Potential Hemostatic Agent Research Articles

Iron(III) Monoglycerolate as a New Biocompatible Precursor in the Synthesis of Bioactive Nanocomposite Glycerohydrogels.

Nanocomposite glycerohydrogels based on biocompatible elementcontaining glycerolates are of practicular interest for biomedical applications. Using two biocompatible precursors, silicon and iron glycerolates, a new bioactive nanocomposite silicon‒iron glycerolates hydrogel was obtained by sol-gel method. The composition and structural features of the hydrogel were studied using a complex of modern analytical techniques, including TEM, XRD, and AES. On the example of experimental animals hemostatic activity of the hydrogel was studied, as well as primary toxicological studies were carried out. The composition of dispersed phase and dispersion medium of silicon‒iron glycerolates hydrogel was determined. The structural features of hydrogel were revealed and its structure model was proposed. It was shown that silcon-iron glycerolates hydrogel is nontoxic, and exhibits pronounced hemostatic activity. Silicon-iron glycerolates hydrogel is a potential hemostatic agent for topical application in medical and veterinary practice.

Iron(III) Monoglycerolate: A Potential Hemostatic Agent for Topical Application

Background: Glycerolates of biogenic elements are of interest because of their pharmacological activity. Some of them are used as active substances in agents for topical application and as biocompatible precursors in sol-gel synthesis of bioactive materials. Objective: In this work, morphostructural feature, ability to hydrolyze, and the pharmacological activity of previously synthesized iron(III) monoglycerate were studied. Methods: Analytical techniques, including SEM, TEM, XRD, TGA, IR spectroscopy, DLS and ELS, were used. Hemostatic activity was studied in vivo, and primary toxicological studies were carried out on experimental animals. Antimicrobial activity was studied using the agar diffusion method. Results: When dispersed in glycerol, solid crystalline iron(III) monoglycerolate transforms into an amorphous state, forming aggregates with an average particle size of 250 nm (according to DLS data). It slowly hydrolyzes in water at room temperature, while hydrolysis does not take place in an aqueous glycerol media. Iron(III) monoglycerolate is nontoxic and exhibits pronounced hemostatic activity and low antibacterial activity (relative to the strain S. аureus). Conclusion: Iron(III) monoglycerolate can be considered a potential hemostatic agent, showing promise for topical application in medical and veterinary practice, as well as a novel biocompatible precursor in the sol-gel synthesis of practically useful substances.

Tranexamic acid (class I drug) reduced and capped gold nanoparticles as a potential hemostatic agent with enhanced performance

External hemostatic agents play a crucial role in stabilizing an impaired process during pathological conditions. The idea is to stabilize the in vivo system as soon as possible. This study uses a class I hemostatic drug tranexamic acid as a reducing and capping agent for synthesizing the gold nanoparticles (Tr-AuNPs). Being the synthetic analogue of lysine and a biologically inspired alkylamine molecule, the chemistry can be fine-tuned for stable material that can simultaneously target the intrinsic and extrinsic hemostatic pathway, making it promising for hemostatic applications. The Tr-AuNPs of hydrodynamic diameter ∼46 nm were synthesized and evaluated physio-chemically using various analytical techniques wherein they showed hemocompatibility and increased thrombus weight compared to the native drug. The decrease in prothrombin time (PT) and international normalized ratio supported by the dynamic thromboelastography (TEG) study indicates the prepared nano-conjugate’s potential in reducing time for attaining hemostasis as compared to the native tranexamic acid drug. At a 9 μg ml−1 concentration, Tr-AuNPs had a procoagulant effect, shown by decreased reaction time (R) and coagulation time (K) with improved α angle and MA. There was a significant increase in the rate of coagulation in vivo by Tr-AuNPs, i.e. (52 s) compared to the native tranexamic acid (360 s). Radiolabelling studies ascertained the in vivo biocompatibility (non-invasive distribution, residence, clearance, and stability) of the Tr-AuNPs. The short-term toxicity studies were conducted to establish a proof of concept for the biomedical application of the material. The results highlighted the use of biologically alkyl amine molecules as capping and reducing agents for the synthesis of nanoparticles, which have shown a synergistic effect on the coagulation cascade while holding the potential for also acting as potential theranostic agents.

