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Thrombosis and intimal hyperplasia (IH) are the main factors affecting the long-term patency of small-diameter vascular grafts (SDVGs). Fabricating a confluent endothelial cell (EC) layer on surfaces with physiological elasticity to mimic vascular endothelium should be an effective strategy to prevent restenosis that is caused by thrombosis and IH. However, the vascular endothelialization process is time-consuming and always constrained by hemocompatibility of the vascular grafts, since excellent hemocompatibility could guarantee a sufficient time window for the endothelialization process. Tetramethylpyrazine (TMP)-derived polyurethane (PU) with improved hemocompatibility and accelerated endothelialization ability is synthesized by incorporating TMP moieties into PU backbones. Results show that TMP-contained PU films possess improved hemocompatibility by down-regulating platelet adhesion/activation and increasing the clotting time. Furthermore, the in vitro human umbilical vein endothelial cell (HUVEC) test demonstrates that the introduction of TMP can significantly promote HUVEC adhesion and proliferation, and thus accelerate luminal endothelialization of vascular grafts. Moreover, the TMP-containing PU films exhibit excellent biocompatibility especially for HUVECs, and their excellent, adjustable elasticity (1123%) guarantees compliance accommodation of vascular grafts. This newly synthesized TMP-containing material with multiple biological functions is expected to make up for the shortcomings of available SDVGs in clinical practice, and has significant potential in improving the long-term patency of SDVGs.

To address the adverse reactions caused by the implantation of blood-contacting materials, researchers have developed different strategies, of which mimicking multiple key features of endothelial cells is the most effective. However, simultaneously immobilizing multiple chemical components on a single material surface and maintaining the effects of individual components are challenging. In this work, endothelium-mimicking silicone surfaces were developed by incorporating the antifouling polymer poly(oligo(ethylene glycol) methacrylate), the glycosaminoglycan analog poly(sodium 4-vinyl-benzenesulfonate) and a nitric oxide catalyst (selenocystamine dihydrochloride). Through the rational regulation of multiple chemical components, the surfaces harmoniously resisted nonspecific protein adsorption, platelet adhesion and activation and smooth muscle cell hyperproliferation while promoting endothelial cell proliferation and migration. The coculture experiment with HUVECs and HUVSMCs showed that the optimum selectivity of HUVECs/HUVSMCs was ∼1.7. This work contributes insight into the control of antifouling properties and endothelial selectivity, providing a new avenue for the development of blood-contacting materials.

Given the risks of poor patient compliance and bleeding associated with current dual antiplatelet therapies, it is urgent to develop the next generation of cardiovascular stents with anticoagulation and rapid endothelialization capabilities. Inspired by the prominent bioactivity and bioavailability of zeolitic imidazolate framework-90 (ZIF-90) in driving endothelial cell (EC) morphogenesis, this research proposes a "synergistic anticoagulant and endothelial regeneration strategy" depending on mussel-inspired phospholipid copolymer (MIPC) and ZIF-90. Depending on the copolymerization of the catechol with dopamine (Dopa) monomers, Dopa/MIPC coating was immobilized on the surface of CoCr via a one-pot process for resisting the initial thrombosis induced by platelets and fibrinogen. Meanwhile, ZIF-90 was loaded on the coating via coordination effect, aiming to accelerate the proliferation and migration of ECs. Compared with CoCr, the well-designed CoCr-Dopa/MIPC@ZIF-90 not only reduced fibrinogen adhesion by approximately 40 % and platelet adhesion by almost 55 %, but also promoted the proliferation and migration of ECs significantly in vitro. Furthermore, the blood flow velocity of CoCr-Dopa/MIPC@ZIF-90 stent was similar to natural aorta and ECs coverage on it was greatly strengthened after 30 days in a rat aorta vascular stent implantation model. Collectively, CoCr-Dopa/MIPC@ZIF-90 exhibited obvious superiority in reducing the formation of thrombus and promoting endothelial regeneration, which might meet the high requirement for the next generation of vascular stent., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Parkinson's disease (PD) is the second-most prevalent neurodegenerative disease worldwide, which worsens with advancing age. It is a common movement disorder and is often associated with several vascular diseases with decreased stroke frequency. Circulating platelets substantially regulate vascular complications, including stroke, and share striking similarities with PD neurons. Although structural alterations in platelets are well-documented in PD, their functional parameters remain unclear. This study aimed to investigate the functional abnormalities in platelets associated with PD by evaluating key functional aspects such as adhesion, activation, secretion, aggregation, and clot retraction. To achieve this, we treated human blood platelets with 6-hydroxydopamine or 6-OHDA, that selectively destroys dopaminergic neurons, thereby creating an in vitro experimental model that closely resembles the pathogenic environment in PD, and examine its impact on platelet functions. In our study, platelet adhesion was assessed and further evaluated by a microplate reader, activation and secretion by a flow cytometer, aggregation by aggregometer, and clot retraction by Sonoclot. Phase-contrast and confocal microscopic studies further verified the results from the above experiments. Our findings showed that 6-OHDA treatment significantly inhibited thrombin (a platelet agonist)-induced functions, including adhesion, activation, aggregation, secretion, and clot retraction in human-washed platelets. In summary, this research provides pioneering evidence that 6-OHDA induces abnormal platelet functions, shedding light on the previously unexplored processes by which 6-OHDA affects platelet activity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 International Brain Research Organization (IBRO). Published by Elsevier Inc. All rights reserved.)

To expand the selection of raw material for fabricating extracorporeal membrane oxygenation (ECMO) and promote its application in lung disease therapy, polyether ether ketone hollow fiber membrane (PEEK-HFM) with designable pore characteristics, desired mechanical performances, and excellent biocompatibility was selected as the potential substitute for existing poly (4-methyl-1-pentene) hollow fiber membrane (PMP-HFM). To address the platelet adhesion and plasma leakage issues with PEEK-HFM, a natural anticoagulant heparin was grafted onto the surface using ultraviolet irradiation. Additionally, to explore the substitutability of the heparin layer while considering cost and scalability, a heparin-like layer composed of copolymers of acrylic acid and sodium p-styrenesulfonate was also constructed on the surface of PEEK-HFM Even though the successful grafting of heparin and heparin-like layers on the PEEK-HFM surface reduced the pore parameters, improvements in surface hydrophilicity also prevented the platelet-adhesion phenomenon and improved the anticoagulant behaviour, making it a viable alternative for commercial PMP-HFMs in ECMO production. Furthermore heparin-modified and heparin-like modified PEEK-HFMs demonstrated similar performance, indicating that synthetic layers can effectively replace natural heparin. This study holds practical and instructive significance for future research and the application of membranes in the development of oxygenators., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The study focuses on developing a bioactive shape memory sponge to address the urgent demand for short-term rapid hemostasis and long-term wound healing in noncompressible hemorrhage cases. A composite sponge was created by spontaneously generating pores and double cross-linking under mild conditions using biomimetic collagen fibril (BCF) and oxidized alginate (OA) as natural backbone, combined with an inert calcium source (Ca) from CaCO 3 -GDL slow gelation mechanism. The optimized BCF/OACa (5/5) sponge efficiently absorbed blood after compression and recovered to its original state within 11.2 ± 1.3 s, achieving physical hemostatic mechanism. The composite sponge accelerated physiological coagulation by promoting platelet adhesion and activation through BCF, as well as enhancing endogenous and exogenous hemostatic pathways by Ca 2+ . Compared to commercial PVA expanding hemostatic sponge, the composite sponge reduced bleeding volume and shortened hemostasis time in rat liver injury pick and perforation wound models. Additionally, it stimulated fibroblast migration and differentiation, thus promoting wound healing. It is biodegradable with low inflammatory response and promotes granulation tissue regeneration. In conclusion, this biocomposite sponge provides multiple hemostatic pathways and biochemical support for wound healing, is biologically safe and easy to fabricate, process and use, with significant potential for clinical translation and application., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Anticoagulation treatment for patients with high bleeding risk during hemodialysis is challenging. Contact between the dialysis membrane and the blood leads to protein adsorption and activation of the coagulation cascade reaction. Activated coagulation Factor X (FXa) plays a central role in thrombogenesis, but anticoagulant modification of the dialysis membrane is rarely targeted at FXa. In this study, we constructed an anticoagulant membrane using the polydopamine coating method to graft FXa inhibitors (apixaban and rivaroxaban) on the membrane surface. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the membranes. The apixaban- and rivaroxaban - modified membranes showed lower water contact angles, decreased albumin protein adsorption, and suppressed platelet adhesion and activation compared to the unmodified PES membranes. Moreover, the modified membranes prolonged the blood clotting times in both the intrinsic and extrinsic coagulation pathways and inhibited FXa generation and complement activation, which suggested that the modified membrane enhanced biocompatibility and antithrombotic properties through the inhibition of FXa. Targeting FXa to design antithrombotic HD membranes or other blood contact materials might have great application potential.

