Plasma Coagulation Research Articles

Integrated network pharmacology and metabolomics reveal vascular protective effects of Ilex pubescens on thromboangiitis obliterans

BackgroundIlex pubescens Hook. et Arn (IP), traditionally known for its properties of promoting blood circulation, swelling and pain relief, heat clearing, and detoxification, has been used in the treatment of thromboangiitis obliterans (TAO). Despite its traditional applications, the specific mechanisms by which IP exerts its therapeutic effects on TAO remain unclear. Aim of the studyThis study aims to uncover the underlying mechanisms in the therapeutic effects of IP on TAO, employing network pharmacology and metabolomic approaches. MethodsIn this study, a rat TAO model was established by injecting sodium laurate through the femoral artery, followed by the oral administration of IP for 7 days. Plasma coagulation parameters were measured to assess the therapeutic effects of IP. The potential influence on the femoral artery and gastrocnemius muscle was histopathologically evaluated. Network pharmacology was employed to predict relevant targets and model pathways for TAO. Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) was used for the metabolic profile analysis of rat plasma. Immunohistochemistry (IHC) was used to verify the mechanisms by which IP promotes blood circulation in TAO. ResultsThe study revealed that IP improved blood biochemical function in TAO and played a significant role in vascular protection and maintaining normal blood vessels and gastrocnemius morphologies. Network pharmacology showed that IP compounds play a therapeutic role in modulating lipids and atherosclerosis. Metabolomic analysis revealed that the pathways involved in sphingolipid metabolism and steroid biosynthesis were significantly disrupted. The joint analysis showed a strong correlation between lysophosphatidylcholine and IP components, including triterpenoid and iridoid components, which support the curative action of IP through the modulation of sphingolipid metabolism. Furthermore, decreased expression levels of SPHK1/S1PR1, TNF-α, IL-1β, and IL-6 were observed in the IP-treated group, suggesting that IP exerts a protective effect on the vasculature primarily by regulating of the SPHK1/S1PR1 signaling pathway. ConclusionIn this study, we found that IP protects the vasculature against injury and treats TAO by regulating the steady-state disturbance of the sphingolipid pathway. These findings suggest that IP promotes vasculature by modulating sphingolipid metabolism and SPHK1/S1PR1 signaling pathway and reduce levels of inflammatory factors, offering new insights into its therapeutic potential.

Selective but not pan-CDK inhibition abrogates 5-FU-driven tissue factor upregulation in colon cancer

Thromboembolic events are complications in cancer patients and hypercoagulability has been linked to the tissue factor (TF) pathway, making this an attractive target. Here, we investigated the effects of chemotherapeutics and CDK inhibitors (CDKI) abemaciclib/palbociclib (CDK4/6), THZ-1 (CDK7/12/13), and dinaciclib (CDK1/2/5/9) alone and in combination regimens on TF abundance and coagulation. The human colorectal cancer (CRC) cell line HROC173 was treated with 5-FU or gemcitabine to stimulate TF expression. TF+ cells were sorted, recultured, and re-analyzed. The effect of treatment alone or in combination was assessed by functional assays. Low-dose chemotherapy induced a hypercoagulable state and significantly upregulated TF, even after reculture without treatment. Cells exhibited characteristics of epithelial-mesenchymal transition, including high expression of vimentin and mucin. Dinaciclib and THZ-1 also upregulated TF, while abemaciclib and palbociclib downregulated it. Similar results were observed in coagulation assays. The same anticoagulant activity of abemaciclib was seen after incubation with peripheral immune cells from healthy donors and CRC patients. Abemaciclib reversed 5-FU-induced TF upregulation and prolonged clotting times in second-line treatment. Effects were independent of cytotoxicity, senescence, and p27kip1 induction. TF-antibody blocking experiments confirmed the importance of TF in plasma coagulation, with Factor XII playing a minor role. Short-term abemaciclib counteracts 5-FU-induced hypercoagulation and eventually even prevents thromboembolic events.

