and excellent shape memory, which effectively concentrates coagulation factors. The results of in vitro tests demonstrated that the proposed sponges exhibited enhanced blood clotting ability (BCI < 10%) and superior cohesion with red blood cells (∼100) and platelets (∼80%) compared to commercially available hemostatic products. The in vivo host response results exhibited biosafety with no systemic and significant local inflammatory response by hematological, pathological, and biochemical parameter assessments. In a rat femoral artery complete excision model, the application of alginate/k/polyp nanocomposite sponges resulted in a complete hemostasis time of 60 s by significant reduction of hemostasis time (∼6.7-8.3 fold) and blood loss (∼2-2.8-fold) compared to commercially available hemostatic agents (P < 0.001). In conclusion, distinct physical characteristics accompanied by unique chemical composition multifunctional sponges activate hemostasis synergistically by triggering the XII, XI, X, IX, V, and II factors and the contact pathway and have the ability of rapid hemostasis in noncompressible severe bleeding.

Chitosan Hemostatic Dressings: Properties and Surgical Applications

Wounds caused by trauma and/or surgery represent a significant challenge in contemporary medical practice, requiring innovative approaches to promote optimal healing and reduce the risk of bleeding and complications resulting from it. In this context, chitosan, a natural polysaccharide derived from chitin, represents an ideal material for the study and application of medical devices, in the form of dressings, in wound management for pre- and/or post-operative wounds due to its ability to induce hemostasis and its high biocompatibility with biological tissues. The aim of this work was to discuss the structural characteristics, properties and application of chitosan-based hemostatic dressings in hemostatic processes resulting from pre- or post-surgical approaches.

Coagulant Protein-Free Blood Coagulation Using Catechol-Conjugated Adhesive Chitosan/Gelatin Double Layer

Since the discovery of polyphenolic underwater adhesion in marine mussels, researchers strive to emulate this natural phenomenon in the development of adhesive hemostatic materials. In this study, bio-inspired hemostatic materials that lead to pseudo-active blood coagulation, utilizing traditionally passive polymer matrices of chitosan and gelatin are developed. The two-layer configuration, consisting of a thin, blood-clotting catechol-conjugated chitosan (CHI-C) layer and a thick, barrier-functioning gelatin (Geln) ad-layer, maximizes hemostatic capability and usability. The unique combination of coagulant protein-free condition with CHI-C showcases not only coagulopathy-independent blood clotting properties (efficacy) but also exceptional clinical potential, meeting all necessary biocompatibility evaluation (safety) without inclusion of conventional coagulation triggering proteins such as thrombin or fibrinogen. As a result, the CHI-C/Geln is approved by the Ministry of Food and Drug Safety (MFDS, Republic of Korea) as a class II medical device. Hemostatic efficacy observed in multiple animal models further demonstrates the superiority of CHI-C/Geln sponges in achieving quick hemostasis compared to standard treatments. This study not only enriches the growing body of research on mussel-inspired materials but also emphasizes the potential of biomimicry in developing advanced medical materials, contributing a promising avenue toward development of readily accessible and affordable hemostatic materials.

Synthesis and characterization of thermosensitive 2-hydroxypropyl-trimethylammonium chitin and its antibacterial sponge for noncompressible hemostasis and tissue regeneration

Noncompressible hemorrhage is a leading cause of preventable death in battlefield/civilian trauma. The development of novel injectable and biodegradable hemostatic sponges, with rapid shape recovery and excellent antibacterial activity that can control hemorrhage in noncompressible bleeding sites and promote in situ tissue regeneration is still urgently needed. In this study, thermo/pH sensitive 2-hydroxypropyl-trimethylammonium chitins (QCHs) with low degree of quaternization substitution (DS: 0.07-0.23) and high degree of acetylation (DA: 0.91-0.94) were synthesized homogeneously for the first time. Their chemical compositions including DS and DA were characterized accurately by proton NMR for the first time. High strength QCH based sponges with good water/blood absorbency, rapid shape recovery and good antibacterial activity were prepared without using any crosslinkers but only due to their thermosensitive property, since they are soluble at low temperature but insoluble at high temperature. Compared with commercial products, the QCH sponges with cationic groups had the stronger pro-coagulant ability, better hemostatic effect in normal/heparinized liver perforation and femoral artery models in rats and porcine subclavian arteriovenous resection model. Moreover, the porous structure and biodegradability of the QCH sponges could promote in situ tissue regeneration. Overall, the QCH sponges show great clinical translational potential for noncompressible hemorrhage and tissue regeneration.

