Low molecular weight heparins and their clinical applications

Quality control, safety assessment and preparation approaches of low molecular weight heparin

Low Molecular Weight Heparins (LMWHs) are well-established for use in the prevention and treatment of thrombotic diseases, and as a substitute for unfractionated heparin (UFH) due to their predictable pharmacokinetics and subcutaneous bioavailability. LMWHs are produced by various depolymerization methods from UFH, resulting in heterogeneous compounds with similar biochemical and pharmacological properties. However, the delicate supply chain of UFH and potential contamination from animal sources require new manufacturing approaches for LMWHs. Various LMWH preparation methods are emerging, such as chemical synthesis, enzymatic or chemical depolymerization and chemoenzymatic synthesis. To establish the sameness of active ingredients in both innovator and generic LMWH products, the Food and Drug Administration has implemented a stringent scientific method of equivalence based on physicochemical properties, heparin source material and depolymerization techniques, disaccharide composition and oligosaccharide mapping, biological and biochemical properties, and in vivo pharmacodynamic profiles. In this review, we discuss currently available LMWHs, potential manufacturing methods, and recent progress for manufacturing quality control of these LMWHs.

Nano-anticoagulant based on carrier-free low molecular weight heparin and octadecylamine with an albumin shuttling effect

Low-molecular-weight heparin (LMWH), derived from unfractionated heparin (UFH), has enhanced anticoagulant efficacy, long duration of action, and extended half-life. Patients receiving LMWH for preventive therapies would strongly benefit from its long-term effects, however, achieving this is challenging. Here, we design and evaluate a nanoengineered LMWH and octadecylamine conjugate (LMHO) that can act for a long time while maintaining close to 97 ± 3% of LMWH activity via end-specific conjugation of the reducing end of LMWH. LMHO can self-assemble into nanoparticles with an average size of 105 ± 1.7 nm in water without any nanocarrier and can be combined with serum albumin, resulting in a lipid-based albumin shuttling effect. Such molecules can circulate in the bloodstream for 4-5 days. We corroborate the self-assembly capability of LMHO and its interaction with albumin through molecular dynamics (MD) simulations and transmission electron microscopy (TEM) analysis. This innovative approach to carrier-free polysaccharide delivery, enhanced by nanoengineered albumin shuttling, represents a promising platform to address limitations in conventional therapies.

Butyrate Increases Heparin Synthesis and Storage in Human Mast Cells

Sulphated glycosaminoglycans (GAGs) such as heparin are a major component of mast cell granules and form the matrix within which biogenic mediators are stored. Since GAGs released from mast cells also play an important role in helminth expulsion, understanding GAG storage can offer new insights into mast cell function. Sodium butyrate (NaBu), a short-chain fatty acid, causes ultrastructural changes within the granules of human mast cells (HMC-1) and increases their histamine content. Therefore, we hypothesized that NaBu treatment would also modify the storage of polysaccharides such as GAGs. NaBu (1 mM) significantly increased GAG content and granularity in a time- and concentration-dependent manner without affecting cell viability and metabolic activity. NaBu increased the expression of enzymes associated with heparin biosynthesis (GLCE, NDST1, NDST2, HS6ST1, and GALT1) in a time-dependent manner. A cholesteryl butyrate emulsion (CholButE) increased heparin content after 24 and 48 h and modestly altered the expression of genes involved in heparin biosynthesis. Similar to NaBu, CholButE reduced cell proliferation without significantly altering viability or metabolic activity. These data show that butyrate increases the synthesis and storage of heparin in human mast cells, perhaps by altering their metabolic pathways.

Glycosaminoglycan microarrays for studying glycosaminoglycan-protein systems

More than 3000 proteins are now known to bind to glycosaminoglycans (GAGs). Yet, GAG-protein systems are rather poorly understood in terms of selectivity of recognition, molecular mechanism of action, and translational promise. High-throughput screening (HTS) technologies are critically needed for studying GAG biology and developing GAG-based therapeutics. Microarrays, developed within the past two decades, have now improved to the point of being the preferred tool in the HTS of biomolecules. GAG microarrays, in which GAG sequences are immobilized on slides, while similar to other microarrays, have their own sets of challenges and considerations. GAG microarrays are rapidly becoming the first choice in studying GAG-protein systems. Here, we review different modalities and applications of GAG microarrays presented to date. We discuss advantages and disadvantages of this technology, explain covalent and non-covalent immobilization strategies using different chemically reactive groups, and present various assay formats for qualitative and quantitative interpretations, including selectivity screening, binding affinity studies, competitive binding studies etc. We also highlight recent advances in implementing this technology, cataloging of data, and project its future promise. Overall, the technology of GAG microarray exhibits enormous potential of evolving into more than a mere screening tool for studying GAG - protein systems.

Effect of levan polysaccharide on chronological aging in the yeast Saccharomyces cerevisiae

Levan is a fructose-based biopolymer with diverse applications in the medicinal, pharmaceutical, and food industries. However, despite its extensive biological and pharmacological actions, including antioxidant, anti-inflammatory, and antidiabetic properties, research on its anti-aging potential is limited. This study explored levan's impact on the chronological lifespan (CLS) of yeast Saccharomyces cerevisiae for the first time. The results show that levan treatment significantly extended the CLS of wild-type (WT) yeast by preventing the accumulation of oxidative stress markers (reactive oxygen species, malondialdehyde, and protein carbonyl content) and ameliorating apoptotic features such as reduced mitochondrial membrane potential, loss of plasma membrane integrity, and externalization of phosphatidylserine. By day 40 of the CLS, a significant increase in yeast viability of 6.8 % (p < 0.01), 11.9 % (p < 0.01), and 20.8 % (p < 0.01) was observed at 0.25, 0.5, and 1 mg/mL of levan concentrations, respectively, compared to control (0 %). This study's results indicate that levan treatment substantially modulates the expression of genes involved in the TORC1/Sch9 pathway. Moreover, levan treatment significantly extended the CLS of yeast antioxidant-deficient mutant sod2Δ and antiapoptotic gene-deficient mutant pep4Δ. Levan also extended the CLS of signaling pathway gene-deficient mutants such as pkh2Δ, rim15Δ, atg1, and ras2Δ, while not affecting the CLS of tor1Δ and sch9Δ.

Hemorrhage induced by antithrombotic agents: new insights from a real-world pharmacovigilance study

BACKGROUND

Hemorrhage represents the most common and serious side effect of antithrombotic agents. Many studies have compared the risk of bleeding between different antithrombotic agents, but analysis of time-to-onset for hemorrhage induced by these drugs is yet sparse.

METHODS

We conducted a retrospective study based on the adverse drug reaction reports on antithrombotic agents collected by the Henan Adverse Drug Reaction Monitoring Center. We assessed the reporting odds ratio to determine the disproportionate reporting signals for bleeding and the Weibull shape parameter was used to evaluate the time-to-onset data.