Endoscopic argon plasma coagulation (APC) treatment for dumping syndrome and post-bariatric hypoglucemia in patients with ROUX-EN-Y gastric bypass

Endoscopic argon plasma coagulation (APC) treatment for dumping syndrome and post-bariatric hypoglucemia in patients with ROUX-EN-Y gastric bypass

May 2024 Medical Image of the Month: Hereditary Hemorrhagic Telangiectasia in a Patient on Veno-Arterial Extra-Corporeal Membrane Oxygenation

No abstract available. Manuscript truncated after 150 words. A 54-year-old man with a complex cardiac history, including Tetralogy of Fallot requiring Blalock-Taussig shunt in infancy, infundibular patch repair at age 7, and bioprosthetic tricuspid valve replacement at age 52, had ongoing frequent hospitalizations with decompensated right ventricular heart failure secondary to native pulmonary valve mixed stenosis plus regurgitation and left pulmonary artery stenosis. His case was further complicated by his history of hereditary hemorrhagic telangiectasia (HHT) with recurrent epistaxis and recent GI bleeds with multiple angiodysplastic lesions throughout the stomach, duodenum, and descending colon which were previously treated with argon plasma coagulation. The patient was admitted to our hospital in NYHA class IV heart failure receiving a continuous dopamine infusion and aggressive diuresis. Upon admission, a right heart catheterization demonstrated severe pulmonary valve regurgitation, left pulmonary artery stenosis, and systemic hypoxemia suggestive of an intrapulmonary shunt. Admission transthoracic echocardiogram demonstrated normal left ventricular ejection fraction of 55-60%, a …

Development of a rapid HPLC-fluorescence method for monitoring warfarin metabolites formation: In vitro studies for evaluating the effect of piperine on warfarin metabolism and plasma coagulation

Warfarin, a widely prescribed anticoagulant, is highly effective for various coagulation disorders. However, its efficacy is limited by a narrow therapeutic index and frequent drug interactions, especially those involving metabolism by Cytochrome P450 (CYP450) enzymes. Piperine, found in black and long pepper, possesses blood-thinning properties and has been observed to inhibit CYP3A and CYP2C enzymes linked to warfarin metabolism. This study investigated the effect of piperine on warfarin metabolism in liver microsomes using a rapid and sensitive HPLC-Fluorescence method. The use of PFP (pentafluorophenyl) column with core shell particles provided the selectivity and resolution to resolve warfarin and its 4-, 6-, 7-, and 10-hydroxy metabolites in addition to the internal standard naproxen in less than 3 min. This is the fastest analytical assay for warfarin and its major metabolites reported to date, making it ideal for metabolic studies. The applicability of the method was demonstrated by monitoring the metabolism of S-warfarin in human and rat liver microsomes, and evaluating the inhibitory effect of piperine on metabolite formation. The results showed that piperine inhibited the formation of the major metabolite, 7-hydroxywarfarin, with half-maximal inhibitory concentration (IC50) 14.2 μM and 3.2 μM in human and rat liver microsomes, respectively. Furthermore, coagulation studies in vitro using rat plasma showed that piperine does not affect prothrombin time (PT) and activated partial thromboplastin time (aPTT). This study suggested that piperine may present a potential drug interaction with warfarin at the metabolism level, but has no direct effect on the activation of the extrinsic or intrinsic coagulation cascades. Further clinical investigation is therefore required, as piperine may increase the bioavailability of warfarin, thus increasing risk of serious adverse events in patients.

Evaluation of thrombomodulin/thrombin activatable fibrinolysis inhibitor function in plasma using tissue-type plasminogen activator-induced plasma clot lysis time

