Research On High-throughput Automated Detection Methodof Cell Mechanical Properties Bsed On Dielectrophoresis Microfluidic Chip

Cell mechanics is closely related to and interact with cellular functions.Using mechanical properties as biomarkers can characterize the physiological functions of cells to a certain extent,to effectively reveal the type,state,and change mechanism of cells.It has important guiding significance for cell mechanism research,disease diagnosis,and drug development.Therefore,methods for measuring and analyzing the mechanical properties of cells are currently receiving increasing attention.Although there have been some developments in the measurement technology of cell mechanical properties,these technologies have more or fewer defects such as complex operation,low throughput,long measurement time,high cost,and inaccurate manual measurement,resulting in limited measurement data.To support biologically meaningful results,high-throughput,automated measurement technology is the key to achieving biostatistically meaningful measurement results.Aiming at this bottleneck problem,this paper innovatively combines dielectrophoresis microfluidic chip with automatic control technology,proposes an effective solution to automatically obtain large-scale cell mechanical property data,and conduct biological cell experimental research to confirm this method’s reliability.The microfluidic chip integrates the functions of cell array capture,dielectrophoretic stretching,and cell release,and achieves the purpose of high-throughput measurement of mechanical properties at the single-cell level through multi-batch measurement;the automatic control scheme combines the image detection algorithm based on deep learning with the hardware operating system,which ensures the automation of the cyclic measurement process and improves the measurement efficiency.This method provides an efficient way to address the low-throughput problem of cell mechanical properties measurement and improves the biostatistical significance of cell measurement studies.The dissertation mainly focuses on the following four aspects:First,the research on the mechanism of cell manipulation based on hydrodynamics and dielectrophoresis was carried out.The principle of cell capture and release at the specially designed capture port position under Stokes flow and the principle of cell stretching under dielectrophoresis were expounded.The study of these two cell operating mechanisms has laid a solid theoretical foundation for the design of microfluidic chips.Then,the design and fabrication method of microfluidic chip integrating hydrodynamics and dielectrophoresis were studied.The structure of the integrated cell capture-stretch-release microfluidic chip with automation concept was explored and designed,and the design has undergone rigorous simulation analysis to confirm its reliability.And the preparation process of the chip was studied,so that the preparation of the chip has laid a foundation for the subsequent automated experiments.Then,the consruction of the automatic measurement platform of cell mechanical properties and the systematic research on the combination of software and hardware were carried out.Comparing the advantages and disadvantages between traditional image algorithms and deep learning algorithms,and the YOLOv5 algorithm was used to achieve accurate cell identification.In addition,the control of the function signal generator and the micro-flow syringe pump was realized by using the serial communication technology.The automatic control algorithm was designed based on the image and hardware control,which lays the foundation for the following experiments in the system control.Finally,the experimental research based on microfluidic chip and automation system was carried out.Aiming at HUVEC and MCF-10A cells,the differences and reasons of mechanical properties in different physiological states after reagent treatment were analyzed in detail,and the automatic measurement system was used to extract a large batch of experimental data,and the difference in Young’s modulus of cells was measured.These two experiments also prove that the measurement system has a wide applicability,and can obtain statistically significant results by measuring different cells,providing a new and effective solution for drug screening and pathological detection.