Functional evaluation of mineral trioxide aggregate cement with choline dihydrogen phosphate.

To improve the cytocompatibility of mineral trioxide aggregate (MTA) cement and its ability for reparative dentin formation, the effect of adding choline dihydrogen phosphate (CDHP), which is reported to be biocompatible, to MTA cement was investigated. The L929 cell proliferation showed that the addition of CDHP improved cell viability. The addition of CDHP shortened the setting time of MTA cement, with a significant decrease in consistency above 0.

Mechanical and Biocompatibility Properties of Calcium Phosphate Bioceramics Derived from Salmon Fish Bone Wastes.

Natural calcium phosphates derived from fish wastes are a promising material for biomedical application. However, their sintered ceramics are not fully characterized in terms of mechanical and biological properties. In this study, natural calcium phosphate was synthesized through a thermal calcination process from salmon fish bone wastes.

Preparation of chitosan-hydroxyapatite composite mono-fiber using coagulation method and their mechanical properties.

Autograft has been carried out for anterior cruciate ligament (ACL) reconstruction surgery. However, it has negative aspect because patients lose their healthy ligaments from other part. We focus on a chitosan-hydroxyapatite (HAp) composite fiber as a scaffold of ligament regeneration.

Alternating Current Electrophoretic Deposition for the Immobilization of Antimicrobial Agents on Titanium Implant Surfaces.

One prominent cause of implant failure is infection; therefore, research is focusing on developing surface coatings that render the surface resistant to colonization by micro-organisms. Permanently attached coatings of antimicrobial molecules are of particular interest because of the reduced cytoxicity and lower risk of developing resistance compared to controlled release coatings. In this study, we focus on the chemical grafting of bioactive molecules on titanium.

Photoluminescence and doping mechanism of theranostic Eu/Fe dual-doped hydroxyapatite nanoparticles.

Theranostic nanoparticles currently have been regarded as an emerging concept of 'personalized medicine' with diagnostic and therapeutic dual-functions. Eu doped hydroxyapatite (HAp) has been regarded as a promising fluorescent probe for imaging applications. Additionally, substitution of Ca with Fe in HAp crystal may endow the capability of producing heat upon exposure to a magnetic field.

Evaluation of calcium alginate gel as electrode material for alternating current iontophoresis of lidocaine using excised rat skin.

Iontophoresis (IOP) is a noninvasive method of delivering medication transcutaneously through the skin. The electrodes used in this method should tightly fit to rough and irregular surfaces and be biologically safe, easy to handle and prepare, and cost-effective. To satisfy these requirements, calcium alginate gel can be a candidate electrode for IOP.

In vitro evaluation of calcium alginate gels as matrix for iontophoresis electrodes.

Calcium alginate gel has some unique properties, such as the capability to keep the drugs, bioadhesiveness, safety, and low cost. The purpose of this study is to determine whether calcium alginate gel can be used as a matrix of electrodes for iontophoresis (IOP). We measured the concentration of lidocaine transported from calcium alginate gels with various concentrations of alginic acid using an in vitro experimental cell with square-wave alternating current (AC) application.

Synthesis and luminescence properties of Eu(III)-doped nanoporous silica spheres.

Europium (III) (Eu(3+))-doped nanoporous silica spheres were synthesized, and the states of Eu(3+) ions in the silica framework structure were investigated. The ordered nanopores were preserved with the doping at the Eu(3+) molar concentration to Si up to 10 mol%, and the O-Si-O and Si-OH groups in the structures were clearly rearranged with the doping, indicating the interaction of Eu(3+) with the O atoms. The significant morphological changes in the spheres were observed with the doping.

Immobilization of folic acid on Eu3+-doped nanoporous silica spheres.

Folic acid (FA) was immobilized on Eu(3+)-doped nanoporous silica spheres (Eu:NPSs) through mediation of the 3-aminopropyltriethoxysilane adlayer. The ordered nanopores of Eu:NPS were preserved by the immobilization. The FA-immobilized Eu:NPSs showed the characteristic photoluminescence peak due to interactions between the FA molecules and Eu(3+) ions, and highly dispersed stability in phosphate buffered saline.

