Medical Device Testing Guide - Toxikon Corporation

HEMOCOMPATIBILITY TESTS—ISO 10993-4 (Cont.)
Rev. May 2011
AI02-1
AI02-2
AI03-1
AI04-1
AI04-2
AI05-1
AI05-2
In-vitro Hemocompatibility Assay
Indirect- Sample needed: 10 cm² < 0.5 mm thick, 5 cm² 0.5 mm thick, or 1 g
Direct- Sample needed: 75 cm² < 0.5 mm thick, 50 cm² 0.5 mm thick, or 2.5 g
The In-vitro Hemocompatibility assay is designed to ensure that the test article does not adversely affect the cellular
components of the blood. The test article or its extract is incubated in whole human blood, a test system that is recommended
by ISO guidelines, and the following parameters are measured: Complete Blood Count (CBC), Hematocrit, platelet count,
hemoglobin, mean cell hemoglobin, hemoglobin concentration and mean cell volume. The test is carried out in triplicate and
the results after exposure to the test article are statistically compared to those of the untreated and negative controls (if p ≥ 0.05,
the test article passes).
Approximate turnaround time is two to three weeks.
In-vivo Thrombogenicity in Dogs-Sample needed: 2 units, each ≤ 2“ in length
This test evaluates material(s) intended for blood contact for thrombogenic properties in-vivo. This test is appropriate for
comparing materials to each other in the same animal. Test and control articles are inserted into the jugular or femoral vein.
Control Articles are inserted into the opposite vein. Heparinization is carried out after four hours of insertion, and
exsanguinations soon thereafter. The damage to the test veins is examined and photographed. The extent of the thrombi
formation in the exsanguinated blood is scored on a scale from zero to five. Historically, dogs have been used in
thrombogenicity studies to assess possible human toxicity caused by material that is intended for use in contact with human
blood. ISO 10993-4 guidelines have no published alternative (non-animal) methods. The test is carried out in triplicate and the
results after exposure to the test article are statistically compared to those of the untreated negative controls (if p ≥ 0.05, the test
article passes).
Approximate turnaround time is five to six weeks.
Complement Activation
Indirect- Sample needed: 10 cm² < 0.5 mm thick, 5 cm² 0.5 mm thick, or 1 g
Direct- Sample needed: 75 cm² < 0.5 mm thick, 50 cm² 0.5 mm thick, or 2.5 g
This in-vitro assay is designed to measure complement activation in human plasma as a result of exposure to the test material or
its extract. The measure of complement activation indicates whether a test article is capable of inducing a complement-induced
inflammatory immune response in humans (including production of anaphylotoxins). The assay is evaluated by measuring the
quantity of protein complements C3a and SC5b, in human plasma that has been exposed to the test material. A standard curve
is obtained using control standards. The test is carried out in triplicate and the results after exposure to the test article are
statistically compared to those of the untreated and negative controls (if p ≥ 0.05, the test article passes).
Approximate turnaround time is three to four weeks.
The Prothrombin Time Assay (PT)
Indirect- Sample needed: 10 cm² < 0.5 mm thick, 5 cm² 0.5 mm thick, or 1 g
Direct- Sample needed: 75 cm² < 0.5 mm thick, 50 cm² 0.5 mm thick, or 2.5 g
The Prothrombin Time Assay (PT) test is an in-vitro assay that measures the effect of a test article or its extract on human
blood coagulation time of the extrinsic coagulation system. This assay is a suitable clinical means of determining the presence
and functional ability of Prothrombin in the process of coagulation. Prothrombin is a protein substance, which is produced by
the liver and plays a part in clotting of human blood. During the clotting process, Prothrombin is converted to thrombin,
factors V, VII, and X. The change in clotting ability is indicative of a chance in the concentration of these combined
coagulation factors. The PT procedure measures the time required to generate fibrin polymers via the extrinsic pathway. This
test is particularly appropriate to detect inhibitory effects on the coagulation. The test is carried out in triplicate and the results
after exposure to the test article are statistically compared to those of the untreated and negative controls (if p ≥ 0.05, the test
article passes).
Approximate turnaround time is two to three weeks.
AI06-1
AI06-2
The Unactivated Partial Thromboplastin Time Assay (UPTT)
Indirect- Sample needed: 10 cm² < 0.5 mm thick, 5 cm² 0.5 mm thick, or 1 g
Direct- Sample needed: 75 cm² < 0.5 mm thick, 50 cm² 0.5 mm thick, or 2.5 g
The in-vitro Unactivated Partial Thromboplastin Time Assay (UPTT) measures the effect of a test article on the clotting time of
human plasma. The UPTT assay measures plasma factors involved in the generation of plasma thromboplastin and measures
the time required to generate thrombin and fibrin polymers via the intrinsic pathway. The test article or its extract is compared
to two negative controls and one positive control. This test is particularly appropriate to detect activating effects on the
coagulation. The test is carried out in triplicate and the results after exposure to the test article are statistically compared to
those of the untreated and negative controls (if p ≥ 0.05, the test article passes).
Approximate turnaround time is two to three weeks.
HEMOCOMPATIBILITY TESTS—ISO 10993-4 (Cont.)
15 Wiggins Avenue, Bedford, MA 01730 781.275.3330 www.toxikon.com