Development of measurement system of function analysis of membrane using low-coherence interferometry

低相干干涉膜功能分析测量系统的研制

基本信息

批准号：
11555016
负责人：
HARUNA Masamitsu
金额：
$ 5.95万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Through this research project, we have developed in vivo measurement method for function analysis of membrane, using the low-coherence interferometery. The developed measurement system was used for detection of phase transition of both artificial membrane(DPPC)and rat mesentery. In particular, influence of circumstances of membrane on the phase transition was examined in detail ; as a result, it was found that the phase transition was closely related to the molecular structure of phospholipid bilayers.(1)In our developed system, refractive index and thickness of membrane are measured with an accuracy of 0.1% and 0.1μm, respectively, for detection of phase transition, using the low coherence interferometery. The transmission of membrane changes drastically by phase transition.(2)In the experiment, DPPC and rat mesentery were immersed in buffer solution, and the phase transition was detected by changing pH of buffer solution. In both DPPC and rat mesentery, it was found that the temperat … More ure for the main phase transition became higher as pH decreases. This result indicates that rat mesentery mainly consists of phospholipid bilayers.(3)In the case where ethanol is added to DPPC, the sub phase transition disappears for ethanol concentration of >25mg/ml. This drastic change for phase transition is due to the fact that phospholipid bilayers transforms to an inter digital structure.(4)By addition of surface active agent(palmitic acid), phospholipid bilayers transforms to micelle ; therefore, the normal phase transition disappears completely.(5)On the other hand, phase transition of rat mesentery is not influenced by addition of ethanol and surface active agent. This results suggests that protein and collagen disturb transformation of molecular structure of rat mesentery ; in other words, phospholipid bilayers are maintained in rat mesentery even in the presence of ethanol and surface active agent.(6)In order for in vivo measurement, a tomography image of a piece of rat mesentery was demonstrated, using the ultra-low coherence interferometry, which ere the resolution is only 1.3μm.On the basis of the experimental results, as described above, we are planning to develop a practical measurement system used in the field of physiology. Less

通过这个研究项目，我们开发了一种用于膜功能分析的体内测量方法，该方法使用低相干干涉仪来检测人工膜（DPPC）和大鼠肠系膜的相变。详细研究了膜的环境对相变的影响，结果发现相变与磷脂双层的分子结构密切相关。(1)在我们开发的系统中，膜的折射率和厚度是使用低相干干涉仪，测量精度分别为0.1%和0.1μm，用于检测相变。相变导致膜的透射率发生显着变化。(2)实验中，将DPPC和大鼠肠系膜浸入缓冲液中。通过改变缓冲溶液的 pH 值来检测相变，在 DPPC 和大鼠肠系膜中，发现主要相变的温度随着 pH 值的升高而升高。该结果表明，大鼠肠系膜主要由磷脂双层组成。(3)在DPPC中添加乙醇的情况下，当乙醇浓度>25mg/ml时，亚相变消失。这种相变的剧烈变化是由于。 (4)通过添加表面活性剂(棕榈酸)，磷脂双层转变为胶束； (5)另一方面，乙醇和表面活性剂的添加不影响大鼠肠系膜的相变，换句话说，蛋白质和胶原蛋白干扰了大鼠肠系膜分子结构的转变。，即使在乙醇和表面活性剂存在的情况下，大鼠肠系膜中仍保留磷脂双层。（6）为了进行体内测量，使用超低相干干涉测量，其分辨率仅为1.3μm。根据上述实验结果，我们计划开发一种用于生理学领域的实用测量系统。