Evaluation specimen and evaluation device

Abstract

To provide an evaluation sample used in an evaluation test capable of evaluating blood compatibility of a medical device about blood clotting activity, platelet activity, and complement activity by a blood circulation system capable of simulating a clinical use method.SOLUTION: An evaluation sample 1 is used in an evaluation test for blood compatibility of a medical device. The evaluation sample has a first activator 10 that promotes the clotting activity and platelet activity of blood used in the evaluation test, and a second activator 20 that promotes the complement activity of the blood.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an evaluation specimen and an evaluation device. [Background technology]

[0002] Various methods for evaluating the blood compatibility of medical devices have been studied (for example, see Patent Document 1 below). Methods for evaluating the blood compatibility of medical devices described in ISO 10993-4 include an in vivo / ex vivo evaluation method that uses animals to simulate clinical use and evaluates the risk of thrombosis at the application site of the medical device through a semi-quantitative evaluation using visual judgment of the degree of thrombus adhesion to the surface of the medical device, and an in vitro evaluation method that uses blood to quantitatively evaluate coagulation, platelet activation, complement, and hematological parameters.

[0003] In vitro evaluation methods often use the static method, which is easier to set conditions for than the blood circulation method and can be performed on a small scale. The static method is an evaluation method in which a medical device is immersed in blood and comes into contact with blood, and is recommended for hemocompatibility evaluation of medical devices that come into contact with blood without blood flow, such as blood bags. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2003 / 014394 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the stationary method, the medical device and blood are in contact in a stationary state, so this is not an evaluation method that simulates clinical use for medical devices that come into contact with circulating blood, such as catheters.

[0006] For this reason, there is a demand for an in vitro evaluation method that simulates clinical use in the blood circulation system.

[0007] Therefore, the present inventors conducted various studies with the aim of constructing an evaluation device capable of simultaneously evaluating thrombus formation, coagulation activity, platelet activity, and complement activity using an in vitro evaluation method that simulates clinical use.

[0008] In constructing the above-mentioned evaluation device, the inventors focused on the importance of an evaluation sample (positive control substance) that can accurately determine that medical devices that are positive in conventional in vivo evaluation are positive, and thereby came up with the present invention.

[0009] That is, the present invention aims to provide an evaluation sample that can be used in an evaluation device that can simultaneously evaluate thrombus formation, coagulation activity, platelet activity, and complement activity in an in vitro evaluation method that simulates clinical use, and that can be appropriately used as a positive control substance.

[0010] Another object of the present invention is to provide an evaluation device used in an evaluation test using the above-mentioned evaluation sample. [Means for solving the problem]

[0011] The evaluation sample according to the present invention, which achieves the above object, is an evaluation sample used in an evaluation test for the blood compatibility of a medical device. The evaluation sample has a first active part that promotes the coagulation activity and platelet activity of the blood used in the evaluation test, and a second active part that promotes the complement activity of the blood. The first active part is at least one selected from the group consisting of polyurethane, latex rubber, and polyurethane elastomer, and the second active part is Zymosan, cobra venom, mannan, agarose At least one selected from the group consisting of:

[0012] The present invention also provides an evaluation device for use in an evaluation test for the blood compatibility of a medical device, which includes a supply section for supplying blood used in the evaluation test, a circulation path for circulating the blood, and an insertion section for inserting an evaluation specimen having a first activation section for promoting coagulation activity and platelet activity of the blood and a second activation section for promoting complement activity of the blood. [Effects of the Invention]

[0013] According to the evaluation sample configured as described above, the first activation part can promote blood coagulation activity and platelet activity, and the second activation part can promote blood complement activity. Therefore, it is possible to provide an evaluation sample that can be used in an evaluation device that can simultaneously evaluate thrombus formation, coagulation activity, platelet activity, and complement activity in an in vitro evaluation method that simulates clinical use, and that can be appropriately used as a positive control substance.