Heparin coatings are widely applied on blood-contact materials to reduce the use of anticoagulants during blood treatment. However, the previous heparin coatings formed via covalent binding or electrostatic bonding commonly require complex surface premodification, and the blood coagulation pathway was significantly inhibited to potentially increase the bleeding risk. This contradicts the intended purpose and deviates from the anticoagulation mechanism of the heparin coatings. Herein, we present a facile and substrate-independent coating, achieved through the co-deposition of dopamine/chitosan followed by electrostatic interaction between heparin and the immobilized chitosan, which could be prepared within 1 hour. This coating prolonged the plasma re-calcification time (PRT) to over 60 minutes, effectively preventing surface-induced thrombosis. Favorable hemocompatibility was reflected in a hemolysis ratio of less than 2%, low levels of platelet adhesion and activation, and low levels of fibrinogen adhesion. We also systematically elucidate the anticoagulant mechanism of the coating, demonstrating why the coating can prevent thrombogenesis without the bleeding risk. Our work not only offers a promising and readily available heparin coating for blood-contact materials, but more importantly, the mechanism exploration supports the practical feasibility of heparin coating in various applications.

Background: We investigated whether the condition of the inner surface of hollow fibers affects the blood compatibility of hemodialyzers., Methods: We used scanning probe microscope/atomic force microscopy (SPM/AFM) to investigate the height of the swelling and flexible layers (thickness and softness) on the inner surfaces of the hollow fibers. Next, we tested the blood compatibility between dialyzers comprising a hollow fiber membrane, in which the other dialyzers, except for PVP, were additionally coated using PS membranes coated with other materials. After blood was injected into the dialyzer and plugged, dynamic stimulation was performed by slightly rotating the dialyzer for 4 h, although there was no blood circulation., Results: The vitamin E-coated polysulfone (PS) membrane showed a higher thickness and softness of the flexible layer than the asymmetric cellulose triacetate membrane without polyvinylpyrrolidone (PVP) and the PS membranes with PVP. We found that the dialyzer with vitamin E coating significantly suppressed the decrease in platelets, increase in β-TG, and increase in PF4 compared to those coated with NV polymer. Additionally, as the adsorbed protein on the inner surface, the total protein, fibronectin, and vWF levels were significantly lower in the vitamin E-coated dialyzer., Conclusion: The thickness and softness of the flexible layer of the inner surface of the hollow fiber membrane in vitro affect differences in blood coagulation performance in clinical research. Future clinical trials are required to confirm our results., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Ryo Takatsuji, Masahide Koremoto, Yuko Saida, and Yoshihiro Hatanaka are employees of Asahi Kasei Medical Corporation. Yoko Fujimoto is an employee of Asahi Kasei Corporation.

The clinical utility of small-diameter vascular grafts (SDVGs) is limited due to the possibility of thrombosis and intimal hyperplasia. These features can delay the development of a functional endothelial cell (EC) monolayer on the luminal surface of grafts. Therefore, the development and fabrication of vascular grafts (VGs) with comparable extracellular matrix (ECM) functions are mandatory to elicit hemocompatible confluent EC monolayers, and angiogenesis behavior inside the body. To promote the interactions between ECs and the surface of electrospun polyacrylic acid-grafted polyhedral oligomeric silsesquioxane-poly(carbonate-urea)-urethane (PAAc-POSS-PCUU), in this research, the surface of nanofibers was modified by covalently immobilizing extracted soluble proteins from aorta (ESPA) using EDC/NHS chemistry. The ATR-FTIR spectroscopy, WCA, and SEM microscopy confirmed the binding of acrylic acid and soluble vascular proteins on the surface of electrospun fibers. The PAAc-POSS-PCUU nanofibers and engineered biomimetic Pro-PAAc-POSS-PCUU nanofibers exhibited excellent biocompatibility indicated by increased survival rate (p < 0.05). Western blotting revealed the increase of VE-cadherin, Tie-2, vWF, and VEGFR-2 in HUVECs after being plated on PAAc-POSS-PCUU and Pro-PAAc-POSS-PCUU scaffolds, indicating appropriate angiogenesis behavior (p < 0.05). Besides, the antioxidant capacity was induced by the increase of SOD and GPx activity (p < 0.05). Additionally, blood compatibility tests revealed that Pro-PAAc-POSS-PCUU nanofibers accelerate the formation of a single EC layer without hemolysis and platelet adhesion. Taken together, Pro-PAAc-POSS-PCUU nanofibers exhibited excellent blood compatibility, and angiogenesis behavior, making them a promising candidate for clinical applications., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024. Published by Elsevier B.V.)

While blood-contacting materials are widely deployed in medicine in vascular stents, catheters, and cannulas, devices fail in situ because of thrombosis and restenosis. Furthermore, microbial attachment and biofilm formation is not an uncommon problem for medical devices. Even incremental improvements in hemocompatible materials can provide significant benefits for patients in terms of safety and patency as well as substantial cost savings. Herein, a novel but simple strategy is described for coating a range of medical materials, that can be applied to objects of complex geometry, involving plasma-grafting of an ultrathin hyperbranched polyglycerol coating (HPG). Plasma activation creates highly reactive surface oxygen moieties that readily react with glycidol. Irrespective of the substrate, coatings are uniform and pinhole free, comprising O─C─O repeats, with HPG chains packing in a fashion that holds reversibly binding proteins at the coating surface. In vitro assays with planar test samples show that HPG prevents platelet adhesion and activation, as well as reducing (>3 log) bacterial attachment and preventing biofilm formation. Ex vivo and preclinical studies show that HPG-coated nitinol stents do not elicit thrombosis or restenosis, nor complement or neutrophil activation. Subcutaneous implantation of HPG coated disks under the skin of mice shows no evidence of toxicity nor inflammation., (© 2024 The Author(s). Advanced Healthcare Materials published by Wiley‐VCH GmbH.)

Most breast implants currently used in both reconstructive and cosmetic surgery have a silicone outer shell, which, despite much progress, remains susceptible to mechanical failure, infection, and foreign body response. This study shows that the durability and biocompatibility of breast implant-grade silicone can be enhanced by incorporating carbon nanomaterials of sp 2 and sp 3 hybridization into the polymer matrix and onto its surface. Plasma treatment of the implant surface can be used to modify platelet adhesion and activation to prevent thrombosis, postoperative infection, and inflammation disorders. The addition of 0.8% graphene flakes resulted in an increase in mechanical strength by 64% and rupture strength by around 77% when compared to pure silicone, whereas when nanodiamond (ND) was used as the additive, the mechanical strength was increased by 19.4% and rupture strength by 37.5%. Composites with a partially embedded surface layer of either graphene or ND showed superior antimicrobial activity and biocompatibility compared to pure silicone. All composite materials were able to sustain the attachment and growth of human dermal fibroblast, with the preferred growth noted on ND-coated surfaces when compared to graphene-coated surfaces. Exposure of these materials to hydrogen plasma for 5, 10, and 20 s led to substantially reduced platelet attachment on the surfaces. Hydrogen-treated pure silicone showed a decrease in platelet attachment for samples treated for 5-20 s, whereas silicone composite showed an almost threefold decrease in platelet attachment for the same plasma treatment times. The absence of platelet activation on the surface of composite materials suggests a significant improvement in hemocompatibility of the material.

In this investigation, the electrospun nanocomposite scaffolds were developed utilizing poly-3-hydroxybutyrate (PHB), zein, and multiwalled carbon nanotubes (MWCNTs) at varying concentrations of MWCNTs including 0.5 and 1 wt%. Based on the SEM evaluations, the scaffold containing 1 wt% MWCNTs (PZ-1C) exhibited the lowest fiber diameter (384 ± 99 nm) alongside a suitable porosity percentage. The presence of zein and MWCNT in the chemical structure of the scaffold was evaluated by FTIR. Furthermore, TEM images revealed the alignment of MWCNTs with the fibers. Adding 1 % MWCNTs to the PHB-zein scaffold significantly enhanced tensile strength by about 69 % and reduced elongation by about 31 %. Hydrophilicity, surface roughness, crystallinity, and biomineralization were increased by incorporating 1 wt% MWCNTs, while weight loss after in vitro degradation was decreased. The MG-63 cells exhibited enhanced attachment, viability, ALP secretion, calcium deposition, and gene expression (COLI, RUNX2, and OCN) when cultivated on the scaffold containing MWCNTs compared to the scaffolds lacking MWCNTs. Moreover, the study found that MWCNTs significantly reduced platelet adhesion and hemolysis rates below 4 %, indicating their favorable anti-hemolysis properties. Regarding the aforementioned results, the PZ-1C electrospun composite scaffold is a promising scaffold with osteogenic properties for bone tissue engineering applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Thrombosis is a key process that determines acute coronary syndrome and ischemic stroke and is the leading cause of morbidity and mortality in the world, together with cancer. Platelet adhesion and subsequent activation and aggregation are critical processes that cause thrombus formation after endothelial damage. To date, high hopes are associated with compounds of natural origin, which show anticoagulant action without undesirable effects and can be proposed as supportive therapies. We investigated the effect of the new combination of four natural compounds, escin-bromelain-ginkgo biloba-sage miltiorrhiza (EBGS), on the initial process of the coagulation cascade, which is the adhesion of platelets to activated vascular endothelium. Our results demonstrated that EBGS pretreatment of endothelial cells reduces platelet adhesion even in the presence of the monocyte-lymphocyte population. Our data indicate that EBGS exerts its effects by inhibiting the transcription of adhesion molecules, including P-selectin, platelet membrane glycoprotein GP1b, integrins αV and β3, and reducing the secretion of the pro-inflammatory cytokines interleukin 6, interleukin 8, and the metalloproteinases MMP-2 and MMP-9. Furthermore, we demonstrated that EBGS inhibited the expression of focal adhesion kinase (FAK), strictly involved in platelet adhesion, and whose activity is correlated with that of integrin β3. The results shown in this manuscript suggest a possible inhibitory role of the new combination EBGS in the reduction in platelet adhesion to activated endothelium, thus possibly preventing coagulation cascade initiation.

