Mizuki Mori
Kanagawa institute of Technology,Japan
Title: Cytotoxicity Evaluation Of Nanodiamond Doped With Ethidium Bromide
Biography
Biography: Mizuki Mori
Abstract
Nano diamond (ND) has higher biological compatibility than the other carbon based nano particles. Because modification of surface functional groups of ND is relatively facile, it is often used as an efficient-carrier of medicinal drugs. In this study, we examined surface modification of both positively charged ND (pND) and negatively charged ND (nND) with ethidium bromide (EtBr) and their biochemical characters.
After alkali treatment of pND and nND, they were mixed with EtBr (weight ratio ND:EtBr=5:1), respectively, and were allowed to stand at the room temperature. Based on the UV absorbance measurement of the supernatant, EtBr was found to be adsorbed on pND and nND with efficiency of 22% and 95%, respectively.
nND-EtBr was revealed to show remarkable cytotoxicity over a dose of 6.25 μg/ml (EtBr concentration was calculated around 1.19 μg/ml) for 48hr treatment to lung cancer cell line(A549), with cell viability of 56%. In a similar manner, effects on the hamster normal lung cell line (CHL/IU)was also evaluated and remarkable cytotoxicity was obtained when nND-EtBr was exposed at 12.5 μg/ml (EtBr concentration was calculated around 2.38 μg/ml) for 48hr treatment with cell viability of 63%. Cytotoxicity of nND itself was also confirmed to both cell line, but their viability was higher than that of nND-EtBr. Among pND and pND-EtBr, we didn’t confirm the difference of cytotoxicity. Moreover, at the concentration of 25 μg/ml nND-EtBr (EtBr=4.75 μg/ml), we also confirmed the fluorescence emission derived from EtBr in cytoplasm of living cell.
As results, we revealed that nND-EtBr complex introduced the higher cytotoxicity than free EtBr and intant ND. And, we confirmed that this complex was penetrated in the living cell. Mechanism of cytotoxicity is now under investigation.