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Kazuyoshi Itoga

Publications and source records attributed to Kazuyoshi Itoga.

3 recordsLinked to original sources

Maskless liquid-crystal-display projection photolithography for improved design flexibility of cellular micropatterns.

We previously developed an all-in-one photopolymerization device by modifying a commercially available liquid crystal display projector (LCDP) for the preparation of micropatterned surfaces and microfluidic channels without the need for expensive photomasks. In the present study, we demonstrate a simple and reliable method for rapid prototyping of cell micropatterning with high resolution using the modified LCDP device. Fabrication of complicated and flexible patterns was achieved using this device with positive-type photoresist in a two-step process. First, micropatterns on the silanized coverslips were fabricated from positive photoresist. Second, acrylamide monomer solution containing polymerization initiator was dropped onto the micropatterned positive photoresist and copolymerized on the silanized coverslips in situ by thermally initiated radical polymerization. After the reaction, the remnant micropatterned photoresist is easily dissolved, resulting in a polyacrylamide-silane micropattern on the coverslip. The resultant polyacrylamide layer is highly hydrophilic and repels both protein adsorption and cell adhesion. Cells seeded on the micropatterned surfaces therefore attach and spread only on unpolymerized silanized glass surfaces, conforming to the pattern design. This technique is therefore useful for inexpensive, rapid prototyping of surface micropatterns using polymer materials.

Acrylic Resins↗

Micropatterned surfaces prepared using a liquid crystal projector-modified photopolymerization device and microfluidics.

A commercial liquid crystal device projector was modified for photopolymerization using its on-board intense light source and a precision optical control circuit. This device projects reduced images generated by a typical personal computer onto the stage where photopolymerization on a surface occurs. This all-in-one device does not require expensive photomasks and external light sources. However, light scattering and diffraction through glass substrates resulted in undesired reactions in areas corresponding to masked (black) domains in mask patterns, limiting pattern resolution. To overcome this shortcoming, two-step surface patterning was developed. First, three-dimensional microstructures of crosslinked silicone elastomer were fabricated with this device and adhered onto silanized glass substrate surfaces, forming microchannels in patterns on the glass support. Then, acrylamide monomer solution containing photoreactive initiator was flowed into these micromold channels and reacted in situ. The resultant polyacrylamide layer was highly hydrophilic and repelled protein adsorption. Cell seeding on these patterns in serum-supplemented culture medium produced cells selectively adhered to different patterns: cells attached and spread only on unpolymerized silanized glass surfaces, not on the photopolymerized acrylamide surfaces. This technique should prove useful for inexpensive, rapid prototyping of surface micropatterns from polymer materials.

Acrylic Resins↗

Cell micropatterning using photopolymerization with a liquid crystal device commercial projector.

Photopolymerization has been widely used for surface micropatterning. The technique often requires photomasks and light sources with appropriate energies or filters. For rapid prototyping of surface photo-micropatterning, we have developed a novel device by modifying a commercially available liquid crystal device projector. In place of the image expansion unit of the projector, we attached an image reduction unit, an adjustable stage, and an optical monitoring unit. The device projected computer-generated images onto surfaces and subjected these patterns to photopolymerization. Micropatterned images can be easily prepared with various software run on personal computers. With the developed photopolymerization device, micropatterning of poly(ethylene glycol) (PEG) was achieved with PEG-diacrylate and a visible light photopolymerization initiator, camphorquinone. Selective cell adhesion control was also achieved on the micropatterned surfaces.

Animals↗