BackgroundThrombin activatable fibrinolysis inhibitor (TAFI) is one of the most important physiological fibrinolysis inhibitors. Its inhibitory efficacy under physiological conditions remains uncertain. ObjectivesElucidate the role of soluble thrombomodulin (sTM)/TAFI axis in the regulation of fibrinlysis. MethodsSince thrombin is required to generate activated TAFI (TAFIa) that targets the C-terminal lysine of partially digested fibrin, a clot lysis assay is suitable for evaluating its function. Using tissue-type plasminogen activator-induced plasma clot lysis time (tPA-PCLT) together with TAFIa inhibitor and recombinant sTM (rsTM), we evaluated the specific function of TM/TAFI in the plasma milieu. ResultstPA-PCLT values were significantly shortened by the TAFIa inhibitor. rsTM supplementation prolonged tPA-PCLT, which was shortened by the TAFIa inhibitor to a time similar to that obtained without rsTM and with the TAFIa inhibitor. Plasma obtained from patients treated with rsTM showed prolonged tPA-PCLT, which was shortened by the TAFIa inhibitor but not further prolonged by rsTM. However, no significant correlation was observed between tPA-PCLT and parameters of TM/TAFI system in the plasma. ConclusionThe role of the TM/TAFI system in regulating fibrinolysis was successfully evaluated using TAFIa inhibitor and rsTM. Trace amounts of soluble TM in normal plasma appeared sufficient to activate TAFI and inhibit fibrinolysis. Further, a therapeutic dose of rsTM appeared sufficient to activate TAFI and regulate fibrinolysis in the plasma milieu.

Clinical, endoscopic and therapeutic features of bleeding Dieulafoy’s lesions: case series and literature review

ObjectiveDieulafoy’s lesions (DLs) are a rare but potentially life-threatening source of gastrointestinal (GI) haemorrhage. They are responsible for roughly 1%–6.5% of all cases of acute non-variceal GI bleeding.Here, we describe...

Endoscopic transoral outlet reduction induces enterohormonal changes in patients with weight regain after Roux-en-Y gastric bypass

Abstract Background and study aims Transoral outlet reduction (TORe) has long been employed in treating weight regain after Roux-en-Y gastric bypass. However, its impact on gut hormones and their relationship with weight loss remains unknown. Patients and methods This was a substudy of a previous randomized clinical trial. Adults with significant weight regain and dilated gastrojejunostomy underwent TORe with argon plasma coagulation (APC) alone or APC plus endoscopic suturing (APC-suture). Serum levels of ghrelin, GLP-1, and PYY were assessed at fasting, 30, 60, 90, and 120 minutes after a standardized liquid meal. Results were compared according to allocation group, clinical success, and history of cholecystectomy. Results Thirty-six patients (19 APC vs. 17 APC-suture) were enrolled. There were no significant baseline differences between groups. In all analyses, the typical postprandial decrease in ghrelin levels was delayed by 30 minutes, but no other changes were noted. GLP-1 levels significantly decreased at 12 months in both allocation groups. Similar findings were noted after dividing groups according to the history of cholecystectomy and clinical success. The APC cohort presented an increase in PYY levels at 90 minutes, while the APC-suture group did not. Naïve patients had significantly lower PYY levels at baseline (P = 0.01) compared with cholecystectomized individuals. This latter group experienced a significant increase in area under the curve (AUC) for PYY levels, while naïve patients did not, leading to a higher AUC at 12 months (P = 0.0001). Conclusions TORe interferes with the dynamics of gut hormones. APC triggers a more pronounced enteroendocrine response than APC-suture, especially in cholecystectomized patients.

Abstract 155: Plasma Kallikrein Is A Key Driver Of Basal Activation Of Coagulation Under Conditions Of C1 Inhibitor Deficiency

