Blood compatibility is the main restriction of blood-contacting medical devices in clinical application, especially long-term blood-contacting medical devices will stimulate the immune defense mechanism of the host, resulting in thrombosis. Heparin anticoagulant coating links heparin molecules to the surface of medical device product materials, improves the compatibility between the material surface interface and the body, and reduces the host immune defense reactions. This study reviews the structure and biological properties of heparin, the market application status of heparin-coated medical products, the insufficiency and improvement of heparin coating, which can provide a reference for the application research of blood contact medical devices.
Humans ; Heparin/chemistry* ; Anticoagulants/chemistry* ; Thrombosis ; Coated Materials, Biocompatible/chemistry* ; Surface Properties

COVID-19 represents the most serious public health event in the past few decades of the 21^st century. The development of vaccines, neutralizing antibodies, and small molecule chemical agents have effectively prevented the rapid spread of COVID-19. However, the continued emergence of SARS-CoV-2 variants have weakened the efficiency of these vaccines and antibodies, which brought new challenges for searching novel anti-SARS-CoV-2 drugs and methods. In the process of SARS-CoV-2 infection, the virus firstly attaches to heparan sulphate on the cell surface of respiratory tract, then specifically binds to hACE2. The S protein of SARS-CoV-2 is a highly glycosylated protein, and glycosylation is also important for the binding of hACE2 to S protein. Furthermore, the S protein is recognized by a series of lectin receptors in host cells. These finding implies that glycosylation plays important roles in the invasion and infection of SARS-CoV-2. Based on the glycosylation pattern and glycan recognition mechanisms of SARS-CoV-2, it is possible to develop glycan inhibitors against COVID-19. Recent studies have shown that sulfated polysaccharides originated from marine sources, heparin and some other glycans display anti-SARS-CoV-2 activity. This review summarized the function of glycosylation of SARS-CoV-2, discoveries of glycan inhibitors and the underpinning molecular mechanisms, which will provide guidelines to develop glycan-based new drugs against SARS-CoV-2.
Antibodies, Neutralizing ; Glycosylation ; Heparin ; Heparitin Sulfate ; Humans ; Polysaccharides/chemistry* ; Receptors, Mitogen/metabolism* ; SARS-CoV-2 ; Spike Glycoprotein, Coronavirus/metabolism* ; COVID-19 Drug Treatment

Heparin and heparan sulfate are a class of glycosaminoglycans for clinical anticoagulation. Heparosan N-sulfate-glucuronate 5-epimerase (C5, EC 5.1.3.17) is a critical modifying enzyme in the synthesis of heparin and heparan sulfate, and catalyzes the inversion of carboxyl group at position 5 on D-glucuronic acid (D-GlcA) of N-sulfoheparosan to form L-iduronic acid (L-IdoA). In this study, the heparin C5 epimerase gene Glce from zebrafish was expressed and molecularly modified in Escherichia coli. After comparing three expression vectors of pET-20b (+), pET-28a (+) and pCold Ⅲ, C5 activity reached the highest ((1 873.61±5.42) U/L) with the vector pCold Ⅲ. Then we fused the solution-promoting label SET2 at the N-terminal for increasing the soluble expression of C5. As a result, the soluble protein expression was increased by 50% compared with the control, and the enzyme activity reached (2 409±6.43) U/L. Based on this, site-directed mutations near the substrate binding pocket were performed through rational design, the optimal mutant (V153R) enzyme activity and specific enzyme activity were (5 804±5.63) U/L and (145.1±2.33) U/mg, respectively 2.41-fold and 2.28-fold of the original enzyme. Modification and expression optimization of heparin C5 epimerase has laid the foundation for heparin enzymatic catalytic biosynthesis.
Animals ; Carbohydrate Epimerases ; biosynthesis ; chemistry ; genetics ; Escherichia coli ; Gene Expression ; Heparin ; metabolism ; Heparitin Sulfate ; metabolism ; Iduronic Acid ; metabolism ; Zebrafish Proteins ; biosynthesis ; chemistry ; genetics