Multifunctional fish-skin collagen-based hydrogel sealant with dual-dynamic-bond cross-linked for rapid hemostasis and accelerated wound healing

Collagen (COL) is the most widespread functional protein. Designing and developing dual-dynamic-bond cross-linked COL adhesive hydrogel sealants with multifunctional is highly advantageous for achieving a superior wound closure effect and hemostasis. In this study, we developed hybrid hydrogels consisting of fish-skin COL, oxidized sodium alginate (OSA), borax and polyvinyl alcohol (PVA) to enhance full-thickness wound healing. The hydrogels were furnished with first-rate self-healing capabilities through the dual-dynamic-bond cross-linking of dynamic Schiff base bonds (COL-OSA) and diol boric acid bonds (OSA-borax) with reversible breakage and re-formation. Moreover, the incorporation of PVA stimulated the formation of hydrogen bonds in the system, bolstering the stability of the hydrogel framework. The prepared hydrogel manifests self-healing, injectability, multifunctional adhesiveness and biodegradability. In vivo assessment of the hemostatic capacity of COSP20 hydrogel was superior to gauze both in the mice liver injury model and mice tail amputation model. In addition, a full-thickness skin wound model in mice revealed that the COSP20 hydrogel facilitated faster wound closure by accelerating reepithelialization, COL deposition and angiogenesis. These findings illustrate the potential of hybrid fish-skin COL-based hydrogels to enhance wound healing and promote rapid tissue repair, and provide new possibilities for the effective utilization of marine fishery resources.

Protective Topical Dual-Sided Nanofibrous Hemostatic Dressing Using Mussel and Silk Proteins with Multifunctionality of Hemostasis and Anti-Bacterial Infiltration

Topical hemostatic agents are preferred for application to sensitive bleeding sites because of their immediate locoregional effects with less tissue damage. However, the majority of commercial hemostatic agents fail to provide stable tissue adhesion to bleeding wounds or act as physical barriers against contaminants. Hence, it has become necessary to investigate biologically favorable materials that can be applied and left within the body post-surgery. In this study, a dual-sided nanofibrous dressing for topical hemostasis is electrospun using a combination of two protein materials: bioengineered mussel adhesive protein (MAP) and silk fibroin (SF). The wound-adhesive inner layer is fabricated using dihydroxyphenylalanine (DOPA)-containing MAP, which promotes blood clotting by aggregation of hemocytes and activation of platelets. The anti-adhesive outer layer is composed of alcohol-treated hydrophobic SF, which has excellent spinnability and mechanical strength for fabrication. Because both proteins are fully biodegradable in vivo and biocompatible, the dressing would be suitable to be left in the body. Through in vivo evaluation using a rat liver damage model, significantly reduced clotting time and blood loss are confirmed, successfully demonstrating that the proposed dual-sided nanofibrous dressing has the right properties and characteristics as a topical hemostatic agent having dual functionality of hemostasis and physical protection.

Hemostatic Agents Do Not Significantly Affect Seroma Formation in Abdominal Body Contouring

BACKGROUND

Objective: Seroma formation is plaguing complication in abdominal body contouring surgery (ABCS) that has been loosely associated with the use of intraoperative hemostatic agents. The aim of this study was to investigate the association between hemostatic agent usage and seroma development following ABCS.

METHODS

A retrospective review of patients undergoing ABCS between 2010 and 2020 was completed. Cases who received hemostatic agents were matched to controls (1:2) based on potential confounders including age, BMI, and ASA score. Demographic data, operative details, and postoperative complications including development of seroma, hematoma, venous thromboembolism, wound dehiscence, and delayed wound healing were collected.

RESULTS

Seven hundred and seven patients were included in the study. Sixty-five patients (9.2%) received at least one hemostatic agent. The most used agents were topical thrombin (n = 33, 50.1%), dry matrices including oxidized cellulose, microporous polysaccharides, and absorbable gelatin matrices (n = 15, 23.1%) followed by combination fibrin sealant/thrombin preparations (n = 9, 14.0%). No significant differences with respect to demographic data or medical comorbidities between the cases and controls were identified. Bivariate analysis demonstrated no significant differences in the rate of development of seroma (OR: 0.83, 95% confidence interval [CI] = 0.23-1.99, p = 0.781), hematoma (OR: 3.72, 95% confidence interval [CI] = 0.95-14.65, p = 0.060), venous thromboembolism (OR: 0.40, 95% confidence interval [CI] = 0.44-3.81, p = 0.433).

CONCLUSION

Hemostatic agent use, regardless of type, does not significantly affect the risk of seroma, hematoma, and venous thromboembolism development, nor does it influence the rates of delayed wound healing or wound dehiscence.

LEVEL OF EVIDENCE III

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Recent Advances in Topical Hemostatic Materials

Untimely or improper treatment of traumatic bleeding may cause secondary injuries and even death. The traditional hemostatic modes can no longer meet requirements of coping with complicated bleeding emergencies. With scientific and technological advancements, a variety of topical hemostatic materials have been investigated involving inorganic, biological, polysaccharide, and carbon-based hemostatic materials. These materials have their respective merits and defects. In this work, the application and mechanism of the major hemostatic materials, especially some hemostatic nanomaterials with excellent adhesion, good biocompatibility, low toxicity, and high adsorption capacity, are summarized. In the future, it is the prospect to develop multifunctional hemostatic materials with hemostasis and antibacterial and anti-inflammatory properties for promoting wound healing.

