biostudies-literatureSelimovic SNIBIB NIH HHSNIDCR NIH HHSNHLBI NIH HHS2020-8https://www.ebi.ac.uk/biostudies/studies/S-EPMC3077828biostudies-literatureUnknown83(6)We describe a microfluidic device for generating nonlinear (exponential and sigmoidal) concentration gradients, coupled with a microwell array for cell storage and analysis. The device has two inputs for coflowing multiple aqueous solutions, a main coflow channel and an asymmetrical grid of fluidic channels that allows the two solutions to combine at intersection points without fully mixing. Due to this asymmetry and diffusion of the two species in the coflow channel, varying amounts of the two solutions enter each fluidic path. This induces exponential and sigmoidal concentration gradients at low and high flow rates, respectively, making the microfluidic device versatile. A key feature of this design is that it is space-saving, as it does not require multiplexing or a separate array of mixing channels. Furthermore, the gradient structure can be utilized in concert with cell experiments, to expose cells captured in microwells to various concentrations of soluble factors. We demonstrate the utility of this design to assess the viability of fibroblast cells in response to a range of hydrogen peroxide (H(2)O(2)) concentrations.Analytical chemistryGenerating nonlinear concentration gradients in microfluidic devices for cell studies.PMC3077828EB008392R21 EB009196R01 HL092836R01 EB008392EB009196HL092836R01 EB008392-01A2RL1 DE019024DE019024R01 HL092836-01A1RL1 DE019024-01R21 EB009196-01Sim WYBae HKhabiry MKim SBHong JWJambovane SKhademhosseini ASelimovic SLee WGJang YHfalseGenerating nonlinear concentration gradients in microfluidic devices for cell studies.We describe a microfluidic device for generating nonlinear (exponential and sigmoidal) concentration gradients, coupled with a microwell array for cell storage and analysis. The device has two inputs for coflowing multiple aqueous solutions, a main coflow channel and an asymmetrical grid of fluidic channels that allows the two solutions to combine at intersection points without fully mixing. Due to this asymmetry and diffusion of the two species in the coflow channel, varying amounts of the two solutions enter each fluidic path. This induces exponential and sigmoidal concentration gradients at low and high flow rates, respectively, making the microfluidic device versatile. A key feature of this design is that it is space-saving, as it does not require multiplexing or a separate array of mixing channels. Furthermore, the gradient structure can be utilized in concert with cell experiments, to expose cells captured in microwells to various concentrations of soluble factors. We demonstrate the utility of this design to assess the viability of fibroblast cells in response to a range of hydrogen peroxide (H(2)O(2)) concentrations.2011-01-01T00:00:00Z2011 Mar2020-10-31T09:42:07Z2019-03-26T22:30:18ZS-EPMC30778282134486610.1021/ac2001737