RESULTS

In the signal detection, crude low molecular weight heparin-hemorrhage was found as a positive signal. The hemorrhage for most antithrombotic agents was random failure profiles. In particular, the hazard of hemorrhage decreased over time for warfarin and clopidogrel and increased for alteplase, nadroparin, and dipyridamole.

CONCLUSION

We found that the risk of bleeding in patients taking Crude low molecular weight heparins was significantly higher compared to other antithrombotic agents, but with a small magnificence, which may be attributed to the severely irrational use of this medication under improper management. Statistics in days, results showed that the risk of bleeding decreased over time for warfarin and clopidogrel and increased for alteplase, nadroparin, and dipyridamole.

Adsorbed polymer conjugates to adaptively inhibit blood coagulation activation by medical membranes

Adaptive drug release can combat coagulation and inflammation activation at the blood-material interface with minimized side effects. For that purpose, poly(styrene-alt-maleic-anhydride) copolymers were conjugated to heparin via coagulation-responsive linker peptides and shown to tightly adsorb onto poly(ethersulfone) (PES)-surfaces from aqueous solutions as monolayers. Coagulation-responsive release of unfractionated as well as low molecular weight heparins from the respective coatings was demonstrated to be functionally beneficial in human plasma and whole blood incubation with faster release kinetics resulting in stronger anticoagulant effects. Coated poly(ethersulfone)/poly(vinylpyrrolidone) (PES/PVP) flat membranes proved the technology to offer an easy, effective and robust anticoagulant interfacial functionalization of hemodialysis membranes. In perspective, the modularity of the adaptive release system will be used for inhibiting multiple activation processes.

A review on multifaceted biomedical applications of heparin nanocomposites: Progress and prospects

Advances in polymer-based nanocomposites have revolutionized biomedical applications over the last two decades. Heparin (HP), being a highly bioactive polymer of biological origin, provides strong biotic competence to the nanocomposites, broadening the horizon of their applicability. The efficiency, biocompatibility, and biodegradability properties of nanomaterials significantly improve upon the incorporation of heparin. Further, inclusion of structural/chemical derivatives, fractionates, and mimetics of heparin enable fabrication of versatile nanocomposites. Modern nanotechnological interventions have exploited the inherent biofunctionalities of heparin by formulating various nanomaterials, including inorganic/polymeric nanoparticles, nanofibers, quantum dots, micelles, liposomes, and nanogels ensuing novel functionalities targeting diverse clinical applications involving drug delivery, wound healing, tissue engineering, biocompatible coatings, nanosensors and so on. On this note, the present review explicitly summarises the recent HP-oriented nanotechnological developments, with a special emphasis on the reported successful engagement of HP and its derivatives/mimetics in nanocomposites for extensive applications in the laboratory and health-care facility. Further, the advantages and limitations/challenges specifically associated with HP in nanocomposites, undertaken in this current review are quintessential for future innovations/discoveries pertaining to HP-based nanocomposites.

Low-molecular-weight heparin for the prevention of preeclampsia in high-risk pregnancies without thrombophilia: a systematic review and meta-analysis

OBJECTIVES

To systematically evaluate the efficacy of low molecular weight heparin (LMWH) to prevent preeclampsia in high risk pregnant women without thrombophilia.

SEARCH STRATEGY

PubMed, Embase and the Cochrane library were searched for articles published before 1st August 2022 using the combination keywords "preeclampsia", "Low Molecular Weight Heparin", "LMWH", "Heparin, Low Molecular Weight", "Dalteparin", "Nadroparin", and "Tinzaparin".

SELECTION CRITERIA

Randomized controlled trials evaluating the use of LMWH in pregnant women at high risk of preeclampsia without thrombophilia.

DATA COLLECTION AND ANALYSIS

Ten studies were included in the meta-analysis (1758 patients in total). Outcomes were expressed as relative risk (RR) with 95% confidence intervals (CI).

RESULTS

LMWH reduced the incidence of PE (RR = 0.67; 95% CI = 0.50-0.90; P = 0.009) in high risk pregnant women without thrombophilia. Subgroup analysis found that the prophylactic effect of LMWH was only significant in studies using low-dose aspirin (LDA) as the primary intervention. The combination of LMWH and LDA was also effective for the prevention of preterm birth and fetal growth restriction, but had no effect on the incidence of placenta abruption.

CONCLUSION

For women at high risk of developing preeclampsia without thrombophilia, the combination of LMWH and low-dose aspirin is effective for the prevention of preeclampsia, preterm birth and fetal growth restriction and is superior to LDA alone.

Research Progress on Antiviral Activity of Heparin

Heparin, as a glycosaminoglycan, is known for its anticoagulant and antithrombotic properties for several decades. Heparin is a life-saving drug and is widely used for anticoagulation in medical practice. In recent years, there have been extensive studies that heparin plays an important role in non-anticoagulant diseases, such as anti-inflammatory, anti-viral, anti-angiogenesis, anti-neoplastic, anti-metastatic effects, and so on. Clinical observation and in vitro experiments indicate that heparin displays a potential multitarget effect. In this brief review, we will summarize heparin and its derivative's recently studied progress for the treatment of various viral infections. The aim is to maximize the benefits of drugs through medically targeted development, to meet the unmet clinical needs of serious viral diseases.

Efficacy and Safety of Rivaroxaban Versus Enoxaparin in Prevention of Recurrence of Venous Thrombo-Embolism Events in Cancer Patients: A Meta-Analysis

OBJECTIVE

To examine the effectiveness of rivaroxaban compared to enoxaparin in patients diagnosed with cancer and venous thromboembolism.

METHODS

A search of Pub Med, Scopus, and Google Scholar, from inception through April 2023 was conducted. Articles comparing rivaroxaban with enoxaparin in patients with cancer and VTE/PE/DVT were included. Review Manager Version 5.2 was utilised for the analysis of the following outcomes; VTE, PE, DVT, major bleeding, and mortality.

RESULTS

A total of 8 articles and 2276 patients were included in the final analysis. Pooled analysis showed that rivaroxaban had a statistically insignificant reduced association with VTE occurrence (RR:0.83, 95% CI:0.58-1.18, P:0.3) as well as a statically insignificant reduction in major bleeding (RR:0.79, 95% CI:0.53-1.18, P:0.25). Analysis showcased that there was an insignificant reduction of mortality rivaroxaban as compared to enoxaparin (RR:0.74, 95% CI: 0.46-1.20, P:0.23).

CONCLUSION

Rivaroxaban can serve as a viable alternative to enoxaparin, with no appreciable drawbacks, for preventing and managing VTE in patients with malignancy.

