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Chien C.-S.,Chimei Foundation Hospital | Ko Y.-S.,Southern Taiwan University of Science and Technology | Kuo T.-Y.,Southern Taiwan University of Science and Technology | Liao T.-Y.,Southern Taiwan University of Science and Technology | And 2 more authors.
Advanced Materials Research | Year: 2011

Hydroxyapatite (HA) is a frequently used bioactive coating material. However, when HA coating is soaked in the simulated body fluid (SBF), it is usually detached from substrate material due to its high dissolution rate in the solution. Recently, it is found that Fluorapatite (FA) has a better anti-dissolution ability than HA. In this study, Fluorapatite was mixed with TiO2 powder (either Anatase phase (A) or Rutile phase (R)) as a coating material precursor, and then be deposited on Ti-6Al-4V substrate to form the coating layer by using Nd-YAG laser cladding process. After soaking in SBF for various days, it is observed that dense ball-like apatite grew faster on the surface of the FA+R coating layer than that on the surface of the FA+A specimens. The corresponding Ca/P ratios of FA+R specimens also dropped faster than FA+A ones. © (2011) Trans Tech Publications. Source


Chien C.S.,Chimei Foundation Hospital | Liao T.Y.,Southern Taiwan University of Science and Technology | Hong T.F.,National Pingtung University of Science and Technology | Kuo T.Y.,Southern Taiwan University of Science and Technology | And 2 more authors.
Surface and Coatings Technology | Year: 2011

Biomedical implants are generally coated with a thin layer of hydroxyapatite (HA) using a plasma spraying or pulsed laser deposition method. However, the bonding strength between the coating layer and the substrate is relatively low. Moreover, the high temperature of the deposition process causes a structural instability of the HA, and therefore degrades its bioactivity and reduces the service life of the coating layer following implantation. Accordingly, the present study replaces HA with fluorapatite (FA) as the coating material, and examines the effects of two different binders, namely polyvinyl alcohol (PVA) and water glass (WG), on the properties of FA coatings deposited on Ti-6Al-4V substrates using an Nd-YAG laser cladding process. Scanning electron microscopy (SEM) observations reveal that the FA coating has a coral- and dendrite-like structure when mixed with the PVA binder, but a pure dendrite-like structure when mixed with the WG binder. In addition, the Ca/P value of the WG-based FA coating is significantly higher than that of the PVA-based coating. Fluorapatite, Al2O3, CaTiO3 and Ca3(PO4)2 phases are observed in both coating layers. However, the XRD analysis results indicate that the microstructure of the WG sample is dominated by Ca3(PO4)2 phase while that of the PVA sample is dominated by FA. After soaking in SBF, it was observed that the specimen produced with PVA binder or less laser output power possessed a better apatite induction ability. © 2010 Elsevier B.V. Source


Chien C.S.,Chimei Foundation Hospital | Chien C.S.,Southern Taiwan University of Science and Technology | Kuo T.Y.,Southern Taiwan University of Science and Technology | Liu C.W.,Southern Taiwan University of Science and Technology | And 4 more authors.
Materials Research Innovations | Year: 2015

In this paper, hydroxyapatite or fluorapatite, was clad on the Ti-6Al-4V substrate by Nd-YAG laser technology, respectively. Scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction were utilised to compare the differences of microstructures, chemical compositions and the compounds in the coating layer and transition layer of samples. The results show that CaTiO3, TiO2, Al2O3 and Ca2P2O7 are compounds in the coating layer of hydroxyapatite cladding sample, and CaTiO3 is the main phase which appears a dendrite-like structure feature. Besides, the dendrite-like CaTiO3 phase, few compounds of TiO2, Al2O3 and the granular residual FA were found that dispersed between interdendritic areas in the coating layer of fluorapatite cladding sample. Compared with these hydroxyapatite and fluorapatite cladding samples, the distribution feature of elements Ca, P, Ti in the coating layer and transition layer is similar, but relatively higher amount of Ca, P and lower Ca/P ratio were found in the coating layer of fluorapatite cladding sample. © W. S. Maney & Son Ltd 2015. Source


Chien C.S.,Chimei Foundation Hospital | Hong T.F.,National Pingtung University of Science and Technology | Han T.J.,Southern Taiwan University of Science and Technology | Kuo T.Y.,Southern Taiwan University of Science and Technology | Liao T.Y.,Southern Taiwan University of Science and Technology
Applied Surface Science | Year: 2011

The laser clad coating technique can help to produce metallurgical bonding with high bonding strength between the coating layer and the substrate, which has been gradually applied for hydroxyapatite (HA) coating on metallic substrates. In this study, HA powder is mixed with two different binders, namely water glass (WG) and polyvinyl alcohol (PVA), respectively, and is then clad on Ti-6Al-4V substrates using an Nd:YAG laser system under various processing conditions. The microstructure, chemical composition and hardness of the coating layer and transition layer of the various samples are then systematically explored. The experimental results show that the coating layers of the various samples all contain both cellular dendrites and rod-like piled structures, while the transition layers contain only cellular dendrites. For all samples, the coating layer consists mostly of CaTiO3, Ca2P 2O7, CaO and HA phases, whereas the transition layer contains primarily CaTiO3, Ca2P2O7, Ti3P, Ti and HA phases. In addition, the transition layer of the WG samples also contains SiO2 and Si2Ti phases. In all of the specimens, the transition layer has a higher average hardness than the substrate or coating layer. Moreover, the transition layer in the WG sample is harder than that in the PVA sample. © 2010 Elsevier B.V. All rights reserved. Source


Chien C.-S.,Chimei Foundation Hospital | Ho H.-O.,Taipei Medical University | Liang Y.-C.,Taipei Medical University | Ko P.-H.,Taipei Medical University | And 2 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2012

The goal of this study was to assess the incorporation of exudates of human platelet-rich fibrin (hPRF) that is abundant in platelet cytokines and growth factors into biodegradable fibrin (FB) scaffolds as a regeneration matrix for promoting chondrocyte proliferation and re-differentiation. hPRF was obtained from human blood by centrifugation without an anticoagulant, and the exudate of hPRF was collected and mixed with bovine fibrinogen, and then thrombin was added to form the FB scaffold. Proliferation and differentiation of human primary chondrocytes and a human chondrosarcoma cell line, the SW-1353, embedded in the three-dimensional (3D) scaffolds and on the two-dimensional (2D) surface of the FB scaffolds so produced were evaluated in comparison with an agarose (AG) scaffold serving as the control. Results demonstrated that the amounts of these cytokines and growth factors in hPRF exudates were higher than those in the blood-derived products except for TGF-β1. Chondrocytes and SW1353 cells on the 2D and 3D FB scaffolds with the addition of the exudates of PRF exhibited more-available proliferation and differentiation than cells on 2D and 3D FB and AG scaffolds. It was concluded that FB scaffolds can provide an appropriate environment for chondrocyte proliferation and re-differentiation, and it could be improved by adding exudates of hPRF. These 3D scaffolds have great promise for cartilage tissue engineering. © 2012 WILEY PERIODICALS, INC. Source

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