Hemostasis is the first step of emergency medical treatment. It is particularly important to develop rapid-acting and efficacious hemostatic materials. Carboxymethyl chitosan (CMCS), sodium alginate (SA) and Resina Draconis (RD) were composited uniformly by polyelectrolyte blending. Their composite sponges (CMCS/SA/RD) were prepared by freeze-induced phase separation. CMCS/SA/RD sponges were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, and their blood absorption and hemolysis ratio were analyzed. The hemostatic effect of the composite sponges was evaluated by coagulation in vitro and in vivo. The composite sponges had a porous network structure. The water absorption ratio was >8000 %, and hemolysis ratio was <5 %. CMCS/SA/RD-II and CMCS/SA/RD-III composite sponges shortened the coagulation time in vitro by 11.33 s and 9.66 s, the hepatic hemostasis time by 13.8 % and 23.3 %, and the hemostasis time after mouse-tail amputation by 28.9 % and 23.9 %, respectively. A preliminary study on its coagulation mechanism showed that CMCS/SA/RD had significant effects on erythrocyte adsorption, platelet adhesion, and shortening of the activated partial thromboplastin time., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Surface modification using zwitterionic 2-methacryloyloxyethylphosphorylcholine (MPC) polymers is one of the most reasonable ways to prepare medical devices that can suppress undesired biological reactions such as blood coagulation. Usable MPC polymers are hydrophilic and water soluble, and their surface modification strategy involves exploiting the copolymer structures by adding physical or chemical bonding moieties. In this study, we developed copolymers composed of MPC, hydrophobic anchoring moiety, and chemical cross-linking unit to clarify the role of hydrophobic interactions in achieving biocompatible and long-term stable coatings. The four kinds of MPC copolymers with cross-linking units, such as 3-methacryloxypropyl trimethoxysilane (MPTMSi), and four different hydrophobic anchoring moieties, such as 3-(methacryloyloxy)propyltris(trimethylsiloxy)silane (MPTSSi) named as PMMMSi, n -butyl methacrylate (BMA) as PMBSi, 2-ethylhexyl methacrylate (EHMA) as PMESi, and lauryl methacrylate as PMLSi, were synthesized and coated on polydimethylsiloxane, polypropylene (PP), and polymethyl pentene. These copolymers were uniformly coated on the substrate materials PP and poly(methyl pentene) (PMP), to achieve hydrophilic and electrically neutral coatings. The results of the antibiofouling test showed that PMBSi repelled the adsorption of fluorescence-labeled bovine serum albumin the most, whereas PMLSi repelled it the least. Notably, all four copolymers suppressed platelet adhesion similarly. The variations in protein adsorption quantities among the four copolymer coatings were attributed to their distinct swelling behaviors in aqueous environments. Further investigations, including 3D scanning force microscopy and neutron reflectivity measurements, revealed that the PMLSi coating exhibited a higher water intake under aqueous conditions in comparison to the other coatings. Consequently, all copolymer coatings effectively prevented the invasion of platelets but the proteins penetrated the PMLSi network. Subsequently, the dynamic stability required to induce shear stress was evaluated using a circulation system. The results demonstrated that the PMMMSi and PMLSi coatings on PMP and PP exhibited exceptional platelet repellency and maintained high stability during circulation. This study highlights the potential of hydrophobic moieties to improve hemocompatibility and stability, offering potential applications in medical devices.

Blood-biomaterial compatibility is essential for tissue repair especially for endovascular biomaterials where small-diameter vessel patency and endothelium formation is crucial. To address this issue, a composite biomaterial termed PFC fabricated from poly (glycerol sebacate), silk fibroin, and collagen was used to determine if functionalization with syndecan-4 (SYN4) would reduce thrombogenesis through the action of heparan sulfate. The material termed, PFC&#95;SYN4, has structure and composition similar to native arterial tissue and has been reported to facilitate the binding and differentiation of endothelial colony-forming cells (ECFCs). In this study, the hemocompatibility of PFC&#95;SYN4 was evaluated and compared with non-functionalized PFC, electrospun collagen, ePTFE, and bovine pericardial patch (BPV). Ultrastructurally, platelets were less activated when cultured on PFC and PFC&#95;SYN4 compared to collagen where extensive platelet degranulation was observed. Quantitatively, 31% and 44% fewer platelets adhered to PFC&#95;SYN4 compared to non-functionalized PFC and collagen, respectively. Functionalization of PFC resulted in reduced levels of complement activation compared to PFC, collagen, and BPV. Whole blood clotting times indicated that PFC&#95;SYN4 was less thrombogenic compared with PFC, collagen, and BPV. These results suggest that syndecan-4 functionalization of blood-contacting biomaterials provides a novel solution for generating a reduced thrombogenic surface., (© 2023. The Author(s).)

Humans often have bleeding, which exerts substantial selective pressure on the coagulation system to optimize hemostasis in a variety of situations. Uncontrolled hemorrhage due to severe trauma leads to morbidity and mortality. Although nonbiological surfaces such as silicates can activate coagulation factor XII (FXII), the presence of Zn (Zinc) in the material stimulates and activates the various steps in the coagulation cascade. This results in blood clotting. The Zn@SiO 2 nanocomposite has an excellent hemostatic property that establishes hemostasis by activating the factors responsible for the formation of a stable clot called fibrin mesh. This can be used as a hemostatic agent during surgeries and in any other trauma condition related to bleeding. Zn@SiO 2 was synthesized and characterized with XRD, FTIR and HRTEM. It is analyzed for its RBC (Red Blood Corpuscles) aggregation and Platelet adhesion ability, fibrin formation, thrombus formation and prothrombin time (PT), Activated Partial Thromboplastin Time (aPTT), D-dimer for its ability to activate the coagulation cascade to achieve stable clotting., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: During the transition from dual antiplatelet therapy (DAPT) to single antiplatelet therapy (SAPT), previous studies have raised concerns about a rebound effect. We compared platelet and inflammatory cell adhesion on different types of stents in the setting of clopidogrel presence and withdrawal., Methods: In Experiment 1, three pigs were administered with DAPT, that is, clopidogrel and acetylsalicylic acid (ASA), for 7 days. Each animal underwent an extracorporeal carotid arteriovenous shunt model implanted with fluoropolymer-coated everolimus-eluting stent (FP-EES), biodegradable-polymer sirolimus-eluting stent (BP-SES), and biodegradable-polymer everolimus-eluting stents (BP-EES). In Experiment 2, two pigs were administered DAPT, clopidogrel was then withdrawn at day 7, and SAPT with ASA was continued for next 21 days. Then flow-loop experiments with the drawn blood from each time point were performed for FP-EES, BioLinx-polymer zotarolimus-eluting stents (BL-ZES), and BP-EES. The rebound effect was defined as the statistical increase of inflammation and platelet adhesion assessed with immunohistochemistry on the stent-strut level basis from baseline to day-14 or 28., Results: Both experiments showed platelet adhesion value was highest in BP-EES, while the least in FP-EES during DAPT therapy. There was no increase in platelet or inflammatory cell adhesion above baseline values (i.e., no therapy) due to the cessation of clopidogrel on the stent-strut level. Monocyte adhesion was the least for FP-EES with the same trend observed for neutrophil adhesion., Conclusions: No evidence of rebound effect was seen after the transition from DAPT to SAPT. FP-EES demonstrated the most favorable antithrombotic and anti-inflammatory profile regardless of the different experimental designs., (© 2024 Wiley Periodicals LLC.)

Natural and synthetic colorants present in food can modulate hemostasis, which includes the coagulation process and blood platelet activation. Some colorants have cardioprotective activity as well. However, the effect of genipin (a natural blue colorant) and synthetic blue colorants (including patent blue V and brilliant blue FCF) on hemostasis is not clear. In this study, we aimed to investigate the effects of three blue colorants-genipin, patent blue V, and brilliant blue FCF-on selected parameters of hemostasis in vitro. The anti- or pro-coagulant potential was assessed in human plasma by measuring the following coagulation times: thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (APTT). Moreover, we used the Total Thrombus formation Analysis System (T-TAS, PL-chip) to evaluate the anti-platelet potential of the colorants in whole blood. We also measured their effect on the adhesion of washed blood platelets to fibrinogen and collagen. Lastly, the cytotoxicity of the colorants against blood platelets was assessed based on the activity of extracellular lactate dehydrogenase (LDH). We observed that genipin (at all concentrations (1-200 µM)) did not have a significant effect on the coagulation times (PT, APTT, and TT). However, genipin at the highest concentration (200 µM) and patent blue V at the concentrations of 1 and 10 µM significantly prolonged the time of occlusion measured using the T-TAS, which demonstrated their anti-platelet activity. We also observed that genipin decreased the adhesion of platelets to fibrinogen and collagen. Only patent blue V and brilliant blue FCF significantly shortened the APTT (at the concentration of 10 µM) and TT (at concentrations of 1 and 10 µM), demonstrating pro-coagulant activity. These synthetic blue colorants also modulated the process of human blood platelet adhesion, stimulating the adhesion to fibrinogen and inhibiting the adhesion to collagen. The results demonstrate that genipin is not toxic. In addition, because of its ability to reduce blood platelet activation, genipin holds promise as a novel and valuable agent that improves the health of the cardiovascular system and reduces the risk of cardiovascular diseases. However, the mechanism of its anti-platelet activity remains unclear and requires further studies. Its in vivo activity and interaction with various anti-coagulant and anti-thrombotic drugs, including aspirin and its derivatives, should be examined as well.

