A Study For Patterning Multiple Types Of Cells On The Same Substrate

The aim of patterning multiple types of cells on the same substrate is to control of the cellular environment with precisely way. This technique is crucial for understanding the mechanism of cell-cell interactions.Fabrication of the microstructures in all experiments followed a traditional soft lithography method. We have combined microcontact printing, microfluidics and electrochemistry for patterning multiple types of cells on the same substrate.Our method employs a polyethyleneglycol(PEG)-terminated alkanethiol, to form a self-assembled monolayers (SAMs) on the gold surface that resists adsorption of proteins and adhesion of cells. A poly(dimethylsiloxane) (PDMS) stamp with embedded microfluidic channels to carry out selective electrochemical desorption of SAM from the gold substrate and then, different types cells are delivered to these areas for attachment. This procedure allows patterned difference types of cells in stripes (continuous patterns).In another approach, our method starts with mierocontact printing (μCP) to form a pattern of self-assembled monolayers (SAMs) on gold substrate. The methyl-terminated alkanethiol form series of lines on the gold substrate, which can adsorb protein form solution and promote the attachment of cells. Non-printed regions are subsequently loaded with a SAM by immersing the substrate in a polyethyleneglycol(PEG)-terminated alkanethiol solution to resist adsorption of proteins and adhesion of cells. To pattern different types of cells in discontinuous patterns, a PDMS stamp with embedded microfluidic channels is placed onto the substrate to form enclosed microchannels. After we filled the channels with solutions of the extracellular matrix (ECM) protein and then cells, cells attach on the areas of methyl-terminate thiol within the channel.We using Hela cell and NIH3T3 cell as model cell, establish methods of patterning different types of cells in continuous patterns and discontinuous patterns. These system could have a variety of applications in biology, biomedical engineering and drug screening.