[0014] Furthermore, according to the evaluation device configured as described above, it is possible to provide an evaluation device that can be used in an evaluation test using the above-mentioned evaluation sample. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a front view showing an evaluation sample according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. [Figure 3] 1 is a schematic diagram illustrating an evaluation device according to an embodiment of the present invention. [Figure 4] 1 is a photograph showing a negative control substance after circulating in the blood when an evaluation test was carried out with an ACT (activated clotting time) of about 200 seconds. [Figure 5] This is a photograph showing the negative control substance after blood circulation when an evaluation test was conducted with an ACT of about 300 seconds. [Figure 6] This is a photograph showing an evaluation sample (positive control substance) after blood circulation when an evaluation test was performed with an ACT of about 200 seconds. [Figure 7]This is a photograph showing an evaluation sample (positive control substance) after blood circulation when an evaluation test was performed with an ACT of about 300 seconds. [Figure 8] 1 is a photograph showing an evaluation sample (positive control substance) when an in vivo thrombosis test was performed. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0017] An evaluation sample 1 according to this embodiment will be described below with reference to Figures 1 and 2. Figure 1 is a front view showing the evaluation sample 1 according to this embodiment. Figure 2 is a cross-sectional view taken along line 2-2 in Figure 1.

[0018] Evaluation sample 1 is used in an evaluation test for the blood compatibility of a medical device. In an evaluation test, it is important to be able to distinguish between negative and positive results. Evaluation sample 1 is used as a positive control substance to properly determine a positive result in a blood compatibility evaluation test system for a medical device. As used herein, "positive" means that the sample significantly promotes thrombus formation, coagulation activity, platelet activity, and complement activity in a medical device blood compatibility evaluation test system compared to medical devices with a proven track record of clinical use.

[0019] As shown in Figures 1 and 2, the evaluation specimen 1 has a first active part 10 consisting of a main body portion extending in the axial direction, and a second active part 20 consisting of a covering portion arranged to cover part of the outer surface of the main body portion.

[0020] The first active part 10 promotes blood coagulation activity and platelet activity. As shown in Figures 1 and 2, the first active part 10 is a string body with a circular cross section.

[0021] The diameter of the first active part 10 is not particularly limited as long as it can be inserted through the insertion part of the evaluation device described below, blood flows around the first active part 10 when inserted, and it is not significantly different from the diameter of the medical device to be evaluated. The axial length of the first active part 10 is not particularly limited, but is 100 to 300 mm.

[0022] Furthermore, a textured surface is applied to the surface of the first active portion 10. The width of the grooves in the textured uneven shape is not particularly limited.

[0023] The material constituting the first active portion 10 is not particularly limited, and polymeric materials, metal materials, etc. can be appropriately used. Examples of polymeric materials include polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or mixtures thereof), polyolefin elastomers, crosslinked polyolefins, polyvinyl chloride, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, polyurethane elastomers, latex rubber, fluororesins, polycarbonates, polystyrenes, polyacetals, polyimides, polyetherimides, ethylene-tetrafluoroethylene copolymers (ETFE), tetrafluoroethylene-hexafluoropropylene copolymers (FEP), polyether ether ketones (PEEK), and polyvinylidene fluoride (PVDF). Examples of metal materials include stainless steel (SUS) such as SUS304, SUS316, SUS316L, SUS420J2, and SUS630, gold, platinum, silver, copper, nickel, cobalt, titanium, iron, aluminum, and tin, as well as nickel-titanium (Ni-Ti) alloys, nickel-cobalt (Ni-Co) alloys, cobalt-chromium (Co-Cr) alloys, and zinc-tungsten (Zn-W) alloys. To enhance thrombus formation, blood coagulation, and / or platelet activation, first active portion 10 preferably contains at least one of polyurethane, latex rubber, and polyurethane elastomer, and more preferably is composed of at least one of polyurethane, latex rubber, and polyurethane elastomer. These materials may be used alone or in combination.

[0024] The second active portion 20 promotes complement activity in blood. The axial length of the region R where the second active portion 20 is provided is not particularly limited, but is in the range of 30 to 50 mm.

