Articles by Siew-Eng How in JoVE
Fabrication of a Multiplexed Artificial Cellular MicroEnvironment Array Yasumasa Mashimo1,2, Momoko Yoshioka1, Yumie Tokunaga1, Christopher Fockenberg1, Shiho Terada1, Yoshie Koyama1, Teiko Shibata-Seki2, Koki Yoshimoto1, Risako Sakai1, Hayase Hakariya1, Li Liu1, Toshihiro Akaike3, Eiry Kobatake2, Siew-Eng How4, Motonari Uesugi1,5, Yong Chen1,6, Ken-ichiro Kamei1 1Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, 2Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 3Biomaterials Center for Regenerative Medical Engineering, Foundation for Advancement of International Science, 4Faculty of Science and Natural Resources, Universiti Malaysia Sabah, 5Institute for Chemical Research, Kyoto University, 6Ecole Normale Supérieure This article describes the detailed methodology to prepare a Multiplexed Artificial Cellular MicroEnvironment (MACME) array for high-throughput manipulation of physical and chemical cues mimicking in vivo cellular microenvironments and to identify the optimal cellular environment for human pluripotent stem cells (hPSCs) with single-cell profiling.
Other articles by Siew-Eng How on PubMed
Optimization of Extraction Time and Temperature on Antioxidant Activity of Schizophyllum Commune Aqueous Extract Using Response Surface Methodology Journal of Food Science and Technology. Apr, 2013 | Pubmed ID: 24425917 Central composite design of response surface methodology (RSM) was employed to optimize the extraction time (X 1 : 99.5-290.5 min) and temperature (X 2 : 30.1-54.9 °C) of Schizophyllum commune aqueous extract with high antioxidant activities and total phenolic content (TPC). Results indicated that the data were adequately fitted into four second-order polynomial models. The extraction time and temperature were found to have significant linear, quadratic and interaction effects on antioxidant activities and TPC. The optimal extraction time and temperature were: 290.5 min and 35.7 °C (DPPH(•) scavenging ability); 180.7 min and 41.7 °C (ABTS(•+) inhibition ability); 185.2 min and 42.4 °C (ferric reducing antioxidant power, FRAP); 290.5 min and 40.3 °C (TPC). These optimum conditions yielded 85.10%; 94.31%; 0.74 mM Fe(2+) equivalent/100 g; 635.76 mg gallic acid equivalent/100 g, respectively. The yields of antioxidant activities and TPC obtained experimentally were close to its predicted values. The establishment of such model provides a good experimental basis employing RSM for optimizing the extraction time and temperature on antioxidants from S. commune aqueous extract.
Microfluidic-Nanofiber Hybrid Array for Screening of Cellular Microenvironments Small (Weinheim an Der Bergstrasse, Germany). May, 2017 | Pubmed ID: 28272774 Cellular microenvironments are generally sophisticated, but crucial for regulating the functions of human pluripotent stem cells (hPSCs). Despite tremendous effort in this field, the correlation between the environmental factors-especially the extracellular matrix and soluble cell factors-and the desired cellular functions remains largely unknown because of the lack of appropriate tools to recapitulate in vivo conditions and/or simultaneously evaluate the interplay of different environment factors. Here, a combinatorial platform is developed with integrated microfluidic channels and nanofibers, associated with a method of high-content single-cell analysis, to study the effects of environmental factors on stem cell phenotype. Particular attention is paid to the dependence of hPSC short-term self-renewal on the density and composition of extracellular matrices and initial cell seeding densities. Thus, this combinatorial approach provides insights into the underlying chemical and physical mechanisms that govern stem cell fate decisions.