C1 inhibitor (C1INH) functions as a key endogenous inhibitor of contact pathway coagulation factors XII, XI and plasma kallikrein (PKa). Patients with a congenital deficiency in C1INH suffer from a rare swelling disorder called hereditary angioedema (HAE) caused by excess bradykinin generation. Patients with HAE also have elevated circulating levels of markers of activation of coagulation and an increased risk of venous thromboembolism, phenotypes recapitulated in C1INH-deficient mice. We sought to evaluate the molecular mechanism by which C1INH deficiency leads to increased basal activation of coagulation and venous thrombosis. We hypothesized that PKa serves as a key driver of activation of coagulation in humans and mice with congenital C1INH deficiency. Patients with C1INH deficiency-associated HAE were treated with the PKa inhibitor lanadelumab with plasma samples collected before and after treatment. Plasma levels of coagulation markers and contact pathway-initiated thrombin generation were determined. C1INH-deficient mice were treated with the PKa inhibitor avoralstat, the FXIIa inhibitor garadacimab, FXII small interfering RNAs, FXI antisense oligonucleotides, the anti-tissue factor antibody 1H1 or appropriate controls and plasma coagulation markers were measured. Treatment of HAE patients with the PKa inhibitor lanadelumab significantly reduced plasma levels of prothrombin fragment 1.2, thrombin antithrombin (TAT) complexes and D-dimer at 6 months after treatment initiation (P<0.05). Interestingly, landalumab had no significant effect on contact pathway-initiated thrombin generation. In experiments with C1INH deficient mice, TAT complexes were significantly reduced by PKa inhibition (P<0.01) but not by inhibition of FXIIa or FXIa. Interestingly, tissue factor inhibition also significantly reduced plasma TAT complexes (P<0.01). This data suggests that under conditions of C1INH deficiency PKa potentiates activation of coagulation through a non-canonical pathway involving tissue factor. These findings demonstrate that C1INH is a physiologically relevant anticoagulant with C1INH deficiency resulting in enhanced kallikrein-mediated activation of basal coagulation.

ANTICOAGULANT PROPERTIES OF RECOMBINANT ANNEXIN А5

Aim: Because of its involvement in membrane properties, annexin A5 has a significant impact on membrane-dependent processes within hemostasis, including the initiation of the coagulation cascade, the activation of factor X and prothrombin, and the function of protein C on membrane surfaces. By binding to phosphatidylserine, annexin A5 acts as a protective shield, masking exposed phospholipid surfaces and exerting a general anticoagulant effect. Considering the significant influence of annexin A5 on the activation of hemostatic compounds on cell surfaces, it is crucial to further investigate its mechanisms. Methods: After purification of polyHis-Tag proteins by immobilized metal affinity chromatography from E. coli Rosetta cell biomass, we checked the purity of the eluate by SDS-PAGE. We performed APTT test, PT test and platelet aggregation to find out the anticoagulation influence of recombinant annexin A5 in these tests. Results: Annexin in the highest concentration of 40 μg/ml prolonged blood plasma clotting time in activated partial thrombin time by almost 50%, blood plasma clotting time in prothrombin time by almost 15% and did not influence the rate of platelet aggregation. Conclusion: It can be assumed that its anticoagulant effect is directed to the enzyme complexes of the hemostasis system and does not extend to platelet receptors. The obtained protein can be used to study the activation of hemostatic components on cell surfaces.

Spontaneous reperfusion in STEMI: Its mechanisms and possible modulation.

Patients with transient ST-segment elevation myocardial infarction or spontaneous reperfusion, which occurs in approximately 20% of patients with ST-segment elevation myocardial infarction (STEMI), have smaller infarcts and more favorable clinical outcomes than patients without spontaneous reperfusion. Understanding the mechanisms underlying spontaneous reperfusion is therefore important since this may identify possible novel therapeutic targets to improve outcomes in patients with STEMI. In this review, we discuss some of the possible determinants of spontaneous reperfusion including pro-thrombotic profile, endogenous fibrinolytic status, lipoprotein(a) (Lp[a]), inflammatory markers, and neutrophil extracellular traps (NETs). Effective (rapid) endogenous fibrinolysis, as assessed in whole blood in vitro, using a point-of-care technique assessment of global thrombotic status, has been strongly linked to spontaneous reperfusion. Lp(a), which has a high degree of homology to plasminogen, may impair fibrinolysis through competitive inhibition of tissue plasminogen activator-mediated plasminogen activation as well as tissue plasminogen activator-mediated clot lysis and contribute to pathogenic clot properties by decreasing fibrin clot permeation. NETs appear to negatively modulate clot lysis by increasing thrombin fiber diameter and inhibiting plasmin-driven lysis of plasma clots. There are limited data that oral anticoagulation may modulate endogenous fibrinolysis but antiplatelet agents currently appear to have no impact. Phase III trials involving subcutaneous P2Y12 or glycoprotein IIb/IIIa inhibitors, oral factor XIa inhibitors, interleukin-6 inhibitors, and apolipoprotein(a) antisense oligonucleotides in patients with cardiovascular disease are ongoing. Future studies will be needed to determine the impact of these novel antithrombotic, anti-inflammatory, and lipid-lowering therapies on endogenous fibrinolysis and spontaneous reperfusion.