Recent advances in the application of clay-containing hydrogels for hemostasis and wound healing

INTRODUCTION

Immediate control of bleeding and anti-infection play important roles in wound management. Multiple organ dysfunction syndrome and death may occur if persistent bleeding, hemodynamic instability, and hypoxemia are not addressed. The combination of clay and hydrogel provides a new outlet for wound hemostasis. In this review, the current research progress of hydrogel/clay composite hemostatic agents was reviewed.

AREAS COVERED

This paper summarizes the characteristics of several kinds of clay including kaolinite, montmorillonite, laponite, sepiolite, and palygorskite. The advantages and disadvantages of its application in hemostasis were also summarized. Future directions for the application of hydrogel/clay composite hemostatic agents are presented.

EXPERT OPINION

Clay can activate the endogenous hemostatic pathway by increasing blood cell concentration and promoting plasma absorption to accelerate the hemostasis. Clay is antimicrobial due to the slow release of metal ions and has a rich surface charge with a high affinity for proteins and cells to promote tissue repair. Hydrogels have some properties such as good biocompatibility, strong adhesion, high stretchability, and good self-healing. Despite promising advances, hydrogel/clay composite hemostasis remains a limitation. Therefore, more evidence is needed to further elucidate the risk factors and therapeutic effects of hydrogel/clay in hemostasis and wound healing.

Recent advances of chitosan as a hemostatic material: Hemostatic mechanism, material design and prospective application

Uncontrolled hemorrhage arising from surgery or trauma may cause morbidity and even mortality. Therefore, facilitating control of severe bleeding is imperative for health care worldwide. Among diverse hemostatic materials, chitosan (CS) is becoming the most promising material owing to its non-toxic feature, as well as inherently hemostatic performance. However, further enhancing hemostatic property of CS-based materials without compromising more beneficial functions remains a challenge. In this review, representative hemostatic mechanisms of CS-based materials are firstly discussed in detail, mostly including red blood cells (RBCs) aggregation, platelet adherence and aggregation, as well as interaction with plasma proteins. Also, various forms (involving powder/particle, sponge, hydrogel, nanofiber, and other forms) of CS-based hemostatic materials are systematically summarized, mainly focusing on their design and preparation, characteristics, and comparative analysis of various forms. In addition, varied hemostatic applications are described in detail, such as skin wound hemostasis, liver hemostasis, artery hemostasis, and heart hemostasis. Finally, current challenges and future directions of functional design of CS-based hemostatic materials in diverse hemostatic applications are proposed to inspire more intensive researches.

Preparation and application of hemostatic microspheres containing biological macromolecules and others

Bleeding from uncontrollable wounds can be fatal, and the body's clotting mechanisms are unable to control bleeding in a timely and effective manner in emergencies such as battlefields and traffic accidents. For irregular and inaccessible wounds, hemostatic materials are needed to intervene to stop bleeding. Hemostatic microspheres are promising for hemostasis, as their unique structural features can promote coagulation. There is a wide choice of materials for the preparation of microspheres, and the modification of natural macromolecular materials such as chitosan to enhance the hemostatic properties and make up for the deficiencies of synthetic macromolecular materials makes the hemostatic microspheres multifunctional and expands the application fields of hemostatic microspheres. Here, we focus on the hemostatic mechanism of different materials and the preparation methods of microspheres, and introduce the modification methods, related properties and applications (in cancer therapy) for the structural characteristics of hemostatic microspheres. Finally, we discuss the future trends of hemostatic microspheres and research opportunities for developing the next generation of hemostatic microsphere materials.

An architecturally rational hemostat for rapid stopping of massive bleeding on anticoagulation therapy

Hemostatic devices are critical for managing emergent severe bleeding. With the increased use of anticoagulant therapy, there is a need for next-generation hemostats. We rationalized that a hemostat with an architecture designed to increase contact with blood, and engineered from a material that activates a distinct and undrugged coagulation pathway can address the emerging need. Inspired by lung alveolar architecture, here, we describe the engineering of a next-generation single-phase chitosan hemostat with a tortuous spherical microporous design that enables rapid blood absorption and concentrated platelets and fibrin microthrombi in localized regions, a phenomenon less observed with other classical hemostats without structural optimization. The interaction between blood components and the porous hemostat was further amplified based on the charged surface of chitosan. Contrary to the dogma that chitosan does not directly affect physiological clotting mechanism, the hemostat induced coagulation via a direct activation of platelet Toll-like receptor 2. Our engineered porous hemostat effectively stopped the bleeding from murine liver wounds, swine liver and carotid artery injuries, and the human radial artery puncture site within a few minutes with significantly reduced blood loss, even under the anticoagulant treatment. The integration of engineering design principles with an understanding of the molecular mechanisms can lead to hemostats with improved functions to address emerging medical needs.

