ASTM F2258-05(2015)
(Test Method)Standard Test Method for Strength Properties of Tissue Adhesives in Tension
Standard Test Method for Strength Properties of Tissue Adhesives in Tension
SIGNIFICANCE AND USE
4.1 The utility, range, and efficacy of adhesives in clinical medicine are well documented in the literature. Whether being used as an adhesive, hemostatic, sealant, or carrier for drugs or growth factors, or both, the scope of adhesive use in clinical medicine continues to expand. There are several factors which are vital to the success and efficacy of a medical tissue adhesive including, (1) adequate tissue bonding strength, (2) tissue compatibility, (3) acceptable biodegradable properties when the adhesive is used internally, (4) availability, (5) ease of application, and (6) cost.
4.2 Medical adhesives are currently used for a variety of applications and tissue types. Applications range from fixation of external tissues to internal application for use with either similar or dissimilar opposing surfaces. While the biological or chemical makeup, or both, of the adhesive may define its characteristics, additional mechanical factors including adhesive volume or method of application, or both, may also contribute significantly toward the performance of the adhesive. In an effort to fairly and adequately quantify adhesive bonding strength for medical adhesives, it is important to develop a consistent, reproducible testing standard for evaluative and comparative purposes. Due to the fact that the adhesives will be used on or in living tissues, a readily available biological testing surface is preferred.
4.3 The data generated from a standardized testing method on biologic tissue may vary from that found in vivo, however, testing results should offer valuable information on the potential bonding capacity and for the preparation of subsequent in vivo experiments.
4.4 The complexity and variety of individual applications for tissue adhesive devices, even within a single indicated use (surgical procedure), is such that the results of a tensile test are not suitable for determining allowable design stresses without thorough analysis and understanding of the applica...
SCOPE
1.1 This test method is intended to provide a means for comparison of the adhesive strengths of tissue adhesives intended for use as surgical adhesives or sealants, or both, on soft tissue. With the appropriate choice of substrate, it may also be used for purposes of quality control in the manufacture of tissue adhesive based medical devices.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2258 − 05 (Reapproved 2015)
Standard Test Method for
Strength Properties of Tissue Adhesives in Tension
This standard is issued under the fixed designation F2258; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope for use in closing wounds (surgical or traumatic) or for sealing
against leakage of body fluids.
1.1 This test method is intended to provide a means for
3.2.2 tissue sealant—a surface coating with adequate adhe-
comparison of the adhesive strengths of tissue adhesives
sive strength to prevent leakage of body fluids.
intended for use as surgical adhesives or sealants, or both, on
softtissue.Withtheappropriatechoiceofsubstrate,itmayalso
4. Significance and Use
be used for purposes of quality control in the manufacture of
4.1 The utility, range, and efficacy of adhesives in clinical
tissue adhesive based medical devices.
medicine are well documented in the literature.Whether being
1.2 The values stated in SI units are to be regarded as
usedasanadhesive,hemostatic,sealant,orcarrierfordrugsor
standard. No other units of measurement are included in this
growth factors, or both, the scope of adhesive use in clinical
standard.
medicine continues to expand. There are several factors which
1.3 This standard does not purport to address all of the
arevitaltothesuccessandefficacyofamedicaltissueadhesive
safety concerns, if any, associated with its use. It is the
including, (1) adequate tissue bonding strength, (2) tissue
responsibility of the user of this standard to establish appro-
compatibility, (3) acceptable biodegradable properties when
priate safety and health practices and determine the applica-
the adhesive is used internally, (4) availability, (5) ease of
bility of regulatory limitations prior to use.
application, and (6) cost.
4.2 Medical adhesives are currently used for a variety of
2. Referenced Documents
applications and tissue types.Applications range from fixation
2.1 ASTM Standards:
of external tissues to internal application for use with either
D907Terminology of Adhesives
similarordissimilaropposingsurfaces.Whilethebiologicalor
E4Practices for Force Verification of Testing Machines
chemical makeup, or both, of the adhesive may define its
2.2 American Association of Tissue Banks Standards:
characteristics, additional mechanical factors including adhe-
Standards for Tissue Banking
sive volume or method of application, or both, may also
contribute significantly toward the performance of the adhe-
3. Terminology
sive. In an effort to fairly and adequately quantify adhesive
3.1 Definitions—Many terms in this test method are defined
bonding strength for medical adhesives, it is important to
in Terminology D907.
develop a consistent, reproducible testing standard for evalua-
tive and comparative purposes. Due to the fact that the
3.2 Definitions:
adhesives will be used on or in living tissues, a readily
3.2.1 tissue adhesive—for the purposes of this test method,
available biological testing surface is preferred.
tissue adhesive is defined as a compound or system intended
4.3 The data generated from a standardized testing method
on biologic tissue may vary from that found in vivo, however,
ThistestmethodisunderthejurisdictionofASTMCommitteeF04onMedical
testing results should offer valuable information on the poten-
andSurgicalMaterialsandDevicesandisthedirectresponsibilityofSubcommittee
tial bonding capacity and for the preparation of subsequent in
F04.15 on Material Test Methods.
vivo experiments.
