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Sapporo, Japan

Yin H.,Hokkaido University | Akasaki T.,Hokkaido University | Lin Sun T.,Hokkaido University | Nakajima T.,Hokkaido University | And 5 more authors.
Journal of Materials Chemistry B | Year: 2013

Polyzwitterionic materials, which have both cationic and anionic groups in the polymeric repeat unit, show excellent anti-biofouling properties and are drawing more attention in the biomedical field. In this study, we have successfully synthesized novel single network hydrogels and double network (DN) hydrogels from the zwitterionic monomer, N-(carboxymethyl)-N,N-dimethyl-2- (methacryloyloxy) ethanaminium, inner salt (CDME). The polyCDME (PCDME) single network hydrogel behaves like a hydrophilic neutral hydrogel and its properties are not sensitive to temperature, pH, or ionic strength over a wide range. DN hydrogels using the poly(2-acrylamido-2-methylpropanesulfonic) (PAMPS) as the first network and PCDME as the second network, having a Young's modulus of 0.2-0.9 MPa, possess excellent mechanical strength (fracture stress: 1.2-1.4 MPa, fracture strain: 2.2-6.0 mm/mm) and toughness (work of extension at fracture: 0.9-2.4 MJ m-3) depending on the composition ratio of PCDME to PAMPS. The strength and toughness of the optimized PAMPS/PCDME DN is comparable to the normal PAMPS/PAAm DN hydrogels that use poly(acrylamide) (PAAm) as the second network. By macrophage adhesion test, both the PCDME hydrogels and the PAMPS/PCDME DN hydrogels have shown excellent anti-biofouling properties. These results demonstrate that the PCDME-based DN hydrogels have high potential as a novel soft and wet biomaterial. © 2013 The Royal Society of Chemistry. Source


Nagayama M.,Hokkaido University | Shimizu K.,Primary Cell Co. | Taira T.,Primary Cell Co. | Uchida T.,Hokkaido University | Gohara K.,Hokkaido University
FEBS Letters | Year: 2010

Time-lapse observation of adipocytes during catecholamine-induced lipolysis clearly shows that shrinking of existing lipid droplets (LDs) occurs in some adipocytes and that small LDs are newly developed in almost all cells. Immunofluorescence imaging reveals that activation and localization of hormone-sensitive lipase (HSL) on the surface of LDs, which are required for conferring maximal lipolysis, are necessary for the shrinking of the LDs. However, not all adipocytes in which phosphorylated HSL is localized on LDs exhibit shrinking of LDs. The simultaneous shrinking and development of LDs yield apparent fragmentation and dispersion of LDs in adipocytes stimulated with catecholamine. © 2009 Federation of European Biochemical Societies. Source


Yamaguchi M.,Japan National Institute of Advanced Industrial Science and Technology | Ikeda K.,Japan National Institute of Advanced Industrial Science and Technology | Suzuki M.,Japan National Institute of Advanced Industrial Science and Technology | Kiyohara A.,Kwansei Gakuin University | And 6 more authors.
Langmuir | Year: 2011

Micropatterning techniques have become increasingly important in cellular biology. Cell patterning is achieved by various methods. Photolithography is one of the most popular methods, and several light sources (e.g., excimer lasers and mercury lamps) are used for that purpose. Vacuum ultraviolet (VUV) light that can be produced by an excimer lamp is advantageous for fabricating material patterns, since it can decompose organic materials directly and efficiently without photoresist or photosensitive materials. Despite the advantages, applications of VUV light to pattern biological materials are few. We have investigated cell patterning by using a template of a microstructured organosilane layer fabricated by VUV lithography. We first made a template of a microstructured organosilane layer by VUV lithography. Cell adhesive materials (poly(d-lysine) and polyethyleneimine) were chemically immobilized on the organosilane template, producing a cell adhesive material pattern. Primary rat cardiac and neuronal cells were successfully patterned by culturing them on the pattern substrate. Long-term culturing was attained for up to two weeks for cardiac cells and two months for cortex cells. We have discussed the reproducibility of cell patterning and made suggestions to improve it. © 2011 American Chemical Society. Source


Nishimura M.,Hokkaido Information University | Nishimura M.,Section of Research and Development | Ohkawara T.,Hokkaido Information University | Kagami-Katsuyama H.,Hokkaido Information University | And 5 more authors.
Journal of Functional Foods | Year: 2014

Adlay has been used as a traditional Chinese medicine and nutrient for its beneficial effects on bowel movements and skin care. This study examined the effect of enzymatic degradation product of adlay, "Super Hatomugi" (SPH) on human skin and the intestinal flora in a randomized, double-blind placebo-controlled study. The subjects were divided into three groups: 500. mg SPH, 1000. mg SPH, and placebo, taken daily for 4. weeks. Hematological and skin condition examinations as well as an analysis of intestinal flora were performed 2. weeks before and 10. weeks after the start of the SPH intake. Skin condition was improved by SPH intake as revealed by a reduction in the number of nucleated epidermal cells. In addition, an increase in the fecal population of Bacteroidetes followed the SPH intake. These results show the possibility that SPH improves the skin condition and changes the proportions of intestinal flora. © 2014 The Authors. Source


Uchida T.,Hokkaido University | Nagayama M.,Hokkaido University | Taira T.,Primary Cell Co. | Shimizu K.,Primary Cell Co. | And 2 more authors.
Cryobiology | Year: 2011

The increase in demand for primary cardiomyocytes necessitates advanced methods for their stable supply. In this study, we investigated the optimal temperature range for preserving dissociated cardiomyocytes for 72. h while maintaining their normal growth and beating functions. Neonatal rat cardiomyocytes dissociated by collagenase and suspended in the culture medium were preserved at temperatures from -2 to 35 °C for 72. h. The cardiomyocytes preserved at temperatures below 20 °C maintained the initial dispersed states, whereas they aggregated robustly at higher temperatures. The viability of the dispersed cells after preservation was more than 80%. After the preservation, the microscopic observations during the 7-days cultivation indicated that these dispersed cardiomyocytes grew normally to form a confluent monolayer, and beat spontaneously and regularly during culture, as did the fresh cells. These systematic evaluations indicated that the optimal temperature ranged from 3 to 20 °C. Below this optimal temperature range, the cell activities decreased slightly with temperature. The robustly aggregated cardiomyocytes exhibited weak growth and low beating rates, although some cardiomyocytes still survived. The optimal conditions, which consist of a wider temperature range and longer preservation period than the present commercially used conditions, allowed milder temperature control and thus more economical transportation for the dissociated primary cardiomyocytes. © 2011 Elsevier Inc. Source

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