Cells on patterns

The induction of stereotyped cell activities through the control of the number, density, and maturation state of FAs is emerging as a key point in understanding the 

Generating Micro- and Nanopattems on Polymeric Materials. Edited by A. del Campo and E. Arzt Copyri t 2011 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-S27-32508-5 

In the next section we will define the substrate physicochemical properties which are read by cells and provide details on the parameter ranges that are of use in cellular studies. The final part of each sub-section will provide an overview of the techniques currently applied to independently control the defined substrate parameters. 

Living cells grow and exert their activities while embedded in a dense and complex environment, the extracellular matrix (ECM). The ECM itself contains an array of structural and directional cues that ultimately guide and support both the polarization of individual cells and the morphogenesis of multicellular structures such as tissues and organs [11]. 

1) Density of adhesion points - The density of ligands is a critical parameter that triggers the initial clustering and the subsequent enlargement of FAs. 

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Sakurai K, Teramura Y, Iwata H (2011) Cells immobilized on patterns printed in DNA by an inkjet printer. Biomaterials 32 3596-3602... 

Cu(111) to a lesser extent than on the other two low-index planes. This adsorption results in formation of an ordered structure above 103 L at room temperature, which is displayed as an oblique unit cell [ ]. This pattern has been previously reported (16). It is interesting that it has not been observed by other workers, possibly because of the extreme O2 exposures required and the faintness of the pattern. 

From both the cellular end-on or the axial fish-scale smoke foil, the average cell size A can be measured. The end-on record gives the cellular pattern at one precise instant. The axial record, however, permits the detonation to be observed as it travels along the length of the foil. It is much easier by far to pick out the characteristic cell size A from the axial record thus, the end-on pattern is not used, in general, for cell-size measurements. 

The cambium layer of plant stems (Fig. 1-16) differentiates continuously to form phloem on the outside of the cambium and xylem on the inside. At the same time, cambium cells are retained. Thus, at each cell division one daughter cell becomes a differentiated cell, while another remains the less differentiated cambium. This pattern of continuous differentiation from a line of stem cells with constant properties is found in animals as well as in plants. In the differentiation of cambium it appears that chemical signals obtained from the surrounding cells on either the inside or the outside of the cambium layer determine whether the differentiated cell becomes phloem or xylem. Sucrose, auxin, and cytokinins are all involved. 

Thus it appears that these drugs act at different points to modify cell cycle behavior. The implications of these results in the regulation of glycoconjugate metabolism and their involvement in tumor promotion remains to be seen. Further studies on changes in glycoconjugate metabolism and cell surface patterns as a function of cell cycle should prove very fruitful. 

Lasch, P. and Naumann, D. (1998) FT-IR microspectroscopic imaging of human carcinoma in thin sections based on pattern recognition techniques. Cell. Mol. Biol. 44(1), 189-202. 

Chick embryo heart muscle cells were patterned and grown on a fibronectin (FN) surface patterned by PDMS stamping. The PBS solution (containing Ca2+ and K+) was used to stimulate spontaneous muscle contraction [198]. Laminar flows provide a reaction path (buffer plus 1-octanol) and a control patch (buffer only) for study of communication between excitable cells (cardiomyocytes) through gap junctions (see Figure 8.18) [198]. 

Whitesides and coworkers describe the use of an elastomeric membrane to pattern proteins and cells on bacteriological polystyrene (PS), glass, and poly(dimethyl-siloxane) (PDMS) substrates [92], A patterned PDMS membrane was casted from lithographically structured photoresists and brought into close contact with the substrates (Fig. 6). When incubated with a solution of fibronectin (FN), adsorption of the cell-adhesion-mediating protein to the surface was restricted to the exposed areas. The membrane was peeled off and cells were seeded from a serum-free medium. Passivation to cell attachment of the untreated portions of the surface was achieved by adding 1% bovine serum albumin (BSA) to the cell-seeding medium, which... 

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