碩士 / 國立清華大學 / 生醫工程與環境科學系 / 103 / It was 1970 that Arthur Ashkin first succeeded to trap and manipulate particles by using optical tweezers. Since then, optical tweezers start to be developed and improved. Up to now, optical tweezers which are made of lasers are already become one of the most applied technology in the field of biology and physics.
Fucoidan is a polysaccharide, and it’s mainly refined from the brown alga. Due to its various characteristics, including anticoagulant and antithrombotic, antivirus, antitumor and immunomodulatory, though it is classify as healthy food so far, it has a high potential for medical, that’s the reason why the fucoidan has been extensively studied for decades.
In this research, we used an optical tweezers system combined with a piezoelectric platform which has a high displacement resolution, and applied them to measure the viscoelasticity and complex shear modulus of the fucoidan in different concentration, pH value, and temperature. The fucoidan solutions were made in different concentrations (i.e. by blending the fucoidan and PBS buffer together) at different pH value (i.e. by adding acetic acid and sodium hydroxide,) and adding in different additives. We proceeded using the optical tweezers to catch the polystyrene microsphere, and measure the thermal motion of it in the solution, and then we calculated the viscosity changing and the rheology of the fucoidan solution under
different conditions.
We investigated the characteristics of fucoidan using optical tweezers based on the microrheology in this experiment. In contrary to the traditional measure by rheometer, our investigation can expand the range of sampling frequency and decrease the cost of experimental consumables. After the investigation, we concluded that the higher the concentration goes, the larger the viscosity is. High temperature could break the hydrogen bond and the connection between molecules of fucoidans , when the temperature is above 70 degrees, the structure become totally damaged. The structure of fucoidans is more stable in neutral pH, however in other pH′s, fucoidans are easily hydrolyzed or isomerized. If saline is added to the solution, viscosity and elasticity get lower due to the electrostatic interactions between the ions. In this research, we studied the characteristics of the fucoidan under different conditions and with different chemical additives. The investigations have the potential apply to the research of the bromatology or biochemistry.
| Identifer | oai:union.ndltd.org:TW/103NTHU5810031 |
| Date | January 2015 |
| Creators | Huang, Jen Hao, 黃仁豪 |
| Contributors | Wu,Chien Ming, 吳見明 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 69 |
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