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Algae as a Source of Polysaccharides and Potential Applications
Published in Sanjeet Mehariya, Shashi Kant Bhatia, Obulisamy Parthiba Karthikeyan, Algal Biorefineries and the Circular Bioeconomy, 2022
Sonal Tiwari, E Amala Claret, Vikas S. Chauhan
In blood coagulation, fucoidan fraction from Nemacystus decipiens can increase the amount of plasminogen activator inhibitor: tissue plasminogen activator, which has fibrinolytic activity and can be utilized as an antithrombotic medication. The administration of low molecular weight fucoidan decreased the development of arterial thrombosis (Cui et al., 2018). Fucoidans isolated from Ecklonia cava were investigated for their anticoagulant effects by measuring prothrombin time, thrombin time, and activated partial thromboplastin time (Athukorala et al., 2006). The anticoagulant activity of a sulfated ramified polysaccharide isolated from Codium divaricatum was shown to be dose-dependent (Li et al., 2015). The synthesis and distribution of sulphate groups in the structure of sulfated galactan impact venous antithrombotic and anticoagulant properties. There are also higher anticoagulant effects with higher sulfate-content carrageenans, such as λ-carrageenans, than with lower sulfate-content carrageenans like κ-carrageenans (Necas and Bartosikova, 2013).
Biomedical Applications of pH-Responsive Membranes
Published in Randeep Singh, Piyal Mondal, Mihir Kumar Purkait, pH-Responsive Membranes, 2021
Randeep Singh, Piyal Mondal, Mihir Kumar Purkait
The hydrophilic part of f-MWCNT contributed to the –COOH and –OH groups, whereas sulfonated polymers provided the –SO2H group in the membrane composition. The formulated HD membranes were characterized by FTIR, FESEM, and contact angle. The AFM was used for the estimation of the surface roughness and surface profile studies, whereas flux rate and rejection rate were also determined. The biocompatibility results revealed that sulfonated-NC-based membranes had reduced 55% (BSA), 65% (lysozyme) adsorption, and 74.80% hemolysis process. It also demonstrated higher clotting time of prothrombin (PT), thrombin (TT), activated partial thrombin time (APTT), and plasma re-calcification time (PRT). The dialysis results indicated that, compared to the pristine PES membrane, the clearance ratio of lysozyme, urea, and creatinine solutes increased up to 32.4%, 59.2%, and 57.3%, respectively. Thus, the blending of S-PES and NCs in the PES membrane highly improved the biocompatibility and removal ability of uremic solutes.
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Published in Joseph C. Salamone, Polymeric Materials Encyclopedia, 2020
By partial modification of acrylonitrile polymers by the reaction with natrium azide polymeric products useful for the making of artificial fiber and water dilutable paints were obtained.49 Water–soluble tetrazolcontaining polymers show a variable biological activity. Their acute toxicity varies from LD50 = 166 mg/kg for p-5VT to 1340 mg/kg for IPT-VPD copolymer. Similar to the most of polyacids, polymers of 5VT and IPT possess anticoagulant activity.50 p-IPT is a direct blood anticoagulant with activity approaching to heparin but there are some differences in mechanisms of their action. Thus, p-IPT affects only the initial stages of blood coagulation (increase of the time of thromboplastinthrombin creation, fibrin polymerization and recalcification) but has no influence on prothrombin consumption index and thrombin time.
Heparinized PCL/keratin mats for vascular tissue engineering scaffold with potential of catalytic nitric oxide generation
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Xiuzhen Wan, Yanfang Wang, Xingxing Jin, Pengfei Li, Jiang Yuan, Jian Shen
APTT, PT and TT were applied to evaluate the anticoagulant potential in vitro. According to Figure 4, the APTT value of PCL was a bit longer than that of PPP, indicating its good blood compatibility. Regarding to PCL/keratin mats, the APTT value was significantly prolonged because S-carboxymethyl keratin was introduced. It was well known that the hydrophilicity of carboxyl groups were benefit to blood compatibility. In the term of heparinized mats, the APPT value was prolonged by almost 43 s compared with PPP. It indicated the conjugated heparin effectively impacts the intrinsic coagulation pathway [42]. Prothrombin time (PT) was used to detect the coagulation time in the extrinsic pathway. PT value for heparinized PCL/keratin mats just only prolonged for 1 s (Figure 4b). TT was used to test the clot formation time for the thrombin conversion of fibrinogen into insoluble fibrin protein. The longer TT clotting time suggested the slower conversion speed, resulting in thrombus inhibition. TT clotting time for heparinized PCL/keratin mats was prolonged about 3 s (Figure 4c).