Antibacterial and hemostatic chitin sponge directly constructed from Pleurotus Eryngii via top-down approach

Chitin, the second most abundant polysaccharide on earth, possesses unique characteristics, including biosafety, biodegradability, and procoagulant activity, making it an attractive material for hemostasis. However, the conventional bottom-up construction of chitin-based materials is intricate and time-consuming. In this study, we have developed a top-down strategy to prepare a 3D porous chitin-based hemostatic sponge with exceptional hemostatic properties and antibacterial activity, directly from the spongy Pleurotus eryngii. The top-down method involves deproteinization, in situ quaternization, and tannin acid crosslinking. The obtained sponge has an interconnected microporous structure with high porosity (89.7 ± 3.2 %), endowing it with high water absorption (2047 ± 105 %) and rapid water-triggered shape-memory behavior (< 2 s). The sponge exhibits superior blood coagulant activity and outperforms standard medical gauze, gelatin sponge, and chitosan sponge in both topical artery and non-compressive liver puncture wound. In addition, the sponge exhibited significant antibacterial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli. In summary, this study provides a straightforward and practical approach for constructing an antibacterial and hemostatic chitin sponge that could be a valuable option for treating bleeding wounds.

Neocapsular reconstruction for challenging partial nephrectomy: A feasibility study in a porcine model and recent clinical experience

OBJECTIVES

Multifocal renal masses and large central-endophytic tumors can be challenging for partial nephrectomy (PN) due to the paucity of capsule remaining after tumor removal. Our objective was to develop a neocapsule to provide tamponade and test its feasibility/safety in a porcine model.

METHODS

Eight live pigs (50-70 kg) underwent unclamped open right flank PN. Renal defects were 1 cm deep and had moderate ongoing venous bleeding. A 6 × 9 inch sheet of Nu-knit® was used for neocapsular reconstruction with Fibrillar™ packing to provide modest tamponade and preclude ongoing bleeding. Blood chemistry and hemoglobin (Hb) levels were drawn preoperatively and postoperative Days 3/5/8. On postoperative Day 8, euthanasia was performed, and both kidneys were inspected and analyzed for histologic changes.

RESULTS

PN defects ranged from 1 × 1 × 1 cm to 4 × 2 × 1 cm; four pigs had PN performed in both poles and four in one pole. Neocapsular reconstruction was successful (n = 8), with no perioperative complications. Median baseline Hb was 10.4 g/dL, and median Hb postoperative Days 3/5/8 were 10.0/10.8/10.6 g/dL, respectively. Median baseline serum creatinine (SCr) was 1.9 mg/dL, and median SCr postoperative Days 3/5/8 were 1.5/1.4/1.5 mg/dL, respectively. At sacrifice, no significant hematomas were observed. Other than adjacent to the PN site, there were no significant histologic changes in the parenchyma for operative kidneys versus controls. Based on our experience, we recently performed neocapsular reconstruction safely/effectively after extensive PN for multifocal tumors and for an allograft with difficult-to-manage subcapsular hematoma.

CONCLUSIONS

Neocapsular reconstruction after PN or capsular trauma appears feasible and safe and may be considered to reduce the risk of perioperative bleeding. However, further study will be needed to confirm the utility/efficacy of this approach.

Impact Assessment of Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) and Hemostatic Sponge on Vascular Anastomosis Regeneration in Rats

The proper regeneration of vessel anastomoses in microvascular surgery is crucial for surgical safety. Pituitary adenylate cyclase-activating polypeptide (PACAP) can aid healing by decreasing inflammation, apoptosis and oxidative stress. In addition to hematological and hemorheological tests, we examined the biomechanical and histological features of vascular anastomoses with or without PACAP addition and/or using a hemostatic sponge (HS). End-to-end anastomoses were established on the right femoral arteries of rats. On the 21st postoperative day, femoral arteries were surgically removed for evaluation of tensile strength and for histological and molecular biological examination. Effects of PACAP were also investigated in tissue culture in vitro to avoid the effects of PACAP degrading enzymes. Surgical trauma and PACAP absorption altered laboratory parameters; most notably, the erythrocyte deformability decreased. Arterial wall thickness showed a reduction in the presence of HS, which was compensated by PACAP in both the tunica media and adventitia in vivo. The administration of PACAP elevated these parameters in vitro. In conclusion, the application of the neuropeptide augmented elastin expression while HS reduced it, but no significant alterations were detected in collagen type I expression. Elasticity and tensile strength increased in the PACAP group, while it decreased in the HS decreased. Their combined use was beneficial for vascular regeneration.

Progress and future prospects of hemostatic materials based on nanostructured clay minerals

The occurrence of uncontrolled hemorrhage is a significant threat to human life and health. Although hemostatic materials have made remarkable advances in the biomaterials field, it remains a challenge to develop safe and effective hemostatic materials for global medical use. Natural clay minerals (CMs) have long been used as traditional inorganic hemostatic agents due to their good hemostatic capability, biocompatibility and easy availability. With the advancement of science, technology and ideology, CM-based hemostatic materials have undergone continuous innovations by integrating new inspirations with conventional concepts. This review systematically summarizes the hemostatic mechanisms of different natural CMs based on their nanostructures. Moreover, it also comprehensively reviews the latest research progress for CM-based hemostatic hybrid and nanocomposite materials, and discusses the challenges and developments in this field.

