Plasma recalcification time

Fig. 7 C Plasma clotting time measurements, including measurements of plasma recalcification time [PRT], plasma thromboplastin-catalyzed clotting time [PTT], and thrombin-catalyzed clotting time [TT]...

In Vitro Clotting Tests. The plasma recalcification time of citrated human plasma was determined in the presence of heparin-PVA beads and control PVA beads without heparin. Various amounts (10-200 mg) of gel were incubated with 0.5 mL of plasma at room temperature for 5 min. After the addition of 0.5 mL of0.025M CaCl2, the time to clot was noted by tilting the test tube gently each minute, until the beads clumped together or were found to stick to the test tube wall. 

In Vitro Activity of Bound Heparin. The prolongation of the thrombin time caused by the addition of heparin-PVA beads to plasma is contrasted with the negligible effect of PVA beads without heparin in Figure la. A similar prolongation was observed for the plasma recalcification time (Figure lb). In both cases, clumping or adhesion of the beads caused presumably by fibrin was the end point of the assay. 

Blood compatibility of the control PCL and chitosan-g-PCL-h-PEG/heparin multilayer-deposited PCL membrane was measured using static platelet adhesion and plasma recalcification time experiments Cytocompatibity of scaffolds with endothelial cells and vascular smooth muscle cells (vSMCs)... 

The modified polymer beads [347] passed all of the standard battery of biocompatibility tests required by the International Organization for Standardization guidelines (ISO 10993). The tests included in vitro coagulation tests (plasma recalcification time), hemolysis study (extraction method), cytotoxicity study using the ISO elution method, etc. In in vivo experiments, extracts of the polymer beads did not elicit pyrogenic irritation or sensitization reactions in laboratory animals (acute systematic toxicity study in the mouse, acute intracutaneous reactivity study in the rabbit, rabbit pyrogen study). 

NaOH treatment could significantly enhance the blood compatibility of PHBHHx by prolonging plasma recalcification time, plasma prothrombin time, and kinetic clotting time and by decreasing platelet activation. By comparison, PHBHHx exhibited a substantially better blood compatibility than poly(L-lactic acid) [58]. 

Determined as follows 1 mg of the copolymer was dispersed in a 0.1 ml solution of non-ionogenic surface-active compound at 37 °C for 10 min 0.2 ml of plasma were added to the suspension the mixture was incubated for 15 min at 37 °C 0.1 ml thrombin (5 U/ml) (thrombin time) or 0.2 ml of 0.025 M CaCl2 (recalcification time) were then added and the time of clot formation was measured. 

PEG chains were also grafted to poly(methyl methacrylate) (PMMA) in order to improve the hemocompatibihty of the material. XPS, used in the angle-dependent mode, showed that PMMA tends to be enriched at the surface, except when the PEG side-chains are long and the PEG content is high. The hemocompatibility of these materials, assessed using the recalcification time of platelet-rich plasma, was shown to increase with the PEG concentration at the surface. ... 

PE, PS, lecithin, synthetic phosphatides Ox brain cephalin, egg yolk Folch Recalcification time of human and chicken plasma PS active at low and inhibitory at high concentrations lecithin inactive maximal activity with combination of PS and PE PS and lecithin almost as active combinations of synthetic phosphatides active Hecht and Slotta (1962)... 

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