Research On The Construction Of A Self-circulating Liver Lobule Model Based On AC Electrothermal For Drug Screening

Due to the high cost of pharmaceutical development to conduct toxicity testing on live animals and human organs and the need for basic physiological and pathological research,a substantial collection of work has been devoted towards constructing in vitro tissue models to realize part of the cellular microenvironment and tissue function.From early microfluidic chips for protein fragment testing and multicellular co-culturing to microtissue or micro-organ systems,such as co-culture systems of hepatocytes and liver endothelial cells,the existing models have been extended to MPS(microphysiological systems),and the future trend is to build so-called human-on-chip devices for various pharmacokinetic studies.However,there are still many problems to be solved in the output of the power source.It is a difficult technical problem to realize the closed-loop flow control of the micro-tissue or micro-organ chip.At the same time,how to integrate it with the organ chip is also a research hotspot.This thesis will focus on the process of a minimalist self-circulating chip and its application in the bio-micro liver model.According to the latest research results of the AC electrothermal flow drive model,we rely on the existing high-precision laser engraving machine processing platform in the laboratory to achieve a minimum line width of 20 μm on ITO glass.Based on this,we designed a closed electrothermal flow chip with self-circulation function.The multiphysics coupling of Comsol software is used to obtain the results of simulation analysis of velocity field and temperature field.The theoretically optimal voltage and frequency driving parameters are recorded,which provides a valuable reference for practical platform construction.Through the organic combination of our self-designed minimal electrode processing technology and micro-nano technology,an on-chip self-circulating chip with an alternative liver leaflet module was constructed.We cultured 1.5-day,2.5-day,3.5-day HepG2 hepatocytes and HUVECs endothelial cells for intraplate perfusion,and measured the conductivities and the changes in flow rate at different voltages and frequencies,and performed on the hepatic lobule module area.Real-time temperature monitoring yielded actual input parameters that ensured a basic culture of 10 nL/day and suitable for cell growth.In order to construct a more biomimetic micro-hepatic model,we made a two-layer hepatic lobular model with the auto-sedimentation characteristics of the cells.The HUVECs endothelial cells are closely attached to the type I rat tail collagen liver plate.The cell viability and metabolism of albumin and urea in the hepatic lobular model were measured under static and dynamic culture.In order to realize the application of the model in the drug metabolism scenario,we tested the toxic effects of the drug APAP on the model using the same standard,and verified that the model has the basic metabolic function of the liver.