1、Designation: F756 13F756 17Standard Practice forAssessment of Hemolytic Properties of Materials1This standard is issued under the fixed designation F756; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anu
2、mber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice provides a protocol for the assessment of hemolytic properties of materials used in the fabrication of medicaldevices that wi
3、ll contact blood.1.2 This practice is intended to evaluate the acute in vitro hemolytic properties of materials intended for use in contact withblood.1.3 This practice consists of a protocol for a hemolysis test under static conditions with either an extract of the material or directcontact of the m
4、aterial with blood. It is recommended that both tests (extract and direct contact) be performed unless the materialapplication or contact time justifies the exclusion of one of the tests.1.4 This practice is one of several developed for the assessment of the biocompatibility of materials. Practice F
5、748 may provideguidance for the selection of appropriate methods for testing materials for a specific application. Test Method E2524 provides aprotocol using reduced test volumes to assess the hemolytic properties of blood-contacting nanoparticulate materials; this mayinclude nanoparticles that beco
6、me unbound from material surfaces.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the us
7、er of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Princ
8、iples for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Met
9、hodE2524 Test Method for Analysis of Hemolytic Properties of NanoparticlesF619 Practice for Extraction of Medical PlasticsF748 Practice for Selecting Generic Biological Test Methods for Materials and Devices3. Terminology3.1 Definitions:Definitions of Terms Specific to This Standard:3.1.1 plasma hem
10、oglobinamount of hemoglobin in the plasma.3.1.2 % hemolysisfree plasma hemoglobin concentration (mg/mL) divided by the total hemoglobin concentration (mg/mL)present multiplied by 100. This is synonymous with hemolytic index.3.1.3 comparative hemolysiscomparison of the hemolytic index produced by a t
11、est material with that produced by a standardreference material such as polyethylene under the same test conditions.3.1.4 direct contact testtest for hemolysis performed with the test material in direct contact with the blood.1 This practice is under the jurisdiction of ASTM Committee F04 on Medical
12、 and Surgical Materials and Devicesand is the direct responsibility of Subcommittee F04.16on Biocompatibility Test Methods.Current edition approved Dec. 1, 2013March 1, 2017. Published January 2014April 2017. Originally approved in 1982. Last previous edition approved in 20082013 asF756 08.F756 13.
13、DOI: 10.1520/F0756-13.10.1520/F0756-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not a
14、n ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate.
15、In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.5 extract testtest for hemolysis performed with an isotonic extrac
16、t of the test material, material in contact with blood, asdescribed in Practice F619, in contact with the blood3.1.6 hemolysisdestruction of erythrocytes resulting in the liberation of hemoglobin into the plasma or suspension medium.3.1.7 negative controlmaterial, such as polyethylene, that produces
17、 little or no hemolysis (0.50 mm 60 cm2 : 20.0 mL 21 cm2 : 7.0 mL1.0 mmor intricate geom-etry4.0 g : 20.0 mL 1.4 g : 7.0 mL9.2.2 Samples are cut into appropriate pieces. Transfer each of three nonextracted samples of test and control specimens intoindividual tubes as described in 9.1.3. The recommen
18、ded tube size is 16 125 mm. However the tube size may be any such thatsize as long as the specimen is covered by 7.0 mL of PBS liquid. Place 7.0 mL of PBS into each tube containing the nonextractedsample. Place 7.0 mL of PBS into each of three tubes to serve as the blank.F756 1749.3 TestAdd 1.0 mL o
19、f blood prepared according to 8.4.4 to each tube containing extract, each tube containing a specimen,and the blanks. Cap all tubes.NOTE 4This procedure calls for preparing the sample, adding the diluent to the sample and then adding the blood, which minimizes the time differencefor contact of the sa
20、mple with blood.Alternatively, the blood may be added to the diluent and then the sample added to the prepared solution. Whichevermethod is chosen must be used for the controls as well as the test specimens.9.4 Maintain tubes in a suitable test tube rack for at least 3 h at 37 6 2C in a water bath.
