ABSTRACT
This paper investigates the chemical modification of a cell-repellent poly(ethylene glycol) (PEG)-based polymer to enhance its hydrophilicity with sulfonate groups, and its application in the fabrication of a cell microarray. First, a polymer comprised of a methyl methacrylate (MMA) backbone with PEG side-chains (PMMA-b-PEG) was synthesized from three monomers by radical polymerization and purified. Despite the hydrophilic side-groups in the amphiphilic polymer, the backbone structure's hydrophobicity allows for local adsorption of biomolecules in incubation media with or without serum. To enhance the hydrophilicity of the polymer, we tethered sulfonate groups to the hydroxyl groups on the PEG side chains (PMMA-b-PEG-SO3). The sulfate groups' physical and mechanical movement competitively repels biomolecules approaching the PMMA-b-PEG surface. Polymers modified with sulfonate were characterized by contact angle measurement, FT-IR, NMR, AFM and GPC. PMMA-b-PEG and PMMA-b-PEG-SO3 were successfully micropatterned on polystyrene and glass surfaces, and cell attachment was performed in either serum-free or serum-containing media, resulting in highly resolved cell micropatterns.
Subject(s)
Polyethylene Glycols/chemistry , Polymethyl Methacrylate/chemistry , Sulfones/chemistry , Adsorption , Biocompatible Materials/chemistry , Biopolymers , Models, Molecular , Sulfur Oxides/chemistry , Surface PropertiesABSTRACT
The development of a simple and easily accessible method to control cellular behavior under a spatially controlled surface is critical for fundamental studies in biotechnology. We fabricated a microarray of Spodoptera frugiperda 9 (Sf9) cells on a glass surface by microcontact printing cell-repellent polymeric molecules of poly(ethylene glycol)-branched-poly(methyl methacrylate) as a template for cell micropatterning. The polymer micropatterns enabled the stable confinement of Sf9 cells on the surface, resulting in the formation of a cell microarray. Subsequently, the patterned Sf9 cells were infected with recombinant baculovirus modified with green fluorescent protein (GFP) to form a virus microarray, and GFP expression in the virus microarray was verified with confocal fluorescence microscopy.
Subject(s)
Baculoviridae , Microarray Analysis , Polyethylene Glycols/chemistry , Polymethyl Methacrylate/chemistry , Spodoptera/cytology , Animals , Baculoviridae/genetics , Cell Line , Glass/chemistry , Microarray Analysis/methods , Microscopy, Confocal , Spodoptera/genetics , Spodoptera/virologyABSTRACT
To infect cells with a particular multiplicity of infection, it is essential to know the concentration of virus in the inoculum. Here we describe a highly reliable and controllable method for plaque purification using cell-repellent surfaces micropatterned on the substrate. Micropatterning of localized chemical or biochemical domains has the potential to become a powerful tool in controlling the seeding of cells. The cell array was reliably fabricated with micropatterned surfaces, and the number of cells in a pattern was easily controlled by the cell density in the media and micropattern size. The cell micropatterns were infected with baculoviruses to form an array of virus plaques. GFP-modified and wild-type baculoviruses were used to verify the feasibility of purifying a specific plaque. Using confocal microscopy, GFP-expressing plaques were readily selectable and removable.
