Control of cell adhesion and growth by microfabrication technology and surface chemistry is important in an increasing number of applications in biotechnology and medicine. In this study, we developed a method to fabricate (2-hydroxyethyl methacrylate) (polyHEMA) grids on glass by micromolding in capillaries (MIMIC). As a non-fouling biomaterial, polyHEMA was used to inhibit the nonspecific bonding of cells, whereas the glass surface provided a cell adhesive background. The polyHEMA chemical barrier was directly obtained using MIMIC without surface modification, and the microchannel networks used for capillarity were easily achieved by reversibly bonding the polydimethylsiloxane (PDMS)mold and the glass. After fabrication of the polyHEMA micropattern, individual cytophilic microwells surrounded by cytophobic sidewalls were presented on the glass surface. The polyHEMA micropattern proved effective in controlling the shape and spreading of cells, and square-shaped mouse osteoblast MC3T3-E1 cells were obtained in microwell arrays after incubation for 3 days. Moreover, the widths of the microwells in this micropattern were optimized for use as single-cell arrays. The proposed method could be a convenient tool in the field of drug screening, stem cell research, and tissue engineering.

Cell studies at the single-cell level are becoming more and more critical for understanding the complex biological processes. Here, we present an optimization study investigating the positioning of single cells using micromolding in capillaries technology coupled with the cytophobic biomaterial poly (2-hydroxyethyl methacrylate) (poly (HEMA)). As a cytophobic biomaterial, poly (HEMA) was used to inhibit cells, whereas the glass was used as the substrate to provide a cell adhesive background. The poly (HEMA) chemical barrier was obtained using micromolding in capillaries, and the microchannel networks used for capillarity were easily achieved by reversibly bonding the polydimethylsiloxane mold and the glass. Finally, discrete cell adhesion regions were presented on the glass surface. This method is facile and low cost, and the reagents are commercially available. We validated the cytophobic abilities of the poly (HEMA), optimized the channel parameters for higher quality and more stable poly (HEMA) patterns by investigating the effects of changing the aspect ratio and the width of the microchannel on the poly (HEMA) grid pattern, and improved the single-cell occupancy by optimizing the dimensions of the cell adhesion regions. V C 2015 AIP Publishing LLC.

The homogeneous multiferroic BiFeO3 nanoparticles with average particle size of 85 nm have been successfully synthesized by a simple sol-gel route. The prepared sample was characterized by a variety of techniques, such as X-ray diffractometry, thermogravimetric analysis and differential thermal analysis, differential scanning calorimeter analysis, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The obtained results shows that rapid sintering and subsequently quenching to room temperature are the two vital important factors for the preparation of pure BiFeO3. The magnetic phase transition (TN = 369 °C) and the ferroelectric phase transition (TC = 824.5 °C) were determined, revealing the antiferromagnetic and ferroelectric nature of the as-prepared BiFeO3 nanoparticles. The optical properties of the nanopowders were investigated. The strong band-gap absorption at 486 nm (2.55 eV) of the BiFeO3 nanoparticles may bring some novel applications.