Heparin is a very important anticoagulant drug. Currently, heparin is mainly extracted from porcine mucosa. However, animal-derived heparin shows low anticoagulant activity due to the low proportion of the anticoagulant active unit, the GlcNS6S-GlcA-GlcNS6S3S-Ido2S-GlcNS6S pentasaccharide. In this study we proposed an enzymatic strategy to sulfate the animal-sourced heparin to increase the proportion of anticoagulant pentasaccharide and the anticoagulant activity. First, three sulfotransferases HS2ST, HS6ST, and HS3ST were expressed tentatively in Escherichia coli and Pichia pastoris. After measuring the sulfotransferase activity, we confirmed P. pastoris GS115 is the better host for sulfotransferases production. Then, the maltose binding protein (MBP) and thioredoxin (TrxA) were fused separately to the N-terminal of sulfotransferases to increase enzyme solubility. As a result, the yields of HS2ST and HS6ST were increased to (839±14) U/L and (792±23) U/L, respectively. Subsequent sulfation of the animal-sourced heparin with the recombinant HS2ST, HS6ST and HS3ST increased the anticoagulant activity from (76±2) IU/mg to (189±17) IU/mg.
Animals ; Escherichia coli ; Heparin ; chemistry ; Oligosaccharides ; chemistry ; Pichia ; Sulfotransferases ; biosynthesis ; Swine

OBJECTIVEThis paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs).

DATA SOURCESAll articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect.

STUDY SELECTIONThe articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded.

RESULTSTechnology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol), polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO 2 , heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments.

CONCLUSIONThe surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs.

Animals ; Heparin ; chemistry ; Humans ; Hydrophobic and Hydrophilic Interactions ; Lenses, Intraocular ; Methacrylates ; chemistry ; Ozone ; chemistry ; Phosphorylcholine ; analogs & derivatives ; chemistry ; Ultraviolet Rays

We conducted this study to investigate the synergistic effect of human urine-derived stem cells (USCs) and surface modified composite scaffold for bladder reconstruction in a rat model. The composite scaffold (Polycaprolactone/Pluronic F127/3 wt% bladder submucosa matrix) was fabricated using an immersion precipitation method, and heparin was immobilized on the surface via covalent conjugation. Basic fibroblast growth factor (bFGF) was loaded onto the heparin-immobilized scaffold by a simple dipping method. In maximal bladder capacity and compliance analysis at 8 weeks post operation, the USCs-scaffold(heparin-bFGF) group showed significant functional improvement (2.34 ± 0.25 mL and 55.09 ± 11.81 microL/cm H2O) compared to the other groups (2.60 ± 0.23 mL and 56.14 ± 9.00 microL/cm H2O for the control group, 1.46 ± 0.18 mL and 34.27 ± 4.42 microL/cm H2O for the partial cystectomy group, 1.76 ± 0.22 mL and 35.62 ± 6.69 microL/cm H2O for the scaffold group, and 1.92 ± 0.29 mL and 40.74 ± 7.88 microL/cm H2O for the scaffold(heparin-bFGF) group, respectively). In histological and immunohistochemical analysis, the USC-scaffold(heparin-bFGF) group showed pronounced, well-differentiated, and organized smooth muscle bundle formation, a multi-layered and pan-cytokeratin-positive urothelium, and high condensation of submucosal area. The USCs seeded scaffold(heparin-bFGF) exhibits significantly increased bladder capacity, compliance, regeneration of smooth muscle tissue, multi-layered urothelium, and condensed submucosa layers at the in vivo study.
Adult Stem Cells/cytology/metabolism/*transplantation ; Animals ; Biocompatible Materials/chemistry ; Cell Differentiation ; Fibroblast Growth Factor 2/administration & dosage ; Heparin/administration & dosage ; Humans ; Materials Testing ; Models, Animal ; Poloxamer ; Polyesters ; Rats ; Reconstructive Surgical Procedures ; Regeneration ; Tissue Engineering/*methods ; Tissue Scaffolds/chemistry ; Urinary Bladder/anatomy & histology/physiology/*surgery ; Urine/*cytology

OBJECTIVETo evaluate the anticoagulant and antineoplastic activities of chemically modified low-molecular-weight heparin (LMWH).

METHODSLMWH obtained by splitting unfractionated heparin (UFH) with sodium periodate oxidation and sodium borohydride reduction was subjected to acetylation catalyzed by DCC and DMAP to produce acetylated LMWH (ALMWH). The anticoagulant activity of ALMWH was determined in mice, and its antiproliferative and anti-invasion activities was assessed in human breast cancer cells MDA-MB-231 and MFC-7.