The effects of three different low-molecular-weight heparins on blood loss after intramedullary nailing of trochanteric fractures

PURPOSE

The purpose of this study was to compare the effects of reviparin, dalteparin and enoxaparin on intraoperative blood loss in patients with trochanteric fracture treated with intramedullary nailing.

MATERIALS AND METHODS

This retrospective multicenter study included 100 patients with trochanteric fracture who were divided into three groups according to the low-molecular-weight heparin administered. In all cases, a short third generation Gamma nail was used for osteosynthesis. Complete blood count and number of red blood cell transfusions (RBC) were evaluated.

RESULTS

The mean value of postoperative haemoglobin level was lower in the enoxaparin group compared to the reviparin group, with significant difference (p = 0.001; 95% CI 4.1-18.87). Patients in the dalteparin group received more RBC transfusions compared to the reviparin and enoxaparin group (p = 0.048).

CONCLUSION

The use of enoxaparin and dalteparin in hip fracture patients can result in lower postoperative haemoglobin levels and more RBC transfusions compared to reviparin.

Efficacy and Safety of Apixaban versus Dalteparin as a Treatment for Cancer-Associated Venous Thromboembolism: A Systematic Review and Meta-Analysis

Background and Objectives: Venous thromboembolism (VTE) is common in cancer patients. Anticoagulant therapy with low-molecular-weight heparins (LMWHs) and direct oral anticoagulants (DOACs), such as dalteparin and apixaban, have demonstrated efficacy and safety. However, more comparative research of these drugs is still needed. This study aimed to synthesize evidence on the efficacy of apixaban compared to dalteparin in reducing recurrent VTE, major bleeding, and clinically relevant non-major bleeding associated with cancer. Materials and Methods: We systematically searched the PubMed, Scopus, Web of Science, Embase, Cochrane Library, and ClinicalTrials databases up to 5 January 2023, for randomized controlled trials comparing apixaban versus dalteparin as treatment for cancer-associated VTE. Five studies were included. Effects according to meta-analyses were reported as relative risks (RRs) and their 95% confidence intervals (CIs). Results: It was found that 33 of 734 (4.5%) patients treated with apixaban and 56 of 767 (7.3%) with dalteparin had recurrent VTE as the efficacy outcome (RR 0.49, 95% CI 0.15-1.58, I2 38%). Major bleeding occurred in 25 of 734 patients treated with apixaban (3.4%) and 27 of 767 with dalteparin (3.5%) (RR 1.29, 95% CI 0.31-5.27, I2 59%). Likewise, clinically relevant non-major bleeding occurred in 64 of 734 patients treated with apixaban (8.7%) and 46 of 767 (5.9%) with dalteparin (RR 1.52, 95% CI 1.05-2.19, I2 0%). Conclusions: Apixaban showed a lower risk of recurrent VTE than dalteparin in patients with cancer-associated VTE, albeit with no statistical difference. Statistical significance was observed for no major clinically relevant bleeding but not for major bleeding.

Non-Anticoagulant Activities of Low Molecular Weight Heparins-A Review

Low molecular weight heparins (LMWHs) are derived from heparin through chemical or enzymatic cleavage with an average molecular weight (Mw) of 2000-8000 Da. They exhibit more selective activities and advantages over heparin, causing fewer side effects, such as bleeding and heparin-induced thrombocytopenia. Due to different preparation methods, LMWHs have diverse structures and extensive biological activities. In this review, we describe the basic preparation methods in this field and compare the main principles and advantages of these specific methods in detail. Importantly, we focus on the non-anticoagulant pharmacological effects of LMWHs and their conjugates, such as preventing glycocalyx shedding, anti-inflammatory, antiviral infection, anti-fibrosis, inhibiting angiogenesis, inhibiting cell adhesion and improving endothelial function. LMWHs are effective in various diseases at the animal level, including cancer, some viral diseases, fibrotic diseases, and obstetric diseases. Finally, we briefly summarize their usage and potential applications in the clinic to promote the development and utilization of LMWHs.

Anticoagulant therapy in COVID-19: A narrative review

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can manifest itself in several ways, including coagulopathy and thrombosis. These complications can be the first and sometimes only manifestations of SARS-CoV-2 infection and can occur early or late in the course of the disease. However, these symptoms are more prevalent in hospitalized patients with venous thromboembolism, particularly those admitted to intensive care units. Moreover, various forms of arterial and venous thrombosis, or micro- or macro-vasculature embolisms, have been reported during the current pandemic. They have led to harmful consequences, such as neurological and cardiac events, nearly all resulting from the hypercoagulable state caused by this viral infection. The severe hypercoagulability observed in patients with COVID-19 accounts for most cases of the disease that become critical. Therefore, anticoagulants seem to be one of the most vital therapeutics for treating this potentially life-threatening condition. In the current paper, we present a thorough review of the pathophysiology of COVID-19-induced hypercoagulable state and the use of anticoagulants to treat SARS-CoV-2 infections in different patient groups, as well as their pros and cons.

The Role of Biomarkers, Metabolomics, and COVID-19 in Venous Thromboembolism-A Review of Literature

In recent years, the field of venous thromboembolism has undergone numerous innovations, starting from the recent discoveries on the role of biomarkers, passing through the role of metabolomics in expanding our knowledge on pathogenic mechanisms, which have opened up new therapeutic targets. A variety of studies have contributed to characterizing the metabolic phenotype that occurs in venous thromboembolism, identifying numerous pathways that are altered in this setting. Among these pathways are the metabolism of carnitine, tryptophan, purine, and fatty acids. Furthermore, new evidence has emerged with the recent COVID-19 pandemic. Hypercoagulability phenomena induced by this viral infection appear to be related to altered von Willebrand factor activity, alteration of the renin-angiotensin-aldosterone system, and dysregulation of both innate and adaptive immunity. This is the first literature review that brings together the most recent evidence regarding biomarkers, metabolomics, and COVID-19 in the field of venous thromboembolism, while also mentioning current therapeutic protocols.

Anti-Xa level monitoring of low-molecular-weight heparin during intermittent venovenous hemofiltration

Low-molecular-weight heparin (LMWH) is an anticoagulant used to prevent clotting during blood purification treatments. This study aimed to evaluate the clinical use of the anti-factor Xa level (anti-Xa) for monitoring LMWH anticoagulant levels during intermittent venovenous hemofiltration (IVVHF). This prospective observational study enrolled patients who required IVVHF for renal failure in Beijing Hospital between May 2019 and February 2021. The LMWH anticoagulation was assessed by the coagulation grade of the filter and line. One hundred and ten participants were included. There were 90 patients with a filter and line coagulation grade of ≤ 1 and 20 patients with grade > 1. The anti-Xa level of 0.2 IU/mL was a critical value. The multivariable logistic regression analysis showed that anti-Xa level > 0.2 IU/mL (odd ratio [OR] = 2.263; 95% CI: 1.290-4.871, P = 0.034) and cardiovascular disease (OR = 10.028; 95% CI: 1.204-83.488; P = 0.033) were independently associated with the coagulation grade of the filter and line. Anti-Xa level could monitor LMWH anticoagulation during IVVHF.