Competitive adsorption of fibronectin and albumin on hydroxyapatite nanocrystals.

Competitive adsorption of two-component solutions containing fibronectin (Fn) and albumin (Ab) on hydroxyapatite (HAp) nanocrystals was analyzed using the quartz crystal microbalance with dissipation (QCM-D) technique. Adsorption of the one-component protein (Fn or Ab) and the two-component proteins adjusted to different molar ratios of Fn to Ab at a fixed Fn concentration was investigated. The frequency shift (Δ; Hz) and the dissipation energy shift (Δ) were measured with the QCM-D technique, and the viscoelastic changes of adlayers were evaluated by the saturated Δ/Δ value and the Voigt-based viscoelastic model.

Effect of interfacial proteins on osteoblast-like cell adhesion to hydroxyapatite nanocrystals.

A quartz crystal microbalance with dissipation (QCM-D) technique was employed to detecting the protein adsorption and subsequent osteoblast-like cell adhesion to hydroxyapatite (HAp) nanocrystals. The interfacial phenomena with the preadsorption of three proteins (albumin (BSA), fibronectin (Fn), and collagen (Col)), the subsequent adsorption of fetal bovine serum (FBS), and the adhesion of the cells were investigated. The QCM-D measured the frequency shift (Δf) and dissipation energy shift (ΔD), and the viscoelastic properties of the adlayers were evaluated using ΔD-Δf plot and Voigt-based viscoelastic model.

Detection of interfacial phenomena with osteoblast-like cell adhesion on hydroxyapatite and oxidized polystyrene by the quartz crystal microbalance with dissipation.

The adhesion process of osteoblast-like cells on hydroxyapatite (HAp) and oxidized polystyrene (PSox) was investigated using a quartz crystal microbalance with dissipation (QCM-D), confocal laser scanning microscope (CLSM), and atomic force microscope (AFM) techniques in order to clarify the interfacial phenomena between the surfaces and cells. The interfacial viscoelastic properties (shear viscosity (η(ad)), elastic shear modulus (μ(ad)), and tan δ) of the preadsorbed protein layer and the interface layer between the surfaces and cells were estimated using a Voigt-based viscoelastic model from the measured frequency (Δf) and dissipation shift (ΔD) curves. In the ΔD-Δf plots, the cell adhesion process on HAp was classified as (1) a mass increase only, (2) increases in both mass and ΔD, and (3) slight decreases in mass and ΔD.

A collagen sponge incorporating a hydroxyapatite/chondroitinsulfate composite as a scaffold for cartilage tissue engineering.

Because cartilage has limited potential for self-repair, tissue engineering is expected to replace the present therapies for damaged cartilage, such as total knee arthroplasty. However, scaffolds suitable for cartilage tissue engineering have not been established. We synthesized a novel porous scaffold, a collagen sponge incorporating a hydroxyapatite/chondroitinsulfate composite (pCol-HAp/ChS), containing materials which resemble extracellular matrices in bone and cartilage tissues.

Rapid magnetic catch-and-release purification by hydrophobic interactions.

A reversible, conventional, and rapid purification method of hydrophobically tagged products using hydrophobic magnetic nanoparticles was developed. The reversible purification system entails simply controlling the polarity of solvents. First, for the catching procedure, poor solvents were added into a well-dispersed system of magnetic nanoparticles and tagged products.

Fabrication of hydroxyapatite ultra-thin layer on gold surface and its application for quartz crystal microbalance technique.

We present a method for coating gold quartz crystal microbalance with dissipation (QCM-D) sensor with ultra-thin layer of hydroxyapatite nanocrystals evenly covering and tightly bound to the surface. The hydroxyapatite layer shows a plate-like morphology and less than 20 nm in thickness. The hydroxyapatite sensor operated in liquid with high stability and sensitivity.

Preparation of alginic acid layers on stainless-steel substrates for biomedical applications.

This study is concerned with the blood compatibility of alginic acid layers immobilized on gamma-aminopropyltriethoxysilane (gamma-APS)-grafted stainless-steel (SUS316L). The surfaces were characterized with contact angle measurement and X-ray photoelectron spectroscopy (XPS). The blood compatibility was evaluated in terms of platelet adhesion and blood clotting time.