Micronano Testing Technologies Of Cell Biomechanical And Biochemical Properties At Cell Structure Levels

For medical problems such as efficacy evaluation of drugs,disease diagnosis and so on,traditional detection methods have great limitations,such as long cycle,low efficiency and high risk.Therefore,it is urgent to study new detection methods to improve the solution of related medical problems as soon as possible.In 21 st Century,the WHO made a new definition of disease: all diseases and aging of the body are caused by the damage,aging and death of cells in the body.It is a fundamental method to study and solve the medical problems at the cell level.As we all know,cells are micronano-scale materials,and micronano technology is booming in the world today,so cells can be studied extensively with the aid of advanced micronano techniques.The cell micronano testing technology has such advantages as being nondestructive,label-free,low reagent loss,high efficiency and low cost,etc.Therefore,this paper studies the cell micronano testing technology from three aspects: first,the study of the LOC-DEP method for testing the cellular biomechanical properties at the single cell level;second,the study of the DEP-CSM method for testing the cellular biomechanical properties at the subcellular level;third,the study of the A?NP-SERS method for testing the cellular biochemical properties at the macromolecular level.In summary,the paper investigated the biomechanical / chemical properties of cells on three cell structure-levels respectively: the single cell,subcellular level and macromolecular level;with their own advantages,the three methods are of great significance for the solution of medical problems such as drug efficacy evaluation and disease diagnosis.Firstly,based on the LOC-DEP microfluidic chip,a method of cell biomechanical testing at the single cell level was proposed.A leukemia NB4 cell line was used as the model cell.A LOC-DEP microfluidic chip for cell stretching was designed and fabricated.A concept of the microfluidic system with cell electro-manipulation functions,including three key elements,was proposed for the first time;from the point of view of microfluidic system,an efficient general method for testing cell biomechanical properties based on the LOC-DEP microfluidic chip was proposed.Therefore,the paper,from the research angle of cellular biomechanical properties and based on the cell LOC-DEP testing principle,investigated the relationship between strain and time(?-t)of two kinds of cells before and after drug treatment,and the significance of the difference of their strains at the same time point;providing a new method for rapid evaluation of drug efficacy.Secondly,a DEP-CSM method of cell biomechanical testing at the subcellular level was proposed.A Leukemia NB4 cell line was used as model cells,and the cell biomechanical properties were tested based on the LOC-DEP method,accordingly,the experimental relationship between the strain and the applied voltage(?-U)was obtained.And it confirms that the MST method is the best evaluation method of cell stretching force,so the experimental relationship between cell strain and stretching force(?-F)was defined,which was validated by optical tweezers stretching method.The parameters of actin cytoskeleton were extracted by fitting the modeling curve of actin cytoskeleton model and the ?-F experimental curve of cell stretching,and with the help of skeleton parameters,the phenomenon that the biomechanical properties of cells changes with the change of physiological function of cells was explained.Therefore,from the research angle of cellular biomechanical properties and based on the cell DEP-CSM testing principle,the changes of the important cytoskeleton parameters of microfilament concentration,CAF,and microfilament number,NAF,after drug treatment were investigated;a new method is provided for evaluating the efficacy of skeleton targeting drugs.Finally,an A?NP-SERS method of cell biochemical testing at the macromolecular level was proposed.Three kinds of esophageal cancer cell lines,KYSE150,KYSE 180 and KYSE 410 were used as model cells.Gold nanoparticles(average diameter 15nm)were produced and cultured with cells together,and the in-tunjin cells were formed.The A?NP-SERS Raman spectra of three kinds of esophageal cancer cells were measured by the slide-adherence-drying method;their average Raman spectra were obtained,analyzed and compared,and their similarities and differences were described in detail.The biomechanical properties of three kinds of esophageal cancer cells were studied;on this basis,a combined test method of A?NP-SERS-DEP was proposed to compare and distinguish the malignant degree of three kinds of esophageal cancer cells;so a comprehensive standard for the accurate analysis and judgment of the cell physiological state was proposed.Therefore,from the research angle of cellular biochemical / biomechanical properties and based on the cell A?NP-SERS-DEP testing principle and referring the proposed comprehensive standard,a new method for the accurate diagnosis of the early stage of disease can be provided.