Application of low molecular weight heparins in umbilical artery thrombosis: A case series and review of the literature

RATIONALE

Low molecular weight heparins are widely used in various thrombotic diseases and exert a preventive effect on thrombosis in high-risk patients. Umbilical artery thrombosis (UAT) is a rare occurrence that is difficult to detect during routine prenatal visits but can lead to adverse perinatal outcomes.

PATIENT CONCERNS

The aim of this study was to elucidate the therapeutic effect of low molecular weight heparins on UAT and to provide a new treatment option for the timing of delivery timing.

DIAGNOSES AND INTERVENTIONS

A retrospective study was conducted on cases involving thrombosis of the umbilical cord enrolled from July 2017 to July 2022. Data were acquired and analyzed from medical records and the final diagnosis was confirmed by histopathology. All included patients received LWMHs therapy after initial diagnosis of UAT.

OUTCOMES

The mean age of the 10 pregnant women recruited into this study was 27.9 ± 4.0 year-of-age; 1 (10%) was elderly. The gestational age at diagnosis was 29.9 ± 3.7 weeks, the gestational age at termination was 36.3 ± 2.5 weeks and the mean gestational age of extension was 6.4 ± 4.2 weeks. Low molecular weight heparin sodium was administered after umbilical artery embolism was detected on ultrasound. The LWMHs treatment received by the included patients in this study was subcutaneous injection. The specific usage varies due to the types of LWMHs. Of the 10 cases, 5 (50%) had fetal distress but all fetuses were born alive without neonatal asphyxia. With regards to delivery mode, 9 pregnancies were terminated by cesarean section.

LESSON

Early anticoagulant treatment with LWMHs may improve pregnancy outcomes. The timing and mode of termination of pregnancy should be determined according to the condition of the mother and the fetus along with the gestational age.

Designing Smaller, Synthetic, Functional Mimetics of Sulfated Glycosaminoglycans as Allosteric Modulators of Coagulation Factors

Natural glycosaminoglycans (GAGs) are arguably the most diverse collection of natural products. Unfortunately, this bounty of structures remains untapped. Decades of research has realized only one GAG-like synthetic, small-molecule drug, fondaparinux. This represents an abysmal output because GAGs present a frontier that few medicinal chemists, and even fewer pharmaceutical companies, dare to undertake. GAGs are heterogeneous, polymeric, polydisperse, highly water soluble, synthetically challenging, too rapidly cleared, and difficult to analyze. Additionally, GAG binding to proteins is not very selective and GAG-binding sites are shallow. This Perspective attempts to transform this negative view into a much more promising one by highlighting recent advances in GAG mimetics. The Perspective focuses on the principles used in the design/discovery of drug-like, synthetic, sulfated small molecules as allosteric modulators of coagulation factors, such as antithrombin, thrombin, and factor XIa. These principles will also aid the design/discovery of sulfated agents against cancer, inflammation, and microbial infection.

Prescribing patterns of thromboprophylaxis post-bariatric surgeries: no additional benefits of extended prophylaxis

Background

Venous thromboembolism is one of the critical complications of bariatric surgeries resulting in life-threatening outcomes. The benefits and duration of appropriate thromboprophylaxis in the morbidly obese patients stay unclear. The study aims to compare the benefits of in-hospital thromboprophylaxis versus extended thromboprophylaxis post-bariatric surgery among a cohort with a high prevalence of morbid obesity.

Results

A retrospective observational cohort study was conducted on 229 morbidly obese patients who had undergone bariatric surgery in a tertiary care teaching hospital in Saudi Arabia. Upon discharge, the patients were split either to receive no thromboprophylaxis or enoxaparin 40 mg once or twice daily for 14–21 days post-discharge. Primary outcomes were the clinical difference between the study groups in the percentage of patients who developed a symptomatic venous thromboembolic event during postoperative hospitalization or after discharge. Among patients who received no thromboprophylaxis (n = 119), no one developed a venous thromboembolic event, while, in the extended prophylaxis group (n = 110), 1.82% developed a non-fatal one (P = 0.23). Additionally, no significant difference in percentages of bleeding events occurred in both groups (p = 0.054).

Conclusions

The incidence of venous thromboembolism and bleeding events that occurred with extended thromboprophylaxis were deemed comparable and non-significant to the conventional in-hospital thromboprophylaxis. However, portal thrombosis stays an enigmatic complication despite its documented sparsity in literature.

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Identify Key Genes Correlated to Ischemia-Reperfusion Injury in Aging Livers

Background

With the intensification of population aging, the proportion of aging livers in the donor pool is increasing rapidly. Compared with young livers, aging livers are more susceptible to ischemia-reperfusion injury (IRI) during liver transplantation, which greatly affects the utilization rate of aging livers. The potential risk factors associated with IRI in aging livers have not been fully elucidated.

Methods

In this work, five human liver tissue expression profiling datasets (GSE61260, GSE107037, GSE89632, GSE133815, and GSE151648) and a total of 28 young and aging liver tissues of human (N = 20) and mouse (N = 8) were used to screen and verify the potential risk factors associated with aging livers being more prone to IRI. DrugBank Online was used to screen drugs with potential to alleviate IRI in aging livers.

Results

The gene expression profile and immune cell composition between young and aging livers had significant differences. Among the differentially expressed genes, aryl hydrocarbon receptor nuclear translocator-like (ARNTL), BTG antiproliferation factor 2 (BTG2), C-X-C motif chemokine ligand 10 (CXCL10), chitinase 3-like 1 (CHI3L1), immediate early response 3 (IER3), Fos proto-oncogene, AP-1 transcription factor subunit (FOS), and peroxisome proliferative activated receptor, gamma, coactivator 1 alpha (PPARGC1A), mainly involved in the regulation of cell proliferation, metabolism, and inflammation, were also dysregulated in liver tissues suffered from IRI and could form a FOS-centered interaction network. Nadroparin was screened out with the potential to target FOS in DrugBank Online. In addition, the proportion of dendritic cells (DCs) was significantly upregulated in aging livers.

Conclusions

We combined the expression profiling datasets of liver tissues and samples collected in our hospital for the first time to reveal that the changes in the expression of ARNTL, BTG2, CXCL10, CHI3L1, IER3, FOS, and PPARGC1A and the proportion of dendritic cells may be associated with aging livers being more prone to IRI. Nadroparin may be used to mitigate IRI in aging livers by targeting FOS, and regulation of DC activity may also reduce IRI.