Developing a reliable method to predict thrombocytopenia is imperative in drug discovery. Here, we establish an assay using a microphysiological system (MPS) to recapitulate the in-vivo mechanisms of platelet aggregation and adhesion. This assay highlights the role of shear stress on platelet aggregation and their interactions with vascular endothelial cells. Platelet aggregation induced by soluble collagen was detected under agitated, but not static, conditions using a plate shaker and gravity-driven flow using MPS. Notably, aggregates adhered on vascular endothelial cells under gravity-driven flow in the MPS, and this incident increased in a concentration-dependent manner. Upon comparing the soluble collagen-induced aggregation activity in platelet-rich plasma (PRP) and whole blood, remarkable platelet aggregate formation was observed at concentrations of 30 µg/mL and 3 µg/mL in PRP and whole blood, respectively. Moreover, ODN2395, an oligonucleotide, induced platelet aggregation and adhesion to vascular endothelial cells. SYK inhibition, which mediated thrombogenic activity via glycoprotein VI on platelets, ameliorated platelet aggregation in the system, demonstrating that the mechanism of platelet aggregation was induced by soluble collagen and oligonucleotide. Our evaluation system partially recapitulated the aggregation mechanisms in blood vessels and can contribute to the discovery of safe drugs to mitigate the risk of thrombocytopenia., (© 2024. The Author(s).)

Vessel transplantation is currently considered the "gold standard" treatment for cardiovascular disease. However, ideal artificial vascular grafts should possess good biocompatibility and mechanical strength that match those of native autologous vascular tissue to promote in vivo tissue regeneration. In this study, a series of dynamic cross-linking double-network hydrogels and the resultant hydrogel tubes were prepared. The hydrogels (named PCO), composed of rigid poly(vinyl alcohol) (PVA), flexible carboxymethyl chitosan (CMCS), and a cross-linker of aldehyde-based β-cyclodextrin (OCD), were formed in a double-network structure with multiple dynamical cross-linking including dynamic imine bonds, hydrogen bonds, and microcrystalline regions. The PCO hydrogels exhibited superior mechanical strength, good network stability, and fatigue resistance. Additionally, it demonstrated excellent cell and blood compatibility. The results showed that the introduction of CMCS/OCD led to a significant increase in the proliferation rate of endothelial cells seeded on the surface of the hydrogel. The hemolysis rate in the test was lower than 0.3%, and both protein adsorption and platelet adhesion were reduced, indicating an excellent anticoagulant function. The plasma recalcification time test results showed that endogenous coagulation was alleviated to some extent. When formed into blood vessels and incubated with blood, no thrombus formation was observed, and there was minimal red blood cell aggregation. Therefore, this novel hydrogel tube, with excellent mechanical properties, exhibits antiadhesive characteristics toward blood cells and proteins, as well as antithrombotic properties, making it hold tremendous potential for applications in the biomedical and engineering fields.

Decellularized vascular tissue has high potential as a tissue-engineered vascular graft because of its similarity to native vessels in terms of mechanical strength. However, exposed collagen on the tissue induces blood coagulation, and low hemocompatibility is a major obstacle to its vascular application. Here we report that freeze-drying and ethanol treatment effectively modify collagen fiber structure and drastically reduce blood coagulation on the graft surface without exogenous chemical modification. Decellularized carotid artery of ostrich was treated with freeze-drying and ethanol solution at concentrations ranging between 5 and 99.5 %. Collagen fiber distance in the graft was narrowed by freeze-drying, and the non-helical region increased by ethanol treatment. Although in vitro blood coagulation pattern was similar on the grafts, platelet adhesion on the grafts was largely suppressed by freeze-drying and ethanol treatments. Ex vivo blood circulation tests also indicated that the adsorption of platelets and Von Willebrand Factor was largely reduced to approximately 80 % by ethanol treatment. These results indicate that structural modification of collagen fibers in decellularized tissue reduces blood coagulation on the surface by inhibiting platelet adhesion., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In response to the critical demand for advancements in coronary artery stents, this study addresses the challenges associated with arterial recoil and restenosis post-angioplasty and the imperative to encourage rapid re-endothelialization for minimizing thrombosis risks. We employed an innovative approach inspired by mussel adhesion, incorporating placental anticoagulant protein (AnnexinV) on stent design. The introduction of a post-translationally modified catecholic amino acid L-3,4-dihydroxyphenylalanine (L-Dopa), mimicking mussel characteristics, allowed for effective surface modification of Stainless steel stents through genetic code engineering in AnnexinV (AnxDopa). The efficacy of AnxDopa was analyzed through microscale thermophoresis and flow cytometry, confirming AnxDopa's exceptional binding with phosphatidylserine and activated platelets. AnxDopa coated stainless steel demonstrates remarkable bio-, hemo-, and immuno-compatibility, preventing smooth muscle cell proliferation, platelet adhesion, and fibrin formation. It acts as an interface between the stent and biological fluid, which facilitates the anticoagulation and rapid endothelialization. Surface modification of SS verified through XPS analysis and contact angle measurement attests to the efficacy of AnxDopa mediated surface modification. The hydrophilic nature of the AnxDopa-coated surface enhanced the endothelialization through increased protein absorption. This approach represents a significant stride in developing coronary stents with improved biocompatibility and reduced restenosis risks, offering valuable contributions to scientific and clinical realms alike., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Nowadays, developing vascular grafts (e.g., vascular patches and tubular grafts) is challenging. Bacterial cellulose (BC) with 3D fibrous network has been widely investigated for vascular applications. In this work, different from BC vascular patch cultured with the routine culture medium, dopamine (DA)-containing culture medium is employed to in situ synthesize dense BC fibrous structure with significantly increased fiber diameter and density. Simultaneously, BC fibers are modified by DA during in situ synthesis process. Then DA on BC fibers can self-polymerize into polydopamine (PDA) accompanied with the removal of bacteria in NaOH solution, obtaining PDA-modified dense BC (PDBC) vascular patch. Heparin (Hep) is subsequently covalently immobilized on PDBC fibers to form Hep-immobilized PDBC (Hep@PDBC) vascular patch. The obtained results indicate that Hep@PDBC vascular patch exhibits remarkable tensile and burst strength due to its dense fibrous structure. More importantly, compared with BC and PDBC vascular patches, Hep@PDBC vascular patch not only displays reduced platelet adhesion and improved anticoagulation activity, but also promotes the proliferation, adhesion, spreading, and protein expression of human umbilical vein endothelial cells, contributing to the endothelialization process. The combined strategy of in situ densification and Hep immobilization provides a feasible guidance for the construction of BC-based vascular patches., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Within the pro-metastatic hemato-microenvironment, interaction between platelets and tumor cells provides essential support for tumor cells by inducing Epithelial-Mesenchymal Transition (EMT), which greatly increases the stemness of colon cancer cells. Pharmacologically, although platelet deactivation has proved to be benefit against metastasis, its wide application is severely restricted due to the bleeding risk. Spatholobi Caulis, a traditional Chinese herb with circulatory promotion and blood stasis removal activity, has been proved to be clinically effective in malignant medication, leaving its mechanistic relevance to tumor-platelet interaction largely unknown., Methods: Firstly, MC38-Luc cells were injected into tail-vein in C57BL/6 mice to establish hematogenous metastasis model and the anti-metastasis effects of SEA were evaluated by using a small-animal imaging system. Then, we evaluated the anti-tumor-platelet interaction efficacy of SEA using a tumor-specific induced platelet aggregation model. Platelet aggregation was specifically induced by tumor cells in vitro. Furthermore, to clarify the anti-metastatic effects of SEA is mainly attributed to its blockage on tumor-platelet interaction, after co-culture with tumor cells and platelets (with or without SEA), MC38-Luc cells were injected into the tail-vein and finally count the total of photons quantitatively. Besides, to clarify the blocking pattern of SEA within the tumor-platelet complex, the dependence of SEA on different fractions from activated platelets was tested. Lastly, molecular docking screening were performed to screen potential effective compounds and we used β-catenin blockers to verify the pathways involved in SEA blocking tumor-platelet interaction., Results: Our study showed that SEA was effective in blocking tumor-platelet specific interaction: (1) Through CCK-8 and LDH assays, SEA showed no cytotoxic effects on tumor cells and platelets. On this basis, by the tail vein injection model, the photon counts in the SEA group was significantly lower than model group, indicating that SEA effectively reduced metastasis. (2) In the "tumor-platelet" co-culture model, SEA effectively inhibited the progression of EMT and cancer stemness signatures of MC38 cells in the model group. (3) In mechanism study, by using the specific inhibitors for galectin-3 (GB1107) andWNT (IWR) respectively, we proved that SEA inhibits the activation of the galectin-3-mediated β-catenin activation., Conclusion: By highlighting the pro-metastatic effects of galectin-3-mediated tumor-platelet adhesion, our study provided indicative evidence for Spatholobi Caulis as the representative candidate for anti-metastatic therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier GmbH.)

