Difference between revisions of "Team:HSiTAIWAN/Project/Framework"

Framework

In this project, we design a bio-kit package consisting of different types of E. coli to detect various heavy metals and toxin in Chinese medicines. We expect that when these E. coli detect certain types of heavy metal or toxin, they will express fluorescence. By examining the intensity of fluorescence, we can analyze the amount of specific substance inside the testing subject. Aside from just detecting, we want to measure in quantities. Thus, we designed a self-regulated circuit. This circuit can regulate itself so that it will produce a controlled amount of fluorescence protein varied by the concentration of toxin. This way, we hope that our device can measure with more precision and accuracy. In addition, considering Chinese herbal medicines are plants and some heavy metal ions are essential micronutrients for their metabolism, we use EDTA to chelate heavy metal ions containing in our testing Chinese herbs to accurately assess levels of heavy metal among these Chinese medicines.

Literatures show that many cases of heavy metal contaminations are involving arsenic, cadmium, lead, and mercury (Chui et al., 2013; Grarvey, Hahn, Lee, & Harbison, 2001; Harris et al., 2011). While some transition metals, such as copper or iron, are often overlooked but threating our health when its accumulation in body reaches toxic levels (Jaishankar, Tseten, Anbalagan, Mathew, & Beeregowda, 2014). Aflatoxin is a toxin which is frequently found in Chinese medicines and reported as a liver carcinogen (Liu, Chang, Marsh, & Wu, 2012). Accordingly, we choose and assemble circuits/biobricks that can detect copper, lead, arsenic, and aflatoxin to create bio-kits in our project.

Equally important is to create a biosafety mechanism to prevent of E. coli from spreading and polluting the environment. In this project, our biosafety mechanism is based and tested on selected herbs that have been approved the functions of suppressing the growth of bacteria, but are absolutely harmless to humans.

The forms of Chinese medicines are usually categorized into raw herbs, herb extracted, and Chinese patent medicines. Chinese patent medicines are manufactured in accordance with particular formula. Chinese patent medicines are regulated by GMP (Good Manufacturing Practice) standard. In Taiwan, all GMP certified pharmaceutical factories must test their patent medicines for heavy metal levels and toxin. In contrast, the sources and quality of raw herbs and herb extracted are more difficult to monitor and control. Accordingly, in this project, we select several common raw herbs and herb extracted as our experimental materials.

Reference

Chui, S. H., Wong, Y. H., Chio, H. I., Fong, M. Y., Chiu, Y. M., Szeto, Y. T., . . . Lam, C. W. K. (2013). Study of heavy metal poisoning in frequent users of Chinese medicines in Hong Kong and Macau. Phytotherapy Research, 27, 859-863.

Grarvey, G. J., Hahn, G., Lee, R. V., & Harbison, R. D. (2001). Heavy metal hazards of Asian traditional remedies. International Journal of Environmental Health Research, 11, 63-71.

Harris, E. S. J., Cao, S., Littlefield, B. A., Craycroft, J. A., Scholten, R., Kaptchuk, T., . . . Eisenberg, D. M. (2011). Heavy metal and pesticide content in commonly prescribed individual raw Chinese herbal medicines. Sci Total Environ., 409(20), 4297-4305.

Jaishankar, M., Tseten, T., Anbalagan, N., Mathew, B. B., & Beeregowda, K. N. (2014). Toxicty, mechanism and health effects of some heavy metals. Interdisciplinary Toxicology, 7(2), 60-72.

Liu, Y., Chang, C. C., Marsh, G. M., & Wu, F. (2012). Population attributable risk of aflatoxin-related liver cancer: systematic review and meta-analysis. Eur J Cancer, 48(1), 2125-2136. doi: 10.1016/j.ejca.2012.02.009