Bio-Medical Materials and Engineering - Volume 23, issue 1-2

Authors: Murabayashi, Shun | Nose, Yukihiko

Article Type: Research Article

Abstract: Bioengineers have contributed to biocompatibility research. Many materials have been designed, synthesized and characterized by use of various analytical instruments. The blood compatibility of materials has been studied by focusing on the blood–material interfacial reactions. Although much information has been accumulated regarding such local reactions, understanding of biocompatibility is still limited. A more global approach to study is needed. A new approach to understanding biocompatibility is proposed and discussed. Three points are stressed: interaction within body's defense system and its effect on blood–material reactions; induction of a systemic reaction by a local reaction, which then affects the blood–material interaction; the …time sequence of such interactions between local and systemic reactions. To establish a logical approach to study biocompatibility is most important at this moment for the future progress in biocompatibility research. Show more

Keywords: Biocompatibility, blood–material interactions, local reactions, systemic reactions, body defense system

DOI: 10.3233/BME-120738

Citation: Bio-Medical Materials and Engineering, vol. 23, no. 1-2, pp. 129-142, 2013

Authors: Takebayashi, Takafumi | Horii, Takashi | Denno, Hiromi | Nakamachi, Nobutoshi | Otomo, Keiko | Kitamura, Saki | Miyamoto, Keiichi | Horiuchi, Takashi | Ohta, Yuji

Article Type: Research Article

Abstract: The stem cell niche is crucial to the control of stem cell fate determination in vitro as well as in vivo, and an understanding of these niches is required for the progression of stem cell and tissue engineering. The goal of our study was to commit human mesenchymal stem cells (hMSCs) to the epithelial lineage. To do this, we cultured bone marrow-derived mesenchymal stem cells (MSCs) on plates coated with type I collagen gel with or without 10 μM all-trans retinoic acid (ATRA). We found depth-dependent differentiation of hMSCs to the epithelial lineage, with the thick collagen gel (1900 …μm) generating more than 80% cytokeratin-18 (CK-18)-positive cells, whereas the thin collagen gel (100 μm) generated significantly fewer CK-18-positive cells. In addition, we found that supplementation of 10 μM ATRA enhanced CK-18 expression and induced cluster-formation in cells grown on the thick collagen gel. The effect of gel depth on hMSC differentiation appears to be caused by partial cytoskeletal disruption. These results suggest that ATRA and a collagen extracellular matrix may have a synergistic effect on differentiation of human mesenchymal stem cells to epithelial lineage. Show more

Keywords: Mesenchymal stem cell, type I collagen gel, epithelial differentiation, all-trans retinoic acid, cytokeratin-18

DOI: 10.3233/BME-120739

Citation: Bio-Medical Materials and Engineering, vol. 23, no. 1-2, pp. 143-153, 2013

Authors: Okamoto, Eiji | Kikuchi, Sakiko | Miura, Hidekazu | Shiraishi, Yasuyuki | Yambe, Tomoyuki | Mitamura, Yoshinori

Article Type: Research Article

Abstract: We developed a new transcutaneous communication system (TCS) that uses the human body as a conductive medium for monitoring and controlling artificial hearts and other artificial organs in the body. In this study, the physiological effect of data current discharged into the body during data transmission was evaluated by an animal experiment using a goat. The external and internal units of the new TCS each mainly consist of a data transmitter and a data receiver. The data transmitter has an amplitude shift keying (ASK) modulator (carrier frequencies: 4 and 10 MHz) and an electrode. The internal unit of …the TCS was fixed on the pericardium and the external unit was placed on the left ear, and each transmitter discharged an ASK-modulated current of 7 mA (RMS) into the conscious goat. The TCS was able to transmit data for 4 weeks under full duplex communication with a transmission rate of 115 kbps. On the 28th postoperative day, an electrocardiogram was measured during data transmission. Cardiac rhythm and waveform of the electrocardiogram were not changed before and during bidirectional data transmission. Also, no adverse effect on the heart was observed by autopsy. Show more

Keywords: Artificial heart, monitoring, transcutaneous communication, intrabody communication

DOI: 10.3233/BME-120740

Citation: Bio-Medical Materials and Engineering, vol. 23, no. 1-2, pp. 155-162, 2013