Improved sample preparation of biomaterials for in vitro genotoxicity testing using reference materials.
New biomaterial related reference materials with known genotoxic properties were produced in order to study the sample preparation and in vitro genotoxicity testing of biomaterials. We incorporated genotoxic substances like benzo[a]pyrene into the biomaterial Tecoflex, a polyurethane frequently used for catheters and other applications. We demonstrated that the model compound benzo[a]pyrene is sufficiently extracted by organic solvents, whereas cell culture medium only extracts very limited quantities. By changing the medium several times during extraction the extracted amount was augmented. Using higher amounts of organic solvent in relation to the reference material's surface led to a higher recovery of extracted benzo[a]pyrene. For the in vitro genotoxicity testing using the Mammalian Cell Gene Mutation Test (HPRT test), Mammalian Chromosome Aberration Test, and bacterial umu- and SOS-tests, concentration of extracts is a prerequisite because of the low sensitivity of the test systems. Often cytotoxicity interferes with the evaluation of genotoxic effects. We demonstrated that some recommendations of the ISO 10993-Part 3 and 12,(1),(2) dealing with the biological evaluation of medical devices, seem to be insufficient, and new rules for the in vitro genotoxicity testing of biomaterials have to be established.
Müller
Boris P
BP
IZKF Biomat., Universitätsklinikum RWTH Aachen, Pauwelsstr. 30, 52074, Germany. boris.mueller@post.rwth-aachen.de
Ensslen
Silke
S
Dott
Wolfgang
W
Hollender
Juliane
J
D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity; D001672:Biocompatible Materials / Q000633:toxicity*; D016466:CHO Cells; D002470:Cell Survival; D006224:Cricetinae; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D006801:Humans; D009152:Mutagenicity Tests; D009602:Nitrosamines / Q000633:toxicity; D011140:Polyurethanes / Q000633:toxicity*; D011794:Quercetin / Q000633:toxicity; D012015:Reference Standards; D012997:Solvents
D001672:Biocompatible Materials; D009602:Nitrosamines; D011140:Polyurethanes; D012997:Solvents; D001564:Benzo(a)pyrene; C062725:Tecoflex; D011794:Quercetin; D004121:Dimethyl Sulfoxide