Mesoporous bioactive glass nanoparticles with biomineralization activity for surgical hemorrhage control

ABSTRACTBioactive glass nanoparticles (BGNs) are good bioactive materials for clinical treatment because of their unique composition and silica-oxygen network structure. Herein, we designed and reported a monodisperse mesoporous bioactive glass nanoparticle with biomineralization activity for surgical hemorrhage control. The results indicated that the BGNs have excellent biomineralization ability. In vivo and in vitro hemostasis studies suggested that BGNs have superior hemostatic properties to GZ (gauze) and GS (commercial gelatin sponge) and validated in vitro thrombosis, platelet adhesion, cytocompatibility and blood compatibility. The particles activated both endogenous and exogenous physiological coagulation pathways and could activate platelets and release Ca2+ to participate in the clotting pathway. Besides, the BGNs have good biocompatibility in vivo. These findings demonstrated that the potential of small diameter mesoporous bioactive glass nanoparticles is likely useful for bleeding control as potential hemostatic agents.

The Potential of Snake Venoms as Coagulation Agent for Hemorrhagic Trauma: A Review

Snake venom contains a variety of proteins and enzymes that can affect blood coagulation and have been investigated for their potential use as hemostatic agents to stop hemorrhage. Hemorrhage can be caused by a variety of factors, including injury, surgery, and certain medical conditions, and can be life-threatening if not controlled. Several components of snake venom have been identified as potential hemostatic agents. One such component is Batroxobin, a metalloproteinase found in the venom of the Bothrops atrox snake. Batroxobin has been shown to activate prothrombin to thrombin, which promotes clot formation and can be used to stop bleeding. Ancrod is a serine protease that can cleave fibrinogen, reducing the concentration of fibrinogen in the blood and preventing clot formation. Ancrod has been used as a hemostatic agent in the past, but its use has been limited due to concerns about its safety and efficacy. Other components of snake venom, such as those found in the venom of Russell's viper and the saw-scaled viper, have been found to have potential as hemostatic agents. These components have been shown to activate factor X and have been investigated as potential treatments for hemorrhage. The use of snake venom as a hemostatic agent is not without its challenges. One of the main concerns is the potential for adverse reactions, including allergic reactions, and the risk of complications such as thrombosis. Additionally, the availability of snake venom is limited, and the production of synthetic versions of these compounds can be challenging. Despite these challenges, the potential of snake venom as a hemostatic agent is promising, particularly in the development of new, more targeted treatments for hemorrhage. Further research is needed to fully understand the mechanisms of action of snake venom-derived hemostatic agents and to develop safe and effective therapeutic agents. In conclusion, snake venom contains a variety of components that have the potential as hemostatic agents to stop hemorrhage. While the use of snake venom-derived hemostatic agents is not without its challenges, these agents have promising potential in the treatment of a range of medical conditions. Keywords: Snake venom, coagulation agent, hemorrhagic trauma

Effects of Horsetail, Alfalfa, Ortie, Chêne and Aleppo oak as Potential Hemostatic Agents on Laboratory Coagulation Tests

This study investigated the effect of ethanol extracts of horsetail, alfalfa, ortie, chêne and aleppo oak on blood coagulation in vitro. Extraction was performed by the maceration method. Extracts were mixed with platelet and plasma, then prothrombin time (PT), activated partial thromboplastin time (APTT) and platelet aggregation tests were conducted. Alfalfa extract had a dose-dependent effect on the PT. Ortie, and horsetail, reduced the PT significantly compared to control group. Alfalfa, horsetail, and ortie reduced the APTT, but their effect was insignificant compared to the control group. The pooled extract showed the highest effect compared to the single extracts in a dose-dependent manner. Horsetail and alfalfa induced platelet aggregation in response to arachidonic acid but not in response to collagen. In the case of ortie, no aggregation occurred regarding the arachidonic acid, and incomplete was observed in response to collagen. Interestingly, blood clotting occurred immediately after adding the chêne, aleppo oak and the pooled extract, and therefore platelet poor plasma (PPP) and platelet rich plasma (PRP) became jelly. Generally, chêne and aleppo oak, as well as pooled extract, were more effective in inducing both primary and secondary coagulation pathways via shortening the PT and APTT, and induction of platelet aggregation.