Comparing the effects of argon plasma coagulation and interferon therapy in patients with vaginal intraepithelial neoplasia: a single-center retrospective study

PurposeThis study aimed to evaluate the clinical efficacy and safety of argon plasma coagulation (APC) therapy and interferon therapy in patients with grade I and II vaginal intraepithelial neoplasia (VaIN).MethodsA total of 112 patients with VaIN were diagnosed via colposcopy-induced biopsy and classified into the APC group (n = 77) and interferon group (n = 35). Clinical data including age, grade, symptoms, historical or concomitant neoplasia of the lower genital tract, indications for hysterectomy, pregnancy history, cytology, human papillomavirus (HPV) subtype, treatment modalities, and clinical outcomes were analyzed, retrospectively. Complications and clinical outcomes were assessed at 6- and 12-month follow-ups.ResultsThere was no significant difference in the HPV clearance rate between the APC (53.42%) and interferon (33.33%) groups at 6 months after treatment. However, the 12-month follow-up of the APC group showed a significantly higher HPV clearance rate as compared to the interferon group (87.67% vs. 51.52%, P < 0.05). The APC group exhibited a significantly higher cure rate (79.22% vs. 40.0%) and lower persistence rate (12.99% vs. 37.14%) than the interferon group (P < 0.05). Adverse reaction analysis revealed that the primary reaction in the APC group was vaginal drainage, in contrast to the increased vaginal discharge in the interferon group; though the difference was significant (68.83% vs. 28.57%, P < 0.05), no serious complications were observed.ConclusionsTreatment with APC is a safe and more effective procedure against VaIN I and II, compared to interferon. APC may serve as a viable alternative to other physiotherapies.

A small-molecule hemostatic agent for the reversal of direct oral anticoagulant–induced bleeding

BackgroundThe bleeding risk associated with direct oral anticoagulants (DOACs) remains a major concern, and rapid reversal of anticoagulant activity may be required. Although specific and nonspecific hemostatic biotherapies are available, there is a need for small-molecule DOAC reversal agents that are simple and cost-effective to produce, store, and administer. ObjectivesTo identify and characterize a small molecule with procoagulant activity as a DOAC reversal agent. MethodsWe sought to identify a small procoagulant molecule by screening a chemical library with a plasma clotting assay. The selected molecule was assessed for its procoagulant properties and its ability to reverse the effects of the DOACs in a thrombin generation assay. Its activity as a DOAC reversal agent was also evaluated in a tail-clip bleeding assay in mice. ResultsThe hemostatic molecule (HeMo) dose-dependently promoted thrombin generation in plasma, with dose values effective in producing half-maximum response ranging between 3 and 5 μM, depending on the thrombin generation assay parameter considered. HeMo also restored impaired thrombin generation in DOAC-spiked plasma and reversed DOAC activity in the mouse bleeding model. HeMo significantly reduced apixaban-induced bleeding from 709 to 65 μL (vs 43 μL in controls; P < .01) and dabigatran-induced bleeding from 989 to 155 μL (vs 126 μL in controls; P < .01). ConclusionHeMo is a small-molecule procoagulant that can counterbalance hemostatic disruption by a thrombin inhibitor (dabigatran) or factor Xa inhibitors (apixaban and rivaroxaban). The compound’s effective clot formation and versatility make it a possible option for managing the inherent hemorrhagic risk during DOAC therapy.