Inhibition of platelet-surface-bound proteins during coagulation under flow II: Antithrombin and heparin

Blood coagulation is a self-repair process regulated by activated platelet surfaces, clotting factors, and inhibitors. Antithrombin (AT) is one such inhibitor that impedes coagulation by targeting and inactivating several key coagulation enzymes. The effect of AT is greatly enhanced in the presence of heparin, a common anticoagulant drug. When heparin binds to AT, it either bridges with the target enzyme or induces allosteric changes in AT leading to more favorable binding with the target enzyme. AT inhibition of fluid-phase enzymes caused little suppression of thrombin generation in our previous mathematical models of blood coagulation under flow. This is because in that model, flow itself was a greater inhibitor of the fluid-phase enzymes than AT. From clinical observations, it is clear that AT and heparin should have strong inhibitory effects on thrombin generation, and thus we hypothesized that AT could be inhibiting enzymes bound to activated platelet surfaces that are not subject to being washed away by flow. We extended our mathematical model to include the relevant reactions of AT inhibition at the activated platelet surfaces as well as those for unfractionated heparin and a low molecular weight heparin. Our results show that AT alone is only an effective inhibitor at low tissue factor densities, but in the presence of heparin, it can greatly alter, and in some cases shut down, thrombin generation. Additionally, we studied each target enzyme separately and found that inactivation of no single enzyme could substantially suppress thrombin generation.

The Effects of Three Different Low-molecular-weight Heparins on Blood Loss After Intramedullary Nailing of Trochanteric Fractures

Background

The three most commonly used low-molecular-weight heparins (LMWH) in Bosnia and Herzegovina for thromboprophylaxis in patients with hip fracture are reviparin, dalteparin and enoxaparin.

Objective

The purpose of this study was to compare the effects of reviparin, dalteparin and enoxaparin on intraoperative blood loss in patients with trochanteric fracture treated with intramedullary nailing.

Methods

This retrospective multicenter study included 100 patients with trochanteric fracture who were divided into three groups according to the low-molecular-weight heparin administered. In all cases, a short third generation Gamma-nail was used for osteosynthesis. Complete blood count and number of red blood cell transfusions (RBC) were evaluated. Results: The mean value of postoperative hemoglobin level was lower in the enoxaparin group compared to the reviparin group, with significant difference (p=0.001; 95% CI: 4.1-18.87). Patients in the dalteparin group received more RBC transfusions compared to the reviparin and enoxaparin group (p=0.048).

Conclusion

The use of enoxaparin and dalteparin in hip fracture patients can result in lower postoperative haemoglobin levels and more RBC transfusions compared to reviparin.

Discovery and development of Factor Xa inhibitors (2015-2022)

As a pathological coagulation process, thrombus can lead to many serious diseases, including ischemic stroke, acute myocardial infarction (AMI), acute coronary syndrome (ACS), and deep venous thrombosis (DVT). And anticoagulant drugs are one of the most effective ways to prevent and treat these diseases. Although macromolecular anticoagulant drugs such as low molecular weight heparins (LMWHs) are widely used in the clinic, their characteristics of requiring injectable use hinder their further promotion in the clinic, and the disadvantages of oral anticoagulant drugs, such as warfarin and dabigatran etexilate, which can easily cause bleeding adverse effects, are also not addressed. Factor Xa (FXa) has gained attention because it lies at the intersection of the coagulation cascade pathways, whereas subsequently introduced Factor Xa inhibitors such as rivaroxaban and apixaban, among others, have gained market popularity because of their high potency for anticoagulation and high specificity for Factor Xa when administered orally. But some of the drawbacks that these Factor Xa inhibitors have simultaneously such as fewer indications and the lack of an effective reversal drug when bleeding occurs are urgently addressed. The development of new Factor Xa inhibitors therefore becomes one means of addressing these questions. This article summarizes the small molecule Factor Xainhibitors developed from 2015 to 2022, classifies them according to their scaffolds, focuses on the analysis of their structure-activity relationships, and provides a brief assessment of them.

The Role and Mechanism of Polysaccharides in Anti-Aging

The elderly proportion of the population is gradually increasing, which poses a great burden to society, the economy, and the medical field. Aging is a physiological process involving multiple organs and numerous reactions, and therefore it is not easily explained or defined. At present, a growing number of studies are focused on the mechanisms of aging and potential strategies to delay aging. Some clinical drugs have been demonstrated to have anti-aging effects; however, many still have deficits with respect to safety and long-term use. Polysaccharides are natural and efficient biological macromolecules that act as antioxidants, anti-inflammatories, and immune regulators. Not surprisingly, these molecules have recently gained attention for their potential use in anti-aging therapies. In fact, multiple polysaccharides have been found to have excellent anti-aging effects in different animal models including Caenorhabditis elegans, Drosophila melanogaster, and mice. The anti-aging qualities of polysaccharides have been linked to several mechanisms, such as improved antioxidant capacity, regulation of age-related gene expression, and improved immune function. Here, we summarize the current findings from research related to anti-aging polysaccharides based on various models, with a focus on the main anti-aging mechanisms of oxidative damage, age-related genes and pathways, immune modulation, and telomere attrition. This review aims to provide a reference for further research on anti-aging polysaccharides.

Efficacy and safety of nafamostat mesilate anticoagulation in blood purification treatment of critically ill patients: a systematic review and meta-analysis

Background

Nafamostat mesilate (NM), a broad-spectrum and potent serine protease inhibitor, can be used as an anticoagulant during extracorporeal circulation, as well as a promising drug effective against coronavirus disease 2019 (COVID-19). We conducted a systematic meta-analysis to evaluate the safety and efficacy of NM administration in critically ill patients who underwent blood purification therapy (BPT).

Methods

The Cochrane Library, Web of Science and PubMed were comprehensively searched from inception to August 20, 2021, for potential studies.

Results

Four randomized controlled trials (RCTs) and seven observational studies with 2723 patients met the inclusion criteria. The meta-analysis demonstrated that conventional therapy (CT) significantly increased hospital mortality compared with NM administration (RR = 1.25, p = 0.0007). In subgroup analyses, the in-hospital mortality of the NM group was significantly lower than that of the anticoagulant-free (NA) group (RR = 1.31, p = 0.002). The CT interventions markedly elevated the risk ratio of bleeding complications by 45% (RR = 1.45, p = 0.010) compared with NM interventions. In another subgroup analysis, NM used exhibited a significantly lower risk of bleeding complications than those of the low-molecular-weight heparin (LMWH) used (RR = 4.58, p = 0.020). The filter lifespan was decreased significantly (MD = −10.59, p < 0.0001) in the NA groups compared with the NM groups. Due to the poor quality of the included RCTs, these results should be interpreted with caution.