Due to its biofunctions similar to NO, the CO gas signaling molecule has gradually shown great potential in cardiovascular biomaterials for regulating the in vivo performances after the implantation and has received increasing attention. To construct a bioactive surface with CO-releasing properties on the surface of magnesium-based alloy to augment the anticorrosion and biocompatibility, graphene oxide (GO) was firstly modified using carboxymethyl chitosan (CS), and then CO-releasing molecules (CORM401) were introduced to synthesize a novel biocompatible nanomaterial (GOCS-CO) that can release CO in the physiological environments. The GOCS-CO was further immobilized on the magnesium alloy surface modified by polydopamine coating with Zn 2+ (PDA/Zn) to create a bioactive surface capable of releasing CO in the physiological environment. The outcomes showed that the CO-releasing coating can not only significantly enhance the anticorrosion and abate the corrosion degradation rate of the magnesium alloy in a simulated physiological environment, but also endow it with good hydrophilicity and a certain ability to adsorb albumin selectively. Owing to the significant enhancement of anticorrosion and hydrophilicity, coupled with the bioactivity of GOCS, the modified sample not only showed excellent ability to prevent platelet adhesion and activation and reduce hemolysis rate but also can promote endothelial cell (EC) adhesion, proliferation as well as the expression of nitric oxide (NO) and vascular endothelial growth factor (VEGF). In the case of CO release, the hemocompatibility and EC growth behaviors were further significantly improved, suggesting that CO molecules released from the surface can significantly improve the hemocompatibility and EC growth. Consequently, the present study provides a novel surface modification method that can simultaneously augment the anticorrosion and biocompatibility of magnesium-based alloys, which will strongly promote the research and application of CO-releasing bioactive coatings for surface functionalization of cardiovascular biomaterials and devices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Degradable magnesium alloy stents are considered to be ideal candidates to replace the traditional non-degradable stents for the treatment of cardiovascular diseases. However, bare magnesium alloy stents usually degrade too fast and show poor hemocompatibility and cytocompatibility, which seriously affects their clinical use. In this study, surface modification based on the MgF 2 layer, polydopamine (PDA) coating, fucoidan and CAG peptides was performed on the Mg-Zn-Y-Nd (ZE21B) magnesium alloy with the purpose of improving its corrosion resistance, hemocompatibility and cytocompatibility for vascular stent application. After modification, the ZE21B alloy showed better corrosion resistance. Moreover, the lower hemolysis rate, platelet adhesion and activation, and fibrinogen adsorption and denaturation proved the improved hemocompatibility of modified ZE21B alloy in in vitro blood experiments. Furthermore, the co-immobilization of fucoidan and CAG peptides significantly promoted the adhesion, proliferation, migration and NO release of endothelial cells (ECs) on the modified ZE21B alloy, and meanwhile the modification with fucoidan and CAG peptides inhibited the adhesion and proliferation of smooth muscle cells (SMCs) and suppressed the expression of proinflammatory factors in the macrophages (MAs). The surface modification obviously enhanced the corrosion resistance, hemocompatibility and cytocompatibility of ZE21B alloy, and provided an effective strategy for the development of degradable vascular stents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Abstract: Activation of von Willebrand factor (VWF) is a tightly controlled process governed primarily by local elements around its A1 domain. Recent studies suggest that the O-glycosylated sequences flanking the A1 domain constitute a discontinuous and force-sensitive autoinhibitory module (AIM), although its extent and conformation remains controversial. Here, we used a targeted screening strategy to identify 2 groups of nanobodies. One group, represented by clone 6D12, is conformation insensitive and binds the N-terminal AIM (NAIM) sequence that is distal from A1; 6D12 activates human VWF and induces aggregation of platelet-rich plasma at submicromolar concentrations. The other group, represented by clones Nd4 and Nd6, is conformation sensitive and targets the C-terminal AIM (CAIM). Nd4 and Nd6 inhibit ristocetin-induced platelet aggregation and reduce VWF-mediated platelet adhesion under flow. A crystal structure of Nd6 in complex with AIM-A1 shows a novel conformation of both CAIM and NAIM that are primed to interact, providing a model of steric hindrance stabilized by the AIM as the mechanism for regulating GPIbα binding to VWF. Hydrogen-deuterium exchange mass spectrometry analysis shows that binding of 6D12 induces the exposure of the GPIbα-binding site in the A1 domain, but binding of inhibitory nanobodies reduces it. Overall, these results suggest that the distal portion of NAIM is involved in specific interactions with CAIM, and binding of nanobodies to the AIM could either disrupt its conformation to activate VWF or stabilize its conformation to upkeep VWF autoinhibition. These reported nanobodies could facilitate future studies of VWF functions and related pathologies., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Binding of blood components to collagen was proved to be a key step in thrombus formation. Intelligent Design of Protein Matcher (IDProMat), a neural network model, was then developed based on the principle of seq2seq to design an antithrombotic peptide targeting collagen. The encoding and decoding of peptide sequence data and the interaction patterns of peptide chains at the interface were studied, and then, IDProMat was applied to the design of peptides to cover collagen. The 99.3% decrease in seq2seq loss and 58.3% decrease in MLP loss demonstrated that IDProMat learned the interaction patterns between residues at the binding interface. An efficient peptide, LRWNSYY, was then designed using this model. Validations on its binding on collagen and its inhibition of platelet adhesion were obtained using docking, MD simulations, and experimental approaches.

Catheter-induced thrombosis is a major contributor to infectious and mechanical complications of biomaterials that lead to device failure. Herein, a dualfunction submicron textured nitric oxide (NO)-releasing catheter was developed. The hemocompatibility and antithrombotic activity of vascular catheters were evaluated in both 20 h in vitro blood loop and 7 d in vivo rabbit model. Surface characterization assessments via atomic force microscopy show the durability of the submicron pattern after incorporation of NO donor S-nitroso-N-acetylpenicillamine (SNAP). The SNAP-doped catheters exhibited prolonged and controlled NO release mimicking the levels released by endothelium. Fabricated catheters showed cytocompatibility when evaluated against BJ human fibroblast cell lines. After 20h in vitro evaluation of catheters in a blood loop, textured-NO catheters exhibited a 13-times reduction in surface thrombus formation compared to the control catheters, which had 83% of the total area covered by clots. After the 7 d in vivo rabbit model, analysis on the catheter surface was examined via scanning electron microscopy, where significant reduction of platelet adhesion, fibrin mesh, and thrombi can be observed on the NO-releasing textured surfaces. Moreover, compared to relative controls, a 63% reduction in the degree of thrombus formation within the jugular vein was observed. Decreased levels of fibrotic tissue decomposition on the jugular vein and reduced platelet adhesion and thrombus formation on the texture of the NO-releasing catheter surface are indications of mitigated foreign body response. This study demonstrated a biocompatible and robust dual-functioning textured NO PU catheter in limiting fouling-induced complications for longer-term blood-contacting device applications. STATEMENT OF SIGNIFICANCE: Catheter-induced thrombosis is a major contributor to infectious and mechanical complications of biomaterials that lead to device failure. This study demonstrated a robust, biocompatible, dual-functioning textured nitric oxide (NO) polyurethane catheter in limiting fouling-induced complications for longer-term blood-contacting device applications. The fabricated catheters exhibited prolonged and controlled NO release that mimics endothelium levels. After the 7 d in vivo model, a significant reduction in platelet adhesion, fibrin mesh, and thrombi was observed on the NO-releasing textured catheters, along with decreased levels of fibrotic tissue decomposition on the jugular vein. Results illustrate that NO-textured catheter surface mitigates foreign body response., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Hitesh Handa is a founder of Nytricx INC, which is involved in exploring possibilities of using nitric oxide-releasing materials for medical applications., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Several Janus kinase (JAK) inhibitors (jakinibs) have recently been approved to treat inflammatory, autoimmune and hematological conditions. Despite emerging roles for JAKs and downstream signal transducer and activator of transcription (STAT) proteins in platelets, it remains unknown whether jakinibs affect platelet function. Here, we profile platelet biochemical and physiological responses in vitro in the presence of five different clinically relevant jakinibs, including ruxolitinib, upadacitinib, oclacitinib, baricitinib and tofacitinib. Flow cytometry, microscopy and other assays found that potent JAK1/2 inhibitors baricitinib and ruxolitinib reduced platelet adhesion to collagen, as well as platelet aggregation, secretion and integrin α IIb β 3 activation in response to the glycoprotein VI (GPVI) agonist collagen-related peptide (CRP-XL). Western blot analysis demonstrated that jakinibs reduced Akt phosphorylation and activation following GPVI activation, where ruxolitinib and baricitinib prevented DAPP1 phosphorylation. In contrast, jakinibs had no effects on platelet responses to thrombin. Inhibitors of GPVI and JAK signaling also abrogated platelet STAT5 phosphorylation following CRP-XL stimulation. Additional pharmacologic experiments supported roles for STAT5 in platelet secretion, integrin activation and cytoskeletal responses. Together, our results demonstrate that ruxolitinib and baricitinib have inhibitory effects on platelet function in vitro and support roles for JAK/STAT5 pathways in GPVI/ITAM mediated platelet function.