Long-term anticoagulant therapy in the aspect of secondary prevention of recurrent pulmonary embolism

Aim. To determine differences in laboratory coagulation parameters using routine and integral monitoring methods in patients depending on anticoagulant therapy &gt;12 months after pulmonary embolism (PE) with a high recurrence risk.Material and methods. The study included 72 patients who, according to indications, received long-term anticoagulant therapy &gt;12 months due to a high risk of recurrent thromboembolism. During the follow-up period (15-20 months from the first pulmonary embolism episode), the plasma coagulation parameters were studied using a conventional panel and D-dimer assessment, as well as a thrombin generation test and thrombodynamics. Patients adherent to prolonged anticoagulation were included in group 1. During the collection period, 8 patients independently stopped taking anticoagulants, despite the high risk of recurrent pulmonary embolism (group 2).Results. There were no significant differences in coagulation parameters and D-dimer levels between the studied groups of patients. In the group of patients continuing to take anticoagulants, there was an increase in clot growth delay parameters in comparison with patients of group 2 according to the thrombodynamics results (p=0,046) and the thrombin generation test in platelet-poor plasma in comparison with reference values (p=0,001).Conclusion. Long-term anticoagulant therapy effectively prevents recurrent venous thromboembolism. In patients after primary pulmonary embolism who refuse anticoagulation, the clot growth delay values are shortened, which indicates an increased risk of recurrent venous thromboembolism. The most stable plasma coagulation parameters are observed in patients taking direct oral anticoagulants.

The Prediction of Milk Whey Extract (MWE) Bioactive Compounds Based on Proximate Analysis and its Effects on Blood Coagulation: A New Approach

The present work demonstrates the milk whey extraction, proximate analysis, and biochemical characterization of bioactive compounds in MWE. Effects of MWE on plasma coagulation and platelet aggregation. Proximate analysis of MWE was done according to AOAC. Whey protein banding was confirmed in 12%, 15%, and 18% SDS-PAGEs. A quantitative analysis of bioactive compounds was done. The anticoagulant effects of MWE were tested using plasma recalcification time in both PRP and PPP, further confirmed by PT and APTT assays and in tail bleeding assays at concentrations of 0-100 µg. The non-toxic property of MWE was screened by edema, hemorrhage, and direct hemolytic activities. MWE proximate analysis showed the presence of both micro- and macronutrients. Qualitative analysis confirmed the presence of proteins and carbohydrates. A similar protein-banding pattern was observed in 12%, 15%, and 18% SDS-PAGE’s in both reduced and non-reduced conditions. MWE prolonged the clotting time of human citrated plasma, both PRP and PPP, against the control 210 sec to 770 sec, suggesting its anticoagulant property. MWE delayed the clot progress of only the APTT ratio (8.99 ± 0.09), and PT was not altered, suggesting its role in an intrinsic pathway of blood coagulation. MWE exhibited antiplatelet activity in PRP against ADP and epinephrine-induced platelet aggregation. The percentage of inhibition was 74% and 100% for ADP and epinephrine, respectively. Interestingly, MWE exhibits nontoxic properties, it does not cause hemolysis, hemorrhage, or edema. Milk whey extraction and studies confirm bioactive compounds, and these exhibit antithrombotic, antiplatelet, and non-toxic properties. Hence, MWE not only acts as a good nutritive source but also may prove tobe a therapeutic bioactive compound in the management of cardiovascular disease.

Determination of thrombin and plasmin activity using the turbidimetric analysis of clot formation and dissolution in human blood plasma

Based on the turbidimetric curve of formation and dissolution of a blood plasma clot initiated by the activated partial thromboplastin time reagent, a method for determining the coagulation component of thrombin activity and fibrinolytic activity of plasmin is proposed. The activity of thrombin was calculated by the value of the lag period, and plasmin by its amidase activity at the moment of complete dissolution of the clot. At the end of the lag period, about 0.45% of the available prothrombin was activated, and at the moment of complete dissolution of the clot 1.05% of the available plasminogen was activated. This method makes it possible to determine the ratio of the thrombin generation rate to that of plasmin, the time of clot formation to the time of its dissolution, as well as the overall hemostasis potential and coagulation and fibrinolytic components and their ratio. Keywords: coagulation, fibrinolysis, global hemostasis assay, plasmin generation, thrombin generation

Snare Tip Soft Coagulation vs. Argon Plasma Coagulation vs. No Margin Treatment After Large Nonpedunculated Colorectal Polyp Resection: A Randomized Trial

Snare Tip Soft Coagulation vs. Argon Plasma Coagulation vs. No Margin Treatment After Large Nonpedunculated Colorectal Polyp Resection: A Randomized Trial