Influence of Lavender Essential Oil on the Physical and Antibacterial Properties of Chitosan Sponge for Hemostatic Applications

Uncontrollable bleeding continues to stand as the primary cause of fatalities globally following surgical procedures, traumatic incidents, disasters, and combat scenarios. The swift and efficient management of bleeding through the application of hemostatic agents has the potential to significantly reduce associated mortality rates. One significant drawback of currently available hemostatic products is their susceptibility to bacterial infections at the bleeding site. As this is a prevalent issue that can potentially delay or compromise the healing process, there is an urgent demand for hemostatic agents with antibacterial properties to enhance survival rates. To mitigate the risk of infection at the site of a lesion, we propose an alternative solution in the form of a chitosan-based sponge and antimicrobial agents such as silver nanoparticles (AgNPs) and lavender essential oil (LEO). The aim of this work is to provide a new type of hemostatic sponge with an antibacterial barrier against a wide range of Gram-positive and Gram-negative microorganisms: Staphylococcus epidermidis 2018 and Enterococcus faecalis VRE 2566 (Gram-positive strains) and Klebsiella pneumoniae ATCC 10031 and Escherichia coli ATCC 35218 (Gram-negative strains).

A Natural Self-Assembled Gel-Sponge with Hierarchical Porous Structure for Rapid Hemostasis and Antibacterial

Developing hemostatic agents with reliable biosafety and high efficiency has paramount clinical significance for saving lives. Herein, inspired from traditional Chinese medicine, a sponge (BC-S) with hierarchical porous structure is proposed for the treatment of bleeding. The BC-S is prepared by a simple self-assembly method employing Bletilla Striata polysaccharide and quaternary amine alkaloids (QA) from Bletilla Striata and Coptidis Rhizoma. The ideal cation donor encapsulated in the helical structure of BSP enlarges the inter-layer space of sponge by the action of electrostatic repulsion, forming wider channels which can accelerate the diversion speed of absorbed blood. Then, platelets and erythrocytes are trapped tightly in the reticular structure and extruded to deformation, activation. Subsequently, fibrin network forms and reinforces the internal multilayer mesh, blocks the outflow of blood. QA is released from the sponge skeleton mainly driven by a combination of surface erosion and potentially solution diffusion among pore to provide long-term antibacterial activity. Benefiting from the well-designed structure and the effective hemostatic mechanism, the BC-S displays more excellent hemostatic performance in different models in vivo and in vitro compared with typical gelatin hemostatic sponge. This work is expected to boost the development of emerging hemostatic agents.

An aminocaproic acid-grafted chitosan derivative with superior antibacterial and hemostatic properties for the prevention of secondary bleeding

Uncontrolled bleeding is one of the leading causes of human mortality. Existing hemostatic materials or techniques cannot meet the clinical requirements for safe and effective hemostasis. The development of novel hemostatic materials has always been of great interest. Chitosan hydrochloride (CSH), a derivative of chitin, is extensively used on wounds as an antibacterial and hemostatic agent. However, the formation of intra- or intermolecular hydrogen bonds between hydroxyl and amino groups limits its water solubility and dissolution rate and affects its effectiveness in promoting coagulation. Herein, we covalently grafted aminocaproic acid (AA) to the hydroxyl and amino groups of CSH via ester and amide bonds, respectively. The solubility of CSH in water (25 °C) was 11.39 ± 0.98 % (w/v), whereas the AA-grafted CSH (CSH-AA) reached 32.34 ± 1.23 % (w/v). Moreover, the dissolution rate of CSH-AA in water was 6.46 times higher than that of CSH. Subsequent studies proved that CSH-AA is non-toxic, biodegradable, and has superior antibacterial and hemostatic properties to CSH. Additionally, anti-plasmin activity can be exerted by the dissociated AA from the CSH-AA backbone, which can help to lessen secondary bleeding.

An All-In-One Transient Theranostic Platform for Intelligent Management of Hemorrhage

Developing theranostic devices to detect bleeding and effectively control hemorrhage in the prehospital setting is an unmet medical need. Herein, an all-in-one theranostic platform is presented, which is constructed by sandwiching silk fibroin (SF) between two silver nanowire (AgNW) based conductive electrodes to non-enzymatically diagnose local bleeding and stop the hemorrhage at the wound site. Taking advantage of the hemostatic property of natural SF, the device is composed of a shape-memory SF sponge, facilitating blood clotting, with ≈82% reduction in hemostatic time in vitro as compared with untreated blood. Furthermore, this sandwiched platform serves as a capacitive sensor that can detect bleeding and differentiate between blood and other body fluids (i.e., serum and water) via capacitance change. In addition, the AgNW electrode endows anti-infection efficiency against Escherichia coli and Staphylococcus aureus. Also, the device shows excellent biocompatibility and gradually biodegrades in vivo with no major local or systemic inflammatory responses. More importantly, the theranostic platform presents considerable hemostatic efficacy comparable with a commercial hemostat, Dengen, in rat liver bleeding models. The theranostic platform provides an unexplored strategy for the intelligent management of hemorrhage, with the potential to significantly improve patients' well-being through the integration of diagnostic and therapeutic capabilities.

