Microfluidic device for high-throughput cellular gradient and dose response studies

Abstract

The ability to form and maintain gradients is essential for the study of response of cells to various stimuli. The invention includes devices and methods for the high-throughput, reproducible formation of gradients for the study of living cells. The invention includes microfluidics device with a lest chamber having a depth flanked by flow-through channels having a deeper depth. Flow of two different fluids through the flow-through channels results in the creation of a gradient by diffusion across the test chamber having essentially no flow.

1 . A microfluidic device for formation and maintenance of gradients comprising:
 at least one reaction unit having a series of test chambers each having a depth, the test chambers being flanked by a first flow-through channel and a second flow-through channel, wherein the flow-through channels have a deeper depth than the test chambers, and each flow-through channel is operably connected to at least one inlet port, and at least one outlet port is operably connected to the flow-through channels.   
     
     
         2 - 9 . (canceled) 
     
     
         10 . The microfluidic device of claim  9 , wherein the valve is actuated through a controller that is operably connected to the valve via a connection channel. 
     
     
         11 . The microfluidic device of  claim 1 , wherein the space between the first flow-through channel and the second flow-through channel is rectangular in shape in a plane of the flow-through channels. 
     
     
         12 . The microfluidic device of  claim 1 , wherein the space between the first flow-through channel and the second flow-through channel trapezoidal in shape in a plane of the flow-through channels. 
     
     
         13 . The microfluidic device of  claim 1 , wherein a side of the first fluid chamber and a side of the second fluid chamber adjacent to the test chambers are essentially parallel at one of two widths. 
     
     
         14 . The microfluidic device of  claim 1 , wherein the device is composed of a biocompatible elastomer. 
     
     
         15 . The microfluidic device of  claim 1 , wherein the device is optically clear. 
     
     
         16 . The microfluidic device of  claim 1 , wherein the device is gas permeable. 
     
     
         17 . The microfluidic device of  claim 14 , wherein the device is composed of polydimethylsulfoxide (PDMS), polyisoprene, polybutadiene, polychloroprene, polyisobutylene, poly(styrene-butadiene-styrene), the polyurethanes, and silicone polymers; or poly(bis(fluoroalkoxy)phosphazene) (PNF, Eypel-F), poly(carborane-siloxanes) (Dexsil), poly(acrylonitrile-butadiene) (nitrile rubber), poly(l-butene), poly(chlorotrifluoroethylene-vinylidene fluoride) copolymers (Kel-F), poly(ethyl vinyl ether), poly(vinylidene fluoride), poly(vinylidene fluoride-hexafluoropropylene) copolymer (Viton), elastomeric compositions of polyvinylchloride (PVC), polysulfone, polycarbonate, polymethylmethacrylate (PMMA), or polytertrafluoroethylene (Teflon). 
     
     
         18 . The microfluidics device of  claim 1 , wherein the gradient has essentially no flow of fluid in the region of gradient generation. 
     
     
         19 . The microfluidics device of  claim 1 , wherein the flow-through channels are mirror-symmetric with respect to each other. 
     
     
         20 . The microfluidics device of  claim 1 , wherein the flow-through channels merge downstream from the test chambers. 
     
     
         21 . The microfluidics device of  claim 1 , further comprising at least one cell inlet port and at least one cell outlet port operably connected to the series of test chambers. 
     
     
         22 . A method of exposing cells to a gradient in a reaction unit with essentially no flow comprising:
 closing fluid flow to flow-through channels of the reaction unit of  claim 21 ;   introducing at least one cell through at least one cell inlet port to at least one test chamber in the reaction unit;   introducing a first fluid into a first flow-through channel and a second fluid into a second flow-through channel in the reaction unit; and   allowing the first fluid and the second fluid to flow through the flow-through channels to the outlet port.   
     
     
         23 . A method for forming and maintaining a gradient in a reaction unit with essentially no flow, comprising the steps of:
 providing at least one reaction unit having a series of test chambers each having a depth, the test chambers being flanked by a first flow-through channel and a second flow-through channel, wherein the flow-through channels have a deeper depth than the test chambers, and each flow-through channel is operably connected to at least one inlet port, and at least one outlet port is operably connected to the flow-through channels.   introducing a first fluid into the first flow-through channel and a second fluid into the second flow-through channel; and   allowing the first fluid and the second fluid to flow through the flow-through channels to the outlet port.   
     
     
         24 . The method of  claim 23 , wherein the first fluid comprises an active agent. 
     
     
         25 . The method of  claim 23 , wherein the second fluid comprises an active agent. 
     
     
         26 . The method of  claim 23 , wherein both the first fluid and the second fluid each comprise an active agent. 
     
     
         27 . The method of  claim 24 , wherein the active agent comprises a drug. 
     
     
         28 . The method of  claim 27 , wherein the cell in the test chamber is sensitive to some concentrations of the drug in the gradient and not sensitive to some concentrations of drug in the gradient.