Human platelet concentrates treated with microbicidal 405 nm light retain hemostasis activity

Chemical and UV light-based pathogen reduction technologies are currently in use for human platelet concentrates (PCs) to enhance safety from transfusion-transmitted infections. Relative to UV light, 405 nm violet-blue light in the visible spectrum is known to be less harmful. Hence, in this report for the first time, we have assessed the global hemostasis activity of PCs stored in plasma and the activities of six plasma coagulation factors (CFs) as a measure of in vitro hemostatic activity following exposure to the microbicidal 405 nm light. Apheresis PC samples collected from each screened human donor (n = 22) were used for testing of PCs and platelet poor plasma (PPP). Both PCs and PPPs were treated for 5 h with 405 nm light to achieve a previously established microbicidal light dose of 270 J/cm2. Activated partial thromboplastin time and prothrombin time-based potency assays using a coagulation analyzer and hemostatic capacity via Thromboelastography were analyzed. Thromboelastography analysis of the light-treated PCs and plasma present in the PCs showed little difference between the treated and untreated samples. Further, plasma present in the PCs during the light treatment demonstrated a better stability in potency assays for several coagulation factors compared to the plasma alone prepared from PCs first and subjected to the light treatment separately. Overall, PCs stored in plasma treated with 405 nm violet-blue light retain activity for hemostasis.

Effect of Seaweed-Derived Fucoidans from Undaria pinnatifida and Fucus vesiculosus on Coagulant, Proteolytic, and Phospholipase A2 Activities of Snake Bothrops jararaca, B. jararacussu, and B. neuwiedi Venom.

Snakebite envenomation (SBE) causes diverse toxic effects in humans, including disability and death. Current antivenom therapies effectively prevent death but fail to block local tissue damage, leading to an increase in the severity of envenomation; thus, seeking alternative treatments is crucial. This study analyzed the potential of two fucoidan sulfated polysaccharides extracted from brown seaweeds Fucus vesiculosus (FVF) and Undaria pinnatifida (UPF) against the fibrinogen or plasma coagulation, proteolytic, and phospholipase A2 (PLA2) activities of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom. The toxicity of FVF and UPF was assessed by the hemocompatibility test. FVF and UPF did not lyse human red blood cells. FVF and UPF inhibited the proteolytic activity of Bothrops jararaca, B. jararacussu, and B. neuwiedi venom by approximately 25%, 50%, and 75%, respectively, while all venoms led to a 20% inhibition of PLA2 activity. UPF and FVF delayed plasma coagulation caused by the venoms of B. jararaca and B. neuwiedi but did not affect the activity of B. jararacussu venom. FVF and UPF blocked the coagulation of fibrinogen induced by all these Bothropic venoms. FVF and UPF may be of importance as adjuvants for SBE caused by species of Bothrops, which are the most medically relevant snakebite incidents in South America, especially Brazil.

Biphasic Calcium Phosphate and Activated Carbon Microparticles in a Plasma Clot for Bone Reconstruction and In Situ Drug Delivery: A Feasibility Study.

The development of bone-filling biomaterials capable of delivering in situ bone growth promoters or therapeutic agents is a key area of research. We previously developed a biomaterial constituting biphasic calcium phosphate (BCP) microparticles embedded in an autologous blood or plasma clot, which induced bone-like tissue formation in ectopic sites and mature bone formation in orthotopic sites, in small and large animals. More recently, we showed that activated carbon (AC) fiber cloth is a biocompatible material that can be used, due to its multiscale porosity, as therapeutic drug delivery system. The present work aimed first to assess the feasibility of preparing calibrated AC microparticles, and second to investigate the properties of a BCP/AC microparticle combination embedded in a plasma clot. We show here, for the first time, after subcutaneous (SC) implantation in mice, that the addition of AC microparticles to a BCP/plasma clot does not impair bone-like tissue formation and has a beneficial effect on the vascularization of the newly formed tissue. Our results also confirm, in this SC model, the ability of AC in particle form to adsorb and deliver large molecules at an implantation site. Altogether, these results demonstrate the feasibility of using this BCP/AC/plasma clot composite for bone reconstruction and drug delivery.