Hemostasis Strategies and Recent Advances in Nanomaterials for Hemostasis

The development of materials that effectively stop bleeding and prevent wound adhesion is essential in both military and medical fields. However, traditional hemostasis methods, such as cautery, tourniquets, and gauze, have limitations. In recent years, new nanomaterials have gained popularity in medical and health fields due to their unique microstructural advantages. Compared to traditional materials, nanomaterials offer better adhesion, versatility, and improved bioavailability of traditional medicines. Nanomaterials also possess advantages such as a high degree and stability, self-degradation, fewer side effects, and improved wound healing, which make them ideal for the development of new hemostatic materials. Our review provides an overview of the currently used hemostatic strategies and materials, followed by a review of the cutting-edge nanomaterials for hemostasis, including nanoparticles and nanocomposite hydrogels. The paper also briefly describes the challenges faced by the application of nanomaterials for hemostasis and the prospects for their future development.

Chitosan-Based Biomaterials for Hemostatic Applications: A Review of Recent Advances

Hemorrhage is a detrimental event present in traumatic injury, surgery, and disorders of bleeding that can become life-threatening if not properly managed. Moreover, uncontrolled bleeding can complicate surgical interventions, altering the outcome of surgical procedures. Therefore, to reduce the risk of complications and decrease the risk of morbidity and mortality associated with hemorrhage, it is necessary to use an effective hemostatic agent that ensures the immediate control of bleeding. In recent years, there have been increasingly rapid advances in developing a novel generation of biomaterials with hemostatic properties. Nowadays, a wide array of topical hemostatic agents is available, including chitosan-based biomaterials that have shown outstanding properties such as antibacterial, antifungal, hemostatic, and analgesic activity in addition to their biocompatibility, biodegradability, and wound-healing effects. This review provides an analysis of chitosan-based hemostatic biomaterials and discusses the progress made in their performance, mechanism of action, efficacy, cost, and safety in recent years.

Development potential of extracellular matrix hydrogels as hemostatic materials

The entry of subcutaneous extracellular matrix proteins into the circulation is a key step in hemostasis initiation after vascular injury. However, in cases of severe trauma, extracellular matrix proteins are unable to cover the wound, making it difficult to effectively initiate hemostasis and resulting in a series of bleeding events. Acellular-treated extracellular matrix (ECM) hydrogels are widely used in regenerative medicine and can effectively promote tissue repair due to their high mimic nature and excellent biocompatibility. ECM hydrogels contain high concentrations of extracellular matrix proteins, including collagen, fibronectin, and laminin, which can simulate subcutaneous extracellular matrix components and participate in the hemostatic process. Therefore, it has unique advantages as a hemostatic material. This paper first reviewed the preparation, composition and structure of extracellular hydrogels, as well as their mechanical properties and safety, and then analyzed the hemostatic mechanism of the hydrogels to provide a reference for the application and research, and development of ECM hydrogels in the field of hemostasis.

Safety and Performance of Hemostatic Powders

Background

Hemorrhage, a sudden and severe leakage of blood due to the disruption of blood vessels, is one of the most common causes of death from injuries worldwide. Severe bleeding accounts for more than 35% of pre-hospital deaths and about 40% of deaths recorded within 24 hours of injury. One of the methods for achieving homeostasis is the use of hemostatic powders. This study compares the basic safety and performance of the most popular hemostatic powders.

Methods

Basic safety of commercially available products were evaluated using MTT, MEM elution assay, and endotoxin testing. The in vitro performance was evaluated using water absorption capacity, water absorption rate, and adhesion strength assays.

Results

4Seal, Starsil, and 4DryField extracts did not cause cytotoxicity in MTT and MEM elution assays. PerClot and SuperClot extracts demonstrated cytotoxic potential in MTT assay, while Arista extract was cytotoxic in both MEM elution and MTT assays. 4Seal has the lowest endotoxin contamination, followed by PerClot, 4DryField, SuperClot, Arista, and Starsil. 4Seal and Starsil showed significantly highest WAR among the tested samples, followed by 4DryField, Arista, PerClot, and SuperClot. Adhesion force is highest for 4Seal, followed by Starsil, PerClot, 4DryField Arista, and SuperClot.

Conclusion

4Seal is the most versatile in terms of safety and functional properties compared to 4DryField, Arista, PerClot, Starsil, and SuperClot.

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

Hemostatic powders provide an important treatment approach for time-sensitive hemorrhage control. Conventional hemostatic powders are challenged by the lack of tissue adhesiveness, insufficient hemostatic efficacy, limited infection control, and so forth. This study develops a hemostatic powder from tricomponent GTP coacervates consisting of gelatin, tannic acid (TA), and poly(vinyl alcohol) (PVA). The physical cross-linking by TA results in facile preparation, good storage stability, ease of application to wounds, and removal, which provide good potential for clinical translation. When rehydrated, the coacervate powders rapidly form a cohesive layer with interconnected microporous structure, competent flexibility, switchable wet adhesiveness, and antibacterial properties, which facilitate the hemostatic efficacy for treating irregular, noncompressible, or bacteria-infected wounds. Compared to commercial hemostats, GTP treatment results in significantly accelerated hemostasis in a liver puncture model (∼19 s, >30% reduction in the hemostatic time) and in a tail amputation model (∼38 s, >60% reduction in the hemostatic time). In the GTP coacervates, gelatin functioned as the biodegradable scaffold, while PVA introduced the flexible segments to enable shape-adaptability and interfacial interactions. Furthermore, TA contributed to the physical cross-linking, adhesiveness, and antibacterial performance of the coacervates. The study explores the tunability of GTP coacervate powders to enhance their hemostatic and wound healing performances.

