High-precision Approach Based On Microfluidic Perfusion Chamber For Quantitative Analysis Of Biophysical Properties Of Cell Membrane

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.