Detection Of Cell Adhesion With Piezoelectric Sensor Dissipator

Pizeozelectric cell-based sensor was used to study cells or special materials. Plentiful information including growth and metabolism of cells, as well as responses to effects of complex and toxic materials can be obtained synchronously by the technology. Because of advantages in detection strategies such as being label-free, real-time, in-situ and non-invasive, this new analytical tecnology has been used widely in clinical diagnostics, environmental monitoring and food safety. Cell viscoelasticity is an important biophysical characteristics relevant to locomotion and deformation abilities of cells, and the foundation of soakage and metastasis of tumor cell. So using piezoelectric cell-based sensor to study cell viscoelasticity is significant in theoretical and practical research.The aim of the thesis is to construct the piezoelectric cell-based sensor dissipation (PCSD) platform and find the response mechanic model of cell adhesion behavior in PCSD based on theory and experiments. By the technology the applications in the interactions of cell-substrate and cell-drugs, viscoelasticity and drugs screening were explored. Not only the task had promoted the analysis methods, but had it provided potential experimental proves for clinic medicine and cell biology.The methods include combining the cell culture technology and transient dissipation technology with a homemade piezoelectric bio-sensor instrument, a real-time analysis system established the PCSD system studying cells behaviors and interactions of cell-substrate and cell-drugs, observing cell images combining invert microscope and scanning electron microscope synchronously. During the application, PCSD and MTT assays were used to verify the results .Some achieved progresses have been obtained as follows:①Combining characteristics of cell adhesion and the multilayer coating model of pizeozelectric sensor, the acoustic impedence analysis model of cell adhesion was established by inletting the equations of sensor responses and impedence of acoustics parameters as follow:Δf/f=Im(Z_L)/πZ_cq ,ΔD=Re(Z_L)/πZ_cq; In the penetration depth of shear acoustic wave, approximation solutions of all layers in cell adhesion model were solved, and the sensor responses to cell adhesion were analyzed.②PCSD platform was constructed, the steability and reproducibility of the system were detected. The results showed the system has steability of≤0.32±0.13 Hz·min^-1, 0.13±0.02×10^-7in gas phase and≤0.29±0.09 Hz·min^-1, 5.21±0.14×10^-7in liquid phase, the reproducibility of RSD=6.55×10^-7.③The PCSD was monitored 2 cell lines (HUVEC and hepatoma cell line HepG2) in 24 hours, and compare the differences of response of cell behavior in PCSD; Detached a confluent cell layer with EGTA, and digested ECM on chip with EDTA; The interactions of cell-substrate and the effects of media concertration were analyed, cell adhesion model was verified; Combining the approximation solutions of impedance equations of cell adhesion system, the sensor responses to cell bebaviors were analyzed in physical sense.④Grounded on cell-based PCSD, the applications in drug screening using HepG2 cells as sensitive element were explored. The interactions of cells and drugs(PTX, VCR and ADM) were monitored, the order of drugs on cytoskeleton was PTX>VCR>ADM. MTT assays and microscopy were operated synchronously, but the varied results were obtained: PTX>VCR>ADM. The differences reflected PCSD was only sensitive to drugs on the cytoskeleton of HepG2 cells. So PCSD would be a useful tool to screen drugs on cytoskeleton.The above results obtained by PCSD provide some implies for the fundamental research in cell engineering. The study of PCSD monitoring tumor cells made anti-cancer drugs to be screened in a new way. The acoustic impedance analysis model of response to cell adhesion behavior in PCSD can gain plenty information on cells. The PCSD technique would be used widely in the future.