RESULTSThe anticoagulant activity of LMWH was decreased significantly after acetylation. The concentrations of commercial LMWH* and ALMWH for doubling the coagulation time (CT) were 33.04 µmol/L and 223.56 µmol/L, respectively, and the IC(50) of ALMWH for doubling CT was 6 times of that of LMWH*. ALMWH and LMWH at 0.1, 0.3, 0.9, 2.7 and 8.1 mmol/L both significantly inhibited the proliferation of MDA-MB-231 and MCF-7 cells in a concentration-dependent manner, but ALMWH produced stronger inhibitory effects. The IC(50) of LMWH and ALMWH for inhibiting cell proliferation was 3168.4 µmol/L and 152.6 µmol/L in MCF-7 cells, and 12299.6 µmol/L and 22.2 µmol/L in MDA-MB-231 cells, respectively. ALMWH and LMWH all markedly suppressed the invasion of MDA-MB-231 cells with comparable effects.

CONCLUSIONChemical modification of structure can endow LMWH with a low anticoagulant and high antiproliferative activities.

Animals ; Anticoagulants ; chemistry ; pharmacology ; Antineoplastic Agents ; chemistry ; pharmacology ; Blood Coagulation ; Blood Coagulation Tests ; Cell Line, Tumor ; Heparin ; chemistry ; Heparin, Low-Molecular-Weight ; chemistry ; pharmacology ; Humans ; Mice

In order to enhance the anticoagulant properties of decellularized biological materials as scaffolds for tissue engineering research via heparinized process, the decellularized porcine liver scaffolds were respectively immobilized with heparin through layer-by-layer self-assembly technique (LBL), multi-point attachment (MPA) or end-point attachment (EPA). The effects of heparinization and anticoagulant ability were tested. The results showed that the three different scaffolds had different contents of heparin. All the three kinds of heparinized scaffolds gained better performance of anticoagulant than that of the control scaffold. The thrombin time (TT), prothrombin time (PT) and activated partial thromboplastin time (APTT) of EPA scaffold group were longest in all the groups, and all the three times exceeded the measurement limit of the instrument. In addition, EPA scaffolds group showed the shortest prepared time, the slowest speed for heparin release and the longest recalcification time among all the groups. The decellularized biological materials for tissue engineering acquire the best effect of anticoagulant ability in vitro via EPA heparinized technique.
Animals ; Anticoagulants ; chemistry ; Biocompatible Materials ; chemistry ; Heparin ; chemistry ; Liver ; Swine ; Tissue Engineering ; Tissue Scaffolds

The aim of this study was to investigate the inhibitory effect of heparin/fibronectin (Hep/Fn) complexes on neointimal hyperplasia following endovascular intervention. Hep/Fn complexes were immobilized onto titanium (Ti) surfaces, with subsequent X-ray photoelectron spectroscopy (XPS), Toluidine Blue O (TBO) and immunohistochemistry methods were used to characterize surface properties. Smooth muscle cell (SMC) cultures were used to evaluate the effect of Hep/Fn complexes on SMC proliferation. Results showed that Hep/Fn complexes successfully immobilized onto Ti surfaces and resulted in an inhibition of SMC proliferation. This study suggests that Hep/Fn surface-immobilized biomaterials develop as a new generation of biomaterials to prevent neointimal hyperplasia, particularly for use in cardiovascular implants.
Biocompatible Materials ; Cell Proliferation ; drug effects ; physiology ; Cells, Cultured ; Fibronectins ; chemistry ; pharmacology ; Heparin ; chemistry ; pharmacology ; Humans ; Immobilized Proteins ; chemistry ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; drug effects ; physiology ; Surface Properties ; Titanium ; chemistry ; Umbilical Arteries

Antithrombin III (AT III) is the most important anti-clotting substance. Recombinant human antithrombin III (rhAT III) expressed in transgenic goat milk attracts more and more attention. Develop an effective purification route for rhAT III is vital to its industrial production. An efficient purification method was developed for the rapid purification of rhAT III by isoelectric precipitation and heparin affinity chromatography. First, casein was effectively removed by isoelectric precipitation. rhAT III was further purified by heparin affinity chromatography. In the process of heparin affinity chromatography, the effects of pH and temperature on the stability of rhAT III were studied, and the effects of operating conditions, elution gradient, flow rate and sample loaded, on the purification efficiency were also studied. Under the optimized conditions, the protein recovery of rhAT III was about 90% with purity over 99%, while its activity recovery was about 50%. Such a purification process is very simple and effective, and it would provide a valuable reference for the further scaling-up of industrial production.
Animals ; Animals, Genetically Modified ; Antithrombin III ; biosynthesis ; Chromatography, Affinity ; Female ; Goats ; Heparin ; Humans ; Mammary Glands, Animal ; metabolism ; Milk ; chemistry ; Recombinant Proteins ; biosynthesis