Recently, the needs for testing and evaluation of implant materials and devices have increased, and have required a new organization capable for such testing and evaluation. This report introduces the activity and trend of the implant materials evaluation center established in JFE Techno-Research Corporation.

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pH-responsive PEGylated nanogels was evaluated the toxicity assay and the disposition. We evaluated 50% of inhibitory concentration (IC_<50>), 10% of hemolytic concentration (HC_<10>) and 50% of lethal dose (LD_<50>) of the pH-responsive PEGylated nanogels for cytotoxicity assay, hemolysis test and acute toxicity test in vivo, respectively. The pH-responsive PEGylated nanogel with the highest (5 mol%) cross-linking density showed significant high IC_<50> value (> 1000 μg/mL) as well as HC_<10> value( 700 μg/mL), and LD_<50> value (> 200 mg/kg), viz., the biocompatibility of the nanogel was significantly improved by increasing with the cross-linking density. From these results, the pH-responsive PEGylated nanogels with high cross-linking density thus described here would be a promising biocompatible carrier for DDS. When PEG density of the nanogels was increased by the Menschutkin reaction using PEG-benzyl bromide, the blood circulation increased significantly.

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Side-effects of anticancer drugs are the serious problem in cancer chemotherapy because anticancer drugs affect not only cancer cells but also normal cells. As the preferential ligand for targeting tumor cells, we focused on 5-aminolevulinic acid (5ALA), which is known as the heme precursor. In this study, the ligand potency of ALA was investigated by comparing the amount of cellular uptake of ALA into the normal cell and that into cancer cell. To evaluate the amount of cellular uptake, ALA was labeled with fluorescent compound. ALA was conjugated with 4-aminofluorescein in three steps. RGM cell which is a cell line derived from normal gastric mucosa of rat and RGK cell which is rat gastric carcinoma mucosal cells were seeded into 24 well plate at a density 1x1O^5 cells/well for 12h. The cells were exposed to each of labelled ALA (ALAFL) or 4-aminofluorescein (FL). The cellular uptakes of each compound were measured using flow cytometer, at 488 nm excitation and 510〜540 nm emission wavelength at time course. The ability to target cancer cell was also evaluated by the comparison between the amount of cellular uptake by RGK and that by RGM. It is clearly shown that the uptake of ALAFL by RGK was amazingly higher than by RGM. Actually, in contrast to FL which was taken up 2.5 times higher by RGK than by RGM, the amount of ALA-FL uptake by RGK was 14 times higher than that by RGM. On the basis of this experiment, it is confirmed that preferential ALA-FL uptake into carcinoma cell indeed took place. ALA-FL is thus, a promising compound, which improve preferential uptake of versatile compounds such as peptide, and drug vehicles to cancerous cells.

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Cells/tissue-processed products have a high potential in the treatment of various diseases where there is a previously unmet medical needs. The use of these products should be confined to medical treatments where a clinical advantage over other products/treatments is expected, because the potential risk of the transmission of infectious agents or of other unknown factors derived from them can not be completely ruled out. For this purpose, the guideline of human cells/tissue-processed products to ensure their basic quality and safety before the clinical trial was established in 2000. Recently, autologous cultured epidermis was approved in October, 2007 through the review processes within the Pharmaceutical Affairs Law of Japan. It is the first medical device of processed human cellular/tissue product in Japan. Furthermore, guidelines on ensuring quality and safety of products derived from processed autologous/allogeneic human cells/tissues were set in 2008. Pharmaceuticals and Medical Devices Agency (PMDA) that is a Japanese regulatory agency working together with Ministry of Health, Labour and Welfare of Japan, performs reviewing the applied cells/tissue-based products. Here the current trends on review of cells/tissue-processed products in Japan are demonstrated.

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Bone-cartilage bi-phase element was constructed of native chondrocyte of beagle and P-TCP scaffold block. Assembling such a regenerative element enables to form arbitral configuration which fits the shape of large defect on joints without sacrificing other part of the body. The bone-cartilage bi-phase element was grafted in a distal femur condyle of a beagle for 2 month. The extracted femur sample including the bi-phase element was scanned by a high-resolution, micro-focus X-ray tomography to investigate the fusion process in vivo. The 3D tomography measurement showed that the hosting cancellous bone intruded into the scaffold and a part of the scaffold was replaced with the cancellous bone. Mechanical properties of grafted element was evaluated by a push-out test, indicating that scaffold was firmly fused with the cancellous bone of the host. Also, a preliminary microarray gene expression analysis was conducted to investigate the effect of X-ray radiation on the regenerative devices.

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In this study, we aimed to construct the in vitro culture method with in vivo function for tissue engineering and biomedical application, and we confirmed effects of spheroid culture system and co-culture system. It is noted that spheroids significantly express a stable level of liver-specific functions (albumin secretion), compared to the usual cell monolayer. Co-cultivation of hepatocyte with endothelial cells was further essential to stabilize hepatocyte viability and liver-specific function. These results suggested that heterotypic cell-cell interaction within spheroid play important roles to maintain hepatocyte viability and liver-specific functions, which is more effective for BAEC than for HUVEC. This co-culture system is highly useful for tissue engineering and biomedical application.

