This paper examines the hypothesis that surfaces resistant to protein adsorption should also be resistant to the adhesion of bacteria (Staphylococcus aureus, Staphylococcus epidermidis) and the attachment and spreading of mammalian cells (bovine capillary endothelial (BCE) cells). The surfaces tested were those of self-assembled monolayers (SAMs) terminated with derivatives of tri(sarcosine) (Sarc), N-acetylpiperazine, permethylated sorbitol, hexamethylphosphoramide, phosphoryl choline, and an intramolecular zwitterion (-CH2N + (CH3)2CH2CH2CH2SO3 -) (ZW); all are known to resist the adsorption of proteins. There seems to be little or no correlation between the adsorption of protein (fibrinogen and lysozyme) and the adhesion of cells. Surfaces terminated with derivatives of Sarc and N-acetylpiperazine resisted the adhesion of S. aureus and S. epidermidis as well as did surfaces terminated with tri(ethylene glycol). A surface that presented Sarc groups was the only one that resisted the adhesion of BCE cells as well as did a surface terminated with tri(ethylene glycol). The attachment of BCE cells to surfaces could be patterned using SAMs terminated with derivatives of Sarc, N-acetylpiperazine, phosphoramide, and the ZW as the attachment-resistant component and methyl-terminated SAMs as the adhesive component.

This paper describes the use of laminar f low of liquids in capillary systems to pattern the cell culture substrate, to perform patterned cell deposition, and to pattern the cell culture media. We demonstrate the patterning of the cell culture substrate with different proteins, the patterning of different types of cells adjacent to each other, the patterned delivery of chemicals to adhered cells, and performing enzymatic reactions over select cells or over a portion of a cell. This method offers a way to simultaneously control the characteristics of the surface to which cells are attached, the type of cells that are in their vicinity, and the kind of media that cells or part of a cell are exposed to. The method is experimentally simple, highly adaptable, and requires no special equipment except for an elastomeric relief that can be readily prepared by rapid prototyping.Efforts to understand the interaction of cells in culture with their environment would benefit from general procedures for patterning both the position of the cells and the characteristics of the environment-that is, the molecular structure of the surface to which the cells are attached, the nature and position of other cells in their vicinity, and the composition of the fluid medium surrounding them. Here we describe procedures that use the laminar flow of multiple parallel liquid streams in rectangular capillaries to pattern the surface of the substrate with adhesion promoters and inhibitors, to deliver cells to the surface of the substrate in patterns, and to localize chemicalsfluorescent labels, nutrients, growth factors, toxins, enzymes, drugs-available to attached cells in the medium. We believe that these procedures will enable new types of studies in fundamental cell biology and cellular metabolism, and that they will also be useful in the fabrication of analytical systems that use cells as sensors.These methods rely on the fact that the flow of liquids in capillaries often has a low Reynolds number (Re) and is laminar (1-4). When two or more streams with low Re are joined into a single stream, also with low Re, by using a junction of appropriate connectivity, the combined streams flow parallel to each other without turbulent mixing. This ability to generate and sustain parallel streams of different solutions in capillaries provides the capability required to pattern: (i) the substrate-by adsorption of adhesion promoters and inhibitors; (ii) the location of the cells-by exposure of patterned substrate to a suspension of cells or by selective deposition of cells onto an unpatterned substrate from laminar streams; or (iii) the medium-by patterned flow. These methods easily generate patterns of parallel stripes, but by using appropriately designed capillary systems (5-7) or multistep procedures, it is possible to generate more complex patterns. MATERIALS AND METHODSDevice Fabrication. A negative relief of poly(dimethylsiloxane) (PDMS) was formed by curing the prepolymer (Sylgard 184, Dow-Corning) on a silanized Si master having a posi...

This paper describes the design and preparation of thin polymeric films that resist the adsorption of proteins and the adhesion of bacteria to an extent comparable to, or better than, self-assembled monolayers (SAMs) that present tri(ethylene glycol) groups. These polymeric films were prepared by the reaction of a polyamine, for example, poly(ethylenimine), with a SAM that presented interchain carboxylic anhydride groups, and by the subsequent conversion of the amino groups of the polymer to amido groups on reaction with acyl chlorides. Polyamines functionalized with acetyl chloride produced films that resisted the adsorption of protein and the adhesion of bacteria to a useful extent. Functionalization of the polyamine with acyl chlorides that were derivatives of oligo(ethylene glycol) resulted in films that were 1−10 times more resistant than those obtained by acetylation. The removal of hydrogen bond donor groups from the surface of the polyamines upon acylation seems to be important for the generation of films that resist the attachment of proteins and bacteria.