In Vitro Cytotoxicity Evaluation Of Plastic Biomedical Devices
Cytotoxic potential of four plastic biomedical devices (intravenous transfusion sets, IV sets; dextrose normal saline bottles, DNS bottles; Ringer lactate bottles, RL bottles; and Ryle's tubes) including 17different brands was evaluated by investigating growth inhibition, percent survival, mitotic index and colony-forming ability (cfa) in L929, an adherent type mouse fibroblast cell line. Experimental sets were exposed with leachates of biomedical products in serumfree minimum essential medium (MEM) for 1 h at 378Cina CO2 incubator. After 1 h, medium was replaced with serumrich MEM containing essential amino acids and reincubated up to 96 h. Cells in serum-free MEM only were processed under identical conditions and served as the control. The leachates from all types of biomedical devices evaluated exhibitedreductioninthegrowthandsurvivalofthecellline in the first 12 h postexposure followed by their gradual recoveryupto96h.Asignificantreductionincellgrowthwas apparent in the six brands of IV sets from 24 h onwards up to 36 h (59% growth inhibition). Though the cfa was also reduced in all the brands tested, the magnitude of reduction was less compared to growth inhibition. The results indicate that leachates of IV sets were more toxic compared to other biomedical devices screened, and growth inhibition assay was found to be more sensitive and suitable for cytotoxicity evaluation of biomedical devices.