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A novel gel actuator exhibits a peristaltic motion is designed. We proposed a new approach of coupling an acid-autocatalytic reaction and a pH-responsive gel in order to cause contraction waves. The poly(AAm-co-AAc) microphase-separated tubular gel was synthesized, which can be inflowed reaction solution to its hollow. We focused on its kinetics and evaluated the characteristics of the microphase-separated gels. And we also demonstrated that the propagation of the contraction region occurs in the tubular gel. Our final goal is to develop a biomimetic chemical robot, which realizes a peristaltic locomotion by forming contraction waves like a snail. [ABSTRACT FROM AUTHOR]

In this paper, we introduce self-oscillating gel actuators for chemical robotics. The polymer gels prepared here have cyclic reaction networks like in a metabolic process itself. With a cyclic reaction, the polymer gel swells–shrinks autonomously. The periodic self-oscillating motion of the gel is produced by the dissipating chemical energy of the oscillatory Belouzov–Zhabotinsky reaction. We have succeeded in making the synthetic polymer gel walk autonomously like a living organism. This experimental fact represents the great possibility of the chemical robot. [ABSTRACT FROM AUTHOR]

Differentiation of committed osteoblasts is controlled by complex activities involving signal transduction and gene expression, and Runx2 and Osterix function as master regulators for this process. Recently, CCAAT/enhancer-binding proteins (C/EBPs) have been reported to regulate osteogenesis in addition to adipogenesis. However, the roles of C/EBP transcription factors in the control of osteoblast differentiation have yet to be fully elucidated. Here we show that C/EBP homologous protein (CHOP; also known as C/EBPζ) is expressed in bone as well as in mesenchymal progenitors and primary osteoblasts. Overexpression of CHOP reduces alkaline phosphatase activity in primary osteoblasts and suppresses the formation of calcified bone nodules. CHOP-deficient osteoblasts differentiate more strongly than their wild-type counterparts, suggesting that endogenous CHOP plays an important role in the inhibition of osteoblast differentiation. Furthermore, endogenous CHOP induces differentiation of calvarial osteoblasts upon bone morphogenetic protein (BMP) treatment. CHOP forms heterodimers with C/EBPβ and inhibits the DNA-binding activity as well as Runx2-binding activity of C/EBPβ, leading to inhibition of osteocalcin gene transcription. These findings indicate that CHOP acts as a dominant-negative inhibitor of C/EBPβ and prevents osteoblast differentiation but promotes BMP signaling in a cell-type-dependent manner. Thus, endogenous CHOP may have dual roles in regulating osteoblast differentiation and bone formation. [ABSTRACT FROM AUTHOR]