Synthesis of cross-linked polymer based on purified Sterculia foetida L. gum as a potential hemostatic agent

A method for purifying the polysaccharides from Sterculia foetida L. gum was developed. The effects of purifying conditions were also studied. Results have shown that the conditions of pH 0.5, temperature of 80°C, and 2.5-h reaction duration gave the best polysaccharides yield. The mineral content and the molecular weight of the obtained polysaccharides were measured for characterization. The cross-linking of the polysaccharides with citric acid in order to achieve a desired polymer was performed successfully. The obtained polymers under different conditions were evaluated for the potential application as a hemostatic agent, including tests of swelling behavior in different fluids, whole-blood clotting time and enzymatic bio-degradation. Results have shown that the citric acid/polysaccharides ratio of 0.01 produced a comparative yield of polymer flakes with increased swelling properties, as well as shortened in vitro blood clotting time and gradual biodegradability in three experimental days. Therefore, the citric acid/polysaccharides ratio of 0.01 was selected for the subsequent experiment to obtain the polymer after 1.5 h of purification, which gave the best swelling properties, 20 times the initial weight, reduced the whole-blood clotting time by 50% and showed a rapid bio-degradation. The results obtained from this study provide essential knowledge on the research of the use of S. foetida gum polysaccharides as a passive hemostatic agent, thereby extending the potential pharmaceutical applications of natural polysaccharides in Vietnam.

Lyophilized platelets inhibit platelet aggregation with simultaneous paradoxical promotion of platelet adhesion.

Lyophilized platelets have been explored as a potential hemostatic agent due to their long-term ambient storage capabilities that make them readily available in various scenarios. Additionally, their high biocompatibility and the key role of platelet interactions in various clinical conditions make them a promising platform for drug delivery. To explore these applications and for wider clinical deployment, the interactions between lyophilized platelets and fresh platelets must be examined. This project characterized receptor expression on the lyophilized platelet surface and their ability to bind fibrinogen using flow cytometry. The effect of lyophilized platelets on aggregation of unaltered platelets was assessed using light transmission aggregometry while the effect on adhesion was evaluated using static and microfluidic assays. Lyophilized platelets maintained significant levels of GPIIb and GPVI receptors on their surface, though the expression was reduced from fresh platelets. Additionally, lyophilized platelets maintained GPIb expression similar to fresh platelets. Furthermore, 15.8% of the lyophilized platelets exhibited the active conformation of the GPIIb/IIIa receptor, indicating a significant increase over fresh platelets. Lyophilized platelets also exhibited an increase in exposed phosphatidylserine and fibrinogen binding. Despite the effect of lyophilized platelets in promoting the adhesion of fresh platelets on a collagen-coated surface, their net effect was inhibitory on platelet aggregation. This study demonstrates that lyophilized platelets can have paradoxical effects on platelet adhesion and aggregation, which could have an impact for clinical applications. Detailed characterization and engineering of these effects will be important for their continued development as a drug delivery platform.

Silk Fibroin Based Formulations as Potential Hemostatic Agents.

Effective hemorrhage control is indispensable for life-threatening emergencies in defense fields and civilian trauma. During major injuries, hemostatic agents are applied externally to mimic and accelerate the natural hemostasis process. Commercially available topical hemostatic agents are associated with several limitations, e.g., burning sensation, necrosis, futile in severe injuries, and high costs of the products. In the present study, we developed silk fibroin fiber-based formulations and evaluated their use as a cost-effective potential hemostatic agent with shortened clotting time. Silk fiber-based powder was produced following the alkaline hydrolysis process, wherein Bombyx mori silk fibroin fibers were treated with sodium hydroxide (NaOH) solution that randomly chopped the silk microfibers. Physicochemical reaction parameters, e.g., reaction temperature, molarity of NaOH solution, and incubation time, were optimized to achieve the maximum yield of microfibers. The surface properties of alkaline hydrolyzed silk microfibers (AHSMf) were analyzed by field emission scanning electron microscopy and energy dispersive X-ray studies. The water uptake capacity of AHSMf and the change in pH and temperature (∼30 °C) during blood clotting were analyzed. Further, the hemostatic potential of AHSMf was evaluated by an in vitro whole blood clotting assay using both goat and human blood. The in vitro studies demonstrated a reduced blood clotting time (CT = 20-30 s), prothrombin time (PT = ∼27%), and activated partial thromboplastin time (APTT = ∼14%) in the presence of AHSMf when compared to silk hydrogel powder (devoid of NaOH). Thus, the developed AHSMf could be a promising material to serve as a potential hemostatic agent.