Heavy metal stabilization remediation in polluted soils with stabilizing materials: a review

The remediation of soil contaminated by heavy metals has long been a concern of academics. This is due to the fact that heavy metals discharged into the environment as a result of natural and anthropogenic activities may have detrimental consequences for human health, the ecological environment, the economy, and society. Metal stabilization has received considerable attention and has shown to be a promising soil remediation option among the several techniques for the remediation of heavy metal-contaminated soils. This review discusses various stabilizing materials, including inorganic materials like clay minerals, phosphorus-containing materials, calcium silicon materials, metals, and metal oxides, as well as organic materials like manure, municipal solid waste, and biochar, for the remediation of heavy metal-contaminated soils. Through diverse remediation processes such as adsorption, complexation, precipitation, and redox reactions, these additives efficiently limit the biological effectiveness of heavy metals in soils. It should also be emphasized that the effectiveness of metal stabilization is influenced by soil pH, organic matter content, amendment type and dosage, heavy metal species and contamination level, and plant variety. Furthermore, a comprehensive overview of the methods for evaluating the effectiveness of heavy metal stabilization based on soil physicochemical properties, heavy metal morphology, and bioactivity has also been provided. At the same time, it is critical to assess the stability and timeliness of the heavy metals' long-term remedial effect. Finally, the priority should be on developing novel, efficient, environmentally friendly, and economically feasible stabilizing agents, as well as establishing a systematic assessment method and criteria for analyzing their long-term effects.

On the development of modular polyurethane-based bioelastomers for rapid hemostasis and wound healing

Massive hemorrhage may be detrimental to the patients, which necessitates the advent of new materials with high hemostatic efficiency and good biocompatibility. The objective of this research was to screen for the effect of the different types of bio-elastomers as hemostatic dressings. 3D loose nanofiber sponges were prepared; PU-TA/Gel showed promising potential. Polyurethane (PU) was synthesized and electrospun to afford porous sponges, which were crosslinked with glutaraldehyde (GA). FTIR and 1H-NMR evidenced the successful synthesis of PU. The prepared PU-TA/Gel sponge had the highest porosity and water absorption ratio. Besides, PU-TA/Gel sponges exhibited cytocompatibility, negligible hemolysis and the shortest clotting time. PU-TA/Gel sponge rapidly induced stable blood clots with shorter hemostasis time and less bleeding volume in a liver injury model in rats. Intriguingly, PU-TA/Gel sponges also induced good skin regeneration in a full-thickness excisional defect model as revealed by the histological analysis. These results showed that the PU-TA/Gel-based sponges may offer an alternative platform for hemostasis and wound healing.

Polysaccharides based rapid self-crosslinking and wet tissue adhesive hemostatic powders for effective hemostasis

Hemostatic powders with flexible shape are widely used for the noncompressible and inaccessible hemorrhage wounds. However, current hemostatic powders display poor wet tissue adhesion and fragile mechanical strength of the powder-supported blood clots, leading to compromised hemostasis efficacy. Herein, a bi-component of carboxymethyl chitosan (CMCS) and aldehyde-modified hyaluronic acid grafted with catechol groups (COHA) was designed. Upon absorption of blood, the bi-component powders (CMCS-COHA) spontaneously self-crosslinks into an adhesive hydrogel within 10 s, tightly adhering to wound tissue to form a pressure-resistant physical barrier. During gelation, the hydrogel matrix captures and locks the blood cells/platelets to generate a robust thrombus in the bleeding sites. Compared with traditional hemostatic powder Celox™, CMCS-COHA displays superior blood coagulation and hemostatic performance. More importantly, CMCS-COHA has inherent cytocompatibility and hemocompatibility. These prominent advantages in rapid and effective hemostasis, adaptability to fit irregulate defective wound, easy preservation, facile usage, and bio-safety, make CMCS-COHA a promising hemostatic in emergency situations.

Sustainable sepiolite-based composites for fast clotting and wound healing

Uncontrolled bleeding and bacterial coinfection are the major causes of death after an injury. Fast hemostatic capacity, good biocompatibility, and bacterial coinfection inhibition pose great challenges to hemostatic agent development. A prospective sepiolite/Ag nanoparticles (sepiolite@AgNPs) composite has been prepared by using natural clay sepiolite as template. A tail vein hemorrhage mouse model and a rabbit hemorrhage model were used to evaluate the hemostatic properties of the composite. The sepiolite@AgNPs composite can quickly absorb fluid to subsequently stop bleeding due to the natural fibrous crystal structure of sepiolite, and inhibit bacterial growth with the antibacterial ability of AgNPs. Compared with commercially-available zeolite material, the as-prepared composite exhibits competitive hemostatic properties without exothermic reaction in the rabbit model of femoral and carotid artery injury. The rapid hemostatic effect was due to the efficient absorption of erythrocyte and activation of the coagulation cascade factors and platelets. Besides, after heat-treatment, the composites can be recycled without significant reduction of hemostatic performance. Our results also prove that sepiolite@AgNPs nanocomposites can stimulate wound healing. The sustainability, lower-cost, higher bioavailability, and stronger hemostatic efficacy of sepiolite@AgNPs composite render these nanocomposites as more favorable hemostatic agents for hemostasis and wound healing.

