Fabrication Of Lipopolysaccharide-induced Obese Type 2 Diabetes Based On Chip Model

In recent years,as people's lifestyles have gradually tended to Westernized diets,the proportion of high-calorie foods and beverages represented by fats and sugars has increased significantly,resulting in an increasing number of overweight and obese people.The incidence of metabolic diseases such as fatty liver,hypertension,type 2 diabetes mellitus(T2DM),and cardiovascular and cerebrovascular diseases is on the rise year by year,and the pathogenesis of diabetes is not yet fully understood.At present,research on diabetes at home and abroad mostly uses animal model and orifice plate model as research carriers,and there are some limitations in research.Therefore,in this experiment,a microfluidic chip was used as a technology platform to construct a model of co-culture of adipose tissue with three-dimensional rat islet cell(INS-1)cells.By adding lipopolysaccharide(LPS)to the culture system to simulate endotoxemia internal environment,so that to establish a pathological model of diabetetes.In this experiment,a microfluidic chip template was fabricated using photoresist technology,and polydimethylsiloxane(PDMS)was used as a chip fabrication material.The chip consists of two parts—the upstream chip and the downstream chip,the upstream chip is the adipose tissue culture chip,and the adipose tissue is suspended in culture;the downstream chip is the INS-1 cell culture chip,and the culture fluid via the upstream chip's adipose culture tank.The culture media flowed into the three-dimensional culture pool of INS-1 cells and exchanged substances through the polycarbonate membrane and the basement membrane-like substance(BME)mixed with INS-1 cells.In this experiment,primary rat adipose tissue was obtained by mechanical method,and was identified by oil red O staining.Basement membrane-like material was used as a substitute for extracellular matrix(ECM)in this experiment.The INS-1 cells were wrapped in BME and seeded in the lower INS-1 cell culture chamber for three-dimensional culture to simulate the growth of islet cells in vivo.The culture medium was driven by a syringe pump,and the flow rate of 1.0 ?L/min was slowly introduced from the upstream chip inlet to construct a co-culture model of adipose tissue and islet cells.In this experiments,we did four groups,blank group,LPS group,adipose tissue group,and adipose tissue + LPS group.Adipose tissue and INS-1 cells were identified by live/dead dyeing and the dynamic changes of inflammatory cytokines IL-6 and insulin in the culture fluid were measured.In this experiment,we successfully constructed diabetes model base on a microfluidic system.This model can be used to simulate the damage of islet cells caused by endotoxemia and obesity,and it can also detect the dynamic changes of cytokines over time,laying a certain in vitro model basis for the study of the pathogenesis of diabetes.