Conclusion

Given the better survival outcomes, lower risk of bleeding, NM anticoagulation seems to be a safe and efficient approach for BPT patients and could yield a favorable filter lifespan. More multi-center RCTs with large samples are required for further validation of this study.

Natural Materials for 3D Printing and Their Applications

In recent years, 3D printing has gradually become a well-known new topic and a research hotspot. At the same time, the advent of 3D printing is inseparable from the preparation of bio-ink. Natural materials have the advantages of low toxicity or even non-toxicity, there being abundant raw materials, easy processing and modification, excellent mechanical properties, good biocompatibility, and high cell activity, making them very suitable for the preparation of bio-ink. With the help of 3D printing technology, the prepared materials and scaffolds can be widely used in tissue engineering and other fields. Firstly, we introduce the natural materials and their properties for 3D printing and summarize the physical and chemical properties of these natural materials and their applications in tissue engineering after modification. Secondly, we discuss the modification methods used for 3D printing materials, including physical, chemical, and protein self-assembly methods. We also discuss the method of 3D printing. Then, we summarize the application of natural materials for 3D printing in tissue engineering, skin tissue, cartilage tissue, bone tissue, and vascular tissue. Finally, we also express some views on the research and application of these natural materials.

Determination of Deep Vein Thrombosis Risk in Patients Staying in an Orthopedics and Traumatology Clinic

Background: Deep vein thrombosis (DVT) is an important life-threatening complication in patients having orthopedic surgery and its risk factors are still debatable. Aim: This study aimed to determine preoperative and postoperative DVT risk, its risk factors and their effects on preoperative and postoperative DVT risk scores in patients having orthopedic surgery and staying in an orthopedics and traumatology clinic. Method: This descriptive, cross-sectional study was performed with 244 patients. Data were gathered with a sociodemographic, health status and prophylaxis for DVT form and the Autar Deep Vein Thrombosis Risk Assessment Scale (Autar DVTRAS). Results: There was a strong significant difference between the preoperative and postoperative mean scores for the Autar DVTRAS (p

Strategies for sustained release of heparin: A review

Heparin, a sulfate-containing linear polysaccharide, has proven preclinical and clinical efficacy for a variety of disorders. Heparin, including unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), and ultra-low-molecular-weight heparin (ULMWH), is administered systematically, in the form of a solution in the clinic. However, it is eliminated quickly, due to its short half-life, especially in the case of UFH and LMWH. Frequent administration is required to ensure its therapeutic efficacy, leading to poor patient compliance. Moreover, heparin is used to coat blood-contacting medical devices to avoid thrombosis through physical interaction. However, the short-term durability of heparin on the surface of the stent limits its further application. Various advanced sustained-release strategies have been used to prolong its half-life in vivo as preparation technologies have improved. Herein, we briefly introduce the pharmacological activity and mechanisms of action of heparin. In addition, the strategies for sustained release of heparin are comprehensively summarized.

Research Progress on Emerging Polysaccharide Materials Applied in Tissue Engineering

The development and application of polysaccharide materials are popular areas of research. Emerging polysaccharide materials have been widely used in tissue engineering fields such as in skin trauma, bone defects, cartilage repair and arthritis due to their stability, good biocompatibility and reproducibility. This paper reviewed the recent progress of the application of polysaccharide materials in tissue engineering. Firstly, we introduced polysaccharide materials and their derivatives and summarized the physicochemical properties of polysaccharide materials and their application in tissue engineering after modification. Secondly, we introduced the processing methods of polysaccharide materials, including the processing of polysaccharides into amorphous hydrogels, microspheres and membranes. Then, we summarized the application of polysaccharide materials in tissue engineering. Finally, some views on the research and application of polysaccharide materials are presented. The purpose of this review was to summarize the current research progress on polysaccharide materials with special attention paid to the application of polysaccharide materials in tissue engineering.

Tinzaparin—a review of its molecular profile, pharmacology, special properties, and clinical uses

Purpose

Low molecular weight heparins (LMWHs) are a group of heterogenous moieties, long used in the prevention and treatment of thrombosis. They derive from heparin and since they are prepared by different methods of depolymerization, they differ in pharmacokinetic properties and anticoagulant profiles, and thus are not clinically interchangeable.

Methods

In this review we provide an overview of tinzaparin's main characteristics and uses.

Results

Tinzaparin which is produced by the enzymatic depolymerization of unfractionated heparin (UFH) can be used for the treatment and prevention of deep venous thrombosis (DVT) and pulmonary embolism (PE); it has been also used in special populations such as elders, obese, pregnant women, and patients with renal impairment and/or cancer with favorable outcomes in both safety and efficacy, with a once daily dose regimen. Furthermore, LMWHs are extensively used in clinical practice for both thromboprophylaxis and thrombosis treatment of COVID-19 patients.

Conclusion

Tinzaparin features support the hypothesis for having a role in immunothrombosis treatment (i.e. in the context of cancer ,COVID-19), interfering not only with coagulation cascade but also exhibiting anti-inflammatory potency.

Purification, biochemical characterization and fibrinolytic potential of proteases produced by bacteria of the genus Bacillus: a systematic literature review

Thrombosis is a hematological disorder characterized by the formation of intravascular thrombi, which contributes to the development of cardiovascular diseases. Fibrinolytic enzymes are proteases that promote the hydrolysis of fibrin, promoting the dissolution of thrombi, contributing to the maintenance of adequate blood flow. The characterization of new effective, safe and low-cost fibrinolytic agents is an important strategy for the prevention and treatment of thrombosis. However, the development of new fibrinolytics requires the use of complex methodologies for purification, physicochemical characterization and evaluation of the action potential and toxicity of these enzymes. In this context, microbial enzymes produced by bacteria of the Bacillus genus are promising and widely researched sources to produce new fibrinolytics, with high thrombolytic potential and reduced toxicity. Thus, this review aims to provide a current and comprehensive understanding of the different Bacillus species used for the production of fibrinolytic proteases, highlighting the purification techniques, biochemical characteristics, enzymatic activity and toxicological evaluations used.

Localized and Generalized Skin Adverse Drug Reactions to Nadroparin Calcium Injection in 6 Cases of Pregnant Women

Background

Despite the increasing number of skin adverse drug reactions caused by nadroparin calcium have been reported, mostly, little is known regarding of their details of clinical characteristics, especially for generalized skin adverse drug reactions. We sought to evaluate localized and generalized characteristics of the skin adverse drug reaction to nadroparin calcium injection in pregnant women.

Methods

A retrospective study was conducted on 6 pregnant women, who experienced localized and generalized skin adverse drug reactions during long-term nadroparin calcium injection. The patients' clinical and imaging information were retrieved from medical records. The skin prick test, patch test, and intradermal test were performed after they stopped lactation. Causality assessment of suspected adverse drug reactions was performed on these cases.