Identification of a modified coagulation factor X with enhanced activation properties as potential hemostatic agent

Hemophilia A and hemophilia B are X-linked inherited bleeding disorders caused by a deficiency of coagulation factor VIII and IX, respectively. Standard of care is prophylactic factor replacement therapy; however, the development of neutralizing antibodies against these factors represents serious complications underlining the need for alternative treatment approaches. Human coagulation factor X has a central role within the blood coagulation system making it an attractive target for the development of alternative treatment strategies for patients with hemophilia. This study focuses on a modified variant of the human coagulation factor X with enhanced hemostatic bypass activity due to insertion of a factor IX derived activation sequence. This molecule design leads to the direct activation of the modified factor X protein by factor XIa allowing it to bypass the need for coagulation factor VIIIa/factor IXa. The modified variant was able to correct in-vitro activated partial prothrombin time of human and murine factor VIII/factor IX deficient plasma. Furthermore, reduced blood loss in factor VIII knock-out mice was observed after intravenous application of the modified factor X variant. In conclusion, these data suggest that the factor X variant described here could potentially serve as a bypassing agent independent of the inhibitor status of hemophilia patients. However, more research is needed to further investigate the potential of this molecule.

Rapid Hemostatic Biomaterial from a Natural Bath Sponge Skeleton.

Uncontrolled bleeding is the main cause of mortality from trauma. Collagen has been developed as an important hemostatic material due to its platelet affinity function. A bath sponge skeleton is rich in collagen, also known as spongin. To understand the hemostatic effect of spongin, spongin materials, SX, SFM and SR were prepared from the bath sponge Spongia officinalis, and hemostatic experiments were performed. The SX, SFM and SR were significantly better than the positive control, type I collagen, in shortening the whole blood clotting time in vitro and hemostasis upon rat tail amputation. In a hemostatic experiment of rabbit common carotid artery injury, the hemostatic time and 3 h survival rate of the SFM group were 3.00 ± 1.53 min and 100%, respectively, which are significantly better than those of the commercial hemostat CELOX-A (10.33 ± 1.37 min and 67%, respectively). Additionally, the SFM showed good coagulation effects in platelet-deficient blood and defibrinated blood, while also showing good biocompatibility. Through a variety of tests, we speculated that the hemostatic activity of the SFM is mainly caused by its hyperabsorbency, high affinity to platelets and high effective concentration. Overall, the SFM and spongin derivates could be potential hemostatic agents for uncontrolled bleeding and hemorrhagic diseases caused by deficiency or dysfunction of coagulation factors.

Surface roughness of silk fibroin/alginate microspheres for rapid hemostasis in vitro and in vivo

Timely hemostatic treatment is important to reduce blood loss and improve survival. To increase the speed of blood coagulation, hemostatic microspheres with varying degrees of surface roughness were prepared by emulsion cross-linking of sodium alginate (SA) and silk fibroin (SF). Surface morphology and hemostatic properties were analyzed with scanning electron microscope (SEM), infrared spectroscopy, and blood coagulation experiments. The results showed that microsphere have the roughest surface when the volume ratio of SA to SF is 2:1 (SF/SA2). These microspheres have the largest number of aggregated red blood cells, the fastest coagulation rates, and the strongest coagulation strength. Not only microspheres are they non-cytotoxic but they also promote cell growth. In vitro and in vivo coagulation experiments demonstrated that SF/SA2 microspheres can reduce bleeding time and volume and improve hemostatic efficiency, which suggests that SF/SA2 microspheres are potential hemostatic agents equipped with excellentbiosecurity.

Medicinal Plants as Potential Hemostatic Agents.

Medicinal plants with a variety of phytochemical ingredients remain a potential source for new drug discovery. The use of medicinal herbs in a wide range of diseases and symptoms, such as bleeding, is prevalent in traditional and ethno medicine worldwide. Thus, this work provides a comprehensive review of medicinal plants or their isolated compounds, with respect to their ethno-medicinal use, which have demonstrated the stimulating effect on the hemostasis process. The relevant studies were withdrawn from electronic databases including Pubmed, EMBASE and Web of Science with a structured search methodology. The total of 17 medicinal plants with hemostatic activity were extracted. The most frequently studied plant families were Compositae, Lamiaceae, Fabaceae, and Asteraceae. Bioactive compounds exerting hemostatic activity included tannins, iridoid glycosides, glycoconjugate, lignan, saponins and phenolic compounds. The most attributed mechanisms include coagulation stimulation via increasing the factor XII activity and plasma fibrinogen levels, the fibrinolysis inhibition, vascular or smooth muscle constriction and platelet aggregation. The most important adverse effects of high dose extract or isolated compounds administration were hepatotoxicity and nephrotoxicity. This review provides a list of medicinal plants with hemostatic activity that could be used as valuable sources of new plant-based hemostatic agents. Furthermore, this could be practical in detecting possible interactions of plants with anticoagulant, antiplatelet, fibrinolytic and antifibrinolytic medications.