CurrenteditionapprovedMay1,2015.PublishedJuly2015.Originallyapproved
in 2003. Last previous edition approved in 2010 as F2258–05 (2010). DOI:
4.4 The complexity and variety of individual applications
10.1520/F2258-05R15.
for tissue adhesive devices, even within a single indicated use
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
(surgicalprocedure),issuchthattheresultsofatensiletestare
Standards volume information, refer to the standard’s Document Summary page on
not suitable for determining allowable design stresses without
the ASTM website.
3 thorough analysis and understanding of the application and
Available from the American Association of Tissue Banks (AATB), 1350
adhesive behaviors.
Beverly Rd., Suite 220-A, McLean, VA 22101.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2258 − 05 (2015)
4.5 This test method may be used for comparing adhesives 6.1.2 Iffreshskinischosen,itshouldbepreparedaccording
or bonding processes for susceptibility to fatigue and environ- the method in Appendix X1.
mentalchanges,butsuchcomparisonsmustbemadewithgreat
6.2 Application Specific Testing:
caution since different adhesives may respond differently to
6.2.1 The strength of any adhesive is highly dependent on
varying conditions.
the test substrate, or adherend. For a specific application, the
preferred substrate is freshly harvested tissue from the target
5. Apparatus
organ of a domestic food animal. Tissue from bovine, porcine,
orovineoriginispreferredduetowideavailabilityandthefact
5.1 Testing Machine, of the constant-rate-of-crosshead-
that relatively large samples of tissue can be harvested from a
movement type and comprising essentially the following:
single source. Ideally, the tissue should be used within 24 h of
5.1.1 Fixed Member, a fixed or essentially stationary mem-
harvest,andshouldbekeptbetween5and10°Cpriortotesting
ber carrying one grip.
if it cannot be used immediately after harvesting. Storage and
5.1.2 Movable Member, a movable member carrying a
handling of tissue samples should be carried out according to
second grip.
the guidelines set forth in Standards forTissue Banking by the
5.1.3 Grips,forholdingthetestspecimenbetweenthefixed
AmericanAssociation of Tissue Banks. The specimens should
member and the movable member of the testing machine can
be brought to the test temperature or other prescribed tempera-
be either the fixed or self-aligning type.
ture (such as body temperature) prior to application of the
5.1.3.1 Fixed Grips are rigidly attached to the fixed and
adhesive.
movable members of the testing machine. When this type of
6.2.2 Fixed tissue should not be used since it has been
gripisused,extremecareshouldbetakentoensurethatthetest
demonstrated that fixatives cause large alterations in the
specimen is inserted and clamped so that the long axis of the
mechanical properties of the tissue and it is probable that the
test specimen coincides with the direction of pull through the
adhesive strength would be affected as well.
centerline of the grip assembly.
6.2.3 Ifthetargetorganisofasizeorgeometry,orboth,that
5.1.3.2 Self-aligning Grips are attached to the fixed and
does not allow fabrication of test samples as shown in Fig. 1,
movablemembersofthetestingmachineinsuchamannerthat
a tissue of similar origin but larger size should be used. For
they will move freely into alignment as soon as any load is
example, if the intended indication is for anastomosis of small
applied so that the long axis of the test specimen will coincide
blood vessels, a larger vessel should be substituted.
with the direction of the applied pull through the center line of
6.2.4 The thickness of the tissue sample should be mini-
the grip assembly. The specimens should be aligned as per-
mized and should not exceed 5 mm.Thicker samples will lead
fectly as possible with the direction of pull so that no rotary
to distortion of the substrate and mixed loading (shear and
motion that may induce slippage or damage to the sample will
tension).Itisalsoimportantthatthethicknessbeasuniformas
occur in the grips; there is a limit to the amount of misalign-
possible.
ment self-aligning grips will accommodate.
6.3 Substrates for Quality Control Testing:
5.1.4 Drive Mechanism,forimpartingtothemovablemem-
6.3.1 For testing that is undertaken as part of a quality
berauniform,controlledvelocitywithrespecttothestationary
control process in the manufacturing of a tissue adhesive
member, with this velocity to be regulated as specified in 9.3.
device, the use of freshly harvested tissue is highly inconve-
5.1.5 Load Indicator, a suitable load-indicating mechanism
nient and may also lead to unacceptable variation in the test
capable of showing the total tensile load carried by the test
results, especially if the failure occurs in the adherend (sub-
specimen when held by the grips. This mechanism shall be
strate failure). Since the purpose of quality control testing is to
essentially free of inertia lag at the specified rate of testing and
shall indicate the load with an accuracy of 61% of the
indicated value, or better. The accuracy of the testing machine
shall be verified in accordance with Practices E4.
5.2 Temperature-controlling Equipment, capable of main-
taining the test temperature to 62°C. If ambient laboratory
conditions are employed, the same degree of control is re-
quired. A water bath or environmental chamber capable of
maintaining 37°C is required for testing on tissue substrates.