[0025] The material constituting the second active section 20 is not particularly limited and may include, for example, immunoglobulins such as IgA, IgD, IgE, IgM, IgG1, IgG2, and IgG3, C-polysaccharide-CRP conjugates, polymeric DNA, bacterial lipopolysaccharides, dextran, dextran sulfate, polyanion-polycation conjugates, zymosan (the pellicle membrane of yeast and gram-negative bacteria), mannan, bacterial wall peptidoglycan, inulin, and polymeric substances such as agarose, proteolytic enzymes such as trypsin and plasmin, microorganisms such as Trypanosoma, Entamoeba histolytica, and Schistosoma, virus-infected cells, tumor cells, uric acid crystals, cardiac muscle mitochondria, retroviruses, and cobra venom. Among these, the complement activator preferably includes at least one of zymosan (particularly zymosan A), cobra venom, mannan, and agarose, and more preferably at least one of zymosan (particularly zymosan A), cobra venom, mannan, and agarose. These complement activators may be used singly or in combination of two or more.

[0026] The amount of the second active part 20 is set to 132.7 g / m per unit surface area of ​​the region R where the second active part 20 is arranged, from the viewpoint of exhibiting sufficient complement activation performance. 2 The upper limit of the amount of the complement activator is not particularly limited, but is usually 265.4 g / m 2 The following is the result.

[0027] <Evaluation Device 90> Next, the configuration of an evaluation device 90 used in an evaluation test for the blood compatibility of a medical device will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing an evaluation device 90 according to an embodiment of the present invention.

[0028] As shown in Figure 3, the evaluation device 90 has a supply unit 91 to which blood used in the evaluation test is supplied, a blood bag 92 to which the supply unit 91 is connected, a circulation path 93 through which the blood circulates, an insertion unit 94 into which the evaluation sample 1 is inserted, a collection unit 95 connected to the circulation path 93 and which collects the blood used in the evaluation test, and a pump 96 for circulating the blood within the circulation path 93.

[0029] The supply part 91 is a three-way stopcock provided above the blood bag 92. The circulation path 93 is a tube. A known sheath can be used as the insertion part 94. The insertion part 94 is provided with a valve (not shown) to prevent backflow of blood. The collection part 95 is a three-way stopcock. The pump 96 can be, for example, a roller pump.

[0030] <Evaluation method using evaluation equipment> Next, an evaluation method using the evaluation device 90 will be described.

[0031] First, each evaluation specimen (negative control substance, positive control substance) 1 is inserted through an insertion part 94 connected to a circulation path 93 and placed at the specimen insertion point of the circulation path 93. Each evaluation specimen is exposed approximately 10 cm from the tip of the insertion part 94.

[0032] Next, 50 mL of physiological saline is injected into the circulation path 93 from the collection portion 95 to perform priming. The priming is performed so that air bubbles in the circulation path 93 are collected in the blood bag 92.

[0033] Next, the air inside the blood bag 92 is removed from the supply part 91 at the top of the blood bag 92 using a syringe.

[0034] Next, 100 mL of test blood is injected from supply part 91 at the top of blood bag 92. After injection, the air inside blood bag 92 is removed again using the syringe.

[0035] Next, the pump 96, which is set to a flow rate of 200 mL / min in the evaluation specimen portion in the circulation path 93, is turned on to start circulating the blood.

[0036] Next, blood samples for measurement are taken 5 minutes, 90 minutes, and 180 minutes after the start of circulation. The blood samples are collected from the sampling portion 95 using a syringe.

[0037] Next, after 180 minutes from the start of circulation, a blood sample for measurement is collected, and then the pump 96 is stopped to terminate circulation. After the pump 96 is stopped, the evaluation specimen is taken out.

[0038] After the specimen is collected, it is examined visually to measure clot formation, and the thrombin-antithrombin III complex (TAT) is measured to measure blood coagulation activity, β-thromboglobulin (β-TG) and platelet count to measure platelet activation, and SC5b-9 is measured to measure complement activation.

[0039] <Example> Examples will be described below.

[0040] First, a Radifocus Introducer IIH Fr.9 (manufactured by Terumo Corporation: sheath portion only) was prepared as a negative control substance.

[0041] Next, as a positive control substance (corresponding to the evaluation sample in this embodiment), a urethane round cord (manufactured by Fuso Rubber Industries Co., Ltd., diameter 3 mm) with a textured surface was prepared by adhering zymosan A (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) to it. The urethane round cord corresponds to the first active part 10, and zymosan A corresponds to the second active part 20.