Local Hemostatic Activity of Psidium guajava Leaves in Swiss Webster Mice

Psidium guajava ( P. guajava ) leaves have been empirically used to stop bleeding. Tannin, one of this plant’s secondary metabolites, may contribute to this activity. However, information regarding its pharmacologicy activity was limited. Therefore, this study was performed to evaluate local hemostatic activity of P. guajava leaves . This study used Duke method with male Swiss Webster mice as test animals. The animals were grouped into three i.e., negative control (distilled water), positive control (epinephrin), and P. guajava group. Its tail was cut (2-3 mm) and the bleeding time was calculated. Statistical analysis was performed using Kruskal-Wallis test and continued with Least Significant Different (LSD) test. The mean (SD) of bleeding time for those groups were 246.00 (22.95), 72.40 (5.55), and 88.40 (7.03), respectively. There was a significant difference between the negative control group with the other two groups, but there was not significant difference between the positive control group and the P. guajava group . In conclusion, P. guajava showed promising local hemostatic activity and can be further developed as potential hemostatic agents. Keywords: Psidium guajava , hemostatic, bleeding time

Synthesis and properties of poly(DEX-GMA/AAc) microgel particle as a hemostatic agent.

Immediate hemorrhage control without secondary injury is pivotal for saving lives. In this study, polymerized glycidyl methacrylate derivative dextran/acrylic acid (poly(DEX-GMA/AAc)) microgel particles were prepared via emulsion polymerization method as a hemostatic agent. Microgel particles with size distribution of 500-800 nm were chosen because they showed more appropriate characteristics of swelling ratio and gelation time. The results revealed that the microgel particles had excellent swelling ratio of 68.95 g g-1 (w/w), which was 8.4 times that of counterpart clinically used microporous polysaccharide hemospheres, Arista. And poly(DEX-GMA/AAc) showed very short gelation time of 10-13 s. As a result, a gelled film could be formed rapidly after poly(DEX-GMA/AAc) absorbed water in blood when used on wounds, and then staunched bleeding. Poly(DEX-GMA/AAc) microgel particles showed better clotting ability than commercial hemostatic agent Flashclot in vitro. In addition, poly(DEX-GMA/AAc) did not cause exothermic burn when absorbing liquid, which was superior to Flashclot. No obvious toxicity was found in cytotoxicity study and skin irritancy test. Blood loss and hemostasis time were dramatically reduced by poly(DEX-GMA/AAc) microgel particles in hemorrhage models of ear vein, ear artery, liver and femoral artery in rabbits. These results indicated that the poly(DEX-GMA/AAc) microgel particles are a potential hemostatic agent with almost no cytotoxicity and good biocompatibility.

Modern topical hemostatic agents and unique representatives of their new generation

Representatives of modern topical hemostatics used most widely in practical medicine, which are conventionally divided according to their nature and mechanism of action, are analyzed. The results of innovative design of new-generation styptics based on polymetalloacrylates are summarized. Potential hemostatic agents with unique properties that can serve as versatile means for rapid blood clotting in a variety of surgical procedures, even for patients with impaired blood coagulation and upon wounds and injuries in emergency situations, for considerable acceleration of wound healing, repair regeneration process in skin burns due to their antimicrobial and anesthetic properties are proposed.

