Hemocompatibility testing

Hemocompatibility tests to evaluate the hemolytic potential of the material with rabbit blood (In vitro hemocompatibility tests ensure that the test material extract does not adversely affect the cellular components of the blood.)... 

In ASTM F78-98 Standard Practice for Selecting Generic Biological Tests Methods for Materials and Devices , the selection test methods to evaluate medical devices is described. Regarding hemocompatibility tests for blood compatibility, hemolysis, and complement activation are described. Under blood compatibility, hemolysis and thrombosis are described as the most obvious examples of incompatibility with blood. It is suggested that thrombogenicity (formation of thromboemboli or platelet activation) be tested under dynamic conditions that simulate in the use procedures for the device. Complement activation is of concern in some cases and should be tested in vitro by assessing the status of various complement components. However, complement activation will probably not represent the only portion of the inflammatory response stimulated by medical devices. 

Sefton, M. V., Perspeetive on hemocompatibility testing. J. Biomed. Mater. Res. 55, 445-446 (2001b). 

FIGURE 46.20 Schematic flowchart diagram of hemocompatibility test. 

However, there is no standard yet concerning size, design, and type of in vitro test systems for blood compatibility (hemocompatibility). In consequence, a wide variety of different test systems are currently applied in the development of new materials. As the dependence of the in vitro alteration of blood on several experimental conditions is rather complex, the comparison of results from hemocompatibility tests performed in different setups and by different incubation procedures remains ambiguous and may even lead to contradicting conclusions depending on the type of experimental approach used [66]. 

Hemocompatibility tests evaluate effects on blood and/or blood components by blood-contacting medical devices or materials. In vivo hemocompatibility tests are usually designed to simulate the geometry, contact conditions, and flow dynamics of the device or material in its dinical application. From the ISO standards perspective, five test categories are indicated for hemocompatibility evaluation thrombosis, coagulation, platelets, hematology, and immimology (complement and leukocytes) (Table 12). 

Table 12 Hemocompatibility - Test methods for implant devices...

SYNTHESIS, STRUCTURAL STUDY AND PRELIMINARY HEMOCOMPATIBILITY TESTS OF AB AND ABA BLOCK COPOLYMERS WITH POLYVINYL AND POLYPEPTIDE BLOCKS... 

In this paper we describe the synthesis and the structure of 5 types of vinyl-peptide block copolymers, namely polybutadiene-poly (ybenzyl-L-glutamate) (BG), polybutadiene-poly(e-carbobenzoxy-L-lysine) (BCK), polystyrene-poly(y-benzyl-L-glutamate) (SG), polys-tyrene-poly(e-carbobenzoxy-L-lysine) (SCK) and poly(y-benzyl-L-glu-tamate)-polybutadiene-poly(y-benzyl-L-glutamate) (GBG), and the results of the hemocompatibility tests performed on some of these polymers. ... 

Hemocompatibility tests were performed with polymer films covering the inner surface of 50 ml round bottomed flasks and obtained by slow evaporation, at 40°C, of a 1 % solution of pol3oner in chloroform using a rotating evaporator. 

Major, T.C., Handa, H., Annich, G.M., Bartlett, R.H., 2014b. Development and hemocompatibility testing of nitric oxide releasing polymers using a rabbit model of thrombogenicity. Journal of Biomaterials Applications 29,479-501. 

Glasmacher, B., Nellen, E., Renl, H., et al. (1999). In vitro hemocompatibility testing of new materials for mechanical heart valves. Material Wiss Werkst 30 (12), 806-808. 

Hemocompatibility tests, such as the Japanese Phamacopoeia (JP) hemolysis test and the American Society for Testing and Materials (ASTM) hemolysis test. 

Hemocompatibility testing includes a full battery of tests required of anything that comes into contact with blood. ISO 10993-4 clearly defines the categories of evaluations to be performed, as well as which types of medical devices need to have which tests performed. The five categories of hemocompatibility testing are thrombosis, coagulation, platelets, hematology, and the complement system. With the exception of thrombosis, all of these tests are in vitro assays. 

The cell compatibility of P3HB-3HH and its blends with P3HB have been tested in a number of in vitro studies using fibroblasts [89,94,115-117], bone marrow cells [49,94,124,279], and chondrocytes [48,89,90,129-131]. However, neither in vivo testing nor hemocompatibility testing have yet been reported. 

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