[0042] The preparation of the positive control substance is described in more detail below. Frozen zymosan A was allowed to return to room temperature. A 20 cm piece of urethane round cord was cut and marked 5 cm and 8 cm from the tip. Zymosan A was weighed out at 0.0375 g on an electronic balance and crushed. Cemedine 3000 Gold (jelly-like) (Cemedine Co., Ltd.) was applied to the entire area between the marks to allow the zymosan A to adhere, and the cord was allowed to air-dry for approximately 2 hours.

[0043] Next, it was confirmed whether the prepared negative control substance and positive control substance could be judged as negative and positive when evaluated using the evaluation device 90.

[0044] Because the evaluation device 90 was designed to be a medical device that comes into short-term contact with circulating blood, the activated clotting time (ACT) was adjusted to a target of 200 to 300 seconds, based on the ACT during clinical PCI. For this reason, the evaluation confirmed whether negative and positive results could be distinguished under two conditions: approximately 200 seconds, which is near the lower limit, and approximately 300 seconds, which is near the upper limit.

[0045] In the evaluation device 90, the flow rate of the circulating blood per minute was controlled by the pump 96 to 200 mL±15%.

[0046] Under the above conditions, evaluation tests of the negative control substance and the positive control substance were carried out using the evaluation method described above.

[0047] After the evaluation test, macroscopic observation was performed to measure thrombus formation, and thrombin-antithrombin III complex (referred to as TAT) was measured to measure blood coagulation activity, β-thromboglobulin (β-TG) and platelet count to measure platelet activation, and SC5b-9 to measure complement activation.

[0048] When macroscopic observation was performed as an evaluation item for thrombus formation, the evaluation was based on the grades in Table 1 below.

[0049] [Table 1]

[0050] Figure 4 shows the negative control substance after blood circulation when an evaluation test was performed with an ACT of approximately 200 seconds, Figure 5 shows the negative control substance after blood circulation when an evaluation test was performed with an ACT of approximately 300 seconds, Figure 6 shows evaluation sample 1 (positive control substance) after blood circulation when an evaluation test was performed with an ACT of approximately 200 seconds, and Figure 7 shows evaluation sample 1 (positive control substance) after blood circulation when an evaluation test was performed with an ACT of approximately 300 seconds.

[0051] As can be seen from Figure 4, with an ACT of 200 seconds, no thrombus adhesion was observed on the surface of the negative control material (thrombus adhesion grade 0). As can be seen from Figure 5, with an ACT of 300 seconds, no thrombus adhesion was observed on the surface of the negative control material (thrombus adhesion grade 0). As can be seen from Figure 6, with an ACT of 200 seconds, thrombus adhesion was observed on the surface of the positive control material (thrombus adhesion grade 4). As can be seen from Figure 7, with an ACT of 300 seconds, slight thrombus adhesion was observed on the surface of the positive control material (thrombus adhesion grade 1).

[0052] Table 2 below shows the results of macroscopic observations, as well as the measurements of TAT, β-TG, platelet count, and complement activation.

[0053] [Table 2]

[0054] Under conditions of an ACT of approximately 200 seconds, the thrombus adhesion grade was 0 for the negative control substance and 4 for the positive control substance. Furthermore, when comparing the values ​​of each parameter, TAT, β-TG, and platelet count, 180 minutes after the start of circulation with the values ​​of the negative control substance, the positive control substance showed a significant increase in TAT and β-TG, and a significant decrease in platelet count. For SC5b-9, the positive control substance showed a rapid increase from 5 minutes after the start of circulation, and clear differences were observed between the negative and positive controls at all time points.

[0055] Under conditions of an ACT of approximately 300 seconds, the thrombus adhesion grade was 0 for the negative control substance and 1 for the positive control substance. Furthermore, when comparing the values ​​of the negative control substance and the positive control substance for each parameter 180 minutes after the start of circulation for TAT and β-TG, a significant increase was observed for the positive control substance. On the other hand, no difference was observed for platelet counts. For SC5b-9, a rapid increase was observed for the positive control substance starting 5 minutes after the start of circulation, and clear differences were observed between the negative and positive control substances at all time points.

