Tuning chitosan properties to enhance blood coagulation.

The search for new hemostatic materials remains a priority for researchers, as the problem of uncontrolled hemorrhage during surgical interventions or traumatic injuries represents a significant challenge. The objective of the study was to identify novel polysaccharide structures with enhanced hemostatic properties based on chitosan. The number of chitosan derivatives with two substituents was synthesized and characterized by H NMR, FTIR.

Ethylenediamine-modified alginate - A hemocompatible platform for polymer-drug conjugates.

The study is dedicated to the synthesis, rheological properties, hemocompatibility, and further modification of water-soluble derivatives of sodium alginate containing fragments of ethylenediamine (Alg-EDA). Alg-EDA with an equal ratio of amide/amine groups and varying degrees of substitution were synthesized by the carbodiimide method. The influence of the molecular weight of Alg-EDA on the attachment of bioactive molecules such as hydroxybenzoic and ferulic acids was determined.

In Vitro Hemocompatibility of Arabinogalactan, Betulin, and Betulin Derivatives.

The hemocompatibility of arabinogalactan, betulin and its derivatives was evaluated in vitro and samples suitable for creation of nanostructures or materials in contact with blood were selected. The prospects of arabinogalactan as a component of the construct (nanostructure) for drug delivery are due to the fact that it did not affect blood/plasma coagulation (at concentrations of 0.0033-3.

Hemorrhagic Activity of Cationic Starch Conjugates with Sterically Hindered Phenol after Intravenous Administration to Guinea Pigs.

Intravenous injection of cationic starch conjugated with sterically hindered phenol (terpenophenol) to guinea pigs did not increase hemorrhagic activity (in doses of 2 and 4 mg/kg) and plasma clotting time in activated partial thromboplastin time and prothrombin time tests (in a dose of 4 mg/kg) in comparison with administration of physiological saline. Intravenous injection of the cationic starch conjugate with the highest content of terpenophenol fragments (4.1%wt) in a dose of 2 mg/kg to guinea pigs leads to a decrease in hemorrhagic activity by 4 times in comparison with the control.

Chemical modification of chitosan for developing of new hemostatic materials: A review.

Uncontrolled bleeding that occurs during surgery, trauma, and in combat conditions is critical and require immediate action. Chitosan is a polysaccharide, obtained from natural sources with unique biological properties. It is often used as basis for local hemostatic agents (LHA).

New N-Methylimidazole-Functionalized Chitosan Derivatives: Hemocompatibility and Antibacterial Properties.

Novel imidazole derivatives of the low molecular weight chitosan N-(2-hydroxypropyl)-1H-1,2,3-triazol-4-yl)methyl)-1-methyl-1H-imidazol-3-ium chitosan chloride (NMIC) were synthesized using copper-catalyzed azide-alkyne cycloaddition (CuAAC). The degrees of substitution (DSs) for the new derivatives were 18-76%. All chitosan derivatives (2000 µg/mL) were completely soluble in water.

Thrombin and Factor Xa Hydrolysis of Chromogenic Substrates in the Presence of Sulfated Derivatives of Galactomannan and Galactoglucomannan Natural Gels.

Polysaccharides are important structural components of all plant species. Gel-like polysaccharides have found wide application in various fields, including medicine, construction, and the food industry. In the present work, galactomannan and galactoglucomannan gel-like polysaccharides were modified with sulfate groups and their anticoagulant activity was studied.

Hemocompatibility of Galactomannan and Galactoglucomannan Sulfates in In Vitro Experiments.

We identified compounds that do not independently provoke aggregation of human platelets and do not affect hemolysis of human erythrocytes in vitro: lacking anticoagulant activity sulfated galactoglucomannan (polydispersity 1.43; degree of sulfation 0.66) in concentrations ≤0.

Effect of Oligochitosan on Experimental Venous Thrombosis in Guinea Pigs.

Oligochitosan Сh10/85 with a molecular weight of 10 kDa and a deacetylation degree of 85% prevented the development of experimental venous thrombosis in guinea pigs after intravenous administration in a dose of 30 mg/kg. In a concentration of 0.005-0.

Hemocompatibility, biodegradability and acute toxicity of acetylated cellulose nanocrystals of different types in comparison.

Promotion of promising cellulose nanocrystals (CNC) is largely dependent on the relationship between their morphology, surface chemical composition, and supramolecular structure with toxicity, hemocompatibility, and biodegradability. This paper outlines comparative and integrated analysis of the mentioned biocompatibility aspects of partially acetylated rod-, and disc-lake morphology of CNC with crystalline cellulose allomorphs I and II. These data have also included the study of CNC obtained from the sulfuric acid solutions.

The Development of New Low-Molecular-Weight Factor Xa Inhibitors that are Potential Anticoagulants.

Background: Despite the introduction of direct oral anticoagulants, the search for new oral anticoagulants remains an urgent task.

Objective: By using docking and scoring, based on physical methods, simple chemical rules, methods of synthesis, and activity measurement, develop new low-molecular-weight inhibitors of factor Xa, which are potential anticoagulants.

Methods: The development of leads was based on chemical synthesis and structure-based drug design methods.

Study of the Blood Compatibility of Sulfated Organosolv Lignins Derived from Abies sibirica and Larix sibirica Wood Pulp.

The effects of sulfated organosolv lignins derived from fir (Abies sibirica) and larch (Larix sibirica) (SLf and SLl; 4-3-7.5% sulfur, median-weight molecular mass 2960-4888 Da), on human blood/plasma clotting, platelet aggregation, and erythrocyte hemolysis were studied in vitro. Antithrombin activities of the samples were below 2 U/mg.

The Therapeutic Approach to Military Culture: A Music Therapist's Perspective.