6. Test Substrate
6.1 For comparative testing, either fresh or frozen split
thickness porcine skin graft may be used.
6.1.1 Frozen split thickness porcine skin that has been
aseptically prepared is available commercially and is preferred
due to ease of use and the potential for more consistent
properties.Itshouldbethawedaccordingtothemanufacturer’s
instructions prior to use. Unused graft may be kept at 2 to 8°C
for up to two weeks after thawing. FIG. 1 Test Fixtures
F2258 − 05 (2015)
demonstrate consistency in the device, substitution of a model run over the edge of the substrate, causing artificially high test
substrate is preferred so long as it is demonstrated that the values. The amount required will have to be determined
adhesive does bond to the adherand. For devices that require experimentally. For adhesives that are delivered with a spray
contact with tissues to cure, Mediskin XenoGraft should be device, controlling the amount and distribution of the material
used for quality control testing as well as comparative testing. will be difficult. It may be necessary to use a template to
prevent overspray. Alternatively, petroleum jelly may applied
7. Test Specimen
to the portion of the tissue outside of the overlap area to
7.1 Specimens with Soft-tissue Substrates shall conform to
prevent bonding.
the form shown in Fig. 1. The only critical dimension is the
8.2.4 Bond the two sides of the test fixture together, taking
bonding surface, which shall be 2.5 6 0.005 cm . The tissue
caretokeepthefixturesalignedandtomaintaintheprescribed
can be bonded to the specimen holder with any suitable
overlap.
adhesive.Gel-typecyanoacrylateadhesiveshavebeenfoundto
8.2.5 Apply a force of approximately 1 to2Ntothe bond
be convenient for this purpose since they adhere well to moist
area until the adhesive sets. For slow-curing adhesives, it may
tissues and cure quickly. In cases where the test adhesive is
be necessary to use a clamping device that can be left in place
based on cyanoacrylates, this test method may not work with
while the fixture is returned to the environmental chamber or
all tissue types since the tissue may pull off of the fixture
water bath.
instead of failing at the test adhesive interface. In this case,
8.3 Measureandrecordthewidthandlengthoftheadhesive
alternative means of securing the tissue to the test fixture may
bond to within 0.05 cm.
needtobeemployedoranalternativetestconfigurationsuchas
8.4 Re-cover the tissue with gauze soaked in PBS, replace
T-Peel or Lap-Shear can be chosen.
the sample in a plastic bag, and return it to the constant
7.2 Specimens with Polymer or Metal Substrates shall
temperature environment.
conform to the form and dimensions shown in Fig. 1.
9. Test Procedure
7.3 Number of Test Specimens—Test at least 10 specimens
of each type. Discard results if failure occurs between the test 9.1 Conditionthetestspecimensfordefiniteperiodsoftime
fixture and the tissue sample and test additional samples to under specified, controlled conditions before testing if desired.
obtain a total of 10 valid tests. Tissue substrates tend to give Forcomparativetesting,theconditioningtimeshouldbe1h 6
higher variances and may require more samples to attain a 15 min. Recommended conditions for tissue adhesives in-
reasonable estimate of the mean strength. tended for internal applications are 37 6 1°C in phosphate
bufferedsaline.Foradhesivesintendedforexternaltopicaluse,
8. Sample Preparation
recommended conditions are 30 6 1°C and 50 6 5% relative
8.1 Tissue Preparation:
humidity. For quality control testing with metal or polymer
8.1.1 Tissue substrate materials should be kept moist at all
substrates, the recommended conditions are 23 6 1°C and 50
times with phosphate buffered saline (PBS).
6 5% relative humidity.
8.1.2 The substrate will be placed face down on gauze
9.2 After conditioning, it is recommended that all speci-
soaked in PBS, and the back side will be patted dry with fresh
mens be stabilized at the test temperature for 15 min before
gauze.
testingifthetesttemperatureisdifferentfromtheconditioning
8.1.3 Theback-sideofthetissuesamplewillbegluedtothe
temperature.Tissuesamplesmustbekeptmoistthroughoutthe
test fixture using a suitable adhesive. When Mediskin Xeno-
process to prevent shrinkage due to drying. For comparative
graft is used, the epidermal surface will be glued to the fixture,
testing, the test conditions should be 23 6 1°C and 50 65%
leaving the dermal surface for test adhesive bonding. Gel-type
relative humidity (see Annex A1).
cyanoacrylate adhesives have been found to be useful for this
9.3 Place the test specimens in the grips of the testing
purpose since they set quickly and adhere to most materials.
machinesothattheappliedloadcoincideswiththelongaxisof
8.1.4 After the adhesive has cured (approximately 10 min
the specimen. Load the specimen to failure at a constant
for cyanoacrylate adhesives), place the fixtures on a cutting
cross-head speed of 2 mm/min.
board and trim the excess tissue away from the fixture using a
sharp scalpel. The scalpel must be held perpendicular to the
9.4 Record the load at failure (maximum load sustained)
boardtoensurethatthetissuesamplehasthesamedimensions
and the typ
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