Cannabis usage has steadily increased as acceptance is growing for both medical and recreational reasons. Medical cannabis is administered for treatment of chronic pain based on the premise that the endocannabinoid system signals desensitize pain sensor neurons and produce anti-inflammatory effects. The major psychoactive ingredient of cannabis is Δ9-tetrahydrocannabinol (THC) that signals mainly through cannabinoid receptor-1 (CBr), which is also present on nonneuron cells including blood platelets of the circulatory system. In vitro, CBr-mediated signaling has been shown to acutely inhibit platelet activation downstream of the platelet collagen receptor glycoprotein (GP)VI. The systemic effects of chronic THC administration on platelet activity and function remain unclear. This study investigates the effects of chronic THC administration on platelet function using a nonhuman primate (NHP) model. Our results show that female and male NHPs consuming a daily THC edible had reduced platelet adhesion, aggregation, and granule secretion in response to select platelet agonists. Furthermore, a change in bioactive lipids (oxylipins) was observed in the female cohort after THC administration. These results indicate that chronic THC edible administration desensitized platelet activity and function in response to GPVI- and G-protein coupled receptor-based activation by interfering with primary and secondary feedback signaling pathways. These observations may have important clinical implications for patients who use medical marijuana and for providers caring for these patients.

Understanding the pathways involved in the formation and stability of the core and shell regions of a platelet-rich arterial thrombus may result in new ways to treat arterial thrombosis. The distinguishing feature between these two regions is the absence of fibrin in the shell which indicates that in vitro flow-based assays over thrombogenic surfaces, in the absence of coagulation, can be used to resemble this region. In this study, we have investigated the contribution of Syk tyrosine kinase in the stability of platelet aggregates (or thrombi) formed on collagen or atherosclerotic plaque homogenate at arterial shear (1000 s -1 ). We show that post-perfusion of the Syk inhibitor PRT-060318 over preformed thrombi on both surfaces enhances thrombus breakdown and platelet detachment. The resulting loss of thrombus stability led to a reduction in thrombus contractile score which could be detected as early as 3 min after perfusion of the Syk inhibitor. A similar loss of thrombus stability was observed with ticagrelor and indomethacin, inhibitors of platelet adenosine diphosphate (ADP) receptor and thromboxane A 2 (TxA 2 ), respectively, and in the presence of the Src inhibitor, dasatinib. In contrast, the Btk inhibitor, ibrutinib, causes only a minor decrease in thrombus contractile score. Weak thrombus breakdown is also seen with the blocking GPVI nanobody, Nb21, which indicates, at best, a minor contribution of collagen to the stability of the platelet aggregate. These results show that Syk regulates thrombus stability in the absence of fibrin in human platelets under flow and provide evidence that this involves pathways additional to activation of GPVI by collagen.

Background: Thrombocytopenia is one of the most common hematological disease that can be life-threatening caused by bleeding complications. However, the treatment options for thrombocytopenia remain limited., Methods: In this study, giemsa staining, phalloidin staining, immunofluorescence and flow cytometry were used to identify the effects of 3,3'-di-O-methylellagic acid 4'-glucoside (DMAG), a natural ellagic acid derived from Sanguisorba officinalis L. (SOL) on megakaryocyte differentiation in HEL cells. Then, thrombocytopenia mice model was constructed by X-ray irradiation to evaluate the therapeutic action of DMAG on thrombocytopenia. Furthermore, the effects of DMAG on platelet function were evaluated by tail bleeding time, platelet aggregation and platelet adhesion assays. Next, network pharmacology approaches were carried out to identify the targets of DMAG. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to elucidate the underling mechanism of DMAG against thrombocytopenia. Finally, molecular docking simulation, molecular dynamics simulation and western blot analysis were used to explore the relationship between DAMG with its targets., Results: DMAG significantly promoted megakaryocyte differentiation of HEL cells. DMAG administration accelerated platelet recovery and megakaryopoiesis, shortened tail bleeding time, strengthened platelet aggregation and adhesion in thrombocytopenia mice. Network pharmacology revealed that ITGA2B, ITGB3, VWF, PLEK, TLR2, BCL2, BCL2L1 and TNF were the core targets of DMAG. GO and KEGG pathway enrichment analyses suggested that the core targets of DMAG were enriched in PI3K-Akt signaling pathway, hematopoietic cell lineage, ECM-receptor interaction and platelet activation. Molecular docking simulation and molecular dynamics simulation further indicated that ITGA2B, ITGB3, PLEK and TLR2 displayed strong binding ability with DMAG. Finally, western blot analysis evidenced that DMAG up-regulated the expression of ITGA2B, ITGB3, VWF, p-Akt and PLEK., Conclusion: DMAG plays a critical role in promoting megakaryocytes differentiation and platelets production and might be a promising medicine for the treatment of thrombocytopenia., (© 2021. The Author(s).)

Increased blood platelet activation plays an important role in cardiovascular diseases (CVDs). Recent experiments indicate that certain fruits and vegetables, including onion, garlic, and beetroot, have anti-platelet potential and therefore may reduce the likelihood of CVDs. While vegetables from the Cucuritaceae family are known to exerting beneficial antioxidant and anti-inflammatory effects, their effects on blood platelet activation are poorly understood. Therefore, the aim of the present study was to determine the effect on platelet adhesion of preparations from selected cucurbits: pumpkin (Cucurbita pepo; fruit without seeds), zucchini (Cucurbita pepo convar. giromontina; fruit with seeds), cucumber (Cucumis sativus; fruit with seeds), white pattypan squash (Cucurbita pepo var. patisoniana; fruit without seeds) and yellow pattypan squash (Cucurbita pepo var. patisoniana, fruit without seeds). It also evaluates the activity of these preparations on enzymatic lipid peroxidation in thrombin-activated washed blood platelets by TBARS assay. The study also determines the anti-platelet properties of these five cucurbit preparations in whole blood by flow cytometry and with the total thrombus-formation analysis system (T-TAS) and evaluates the cytotoxicity of the tested preparations against platelets based on LDH activity. The results indicate that the yellow Cucurbita pepo var. patisoniana preparation demonstrated stronger anti-platelet properties than the other tested preparations, reducing the adhesion of thrombin-activated platelets to collagen/fibrinogen, and inhibiting arachidonic acid metabolism and GPIIb/IIIa expression on 10 µM ADP-activated platelets. None of the preparations was found to cause platelet lysis. Our findings provide new information on the anti-platelet activity of the tested cucurbit preparations and their potential for treating CVDs associated with platelet hyperactivity., (© 2021. The Author(s).)

This study describes a method for the modification of polyurethane small-diameter (5 mm) vascular prostheses obtained with the phase inversion method. The modification process involves two steps: the introduction of a linker (acrylic acid) and a peptide (REDV and YIGSR). FTIR and XPS analysis confirmed the process of chemical modification. The obtained prostheses had a porosity of approx. 60%, Young's Modulus in the range of 9-11 MPa, and a water contact angle around 40°. Endothelial (EC) and smooth muscle (SMC) cell co-culture showed that the surfaces modified with peptides increase the adhesion of ECs. At the same time, SMCs adhesion was low both on unmodified and peptide-modified surfaces. Analysis of blood-materials interaction showed high hemocompatibility of obtained materials. The whole blood clotting time assay showed differences in the amount of free hemoglobin present in blood contacted with different materials. It can be concluded that the peptide coating increased the hemocompatibility of the surface by increasing ECs adhesion and, at the same time, decreasing platelet adhesion. When comparing both types of peptide coatings, more promising results were obtained for the surfaces coated with the YISGR than REDV-coated prostheses.

Ethnopharmacological Relevance: Arnebia euchroma (Royle) I.M.Johnst (AE) has been reported to be a potentially useful medicinal herb for the treatment of several circulatory diseases in traditional Chinese medicine. It shows effects such as "cooling of the blood," promotion of blood circulation, detoxification, and rash clearance., Aim of the Study: To explore the hemostatic effect of the ethyl acetate extract of AE in mice., Materials and Methods: In this study, we explored the effects of AE on bleeding time, blood coagulation time, platelet count, and blood coagulation parameters in normal Kunming mice. Different doses of the AE extract (5, 10, and 20 g kg -1 ·day -1 ) were administered to mice for 14 days. Sodium carboxymethyl cellulose (CMC-Na at 0.5%) and Yunnan Baiyao (0.8 g kg -1 ·day -1 ) were administered as negative and positive control treatments, respectively. Bleeding time, blood coagulation time, platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretions from blood platelets, and blood coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen (FIB) levels were measured on day 15 of administration., Results: Bleeding and blood coagulation time were significantly lower and TT was shorter in the AE extract-treated groups than in the control groups. Furthermore, FIB levels and platelet count were higher, whereas blood platelet aggregation, blood platelet adhesion to fibrinogen, and PF-4 secretion from blood platelets were more obvious in the AE extract-treated groups than in the control group. However, no significant differences were detected for PT and aPTT between the extract-treated and control groups., Conclusions: The ethyl acetate extract of AE showed potential hemostasis effects in mice by shortening the bleeding and coagulation time. In addition, the extract increased platelet count and induced blood platelet aggregation, blood platelet adhesion to fibrinogen, PF-4 secretion from blood platelets, and FIB level, while it shortened TT., (Copyright © 2021. Published by Elsevier B.V.)