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Hydrogenated amorphous carbon (a-C:H) films have many excellent properties such as good biocompatibility including cytocompatibility, chemical stability and high anti-corrosion. Therefore, there are many reports on application of a-C:H film as surface modification technique for biomaterials. The cytocompatibility plasma treatment of amorphous hydrogenated carbon (a-C:H) films has been studied. The combination of these properties makes many applications for wear-resistant surfaces, corrosion protection, and artificial internal organs in electronic devices. In addition, plasma treatment (O_2 and Ar gas) of a-C:H films are obviously improved surface condition and cell adhesion of samples is dramatically enhanced. An extracellular matrix and scaffold engineering from polymeric materials have been widely useful for tissue engineering. As a result, The surface constitutions were controlled by the deposition conditions of the plasma treatment of a-C:H films. The plasma treatment a-C:H film coating is expected as a surface modification technique for coating polymeric scaffold materials.

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Hydrogenated amorphous carbon (a-C:H) film coatings have been collected much attention for biomedical application. a-C:H film has excellent properties such as biocompatibility, anticorrosion and low friction. Recently, it is reported that biocompatibility of a-C:H film can be controlled by surface condition. On the other hand, surface modification with amino-silane coupling agent is useful for improvement of biocompatibility on biomaterials. In order to assess the availability of surface modification with amino-silane coupling agent, the cytocompatibility of the a-C:H film with and without surface modification was discussed. In this experiment, after the a-C:H film deposition, the a-C:H surface was modified by amino-silane coupling agent(APS). The cytocompatibility of a-C:H film with and without APS modification has been investigated under cell culture by in-vitro studies .As results, surface conditions of the a-C:H film with and without APS modification were dramatically improved. The cytocompatibility is obviously improved because the number of cells is increased on the surface with our proposal modification technique and APS treatment.

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We fabricated 3Dimensional cell structure utilizing PELID (Patterning with ELectrostatically-Injected Droplet) method. The PELID has two merits; those are higher resolution than commercial printer and ability to eject highly viscous liquid. These merits are preferable to print liquid with cells precisely and to eject liquid with scaffolds those are relatively high viscosity.

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This paper is concerned with a hopping robot with a leg driven by parallel mechanism and its stabilizing control method. The parallel mechanism enables the robot to swing and to extend the spring leg for posture stabilization and jumping. We have proposed a stabilize method of the hopping robot. The feedback law is derived using two linear systems approximated from the hopping robot. The effectiveness of the proposed feedback law is evaluated by simulations and experiments.

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This paper is concerned with a method of stabilizing the walking of a compass type biped robot. The mechanical energy after the toe landing is predicted, and a suitable hip joint angle for a desired energy is calculated by solving a certian polynomial equation. The hip actuator is controled by PID control so that the hip angle follows the suitable hip angle. We have shown by a simulation that the proposed method of control is effective for stable walking.

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Many of derailment accident occurred in the sharp curved track. Therefore, it is necessary to observe the vehicle derailment coefficient in sharp curved track in order to achieve safer railway transportation. In this study, a friction coefficient estimation method using applied force to the primary spring of railway bogie is numerically investigated.

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Vibration suppression control considering elastic part deformation is one of the indispensable issues in the precision engineering field and a high-density LSI circuit processing. This study aims at suppressing the induced vibration at rapid positioning operation. This control method consists of reduced order model identification and Predictive Repeated control using the anti-phase pitch driving based on an estimated behavior of the identified model. This method improves the positioning performance limit generated by conventional PI feedback control with existing actuator, which has low dynamic characteristics with time lag. This study is to bring model identification in the online process and inspected the necessity of the online model.

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Magnesium (Mg) alloys are lighter than steel. It is said that the attenuation performance of Magnesium alloys is also generally large compared with steel. The application of the Mg alloy to the chuck of the lathe is examined. In the paper, vibration characteristics are experimentally investigated for Mg chuck and steel chuck by impact test and driven lathe. As a result, damping ratio of the Mg alloy is larger than that of steel and vibration amplitude of Mg alloy is smaller than that of steel when lathe is driven.

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The purpose of study is to investigate vibration characteristics of the engine core. The complex eigenvalue analysis and the unbalanced vibration analysis by the transfer matrix method are applied to the engine core. From the result of the unbalanced vibration analysis, the amplitude of the impeller and the turbine are smallness in less than greatest permission operating speed. Therefore, the engine core can be operated in less than greatest permission operating speed.

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The purpose of the study is to investigate characteristics of rotor-blade coupled vibration for steam-turbines. The vibration of torsional mode is induced by torque fluctuations of turbine generator. The torsional mode tends to become near to double frequency of electricity system. In this paper, the vibration characteristics are obtained by the numerical simulation for the rotor-blade turbine model. The eigenvalue analysis and frequency response analysis were done by using FEM analysis software ANSYS.

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The technology that applied a high power ultrasonic vibration to various processing had old history, and partly had been put to practical use. The purpose of this study is to clarify the technique of the device design and manufacturing methods with a lot of know-how when making ultrasonic vibration machining device for trial purposes. In this report, we derive the conditions of shape and the size of the horn with better mechanical performance. The performance is evaluated by measuring the frequency and the amplitude of the ultrasonic vibration, and the power. As a results, the horn with roundness at connection between thin and flange has the effective performance.

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The fluid force of labyrinth seals may cause unstable rotor vibrations in turbo-machineries. In this research, dynamic characteristics of face type labyrinth seals were measured by using a test rig. The rotor-bearing system was supported by soft cage springs, and it was excited using a magnetic bearing. Cross-coupled stiffness, direct damping and effective damping coefficient were calculated and evaluated as dynamic characteristics of the seals. As a result, cross-coupled stiffness increased, and direct damping decreased, when the rotating speed increased. Effective damping coefficient showed that the fluid force of the labyrinth seal stabilizes rotor vibration at bwer rotating speed, and it destabilizes rotor vibration at higher rotating speed.

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