21、Gently invert each tube twiceapproximately every 30 min to maintain contact of the blood and material. In some cases of samples with complicatedconfigurations, it may be necessary to do more inversions to adequately mix the sample.9.5 At the end of the specified incubation time, transfer the fluid t
22、o a suitable tube and centrifuge at 700 to 800 G for 15 minin a standard clinical centrifuge.9.6 Remove the supernatant carefully to avoid disturbing any button of erythrocytes which may be present. Place thesupernatant into a second screw cap tube. Record the presence of any color toin the supernat
23、ant and any precipitate.9.7 Analyze the samples from 9.6 for supernatant hemoglobin concentration using the method in 9.8.9.8 Supernatant Hemoglobin Determination:9.8.1 Add 1.0 mL of supernatant to 1.0 mL of cyanmethemoglobin reagent, or validated diluent.9.8.2 Allow the sample to stand for 15 to 30
24、 min9 for Drabkins or 3 to 5 min for cyanmethemoglobin reagent. Read theabsorbance of the solution with a spectrophotometer at a wavelength of 540 nm.9.8.3 In the unlikely event that A540 exceeds 2, this may signify a procedural or background problem; the problem should beidentified and addressed, a
25、nd the testing repeated.9.8.3.1 Determine the hemoglobin concentration in each supernatant from 9.8using the calibration curve.9.8.3.2 The hemoglobin concentration of supernatant from the test sample or control tubes is calculated as follows (using theabsorbance value obtained in 9.8.2 and correctin
26、g for the dilution factor of 2): :S 5AS 3F 32 (4)The hemoglobin concentration of the blank tube is calculated as follows:B 5AB 3F 32 (5)9.8.3.3 Calculate the % hemolysis or hemolytic index (hemolytic index) as:%hemolysis5supernatant hemoglobin concentration3100%total hemoglobin concentration in tube
27、 (6)In Eq 6the above equation, the , the “total hemoglobin concentration in tube” is calculated by dividing the total bloodhemoglobin concentration obtained in 8.4.4 by 8 to account for the blood dilution inby PBS in the test tubes. Use of this equationassumes that background interference from endog
28、enous plasma and free hemoglobin, and from the extracts, is negligible. Thisassumption can be verified by measuring the supernatant absorbance of the extract solutions and of blood diluted in a test tubecontaining 7 mL of PBS and 1 mL of diluted blood (10 mg/mL) whichthat has been incubated along wi
29、th the test sample tubes.9.8.3.4 The %percent hemolysis is calculated by correcting for the background from the blank sample:Blank corrected %hemolysis5 S 2BT/8!2B 3100% (7)By following the dilution factors set out in subsections 8.4.4 and 9.8.1, Eq 7 can be simplified as follows:Blank corrected %he
30、molysis5 AS 2ABAT 2A B 3100% (8)It should be noted that Eq 8 is only applicable if the dilutions as set out in subsections 8.4.4 and 9.8.1 are strictly followed;otherwise, corrective dilution factors need to be introduced into Eq 7.10. Report10.1 Express results in the form of the corrected % hemoly
31、sis index as described in 9.8.3.4.10.2 The final report, as a minimum shall include the following:10.2.1 Detailed sample and control preparations including generic or chemical names, catalog number, lot or batch number, andother pertinent available designations or descriptions.10.2.2 Detailed sample
32、 and control preparations, including sample size, thickness, configuration of test specimens, and methodof sterilization.10.2.3 Age of blood and type and concentration of anticoagulant used.9 van Kampen E. J., Zijlstra W. G., Adv Clin Chem, 1983;23:199-257. PMID: 6398614, p. 211.F756 17510.2.4 Metho
33、d of hemoglobin determination.10.2.5 Tabulation of total supernatant hemoglobin levels.10.2.6 % HemolysisPercent hemolysis for the test samples, the negative controls, the positive controls, and the blanks. Includemean and standard deviation for each of the replicate samples, blanks, and positive an
34、d negative controls.10.2.7 Other pertinent observations of the experiment.10.3 Conversion of % Hemolysis for reporting purposesThis practice provides a method for determining the propensity of amaterial to cause hemolysis. Pass/fail criteria for the material are subject to consideration of the natur
35、e of the tissue contact,duration of contact, and surface area to body area-to-body ratios, and the nature of the device. Historically a hemolytic grade hadbeen assigned. However, the hemolytic grade is an arbitrarily derived scale, has not been validated, and is based on previous resultsusing a slig
36、htly different procedure. If the assignment of a hemolytic grade is required, the mean hemolytic index of the blankshould be subtracted from the mean hemolytic index of the controls and the test samples. The results of the test sample should becompared to the results of the negative control. control
37、, using the following table as a guide:Hemolytic Index abovethe negative controlHemolytic Grade02 nonhemolytic25 slightly hemolytic5 hemolyticIn addition, if the mean hemolytic index from the replicate test samples is less than 5 but one or more samples gave a hemolyticindex of greater than 5, then
38、the test should be repeated with double the number of test articles.11. Precision and Bias11.1 PrecisionThe precision of this test method is being established. Although this method has been shown to haveintralaboratory repeatability, especially with regards to classification of hemolytic response, i
39、nterlaboratory variation is stillsignificant.11.2 BiasThe bias of this test method includes the quantitative estimates of the uncertainties of the calibration of the testequipment and the skill of the operators. At this time, statements of bias should be limited to the documented performance ofparti
40、cular laboratories.12. Keywords12.1 biocompatibility; blood compatibility; direct contact; extract; hemoglobin; hemolysis testingAPPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 The presence of hemolytic material in contact with blood may produce increased levels of increase blood cell lysis andp
41、roduce increased levels of plasma hemoglobin. This may induce toxic effects or other effects which may stress the kidneys orother organs.X1.2 This practice is presented as a screening procedure for comparing the hemolytic potential of a material with that of a negativecontrol material which is gener
42、ally acknowledged to be appropriate for blood contact applications. Materials with a hemolyticpotential above that of the specified negative control material, which is known to have excellent performance in blood contactingblood-contacting situations, should be carefully considered for use since the
43、y may or may not be a potential cause of in vivohemolysis.X1.3 The procedure as presented is intended as a routine reproducible screening procedure. It is not to be represented as beingthe most sensitive nor the most specific procedure for assessing the hemolytic potential of all materials in all us
44、e applications. Theresults obtained with this procedure are intended to be used in conjunction with the results of other tests in assessing the bloodcompatibility of the test material.F756 176ASTM International takes no position respecting the validity of any patent rights asserted in connection wit
45、h any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible techn
46、ical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideratio
47、n at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harb
48、or Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 177