A main problem in the design of blood-contacting biomaterials has been the deficiency of a systematic understanding of blood-biomaterial interactions and the strategy to modulate blood responses. In this work, different functional groups including carboxyl (COOH), hydroxyl (OH) and zwitterionic sulfobetaine group (⊕N((CH 3 ) 2 )(CH 2 ) 3 SO 3-○- , SMDB) were grafted on the poly (butylene terephthalate) (PBT) film to study how the functional groups modulate blood responses and in terms of interaction with the coagulation system, the complement system, and platelets. The results showed protein absorption and platelet adhesion was stronger on the PBT bearing COOH group than PBT films bearing OH and zwitterionic sulfobetaine groups (total protein (μg/cm 2 ): 32.92 ± 5.89 vs. 22.02 ± 1.44 vs. 19.09 ± 1.59; platelet adhesion (/mm 2 ): 1,626.7 ± 120.1 vs. 1,395.6 ± 363.3 vs. 1,102.2 ± 373.7), which had a rougher and negatively charged surface, and the coagulation system was inhibited by binding fibrinogen (Fg) and coagulation factors. Meanwhile, PBT-PSMDB showed anticoagulant property and induced platelet activation. As a result, complement formation on these two films were less than PBT bearing OH groups by inhibiting the coagulation system (C3a (ng/ml): 3,745.4 ± 143.9 vs. 3,290.9 ± 249.7 vs. 4,887.9 ± 88.9; C5a (ng/ml): 22.1 ± 2.6 vs. 22.3 ± 1.8 vs. 27.9 ± 2.0). On the other hand, PBT bearing OH groups did not facilitate remarkable platelet adhesion and activation, and had no influence on platelet aggregation, hypotonic shock response, and coagulation system. The above results showed that the blood responses were highly interlinked, and could be modulated by grafting with different functional groups on the biomaterial surfaces. These findings may help identify a strategy to design materials with better hemocompatibility for blood contact, filtration, and purification applications., (© 2021 Wiley Periodicals LLC.)

Circulating platelets establish a variety of immunological programs and orchestrate inflammatory responses at the endothelium. Platelets express the innate immunity family of Toll-like receptors (TLRs). While TLR2/TLR1 ligands are known to activate platelets, the effects of TLR2/TLR6 ligands on platelet function remain unclear. Here, we aim to determine whether the TLR2/TLR6 agonists Pam2CSK4 and FSL-1 activate human platelets. In addition, human umbilical vein endothelial cells (HUVECs) and platelets were co-cultured to analyze the role of platelet TLR2/TLR6 on inflammation and adhesion to endothelial cells. Pam2CSK4, but not FSL-1, induced platelet granule secretion and integrin α IIb β 3 activation in a concentration-dependent manner. Moreover, Pam2CSK4 promoted platelet aggregation and increased platelet adhesion to collagen-coated surfaces. Mechanistic studies with blocking antibodies and pharmacologic inhibitors demonstrated that the TLR2/Nuclear factor-κB axis, Bruton's-tyrosine kinase, and a secondary ADP feedback loop are involved in Pam2CSK4-induced platelet functional responses. Interestingly, Pam2CSK4 showed cooperation with immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling to enhance platelet activation. Finally, the presence of platelets increased inflammatory responses in HUVECs treated with Pam2CSK4, and platelets challenged with Pam2CSK4 showed increased adhesion to HUVECs under static and physiologically relevant flow conditions. Herein, we define a functional role for platelet TLR2-mediated signaling, which may represent a druggable target to dampen excessive platelet activation in thrombo-inflammatory diseases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Parra-Izquierdo, Lakshmanan, Melrose, Pang, Zheng, Jordan, Reitsma, McCarty and Aslan.)

Although dressing blood-contacting devices with robust and synergistic antibacterial and antithrombus properties has been explored for several decades, it still remains a great challenge. In order to endow materials with remarkable antibacterial and antithrombus abilities, a stable and antifouling hydrogel coating was developed via surface-initiated polymerization of sulfobetaine methacrylate and acrylic acid on a polymeric substrate followed by embedding of antimicrobial peptides (AMPs), including WR (sequence: WRWRWR-NH 2 ) or Bac2A (sequence: RLARIVVIRVAR-NH 2 ) AMPs. The chemical composition of the AMP-embedded hydrogel coating was determined through XPS, zeta potential, and SEM-EDS measurements. The AMP-embedded antifouling hydrogel coating showed not only good hemocompatibility but also excellent bactericidal and antiadhesion properties against Gram-positive and Gram-negative bacteria. Moreover, the hydrogel coating could protect the AMPs with long-term bioactivity and cover the positive charge of the dotted distributed AMPs, which in turn well retained the hemocompatibility and antifouling capacity of the bulk hydrogels. Furthermore, the microbiological results of animal experiments also verified the anti-infection performance in vivo. Histological and immunological data further indicated that the hydrogel coating had an excellent anti-inflammatory function. Therefore, the present study might provide a promising approach to prevent bacterial infections and thrombosis in clinical applications of blood-contacting devices and related implants.

Objective: platelets possess not only haemostatic but also inflammatory properties, which combined are thought to play a detrimental role in thromboinflammatory diseases such as acute coronary syndromes and stroke. Phosphodiesterase (PDE) 3 and -5 inhibitors have demonstrated efficacy in secondary prevention of arterial thrombosis, partially mediated by their antiplatelet action. Yet it is unclear whether such inhibitors also affect platelets' inflammatory functions. Here, we aimed to examine the effect of the PDE3A inhibitor cilostazol and the PDE5 inhibitor tadalafil on platelet function in various aspects of thromboinflammation. Approach and results: cilostazol, but not tadalafil, delayed ex vivo platelet-dependent fibrin formation under whole blood flow over type I collagen at 1000 s -1 . Similar results were obtained with blood from Pde3a deficient mice, indicating that cilostazol effects are mediated via PDE3A. Interestingly, cilostazol specifically reduced the release of phosphatidylserine-positive extracellular vesicles (EVs) from human platelets while not affecting total EV release. Both cilostazol and tadalafil reduced the interaction of human platelets with inflamed endothelium under arterial flow and the release of the chemokines CCL5 and CXCL4 from platelets. Moreover, cilostazol, but not tadalafil, reduced monocyte recruitment and platelet-monocyte interaction in vitro., Conclusions: this study demonstrated yet unrecognised roles for platelet PDE3A and platelet PDE5 in platelet procoagulant and proinflammatory responses.

Concentrated polymer brushes (CPBs) and semi-dilute polymer brushes (SDPBs) of poly(2-hydroxyethyl methacrylate), poly(2-hydroxyethyl acrylate), poly[poly(ethylene glycol)methyl ether methacrylate] (PPEGMA) and poly(2-methoxyetyl acrylate) were prepared on silica particles and silicon wafers by surface-initiated atom transfer radical polymerization (SI-ATRP). In order to evaluate in vitro blood compatibility, plasma protein adsorption on the brushes was quantified with a BCA protein assay, and the adsorbed proteins on the brushes were identified using high-performance liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). All four CPBs displayed much less protein adsorption than their corresponding SDPBs. Interestingly, the number and type of identified proteins differed on the brushes. Platelet adhesion was then examined on the brushes, whereby CPBs suppressed platelet adhesion to a greater extent than the corresponding SDPBs, although platelet activation was observed on all surfaces. As a result, the CPBs of PPEGMA prevented platelet adhesion the most. After screening the polymers by in vitro evaluation, CPBs of PPEGMA were then grafted on a catheter by SI-ATRP. The catheter with the CPBs was implanted into the jugular vein of a rabbit. The in vivo assessment after three weeks of implantation confirmed that the CPBs caused little coagulation or inflammation, whereas the pristine catheter exhibited inflammation and encapsulation.

