Method for preparing topographically structured microarrays

Abstract

A method for preparing a topographically structured hydrogel microarray is described comprising the steps of a) providing one or more types of biomolecule(s) on top of micropillars of an array of micropillars, preferably by means of robotical spotting, b) providing a partially crosslinked hydrogel on a substrate, preferably attached to a substantially rigid and/or planar substrate, c) simultaneously soft-embossing a hydrogel microwell array and transferring the biomolecule(s) from the micropillars to the microwells by pressing the micropillars of the array of step a) onto the partially crosslinked layer of hydrogel of step b) until substantial completion of crosslinking and d) demolding the array of micropillars of step a) from the hydrogel microwell array of step c). The method according to the invention has the advantages of resulting in higher biochemical patterning precision, allowing for modulation of biochemical parameters by interfacing microarray manufacture with robotic technology and rendering the microarrays obtained compatible with existing read-out systems such as microscopes. Further, the elasticity of the hydrogel can be varied by tuning its shear modulus.

1 - 10 . (canceled) 
     
     
         11 . A microarray comprising a substrate and a hydrogel layer on said substrate, wherein the hydrogel layer is topographically structured with microwells,
 wherein the hydrogel layer has a shear modulus between 1 and 100 kPa, and each of the microwells is functionalized with more than one type of biomolecules.   
     
     
         12 . A method for preparing an array of micropillars, said array of micropillars not having any metal layer deposited thereon, comprising the steps of:
 a) providing a photolithography mask,   b) covering a substrate with a photoresist, wherein the substrate is a substantially planar and rigid silicon wafer,   c) exposing the substrate to the photolithography mask of step a) for at least one cycle followed by development of the photoresist, and   d) etching the substrate to obtain the array of micropillars, wherein each micropillar has a height of 80 to 100 μm and a diameter of 450 μm.   
     
     
         13 . The array of micropillars prepared by a method of  claim 12 , where positions and dimensions of the micropillars are matched to the spotting scheme of a spotting robot. 
     
     
         14 . A kit of parts comprising an array of micropillars according to  claim 13 , at least one of a substantially planar and rigid substrate, and reactants to form a hydrogel exhibiting a shear modulus of between 1 and 100 kPa in substantially cured state. 
     
     
         15 . A screening or cell culture experiment, comprising the step of providing cells on a microarray of  claim 11 . 
     
     
         16 . A microarray according to  claim 11 , wherein said substrate is at least one of a substantially rigid and planar substrate.