Results

The average total dose of nadroparin calcium injection in the 6 cases was 64.17 ± 22.66. Localized skin adverse drug reaction, manifested as erythema at the injection point, appeared after 47.5 ± 17.4 days of subcutaneous injection of nadroparin calcium. Generalized urticaria-like lesions, progressing from the injection site on the abdomen, appeared in 5.17 ± 3.60 days after the first appearance of localized reaction, while laboratory test results revealed essential peripheral blood eosinophilia. All rashes in the 6 cases subsided in 2–5 weeks after drug withdrawal. After delivery, 5 of 6 cases received complete skin tests to evaluate drug hypersensitivity. Results presented positive in the intradermal test within 7 days. Both the skin prick test and skin patch test were negative. Localized skin reactions and generalized urticaria-like adverse drug reactions were considered as definitely and probably caused by nadroparin calcium injection, respectively.

Conclusion

Subcutaneous injection of nadroparin calcium in pregnant women appears to be at risk of localized and generalized urticaria-like adverse drug reaction. It is important to follow up the pregnant woman during nadroparin calcium injection for evaluating adverse drug reactions. Timely detection of symptoms is pivotal in early diagnosis and treatment of adverse drug reactions.

Regional citrate versus heparin anticoagulation for CRRT in critically ill patients: a meta-analysis of RCTS

INTRODUCTION

This study aimed to compare the efficacy and safety of citrate and heparin in continuous renal replacement therapy (CRRT) for critically ill patients.

METHODS

Searched in PubMed, Embase, and Cochrane Library databases.

RESULTS

Analyses showed that there no difference existed in mortality, metabolic alkalosis, circuit loss, and the number of transfused between the two group(RR=0.95, P=0.40; RR=1.73, P=0.40; RR=0.64, P=0.09; RR=1.05, P=0.70). The filter life of the citrate group was longer than heparin group(MD=16.98, P<0.0001). The risk of bleeding and HIT was significantly lower in the citrate(RR=0.32, P<0.00001; RR=0.55, P=0.04). The citrate group was more susceptible to hypocalcemia(RR=4.85, P=0.0004).

CONCLUSION

Citrate anticoagulant therapy should have priority for CRRT in most critically ill patients. This article is protected by copyright. All rights reserved.

Functionalized Hemodialysis Polysulfone Membranes with Improved Hemocompatibility

The field of membrane materials is one of the most dynamic due to the continuously changing requirements regarding the selectivity and the upgradation of the materials developed with the constantly changing needs. Two membrane processes are essential at present, not for development, but for everyday life-desalination and hemodialysis. Hemodialysis has preserved life and increased life expectancy over the past 60-70 years for tens of millions of people with chronic kidney dysfunction. In addition to the challenges related to the efficiency and separative properties of the membranes, the biggest challenge remained and still remains the assurance of hemocompatibility-not affecting the blood during its recirculation outside the body for 4 h once every two days. This review presents the latest research carried out in the field of functionalization of polysulfone membranes (the most used polymer in the preparation of membranes for hemodialysis) with the purpose of increasing the hemocompatibility and efficiency of the separation process itself with a decreasing impact on the body.

Crosslinking of dialdehyde heparin: a new strategy for improving the anticoagulant properties of porcine acellular dermal matrix

The anticoagulant properties of valve materials are essential to maintain blood patency after artificial valve implantation. Porcine acellular dermal matrix (pADM) has low immunogenicity, good biocompatibility, and can reduce calcification by eliminating heterogeneous cells. However, its main component is collagen, which has strong coagulation function and poor anticoagulant activity. When used in heart valve materials, it can easily coagulate and form a life-threatening thrombus. Therefore, it is necessary to improve its anticoagulant performance. The glutaraldehyde (GA) cross-linked valves widely used clinically are easy to calcify with poor anticoagulant performance and cytotoxicity. In this study, dialdehyde heparin containing cross-linking active aldehyde groups was prepared by sodium periodate oxidation, then it was used for crosslinking with pADM to chemically modify its anticoagulant performance. Compared with GA cross-linked pADM (GA-pA), dialdehyde heparin cross-linked pADM (OL-pA) has better thermal stability and biocompatibility, especially its anticoagulant and antiplatelet adhesion were significantly improved, which can reduce the incidence of coagulation, thrombocytopenia and bleeding. In summary, dialdehyde heparin is expected to be applied to modify the anticoagulant properties of pADM and has great potential for the preparation and clinical application of anticoagulant materials such as heart valves and artificial blood vessels.

Effect of low-molecular-weight heparins on anti-Xa peak levels and adverse reactions in Chinese patients with recurrent spontaneous abortion: a single-center, observational study

Objective

To compare three commonly used low-molecular-weight heparins (LWMHs) in the treatment of recurrent spontaneous abortion (RSA) by evaluating the anti-Xa peak levels and adverse reactions.

Methods

In this single-center, observational study, we enrolled 310 patients with RSA in whom anti-Xa levels were measured during pregnancy. Patients were divided into three groups according to the LMWH they used: the nadroparin group, enoxaparin group and dalteparin group. We compared the peak anti-Xa levels and the coagulation status of each group, and analyzed the incidence of adverse reactions, including local allergy, liver and renal dysfunction, and the impact on platelet.

Results

Patients in the enoxaparin group had a higher anti-Xa peak level than those in the nadroparin group (0.80 ± 0.22 IU/ml vs. 0.61 ± 0.24 IU/ml; P <  0.0001), although most patients in the three groups reached the target concentration of anti-Xa. Furthermore, patients in the enoxaparin group had a more stable anti-Xa levels during pregnancy. In addition, patients in the nadroparin group had a higher rate of local allergy than those in the enoxaparin group (60.5% vs. 42.5%; P = 0.004) and those in the dalteparin group (60.5% vs. 33.3%; P = 0.002). Further examination by the type of local allergy indicated a dramatic difference in pruritus and induration between the nadroparin group and the other two groups. No difference was found in the incidence of liver and renal dysfunction and thrombocytopenia.

Conclusion

Compared with nadroparin and daltepatin, enoxaparin showed a better performance regarding anti-Xa levels and the incidence of adverse reactions in the treatment of RSA.

Heparin and Its Derivatives: Challenges and Advances in Therapeutic Biomolecules

Heparin has been extensively studied as a safe medicine and biomolecule over the past few decades. Heparin derivatives, including low-molecular-weight heparins (LMWH) and heparin pentasaccharide, are effective anticoagulants currently used in clinical settings. They have also been studied as functional biomolecules or biomaterials for various therapeutic uses to treat diseases. Heparin, which has a similar molecular structure to heparan sulfate, can be used as a remarkable biomedicine due to its uniquely high safety and biocompatibility. In particular, it has recently drawn attention for use in drug-delivery systems, biomaterial-based tissue engineering, nanoformulations, and new drug-development systems through molecular formulas. A variety of new heparin-based biomolecules and conjugates have been developed in recent years and are currently being evaluated for use in clinical applications. This article reviews heparin derivatives recently studied in the field of drug development for the treatment of various diseases.