Red blood cell–derived microparticles isolated from blood units initiate and propagate thrombin generation

Red blood cell-derived microparticles (RMPs) are small phospholipid vesicles shed from RBCs in blood units, where they accumulate during storage. Because microparticles are bioactive, it could be suggested that RMPs are mediators of posttransfusion complications or, on the contrary, constitute a potential hemostatic agent. This study was performed to establish the impact on coagulation of RMPs isolated from blood units. Using calibrated automated thrombography, we investigated whether RMPs affect thrombin generation (TG) in plasma. We found that RMPs were not only able to increase TG in plasma in the presence of a low exogenous tissue factor (TF) concentration, but also to initiate TG in plasma in absence of exogenous TF. TG induced by RMPs in the absence of exogenous TF was neither affected by the presence of blocking anti-TF nor by the absence of Factor (F)VII. It was significantly reduced in plasma deficient in FVIII or F IX and abolished in FII-, FV-, FX-, or FXI-deficient plasma. TG was also totally abolished when anti-XI 01A6 was added in the sample. Finally, neither Western blotting, flow cytometry, nor immunogold labeling allowed the detection of traces of TF antigen. In addition, RMPs did not comprise polyphosphate, an important modulator of coagulation. Taken together, our data show that RMPs have FXI-dependent procoagulant properties and are able to initiate and propagate TG. The anionic surface of RMPs might be the site of FXI-mediated TG amplification and intrinsic tenase and prothrombinase complex assembly.

Athermal nerve sparing robot-assisted radical prostatectomy: initial experience with microporous polysaccharide hemospheres as a topical hemostatic agent

Microporous polysaccharide hemospheres (MPH) are hemostatic beads engineered from plant starch to accelerate the natural clotting cascade. The purpose of this report is to detail our initial experience with MPH as a topical hemostatic agent during robot-assisted radical prostatectomy (RARP). We examined a single surgeon series of 30 consecutive RARP's dividing patients into MPH or non-MPH groups. The last ten procedures utilized the MPH, which were matched 1:2 to non-MPH procedures for comparison. Nerve-sparing procedures were performed when clinically indicated and all done athermally. All demographic data, length of operation, margin status, blood loss, change in hemoglobin, and need for blood transfusion were prospectively collected and analyzed. The baseline characteristics were the same. The post-operative decrease in hemoglobin was less in the MPH group (1.8 g/dL MPH group vs. 3.2 g/dL non-MPH). One patient in each group required a blood transfusion. These preliminary findings support the role for MPH as a potential hemostatic agent during athermal nerve-sparing RARP.

Achieving Hemostasis With Topical Hemostats: Making Clinically and Economically Appropriate Decisions in the Surgical and Trauma Settings

Achieving hemostasis is a crucial focus of clinicians working in surgical and trauma settings. Topical hemostatic agents—including mechanical hemostats, active hemostats, flowable hemostats, and fibrin sealants—are frequently used in efforts to control bleeding, and new options such as hemostatic dressings, initially used in combat situations, are increasingly being used in civilian settings. To achieve successful hemostasis, a number of vital factors must be considered by surgeons and perioperative nurses, such as the size of the wound; bleeding severity; and the efficacy, possible adverse effects, and method of application of potential hemostatic agents. Understanding how and when to use each of the available hemostatic agents can greatly affect clinical outcomes and help to limit the overall cost of treatment.

Characterization of an Ideal Amphipathic Peptide as a Potential Hemostatic Agent.

We have previously demonstrated that amphipathic helical peptides can accelerate the turnover of the substrate factor X by the enzyme, factor IXa in a gamma-carboxyglutamic acid (Gla) domain dependent manner (Biochemistry,39:12000Biochemistry,39:12000). Such improvement was due to a remarkable decrease in KM and a mild increase in kcat, mimicking the presence of phospholipid membranes. It is hypothesized that amphipathic helical peptides could exert similar activities in other reactions of the blood coagulation cascade, such as thrombin generation and in whole blood clotting. In the present work, we analyze the activity of a 22-amino acid ideal amphipathic helical peptide (IAP) of K7L15 composition, in factor X activation and thrombin generation. The addition of IAP accelerates factor X activation by factor IXa in a concentration dependent manner. IAP also accelerates thrombin generation by factor Xa with a comparable peptide and substrate concentration dependence. Further, the Gla domain is also required for peptide activity confirming the hypothesis this peptide behaves as a membrane mimetic. Using fluorescence spectroscopy and an ELISA-based binding assay, we demonstrate direct binding between IAP and the Gla domain of factor X. Additionally, when IAP is immobilized to a reaction surface, factor X activation and thrombin generation are dramatically enhanced, as compared to the corresponding reactions on untreated surfaces. Finally, activated partial thromboplastin times (APTTs) of pooled plasma are significantly shortened on surfaces treated with IAP, in comparison with clotting times measured on untreated surfaces. The above results suggest that immobilized IAP may serve as a potential hemostatic agent, as demonstrated in isolated critical reactions of the coagulation cascade and in whole plasma.