微小流路中の血液細胞動態とその定量的イメージング計測法に関する研究 Microfluidic Image Cytometry for Quantification of Biological Cell Dynamics
Microfluidic Image Cytometry for Quantification of Biological Cell Dynamics
Microfluidic image cytometry was developed in order to quantify the function of blood plateletaggregation and thrombus formation which was important for diagnosing thrombotic diseases andproviding physiological information on the development of an anti-platelet pharmaceuticals etc.This technique can also be applied to assess the quality control of the transfusion blood products bycounting residual leukocytes which is one of risk factors for induction of the transfusion sideeffects.Conventional cytometric methods were reviewed to clarify the present state and to extract theproblems to be solved. Novel mathematical model for quantification of platelet aggregation wasproposed to extract the important factors. As a result, the temporal changes in the number and sizesof platelet aggregates were found to be appropriate factors for the quantification. A microchannelmimicked a blood vessel was implemented in a microchip fabricated using MEMS (micro electricalmechanical systems) technology and used for this study. Algorithms of image sequence analysis,micro particle image velocimetry technique based on the property of micro flow, and extraction ofthree dimensional position of each cell flowing through the microchannel, and a biocompatiblepolymer coating onto the surface of the microchannel in introducing biological cells, wereconducted to develop a novel method and a prototype system. An interfacial collision micro reactorwhich enables reaction of flowing solid platelet cells with an agonist liquid solution in a microlaminar flow was also developed.Finally, platelet aggregation and thrombus formation in the microchannel could be imaged andquantified using a converted platelet numbers concerned with the platelet aggregate layer. Allfunctions of the system were validated quantitatively by experiments.The proposed technique will be applicable to the quantitative imaging of platelet aggregation oradhesion to injured blood vessels and might become a powerful diagnostic tool for thromboticdiseases in the future.