title: Assessment of oxidative stress and chromosomal aberration inducing potential of three medical grade silicone polymer materials.
abstract: Medical expenditures for devices are increasing along with the ageing of human population and the synthesis of materials such as silicone polymers is on upsurge for manufacturing these devices. The International Organization for Standardization (ISO) emphasizes a battery of tests for preclinical assessment of biocompatibility of medical devices. Genotoxicity assays have become an integral component of these test procedures and it employs a set of in vitro and in vivo experiments to detect mutagens. Hence, this study was performed with an intention to investigate the genotoxic potential of the physiological saline extracts of three medical grade silicone polymer materials by the in vitro chromosomal aberration assay using human peripheral blood lymphocytes. Further, the oxidative stress inducing potential of the material extracts was investigated in vivo in mice liver homogenates using cyclophosphamide as positive control. The investigation revealed that none of the three materials were able to produce marked human lymphocyte chromosomal aberration, suggesting the absence of mutagens. The materials also showed negative results in their oxidative stress inducing potential, which was revealed by the normal levels of lipid peroxidation and unaltered levels of glutathione and its metabolizing enzymes in the mice liver tissue homogenates. It was interesting to observe a significant correlation between the genotoxic and antioxidant parameters investigated. Hence, it is suggested that the estimation of antioxidant status would serve as a better preliminary testing procedure prior to evaluating the genetic and molecular toxicity mechanisms of medical devices and/or materials intended for manufacture of such devices.
authors.affiliation: Toxicology Division, Biomedical Technology Wing, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Kerala, India.
authors.forename: P
authors.initials: P
authors.lastname: Vijayalakshmi
authors.forename: C S
authors.initials: CS
authors.lastname: Geetha
authors.forename: P V
authors.initials: PV
authors.lastname: Mohanan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001672:Biocompatible Materials / Q000633:toxicity*; D002869:Chromosome Aberrations / Q000139:chemically induced*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D008422:Materials Testing; D051379:Mice; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D011108:Polymers / Q000633:toxicity; D012828:Silicones / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D001672:Biocompatible Materials; D009153:Mutagens; D011108:Polymers; D012828:Silicones; D005978:Glutathione