[0056] From the above, under conditions of an ACT of approximately 200 seconds, clear differences were observed between the negative and positive control substances in all evaluation items, making it possible to distinguish between negative and positive. Furthermore, under conditions of an ACT of approximately 300 seconds, no significant differences were observed in macroscopic observation or platelet count, but clear differences were observed in TAT, β-TG, and SC5b-9, indicating that it was possible to distinguish between negative and positive results for blood coagulation ability and complement activation using the measurement results of these sensitive parameters. From the above, it was concluded that when these negative and positive control substances were evaluated using the evaluation device 90, it was possible to determine negative and positive results.

[0057] Next, we evaluated the suitability of evaluation sample 1 as a positive control substance used in the evaluation device 90 by confirming whether it would show thrombogenicity in a NAVI model (non-anticoagulated venous implant model), which has a proven track record in in vivo thrombosis testing. Furthermore, from these results, we verified the consistency between the evaluation device 90, which is an in vitro evaluation system, and the in vivo thrombosis testing.

[0058] The test was conducted in accordance with ISO 10993-4:2017. One test sample per dog was inserted approximately 12-13 cm into the jugular vein of two hound dogs, directed toward the heart, and left in place for four hours. To prevent blood clotting after euthanasia, 500 IU / kg of heparin was administered to heparinize the blood throughout the body. Each dog was euthanized five to 15 minutes later.

[0059] The jugular vein at the placement site was removed and the blood vessel was incised longitudinally. After the incision, thrombus formation around the blood vessel and in evaluation specimen 1 was confirmed.

[0060] In both animals, thrombus formation was confirmed around the entire periphery of evaluation specimen 1 (see Figure 8). The thrombus formation was observed regardless of whether or not it was at the site of zymosan A attachment. According to the criteria of ISO 10993-4, the thrombus formation was rated Grade 4, the highest grade.

[0061] Since significant thrombus formation was observed in the positive control material after placement, it was determined that Evaluation Sample 1 also functions as a positive control material in the in vivo thrombosis test. Therefore, it was concluded that Evaluation Sample 1 is appropriate as a positive control material. Furthermore, it was found that the evaluation results of Evaluation Sample 1 were consistent between the in vitro evaluation system, Evaluation Device 90, and the in vivo thrombosis test.

[0062] The evaluation specimens according to the present invention have been described above through embodiments and modified examples, but the present invention is not limited to the configurations described in the embodiments, and can be modified as appropriate based on the claims. [Explanation of symbols]

[0063] 1 evaluation specimen, 10 first active part, 20 second active part, 90 evaluation equipment, 91 Supply Department, 93 Circulation Route, 94 Insertion part.

Claims

1. An evaluation sample used in an evaluation test for the blood compatibility of a medical device, a first activation part that promotes the coagulation activity and platelet activity of blood used in the evaluation test; and a second active part that promotes complement activity in the blood, The first active portion is at least one selected from the group consisting of polyurethane, latex rubber, and polyurethane elastomer, The evaluation specimen, wherein the second active portion is at least one selected from the group consisting of zymosan, cobra venom, mannan, and agarose.

2. a main body made of a polymer; a covering portion disposed to cover a portion of the outer surface of the main body portion, the first active portion is composed of the main body portion, The evaluation specimen according to claim 1 , wherein the second active portion is formed from the covering portion.

3. The amount of the second active portion is 132.7 to 265.4 g / m per unit area of ​​the region where the second active portion is arranged. ２ The evaluation specimen according to claim 1 or 2,

4. The evaluation specimen according to any one of claims 1 to 3, wherein the first active portion is a string having a circular cross section.

5. The evaluation specimen according to any one of claims 1 to 4, wherein the surface of the first active section is textured.

6. An evaluation device used in an evaluation test for blood compatibility of a medical device, a supply unit to which blood used in the evaluation test is supplied; a circulation path through which the blood circulates; an evaluation specimen having a first active part that promotes blood coagulation activity and platelet activity and a second active part that promotes complement activity of the blood, or an insertion part into which the medical device is inserted; The first active portion is at least one selected from the group consisting of polyurethane, latex rubber, and polyurethane elastomer, The evaluation device, wherein the second active part is at least one selected from the group consisting of zymosan, cobra venom, mannan, and agarose.

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