ABSTRACT
The lung is an important organ in systemic toxicity test of medical devices and is significant in safety evaluation. Based on the authors' understanding of medical devices, this study provides a brief analysis of the lung examination and common problems in systemic toxicity, so as to provide references for the pre-clinical safety evaluation of medical devices. It should be noted that a reasonable risk assessment should be made after comprehensive assessment for specific medical device products.
Subject(s)
Humans , Equipment Safety , Lung , Risk AssessmentABSTRACT
BACKGROUND: As a medical device that is in contact with circulating blood in a large area for a long time, blood compatibility testing of the blood perfusion device is very important. OBJECTIVE: To test the blood compatibility of the test blood perfusion device. METHODS: The resin microparticles in the test blood perfusion device and the marketed blood perfusion device (as a control) were mixed with human anticoagulated blood respectively, and placed on a 37 °C rotating incubator for hematology, platelet, coagulation and complement detection in vitro. The two kinds of resin microparticles were respectively contacted with rabbit semi-anticoagulated blood, and the degree of thrombosis was compared by detecting the remaining fibrinogen content in the plasma. The two resin microparticles were placed in physiological saline, and then diluted anticoagulated rabbit blood was added for hemolysis experiment. The animal experiment was approved by the Ethics Committee of National Institutes for Food and Drug Control. RESULTS AND CONCLUSION: (1) The activated partial thromboplastin time and platelet concentration of the test blood perfusion device resin particle group were greater than those of the control perfusion device resin particle group (P 0.05). (2) In the thrombosis test, there was no statistical difference in the concentration of fibrinogen between the two groups (P > 0.05). (3) The hemolysis rate of the resin microparticles in the test blood perfusion device was 0.2%. (4) The results showed that compared with the resin microparticles in the control perfusion device, the resin microparticles in the test blood perfusion device activated the complement and the coagulation system more severely (relative percentage to the control between 85%-115%), but the effect on the number of platelets is relatively small; the hemolysis rate of the resin particles in the test blood perfusion device is low; and its blood compatibility is acceptable.
ABSTRACT
In China, the evaluation of hemocompatibility of biomaterials is limited to hemolysis, coagulation time,and the number and morphology of platelets adhered on biomaterials. The present research, however, is aimed to establish a method for evaluating the function of sheet biomaterials in platelet activation. Platelet activation caused by glass, polyvinyl chloride or polymethylvinylsiloxane sheets was evaluated by measuring alpha-granule membrane protein (GMP-140) in platelet poor plasma, using a reasonable blood-material contact model vibrating at different speed. The result showed that the difference in platelet activation was not significantly different among the three above-mentioned materials at 140r/m or 200r/m. However, when it comes to 230r/m, significant difference was observed among these three groups, with glass > polyvinyl chloride > polymethylvinylsiloxane. But the order was reversed at 270r/m, which may be due to the different interfacial tension of different materials. Therefore, the method is suitable to evaluate platelet activation caused by sheet biomaterials, but an appropriate vibrating speed should be chosen. The interfacial tension plays an important role in the model and should be considered for results assessment.
Subject(s)
Humans , Biocompatible Materials , Materials Testing , Methods , Platelet Activation , Surface PropertiesABSTRACT
BACKGROUND: In according to ISO-10993-4 and GB/T 16886.4, the in vitro hemo-compatibility evaluation on biomaterieisincludes thrombosis, coagulation factors, platelets and platelet functions, hematology and complement system. However, in thecase of China, the in vitro hemo-compatibility evaluations were performed only thrombosis, coagulation factors and plateletattachment, the investigation on evaluation of platelet and complement activations is less reported.OBJECTIVE: To evaluate the effect of polyethylene, polyvinyl chloride and polymethylvinylsiloxane tubes on platelet activation,and establish a useful method to evaluate the effect of tubular materials on platelet activation.METHODS: Tubes of polyethylene, poiyvinyl chlorid and silastic were established by 3.7 mm inner diameter, 3.5 mm externaldiameter, and 35 cm length, respectively. 1 mL blood was injected into the tube of polyethylene, polyvinyl chlorid and silasUc,respectively. The tubes were connected using a two-way tube, shaken at 140 r/min by 30° sloping for 3.5 hours at 37 ℃.Radiolmmunoassay was employed to detect α-granules protein level of platelet poor plasma, while flow cytometry was used todetect the percentage of positive plateiet of o-granules protein and that of activated gp Ⅱb/Ⅲa composite.RESULTS AND CONCLUSION: Radiolmmunoassay showed that o-granules protein level of plateiet poor plasma in thepolyethylene and polyvinyl chlorid tubes was significantly greater than that in the silastic tube (P < 0.05). There were no significantdifferences in o-granules protein between polyethylene and polyvinyl chlorid (P > 0.05). Flow cytometry indicated that percentageof positive platelet of o-granules protein in the polyethylene and polyvinyl chlorid tubes was significantly greater than that in thesilastic tube (P < 0.05); the percentage in the polyethylene tube was significantly greater than that in the polyvinyl chlorid tube (P <0.05). There was no significant differences in the percentage of positive plateiet of activated gp IIb/IIIa composite between thethree materials (P > 0.05). A useful blood-material contact model was established, and it was considered that o-granules protein isan available parameter for evaluating platelet activation. The percentage of positive platelet of o-granules protein determined byflow cytometry was a more sensitive parameter for evaluating platelet activation.
ABSTRACT
Hemocompatibility is an important component of biocompatibility; it reflects the degree of interaction between material and blood. Hemocompatibility is multifaceted, so that the material's impact on the blood and the underlying mechanism are very complicated. This article presents a review of researches probing the impact of material on blood via contact activation and plasma protein adsorption; via the platelet activated and the formation of thrombin; via the complement system activated and the activation of leukocytes as well as other mechanisms of hemolysis. The current methods for evaluation and the future trend of development are also introduced.
Subject(s)
Humans , Biocompatible Materials , Reference Standards , Blood , Materials Testing , Methods , Platelet Activation , Platelet Adhesiveness , Stress, Mechanical , Surface Properties , ThrombinABSTRACT
In-vitro test is usually conducted as a preliminary screening test in the evaluation of the haemocompatibility of biomaterials for its short-term consuming, convenience and less expense. The selection of appropriate model for blood-biomaterial interaction, the choice of sensitive and specific parameters, and the minimization of additional blood activation are most important in the in-vitro test. In addition, the time and the style of blood-biomaterial interaction, the choice of sensitive and specific parameters, and the minimization of additional blood activation are most important in the in-vitro test. In addition, the time and the style of blood-biomaterial interaction, the selection of primary reference materials and the shear rate should be considered. In recent years, though great progress has been made in the in-vitro evaluation of haemocompatibility of biomaterials, all these influencing factor should be standardized for more effective evaluation of the haemocompatibility of biomaterials.