Culture can broadly be defined as "the values, norms, and assumptions that guide human action" (Wilson 2008, 14). In contrast with the broader civilian society, the experiences and environments within the military community create a unique cultural subset. The United States armed forces are unified by their primary mission to provide external defense, security, and protection, and each branch (Army, Navy, Marine Corp, Air Force, Coast Guard and National Guard) shares a unique core set of values and norms.

Hemocompatibility of Silver Nanoparticles Based on Conjugate of Quaternized Chitosan with Gallic Acid in In Vitro Experiments.

We studied hemocompatibility of silver nanoparticles synthesized on the basis of a conjugate of quaternized chitosan with gallic acid (QChit-Gal). For the three variants of silver particles (Nos. 1, 2, and 3), the QChit-Gal:AgNO ratio was 5:1, 5:3, and 1:1, respectively.

Synthesis of silver nanoparticles using gallic acid-conjugated chitosan derivatives.

In presented study, various chitosan derivatives containing covalently bounded gallic acid were obtained: chitosan with gallic acid (CG), quaternized chitosan with gallic acid (QCG), and succinylated chitosan with gallic acid (SCG). Chitosan derivatives were used as stabilizing and reducing agents in the synthesis of silver nanoparticles (AgNPs). The dimensional characteristics of nanomaterials were determined by transmission electron (TEM), dynamic light scattering (DLS) and atomic force (AFM) microscopy, antibacterial activity (against E.

Synthesis and hemocompatibility of amino (di-)butyldeoxy modified hydroxyethyl starch.

Cationic polymers are of interest as the basis for obtaining various biomaterials. Hydrophilic biopolymers and their modification products are of main interest. Biocompatibility is the prime criterion that makes this material usable for said purposes.

Analysis of the Action of Quaternized Chitosans with Different Molecular Weight on Anticoagulant Activity of Heparins In Vitro.

Quaternized derivatives of chitosan with a substitution degree of 85-98% (highly substituted) synthesized from chitosans with a molecular weight of 5, 10, 20 kDa, with a degree of deacetylation of 89-98%, and the code numbers of QChit 5, QChit 10, QChit 20, respectively, completely neutralize antithrombin activity of unfractionated heparin and partially neutralize aXa activity of low-molecular-weight heparin (clexane), similar to protamine sulfate. The advantages of QChit 5 and QChit 10 over QChit 20 and protamine sulphate are the follows: the effect is achieved at lower concentrations and in greater concentration range; they do not promote platelet aggregation; in a concentration of 0.0072 mg/ml they do not destroy the erythrocyte membranes.

Effect of Nanocrystalline Particles of Chitin on Blood Components in Humans and Experimental Animals.

Nanocrystalline particles of chitin in the form of hydrosol in a concentration of 0.63 mg/ml have no effect on aggregation of human platelets and clotting time of platelet-poor plasma in coagulation tests. ADP-induced aggregation of human platelets was inhibited by these nanoparticles in concentrations of 0.

The Development of New Factor Xa Inhibitors Based on Amide Synthesis.

Background: Factor Xa (FXa) is known to play a central role in blood coagulation cascade and considered to be one of the most attractive targets for oral anticoagulants of new generation.

Objective: Our approach for the development of directly acting oral anticoagulants (DOAC), FXa inhibitors was demonstrated in this work.

Method: Chemical synthesis is the base of our approach for the development of potential inhibitors.

Effect of Xylan Sulfates on Coagulation of Human Blood Plasma.

Sulfated derivatives of xylan (isolated from Bétula pubéscens wood) with average molecular weight ~34 kDa, sulfur content of 11.3-17.5%, a degree of substitution of 0.

Effects of Chitosan Derivative N-[(2-Hydroxy-3-Trimethylammonium)Propyl]Chloride on Anticoagulant Activity of Guinea Pig Plasma.

Intravenous injection of protamine sulfate or quarternized chitosan derivative to guinea pigs after injection of 70 aIIa U/kg non-fractionated heparin shortened plasma clotting time (shown by partial activated thromboplastin time, thrombin time, and prothrombin time). Intravenous injection of protamine sulfate or quarternized chitosan derivative to guinea pigs after injection of 1 mg/kg (100 aXa U/kg) low-molecular-weight heparin (clexane) led to shortening of plasma clotting time in the ReaClot Heparin test and to prolongation of plasma amidolytic activity in the factor Xa chromogenic substrate test.

Effect of Sulfation and Molecular Weight on Anticoagulant Activity of Dextran.

Sulfation (to 2.8) of dextrans with molecular weight of 150 and 20 kDa was followed by the appearance of anticoagulant activity that increased with decreasing their molecular weight and did not depend on antithrombin, plasma inhibitor of serine proteases of the blood coagulation system. Antithrombin activity of dextran sulfate with a molecular weight of 20 kDa reached 12.

Neutralization of anticoagulant activity of heparin by N-[(2-hydroxy-3-trimethylammonium) propyl] chloride derivatives of chitosan.

Alkylated derivatives of low molecular weight chitosan with different substitution degrees of 98, 40, and 9% (I, II, and III respectively) have been synthesized. The structure of the obtained derivatives was defined by spectral assays (IR-spectroscopy and proton magnetic resonance). Chitosan derivatives were characterized with positive zeta-potential (33–51 mV) and solubility from 2 to 100 mg/mL in pH 7.

Dose Dependence of the Anticoagulant Effect of Intravenously Administered Cellulose Sulfate.

Experiments on rabbits showed that increasing the dose of intravenously administered cellulose sulfate from wheat straw (dynamic viscosity 3.4 cP, sulfur content 14.1%) increased plasma clotting time in some coagulation tests and plasma anticoagulant activity.