【作者】 刘威；

【导师】 赵刚；

【作者基本信息】 中国科学技术大学 ， 生物医学工程， 2015， 硕士

【摘要】 细胞膜渗透性是细胞的重要生物物理学性质之一,其在生物工程、再生医学、器官工程和生物保存中扮演着重要角色。而测量细胞膜的渗透性质是通过微装置内胞外溶液渗透压转变的实验测量得到的。然而大多数研究者们并没有对微装置及其相应的实验程序做过系统的研究,这就是为什么不同研究者的之间的测量结果相差很大的原因。本文基于传热传质和对流扩散原理的指导,设计并改进了微灌流腔装置。同时,还通过实验验证和利用有限元分析方法数值计算了微通道以及管路中的胞外溶液的浓度分布变化。对比数据结果后证明,在细胞渗透性实验中使用惯用的理想阶跃浓度函数去拟合细胞膜渗透性参数时会不可避免的带来较大的误差,而本研究中确定浓度函数保证了拟合得到的参数的精确性和可靠性。此外,本文还设计制作了专用来测量卵母细胞渗透的微灌流腔。收集并测试了共计57颗受精失败的卵母细胞的渗透性参数。所得到测量数据为将来的研究提供了有用的参考,同时也丰富了卵母细胞在不同低温保护剂条件下的卵膜渗透性。实验结果还表明,可以在低温保存之前记录卵母细胞添加低温保护剂时的体积变化来评估该卵母细胞的体外受精成功率。最后,本文还对微流控的液滴技术进行了探索,积累了大量相关经验。总之,所述的研究工作有利于更好的理解低温生物学,也有利于设计出更好更稳定的低温保存协议。通过提高实验测量细胞渗透性的精确性,本文的研究工作对改进低温生物学的研究有着巨大的潜力。更多还原

【Abstract】 Cell membrane permeability, one of the key biophysical properties of cells, plays an important role in bioengineering, regenerative medicine, tissue engineering, and biopreservation and biobanking. One featured and cell specific approach has been well established by the cryobiologists for determination of cell membrane permeability, i.e., osmotic shift experiments utilizing microdevices. The design of such microdevices and the corresponding experimental procedures have never been systematically discussed before, and this is the possible reason for that the measured parameters are different by different research groups.In this study, a novel microfluidic perfusion chamber was developed under the guidance of heat and mass transfer, and flow and diffusion theories. The concentration profile for the change of the extracellular solution during an osmotic shift process was carefully determined according to both experimental examination and computational finite element analysis on the fluid flow in both the capillary tube and the microchannel. Comparative experiments revealed that the commonly assumed ideal step function for the concentration changes of extracellular solution during an osmotic shift experiment inevitably introduced overlarge error when determining the cell membrane permeability by fitting the water transport equation to the experimental data, instead, the profile determined by this study effectively ensured the reliability and precision of the fitted parameters.In addition, a novel microperfusion chamber specifically for measuring the oolemma permeability of human mature MII oocytes has also been designed. A total of57inseminated-unfertilized oocytes were obtained and measured in this study. The measurements described in this study provide a useful reference for future research, and they enrich different conditions of oocyte membrane parameters. And the study shows that it can better estimate the likelihood of successful IVF by recording the oocyte volumetric change when adding the CPA before cryopreservation.Finally, this paper also introduced the exploration research on microfluidic droplets technologies and a wealth of relative experience was accumulated.In a word, these measurements will improve our understanding of the cryobiology and will aid in the design of better and more stable protocols for cryopreservation. The work also has great potential for improving cryobiology research by improving the precision of experimentally determined cell membrane permeability.更多还原