Studies On Microfluidic Concentration Gradient Generator And Its Application For Drug Screening

Simulating the concentration gradient in vivo is very important for cell analysis, and microfluidics provides a new platform for the research of new concentration gradient generators. In this work, a new kind of concentration gradient generator based on laminar flow is designed, which can generate a series of precise, stable, easy-controlled and easy-quantified concentration gradients. After that, we had some experiments about drug screening on the chip we designed.Firstly, the new microfluidic chip which has two layers was introduced, the first layer is concentration gradient generator and the second layer is designed for introducing cells. Different streams in the microchannels were mixed based on laminar flow and diffusion effects. These streams were dispensed to the next meandering channels in different proportion, and completely mixed in these channels. In this multi-level network channels, the streams were repeated and mixed in a stepwise manner, and the concentration gradient was formed.We optimized the size of micro chamber for cell culture. The fluorescence quantitative method was used to analyze the distribution of fluorescence dye in the microfluidic chip. The result revealed that the proper flow rate is 0.1 μl/min, and within 0.5-1 h, precise, stable, easy-controlled and easy-quantified concentration gradient was generated.Secondly, we designed some drug screening experiments on anti-tumor drugs and cardiovascular drugs. We investigated the relationship between drug concentration and state of cells.At last, a summary and perspective were given for this microfluidic concentration gradient generator.