Paper PS-FrM6
Patterned Growth of Cells and Biomolecules using a Microplasma Printing System

Friday, November 13, 2009, 10:00 am, Room B2

A versatile system called micro-plasma integrated cell/biomolecule printing system is described. This system enables the creation of patterned cells/biomolecules on various substrates without using any masks, master stamps or chemical treatments. The system operation is based on the integration of two techniques, namely microplasma patterning and cell/biomolecule printing. In microplasma patterning, an atmospheric pressure low-temperature microplasma is generated with a dielectric barrier discharge (DBD) plasma setup consisting of a micro-second pulsed power supply and electrode system. Through micro-plasma integrated cell/biomolecule printing system, we can create chemically and physically predesigned micropatterns and print the cells/biomolecules on designed pattern with precise spatial positioning.

In this study, the authors patterned mouse osteoblast cells on ultra high molecular weight polyethylene films. An O₂/He mixture was used as the working gas for the ignition of a micron-sized discharge. The microplasma nozzle with a tip of 30 µm was navigated on a straight line with a 2mm/s speed to create the micropattern. The physicochemical properties of the microplasma patterned surface were examined by Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS). The SEM data showed that the dynamic microplasma treatment results in an increase of the surface roughness. The surface morphology was changed along the microplasma treated line while the rest of the substrate remained unaffected. The XPS data showed that the atomic concentration of oxygen increased from 5% for the as-received polyethylene film to 18% for the center of the microplasma treated line. Following the micropatterning, mouse osteoblast cells were deposited uniformly on the substrate to determine the effect of microplasma patterning on cell attachment. The biological characterization has been done by live/dead assay where mouse osteoblast cells were labeled and imaged using fluorescence microscopy. The data showed the attachment and survival of the cells strictly along the plasma activated line. With these observations, it is viable to print the cells and dictate their shapes in predetermined locations and arrays through micro-plasma integrated cell/biomolecule printing system.