Case Report: Spontaneous Intramural Hematoma of the Colon Secondary to Low Molecular Weight Heparin Therapy

Background: Hematoma of the colon is a rare hemorrhagic complication that affects patients accepting low molecular weight heparin (LMWH) therapy. Only scarce cases of colon hematoma have been reported, usually in children or patients accepting warfarin therapy. Case summary: A 76-year-old Chinese man was diagnosed with atrial fibrillation and heart failure, with cardiac function NYHA grade III on March 21, 2018. This patient was given LMWH for anticoagulation therapy and developed a colon hematoma on the third day of hospitalization. Abdominal computed tomography (CT) showed the thickening of areas of the colon up to 110 mm × 78 mm in thickness, which was a symptom of colon hematoma. The patient underwent conservative treatment successfully. On March 27, the patient's abdominal pain was alleviated, and a CT scan showed that the intestinal hematoma was absorbed. Conclusions: The most frequent minor bleeding events of LMWH anticoagulation are hemorrhage and subcutaneous hematoma. This case demonstrated that bowel hematoma despite its low incidence should be considered as an ADR of LMWH therapy, especially among patients who present with gastrointestinal symptoms.

A phase I, single and continuous dose administration study on the safety, tolerability, and pharmacokinetics of neorudin, a novel recombinant anticoagulant protein, in healthy subjects

The aim of this study was to evaluate the tolerability, safety, and pharmacokinetics of single and continuous dose administration of recombinant neorudin (EPR-hirudin, EH) by intravenous administration in healthy subjects, and to provide a safe dosage range for phase II clinical research. Forty-four subjects received EH as a single dose of between 0.2 and 2.0 mg/kg by intravenous bolus and drip infusion. In addition, 18 healthy subjects were randomly divided into three dose groups (0.15, 0.30, and 0.45 mg/kg/h) with 6 subjects in each group for the continuous administration trial. Single or continuous doses of neorudin were generally well tolerated by healthy adult subjects. There were no serious adverse events (SAEs), and all adverse events (AEs) were mild to moderate. Moreover, no subjects withdrew from the trial because of AEs. There were no clinically relevant changes in physical examination results, clinical chemistry, urinalysis, or vital signs. The incidence of adverse events was not significantly related to drug dose or systemic exposure. After single-dose and continuous administration, the serum EH concentration reached its peak at 5 min, and the exposure increased with the increase in the administered dose. The mean half-life (T_1/2 ), clearance (Cl), and apparent volume of distribution (Vd) of EH ranged from 1.7 to 2.5 h, 123.9 to 179.7 ml/h/kg, and 402.7 to 615.2 ml/kg, respectively. The demonstrated safety, tolerability, and pharmacokinetic characteristics of EH can be used to guide rational drug dosing and choose therapeutic regimens in subsequent clinical studies. Clinical trial registration: Chinadrugtrials.org identifier: CTR20160444.

Protective effects of polysaccharides on cerebral ischemia: A mini-review of the mechanisms

Cerebral ischemia, a common cerebrovascular disease, is one of the great threats to human health. Nowadays, many drugs used in the treatment of cerebral ischemia such as clot busting drugs, antiplatelet drugs, and neuroprotective drugs have limits. It is urgent finding new effective treatments for the patients. Researches have confirmed that many kinds of polysaccharides from natural resources possess therapeutic effects on cerebral ischemia, but are still lack of a comprehensively understanding. In this paper, based on the pathophysiology of cerebral ischemic injury, we summarize the latest discoveries and advancements of 29 kinds of polysaccharides, focusing on their ameliorating effects on cerebral ischemia and the underlying mechanisms. Several mechanisms are involved, mainly including antioxidant activities, anti-inflammatory activities, regulating neuron apoptosis, as well as resisting nitrosative stress injury. Besides, polysaccharides show protective effects through certain signaling pathways including PI3K/Akt, MAPK, and NF-κB, PARP-1/AIF, JNK3/c-Jun/Fas-L, and Nrf2/HO-1 signaling pathways. The main goal of this mini-review is to emphasize the important roles of polysaccharides in attenuating cerebral ischemic injury through the elucidation of mechanisms.

Beneficial non-anticoagulant mechanisms underlying heparin treatment of COVID-19 patients

Coronavirus disease-2019 (COVID-19) is associated with severe inflammation in mainly the lung, and kidney. Reports suggest a beneficial effect of the use of heparin/low molecular weight heparin (LMWH) on mortality in COVID-19. In part, this beneficial effect could be explained by the anticoagulant properties of heparin/LMWH. Here, we summarise potential beneficial, non-anticoagulant mechanisms underlying treatment of COVID-19 patients with heparin/LMWH, which include: (i) Inhibition of heparanase activity, responsible for endothelial leakage; (ii) Neutralisation of chemokines, and cytokines; (iii) Interference with leukocyte trafficking; (iv) Reducing viral cellular entry, and (v) Neutralisation of extracellular cytotoxic histones. Considering the multiple inflammatory and pathogenic mechanisms targeted by heparin/LMWH, it is warranted to conduct clinical studies that evaluate therapeutic doses of heparin/LMWH in COVID-19 patients. In addition, identification of specific heparin-derived sequences that are functional in targeting non-anticoagulant mechanisms may have even higher therapeutic potential for COVID-19 patients, and patients suffering from other inflammatory diseases.

[Parnaparin sodium - modern therapy options and prevention of venous thromboembolic complications]

Venous thromboembolic complications (VTEC) including pulmonary embolism and acute thrombosis of deep and superficial veins of the lower extremities are often observed in postoperative period. Low-molecular-weight heparin (LMWH) is a common remedy for prevention and treatment of VTEC due to high efficiency, safety, easy use and dosage. According to the modern literature data, LMWH is characterized by different effectiveness in relation to VTEC and risk of bleeding in patients after surgical and traumatological procedures, as well as in ones with severe forms of chronic venous diseases. However, their antithrombin activity varies significantly depending on mean molecular weight. The authors analyze LMWH action mechanism, pharmacokinetic and pharmacodynamic features of LMWH, in particular parnaparin sodium. Efficacy, safety and tolerability of this remedy for various forms of VTEC (superficial and deep vein thrombosis, thrombophlebitis, complicated forms of chronic venous diseases), its advantages for prevention of VTEC after various surgical and orthopedic interventions are considered.