Construction Of A Liver-on-a-chip Model For Investigating Liver Fibrosis In Vitro

Liver fibrosis is the intersection of the course of various chronic liver diseases and is the key pathological process that causes irreversible damage such as liver cirrhosis and liver cancer.At present,no drug for the treatment of liver fibrosis has entered the clinic,and the lack of preclinical in vitro models is the main reason for the delay in the development of drugs for liver fibrosis.Based on the microfluidic chip technology,this project developed a pump-free four-cell hepatic sinusoid physiological model with good stability and convenience.On this basis,this research simulates the stages of liver fibrosis with different triggers and degrees,and investigates the interaction of several major hepatocytes,the levels of fibrotic biomarkers,and the abnormal extracellular accumulation of collagen during liver fibrotic lesions.The main research contents of this paper are as follows:1.Using four functionally stable liver-related cell lines(Hep G2 cells,LX-2 cells,HUVEC cells,and U937 cells)as cell materials,laser-engraved polymethyl methacrylate(PMMA)to fabricate chip structures,constitutes the low-cost,well reproducible engineered liver sinus chip.The chip is driven by a shaking table to provide bionic blood flow.Compared with the traditional well-plate model,the chip maintains a good function of protein synthesis and urea excretion.2.Acetaldehyde acts on the parenchymal cells of the liver sinus chip model to simulate the pathological process of hepatic fibrosis caused by the accumulation of acetaldehyde.3.Using lipopolysaccharide to act on the artificial vein of the liver sinusoid chip to simulate the pathological process of liver fibrosis caused by the accumulation of portal vein toxins after the intestinal barrier is damaged,and to characterize the liver function performance and fibrosis degree of the in vitro model during the test period.4.Using tumor necrosis factor(TNF-α),interleukin(IL-6),and transforming growth factor(TGF-β1)to stimulate the corresponding effector cells in the model respectively,and explore the method of modeling liver fibrosis in the middle and late stages in vitro.5.The therapeutic effect of oxymatrine on liver fibrosis was investigated in the in vitro liver fibrosis model,the result verified the application potential of this model in the screening of liver fibrosis therapeutic drugs.The experimental results show that the physiological model of hepatic sinusoid constructed in this paper has good liver related functions and is better than the traditional orifice plate liver model;The pathological model of hepatic fibrosis based on the physiological model of hepatic sinusoid showed different inducements and degrees,and was similar to the pathological process in vivo;The dose-dependent and time-dependent therapeutic effect of oxymatrine on liver fibrosis was observed in the pathological model of liver fibrosis in the middle and late stage,which shows that the microfluidic chip platform for simulating liver fibrosis in vitro constructed in this paper can be used for preclinical screening of drugs for the treatment of liver fibrosis.