An Electrical Stimulation Culture System for Daily Maintenance-Free Muscle Tissue Production.

Low-labor production of tissue-engineered muscles (TEMs) is one of the key technologies to realize the practical use of muscle-actuated devices. This study developed and then demonstrated the daily maintenance-free culture system equipped with both electrical stimulation and medium replacement functions. To avoid ethical issues, immortal myoblast cells C2C12 were used.

Improved and reproducible cell viability in the superflash freezing method using an automatic thawing apparatus.

Cell cryopreservation stops the biological activity of cells by placing them in the frozen state, and can be used to preserve cells without subculturing, which can cause contamination and genetic drift. However, the freezing process used in cryopreservation can injure or damage the cells due to the cytotoxicity of cryoprotecting agents (CPAs). We have previously reported a CPA-free cryopreservation method based on inkjet technology.

Nylon mesh cryodevice for bovine mature oocytes, easily removable excess vitrification solution.

The aim of this study was to determine pore size of nylon mesh (NM) device suitable for cryosurvival of bovine mature oocytes and to apply the device to vitrification of large quantities of the oocytes. Ten to twelve oocytes were loaded onto an NM device (a square opening 37-, 57- or 77-μm on a side length). After removal of the excess volume of vitrification solution by paper absorption, the oocytes were vitrified-warmed, fertilized and cultured in vitro.

Cryoprotectant-free cryopreservation of mammalian cells by superflash freezing.

Cryopreservation is widely used to maintain backups of cells as it enables the semipermanent storage of cells. During the freezing process, ice crystals that are generated inside and outside the cells can lethally damage the cells. All conventional cryopreservation methods use at least one cryoprotective agent (CPA) to render water inside and outside the cells vitreous or nanocrystallized (near-vitrification) without forming damaging ice crystals.

Toward continuous LC-MS analysis: surface modification of magnetic microparticles with TiO2 for phosphate adsorption.

Continuous liquid chromatography-mass spectrometry (LC-MS) analysis was successfully demonstrated by using magnetic TiO2/Fe3O4 microparticles at the desalination interface. The particles could be prepared easily even on a practical scale at sufficient quality for efficient phosphate adsorption. Not only phosphate but several biomolecules were adsorbed onto the particles in a non-specific manner.

Atmospheric-operable bioactuator powered by insect muscle packaged with medium.

Despite attempts in a number of studies to utilize muscle tissue and cells as microactuators, all of the biohybrid microdevices have been operable only in the culture medium and none have worked in air due to the dry environment. This paper demonstrates an atmospheric-operable bioactuator (AOB) fabricated by packaging an insect dorsal vessel (DV) tissue with a small amount of culture medium inside a capsule. The AOB, consisting of microtweezers and the capsule, was designed based on a structural simulation that took into account the capillary effect.

Voluntary movement controlled by the surface EMG signal for tissue-engineered skeletal muscle on a gripping tool.

We have developed a living prosthesis consisting of a living muscle-powered device, which is controlled by neuronal signals to recover some of the functions of a lost extremity. A tissue-engineered skeletal muscle was fabricated with two anchorage points from a primary rat myoblast cultured in a collagen Matrigel mixed gel. Differentiation to the skeletal muscle was confirmed in the tissue-engineered skeletal muscle, and the contraction force increased with increasing frequency of electric stimulation.

Cardiomyocyte-driven gel network for bio mechano-informatic wet robotics.

This paper reports on a cellular mechano-informatics network gel robot which was powered by culturing cardiomyocytes in the micro gel structure. Contraction activities propagated through the cardiomyocyte gel network will transmit a spatial mechanical wave as information about the chemical and mechanical responses to environmental changes. The cardiomyocyte gel network robot transmits electrically excited potential and mechanical stretch-induced contractions as information carried on the gel network.

Insect biofuel cells using trehalose included in insect hemolymph leading to an insect-mountable biofuel cell.

In this paper, an insect biofuel cell (BFC) using trehalose included in insect hemolymph was developed. The insect BFC is based on trehalase and glucose oxidase (GOD) reaction systems which oxidize β-glucose obtained by hydrolyzing trehalose. First, we confirmed by LC-MS that a sufficient amount of trehalose was present in the cockroach hemolymph (CHL).

Rapidly-moving insect muscle-powered microrobot and its chemical acceleration.

