The hemocompatibility of a polymer containing a phospholipid polar group, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate(BMA)), with human whole blood was evaluated. When human whole blood without an anticoagulant was contacted with polymers, the blood cell adhesion and aggregation on the polymer without the MPC moiety was extensive, and considerable fibrin deposition was observed. This phenomenon was suppressed with an increase in the polymer MPC composition. Thus, the MPC moiety in the copolymer plays an important role in the nonthrombogenic behavior of the copolymer. These results were also confirmed by the whole blood coagulation time on the polymer surface which was determined by Lee-White method. The adsorption of phospholipids and proteins from human plasma on poly(MPC-co-BMA) was investigated to clarify the mechanism of the nonthrombogenicity observed with the polymer. The amount of phospholipids was increased; whereas, adsorbed proteins were decreased with an increase in the MPC composition. From these results, we concluded that the phospholipids adsorbed on poly(MPC-co-BMA) play the most important role in the nonthrombogenicity of the MPC copolymer.

Inkjet printers are capable of printing at high resolution by ejecting extremely small ink drops. Established printing technology will be able to seed living cells, at micrometer resolution, in arrangements similar to biological tissues. We describe the use of a biocompatible inkjet head and our investigation of the feasibility of microseeding with living cells. Living cells are easily damaged by heat; therefore, we used an electrostatically driven inkjet system that was able to eject ink without generating significant heat. Bovine vascular endothelial cells were prepared and suspended in culture medium, and the cell suspension was used as "ink" and ejected onto culture disks. Microscopic observation showed that the endothelial cells were situated in the ejected dots in the medium, and that the number of cells in each dot was dependent on the concentration of the cell suspension and ejection frequency chosen. After the ejected cells were incubated for a few hours, they adhered to the culture disks. Using our non-heat-generating, electrostatically driven inkjet system, living cells were safely ejected onto culture disks. This microseeding technique with living cells has the potential to advance the field of tissue engineering.

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Infrared (IR) spectra were measured for cellulose Ibeta prepared from the mantle of Halocynthia roretzi over a temperature range of 30-260 degrees C to explore the temperature-dependent changes in hydrogen bonds (H-bonds) in the crystal. Structural changes at the phase transition temperature of 220 degrees C are elucidated at the functional group level by perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy. The PCMW2D correlation spectra show that the intensities of bands arising from O3-H3...O5 and O2-H2...O6 intrachain H-bonds dramatically decrease at 220 degrees C, whereas the intensity changes of bands due to interchain H-bonds are not observed adequately. These results suggest that the phase transition is induced by the dissociation of the O3-H3...O5 and O2-H2...O6 intrachain H-bonds. However, the interchain H-bonds are not so much responsible for the transition directly.