Fabrication of a Chitosan-Based Wound Dressing Patch for Enhanced Antimicrobial, Hemostatic, and Wound Healing Application

Wounds are a serious life threat that occurs in daily life. The complex cascade of synchronized cellular and molecular phases in wound healing is impaired by different means, involving infection, neuropathic complexes, abnormal blood circulation, and cell proliferation at the wound region. Thus, to overcome these problems, a multifunctional wound dressing material is fabricated. In the current research work, we have fabricated a wound dressing polymeric patch, with poly(vinyl alcohol) (PVA) and chitosan (Cs) incorporated with a photocatalytic graphene nanocomposite (GO/TiO₂(V-N)) and curcumin by a gel casting method, that focuses on multiple stages of the healing process. The morphology, swelling, degradation, moisture vapor transmission rate (MVTR), porosity, light-induced antibacterial activity, hemolysis, blood clotting, blood abortion, light-induced biocompatibility, migration assay, and drug release were analyzed for the polymeric patches under in vitro conditions. PVA/Cs/GO/TiO₂(V-N)/Cur patches have shown enhanced wound healing in in vivo wound healing experiments on Wister rats. They show higher collagen deposition, thicker granulation tissue, and higher fibroblast density than conventional dressing. A histological study shows excellent re-epithelialization ability and dense collagen deposition. In vitro and in vivo analysis confirmed that PVA/Cs/GO/TiO₂(V-N) and PVA/Cs/GO/TiO₂(V-N)/Cur patches enhance the wound healing process.

Chitosan-Based Hemostatic Hydrogels: The Concept, Mechanism, Application, and Prospects

The design of new hemostatic materials to mitigate uncontrolled bleeding in emergencies is challenging. Chitosan-based hemostatic hydrogels have frequently been used for hemostasis due to their unique biocompatibility, tunable mechanical properties, injectability, and ease of handling. Moreover, chitosan (CS) absorbs red blood cells and activates platelets to promote hemostasis. Benefiting from these desired properties, the hemostatic application of CS hydrogels is attracting ever-increasing research attention. This paper reviews the recent research progress of CS-based hemostatic hydrogels and their advantageous characteristics compared to traditional hemostatic materials. The effects of the hemostatic mechanism, effects of deacetylation degree, relative molecular mass, and chemical modification on the hemostatic performance of CS hydrogels are summarized. Meanwhile, some typical applications of CS hydrogels are introduced to provide references for the preparation of efficient hemostatic hydrogels. Finally, the future perspectives of CS-based hemostatic hydrogels are presented.

A critical review on application of organic, inorganic and hybrid nanophotocatalytic assemblies for photocatalysis of methyl orange dye in aqueous medium

Methyl orange (MO) is a highly carcinogenic and harmful contaminant, which has been extensively reported for its detrimental impact on human and aquatic life. The photodegradation of MO into less toxic products has gained much attention over the past few decades. Herein we have reviewed the recent advancement in designing of nanomaterials (NMs) stabilized on different fabricating assemblies and their application in photocatalysis of MO dye. These photocatalytic systems possess various advantages and disadvantages. Graphene-based supported materials on different NMs are highly reported photocatalysts for photocatalysis of MO dye. Recent advancement, parameters affecting photocatalytic studies, kinetics and photocatalytic mechanism of MO have been thoroughly explained in this review. Future outcomes are also provided for extending the development of scientific research in this field.

Rapid hemostasis of the residual inguinal access sites during endovascular procedures: A case report

BACKGROUND

In endovascular procedures including total percutaneous endovascular aneurysm repair (pEVAR), percutaneous access through the common femoral artery is most commonly performed. Access-site bleeding is a major concern in percutaneous techniques. Herein, we present a case of successful control of continuous oozing using a vascular closure device (VCD) and the application of Surgicel (Johnson & Johnson, United States) over the access tract.

CASE SUMMARY

An 82-year-old man presented with an unruptured abdominal aortic aneurysm measuring 83 mm × 75 mm. The patient had a medical history of atrial fibrillation and was receiving rivaroxaban (15 mg/d). Routine pEVAR was performed using the preclose technique with ProGlide (Abbott, Santa Clara, CA, United States). Significant amount of bleeding was observed at the end of the procedure after the deployment of the closure device at the access site. A sheet of Surgicel was applied to the suture thread using a surgical needle. Surgicel was applied to the surface of the artery along the access tract using a pusher, and hemostasis was immediately attained.

CONCLUSION

This simple technique is an excellent adjunct to control residual bleeding from the access site following VCD use.