Insect dorsal vessel (DV) tissue seems well suited for microactuators due to its environmental robustness and low maintenance. We describe an insect muscle-powered autonomous microrobot (iPAM) and its acceleration with a neuroactive chemical, crustacean cardioactive peptide (CCAP). The iPAM, consisting of a DV tissue and a frame, was designed on the basis of a finite element method simulation and fabricated.

Room temperature operable autonomously moving bio-microrobot powered by insect dorsal vessel tissue.

Living muscle tissues and cells have been attracting attention as potential actuator candidates. In particular, insect dorsal vessel tissue (DVT) seems to be well suited for a bio-actuator since it is capable of contracting autonomously and the tissue itself and its cells are more environmentally robust under culturing conditions compared with mammalian tissues and cells. Here we demonstrate an autonomously moving polypod microrobot (PMR) powered by DVT excised from an inchworm.

Fabrication and evaluation of reconstructed cardiac tissue and its application to bio-actuated microdevices.

In this paper, we proposed to utilize a reconstructed cardiac tissue as microactuator with easy assembly. In a glucose solution, cardiomyocytes can contract autonomously using only chemical energy. However, a single cardiomyocyte is not enough to actuate a microrobot or a mechanical system.

Electrical stimulation of cultured lepidopteran dorsal vessel tissue: an experiment for development of bioactuators.

An insect dorsal vessel (DV) is well suited for a bioactuator since it is capable of contracting autonomously, and its tissue and cells are more environmentally robust under culturing conditions compared with mammalian tissue. In this study, electrical pulse stimulation was examined so as to regulate a bioactuator using the DV tissue. The DV tissue of a larva of Ctenoplusia agnate was assembled on a micropillar array, which was stimulated after culturing for about 3 wk.

Long-term and room temperature operable bioactuator powered by insect dorsal vessel tissue.

We present a bioactuator powered by insect dorsal vessel tissue which can work for a long time at room temperature without maintenance. Previously reported bioactuators which exploit contracting ability of mammalian heart muscle cell have required precise environmental control to keep the cell alive and contracting. To overcome this problem, we propose a bioactuator using dorsal vessel tissue.

Muscle-actuated power generator using cultured cardiomyocytes and PZT fiber.

A novel bio hybrid micro power generator using cardiomyocytes on a polymer wire is proposed. Cultured cardiomyocytes convert chemical energy into kinetic energy efficiently and beat themselves autonomously. PZT fiber was utilized for cell immobilized substrate and electro-mechanical coupling material.

Controllable bio-microactuator powered by muscle cells.

This paper reports a novel autonomous bio-microactuator powered by primary cultured cardiomyocytes and the control and evaluation of the contraction of skeletal muscle cell line C2C12 cells by means of electrical stimulation. To exploit contractions of cardiomyocytes, we fabricated a PDMS bulb-shaped dispenser and allowed cardiomyocytes to directly adhere to it. The displacement of the bulb-shaped dispenser by cardiomyocytes was larger than previously reported.

Culture of insect cells contracting spontaneously; research moving toward an environmentally robust hybrid robotic system.

Here we propose an environmentally robust hybrid (biotic-abiotic) robotic system that uses insect heart cells. Our group has already presented a hybrid actuator using rat heart muscle cells, but it is difficult to keep rat heart muscle cells contracting spontaneously without maintaining the culture conditions carefully. Insect cells, by contrast, are robust over a range of culture conditions (temperature, osmotic pressure and pH) compared to mammalian cells.

Development of an NMR interface microchip "MICCS" for direct detection of reaction products and intermediates of micro-syntheses using a "MICCS-NMR".

The development of an NMR interface microchip and its applications to the real-time monitoring of chemical reactions are described. The microchip device was named "MICCS" (MIcro Channeled Cell for Synthesis monitoring), and the method using it was named "MICCS-NMR". MICCS was inserted into a 5 mm Phi NMR sample tube.

Rapid bonding of Pyrex glass microchips.

A newly developed vacuum hot press system has been specially designed for the thermal bonding of glass substrates in the fabrication process of Pyrex glass microchemical chips. This system includes a vacuum chamber equipped with a high-pressure piston cylinder and carbon plate heaters. A temperature of up to 900 degrees C and a force of as much as 9800 N could be applied to the substrates in a vacuum atmosphere.