Platelet accumulation by VWF under high shear rates at the site of atherosclerotic plaque rupture leads to myocardial infarction and stroke. Current anti-platelet therapies remain ineffective for a large percentage of the population, while presenting significant risks for bleeding. We explore a novel way to inhibit arterial thrombus formation. Theoretically, a negative charge may influence the tertiary structure of VWF to favor the globular configuration by biophysical means without the use of platelet inactivating drugs. We tested this hypothesis experimentally for charged nanoparticles (CNPs) to inhibit thrombus formation in a microfluidic thrombosis assay (MTA). Several different CNPs demonstrated the ability to retard thrombotic occlusion in the MTA. A preliminary study in mice shows that thrombus stability is weaker with CNP administration and bleeding times are not markedly prolonged. The CNPs tested here show promise as a new class of antithrombotic therapies that act by biophysical means rather than biochemical pathways., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Near-physiological in vitro thrombogenicity test systems for the evaluation of blood-contacting endothelialized biomaterials requires co-cultivation with platelets (PLT). However, the addition of PLT has led to unphysiological endothelial cell (EC) detachment in such in vitro systems. A possible cause for this phenomenon may be PLT activation triggered by the applied endothelial cell medium, which typically consists of basal medium (BM) and nine different supplements. To verify this hypothesis, the influence of BM and its supplements was systematically analyzed regarding PLT responses. For this, human platelet rich plasma (PRP) was mixed with BM, BM containing one of nine supplements, or with BM containing all supplements together. PLT adherence analysis was carried out in six-channel slides with plasma-treated cyclic olefin copolymer (COC) and poly(tetrafluoro ethylene) (PTFE, as a positive control) substrates as part of the six-channel slides in the absence of EC and under static conditions. PLT activation and aggregation were analyzed using light transmission aggregometry and flow cytometry (CD62P). Medium supplements had no effect on PLT activation and aggregation. In contrast, supplements differentially affected PLT adherence, however, in a polymer- and donor-dependent manner. Thus, the use of standard endothelial growth medium (BM + all supplements) maintains functionality of PLT under EC compatible conditions without masking the differences of PLT adherence on different polymeric substrates. These findings are important prerequisites for the establishment of a near-physiological in vitro thrombogenicity test system assessing polymer-based cardiovascular implant materials in contact with EC and PLT.

Blood clots (90%) originate from the left atrial appendage (LAA) in non-valvular atrial fibrillation patients and are a major cause of embolic stroke. Long-term anticoagulation therapy has been used to prevent thrombus formation, but its use is limited in patients at a high risk for bleeding complications. Thus, left atrial appendage closure (LAAC) devices for LAA occlusion are well-established as an alternative to the anticoagulation therapy. However, the anticoagulation therapy is still required for at least 45 days post-implantation to bridge the time until complete LAA occlusion by neoendocardium coverage of the device. In this study, we applied an endothelium-mimicking nanomatrix to the LAAC device membrane for delivery of nitric oxide (NO) to enhance endothelialization, with the goal of possibly being able to reduce the duration of the anticoagulation therapy. The nanomatrix was uniformly coated on the LAAC device membranes and provided sustained release of NO for up to 1 month in vitro . In addition, the nanomatrix coating promoted endothelial cell proliferation and reduced platelet adhesion compared to the uncoated device membranes in vitro . The nanomatrix-coated and uncoated LAAC devices were then deployed in a canine LAA model for 22 days as a pilot study. All LAAC devices were not completely covered by neoendocardium 22 days post-implantation. However, histology image analysis showed that the nanomatrix-coated LAAC device had thicker neoendocardium coverage compared to the uncoated device. Therefore, our in vitro and in vivo results indicate that the nanomatrix coating has the potential to enhance endothelialization on the LAAC device membrane, which could improve patient outcomes by shortening the need for extended anticoagulation treatment.

Estrogen therapy is used to treat patients with post-menopausal symptoms, such as hot flashes and dyspareunia. Estrogen therapy also decreases the risk of fractures from osteoporosis in post-menopausal women. However, estrogen increases the risk of venous thromboembolic events, such as pulmonary embolism, but the pathways through which estrogen increase the risk of thromboembolism is unknown. Here, we show that estrogen elicits endothelial exocytosis, the key step in vascular thrombosis and inflammation. Exogenous 17β-estradiol (E2) stimulated endothelial exocytosis of Weibel-Palade bodies (WPBs), releasing von Willebrand factor (vWF) and interleukin-8 (IL-8). Conversely, the estrogen antagonist ICI-182,780 interfered with E2-induced endothelial exocytosis. The ERα agonist propyl pyrazole triol (PPT) but not the ERβ agonist diarylpropionitrile (DPN) induced vWF release, while ERα silencing counteracted vWF release by E2, suggesting that ERα mediates this effect. Exocytosis triggered by E2 occurred rapidly within 15 min and was not inhibited by either actinomycin D or cycloheximide. On the contrary, it was inhibited by the pre-treatment of U0126 or SB203580, an ERK or a p38 inhibitor, respectively, suggesting that E2-induced endothelial exocytosis is non-genomically mediated by the MAP kinase pathway. Finally, E2 treatment enhanced platelet adhesion to endothelial cells ex vivo, which was interfered with the pre-treatment of ICI-182,780 or U0126. Taken together, our data show that estrogen activates endothelial exocytosis non-genomically through the ERα-MAP kinase pathway. Our data suggest that adverse cardiovascular effects such as vascular inflammation and thrombosis should be considered in patients before menopausal hormone treatment., Competing Interests: Declaration of competing interest None to declare., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The interaction of platelet GPIbα with von Willebrand factor (VWF) is essential to initiate platelet adhesion and thrombosis, particularly under high shear stress conditions. However, no drug targeting GPIbα has been developed for clinical practice. Here we characterized anfibatide, a GPIbα antagonist purified from snake (Deinagkistrodon acutus) venom, and evaluated its interaction with GPIbα by surface plasmon resonance and in silico modeling. We demonstrated that anfibatide interferds with both VWF and thrombin binding, inhibited ristocetin/botrocetin- and low-dose thrombin-induced human platelet aggregation, and decreased thrombus volume and stability in blood flowing over collagen. In a single-center, randomized, and open-label phase I clinical trial, anfibatide was administered intravenously to 94 healthy volunteers either as a single dose bolus, or a bolus followed by a constant rate infusion of anfibatide for 24 h. Anfibatide inhibited VWF-mediated platelet aggregation without significantly altering bleeding time or coagulation. The inhibitory effects disappeared within 8 h after drug withdrawal. No thrombocytopenia or anti-anfibatide antibodies were detected, and no serious adverse events or allergic reactions were observed during the studies. Therefore, anfibatide was well-tolerated among healthy subjects. Interestingly, anfibatide exhibited pharmacologic effects in vivo at concentrations thousand-fold lower than in vitro, a phenomenon which deserves further investigation.Trial registration: Clinicaltrials.gov NCT01588132.

Introduction: Although platelets contain a full proteasome system, its role in platelet function is not completely understood yet. Since the proteasome system may be involved in time-delayed processes, platelet responsiveness was investigated after long-term, bortezomib-mediated proteasome inhibition., Materials and Methods: Citrate-anticoagulated whole blood was stored with 5 nM and 1 μM bortezomib for 24 h. Consecutively, aggregation was measured by light transmission in platelet-rich-plasma (PRP). Flow cytometry was performed to determine phosphorylation levels of the vasodilator-stimulated phosphoprotein (VASP), fibrinogen binding, PAC1-antibody binding and purinergic receptor expression in PRP, P2Y12 activity or glycoprotein (GP) Ib and IIb expression in whole blood. P2Y1 and P2X1 activities were assessed by calcium flux-induced fluorescence in washed platelets. Using PRP, adherent platelets on fibrinogen-, collagen- and ristocetin-coated surfaces were visualized and quantified by immunostaining., Results: Under bortezomib, VASP phosphorylation was less inducible and nitric oxide-induced inhibition of fibrinogen binding was slightly reduced. Proteasome inhibition did not tamper adenosine diphosphate-mediated aggregation or purinergic receptor expression and activity. Induced expression of activated fibrinogen receptors and fibrinogen binding were not significantly influenced by incubation with bortezomib for 24 h. Aggregation values with threshold agonist concentrations were increased under bortezomib. Despite unchanged GPIb expression, bortezomib-treated platelets showed enhanced adhesion on coated surfaces., Conclusions: In platelets incubated for 24 h, bortezomib mediates a slight attenuation of inhibitory signaling, associated with facilitated platelet aggregation using threshold agonist concentrations and enhanced adhesion on agonist-coated surfaces., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Systemic inflammation as manifested in sepsis is an excessive, life-threatening inflammatory response to severe bacterial or viral infection or extensive injury. It is also a thrombo-inflammatory condition associated with vascular leakage/hemorrhage and thrombosis that is not effectively treated by current anti-inflammatory or anti-thrombotic drugs. Here, we show that MB2mP6 peptide nanoparticles, targeting the Gα 13 -mediated integrin "outside-in" signaling in leukocytes and platelets, inhibited both inflammation and thrombosis without causing hemorrhage/vascular leakage. MB2mP6 improved mouse survival when infused immediately or hours after onset of severe sepsis. Furthermore, platelet Gα 13 knockout inhibited septic thrombosis whereas leukocyte Gα 13 knockout diminished septic inflammation, each moderately improving survival. Dual platelet/leukocyte Gα 13 knockout inhibited septic thrombosis and inflammation, further improving survival similar to MB2mP6. These results demonstrate that inflammation and thrombosis independently contribute to poor outcomes and exacerbate each other in systemic inflammation, and reveal a concept of dual anti-inflammatory/anti-thrombotic therapy without exacerbating vascular leakage.