Ndドープハイドロキシアパタイト薄膜を用いた湿度センサの特性

A Na-doped hydroxyapatite (Na-HAp) thin film was prepared on a porous Al_2O_3 substrate using a pulsed laser deposition (PLD) technique. Crystallinity and composition were evaluated by X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. A humidity sensor was formed by establishing an inter-digital type Au electrode on the Na-HAp film. The humidity-impedance and humidity response of impedance characteristics were measured by an LCR meter. The results indicated that the Na-HAp thin film sensor showed excellent sensitivity and responsiveness to humidity conditions. 　（和文）　パルスレーザーデポジション(PLD)法により、Ndドープハイドロキシアパタイト(Na-HAp)薄膜を多孔質Al_2O_3基板上に成膜した。薄膜の結晶性や組成はX線回折(XRD)およびエネルギー分散型蛍光X線分析(EDX)によって評価した。Na-HAp薄膜上にインターデジタル型の金電極を設けて、湿度センサとした。インピーダンスの湿度による変化と、湿度応答性をLCRメータにより測定した。その結果、薄膜センサは湿度に対して優れた感度と応答性を示した。This study was partially supported by the Project Research of the Faculty of Biology Oriented Science and Technology No.09-IV, 200

Structural Characterization and Osseointegrative Properties of Pulsed Laser-Deposited Fluorinated Hydroxyapatite Films on Nano-Zirconia for Implant Applications

Standard zirconia implants used in restoration still present problems related to inertness and long-term stability. Various physicochemical approaches have been used to modify the implant surfaces to improve early and late bone-to-implant integration; however, no ideal surface modification has been reported. This study used pulsed laser deposition to deposit a fluorinated hydroxyapatite (FHA) film on a zirconia implant to create a biologically active surface. The film prepared was uniform, dense, and crack-free, and exhibited granular surface droplets; it also presented excellent mechanical strength and favorable biological behavior. The FHA-coated implant was implanted on the femur of Sprague–Dawley rats, and various tests and analyses were performed. Results show that the in vitro initial cell activity on the FHA-coated samples was enhanced. In addition, higher alkaline phosphatase activity and cell mineralization were detected in cells cultured on the FHA-coated groups. Further, the newly formed bone volume of the FHA-coated group was higher than that of the bare micro-adjusted composite nano-zirconia (NANOZR) group. Therefore, the FHA film facilitated osseointegration and may improve the long-term survival rates of dental implants, and could become part of a new treatment technology for implant surfaces, promoting further optimization of NANOZR implant materials

In Vitro and In Vivo Osteogenic Activity of Titanium Implants Coated by Pulsed Laser Deposition with a Thin Film of Fluoridated Hydroxyapatite

To enhance biocompatibility, osteogenesis, and osseointegration, we coated titanium implants, by krypton fluoride (KrF) pulsed laser deposition, with a thin film of fluoridated hydroxyapatite (FHA). Coating was confirmed by scanning electron microscopy (SEM) and scanning probe microscopy (SPM), while physicochemical properties were evaluated by attenuated reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Calcium deposition, osteocalcin production, and expression of osteoblast genes were significantly higher in rat bone marrow mesenchymal stem cells seeded on FHA-coated titanium than in cells seeded on uncoated titanium. Implantation into rat femurs also showed that the FHA-coated material had superior osteoinductive and osseointegration activity in comparison with that of traditional implants, as assessed by microcomputed tomography and histology. Thus, titanium coated with FHA holds promise as a dental implant material