Papers by Keyword: Hydroxyapatite Coating

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Authors: K. Hariharan, G. Arumaikkannu
Abstract: Additive Manufacturing (AM) - is a technology that fabricates the parts directly from 3D CAD model without the need of any process planning. The convergence of AM and life science has evolved into a new paradigm called Bio-Additive Manufacturing (BAM). In this paper, Hydroxyapatite (HA) powder was coated over the customized implant, which will serve as a good candidate for bone substitutes due to its chemical and structural similarity to bone. Computer Tomography (CT) scan data of human tibia bone was collected and stacked in MIMICS image processing software, which converts it into 3D data, then implant was fabricated using Selective Laser Sintering (SLS), an AM technique with polyamide powder. Hydroxyapatite powder was synthesized by wet chemical process and coated over implant using plasma spray coating machine. This coating will produce an intermediate region between the bone and the implant, which will stimulate the tissue growth and bone contact. Micrograph of coated and uncoated implant was analyzed using SEM and EDX. For In-Vitro study human mesenchymal cell was cultured over the coated implant. The viability and proliferation of the cells was studied by examining the morphology of the cell. Thus the implant was fabricated using SLS technique and coated with hydroxyapatite powder which exhibits a favorable and good response to enhance tissue growth.
Authors: Yi Kai Chen, Xue Bin Zheng, Baoe Li, You Tao Xie, Chuan Xian Ding, Soo Wohn Lee
Abstract: In this paper, antibacterial silver-containing hydroxyapatite coating was prepared by vacuum plasma spraying method and osteoblasts were seeded onto the surface of the coating to evaluate its cytocompatibility. The results indicated that the cells proliferated well on the samples, and the proliferation rate on the silver-containing hydroxyapatite coating was a little bit higher than that on the silver-free hydroxyapatite coating. The contact angle of water drop on the coating was measured, and it was found that the contact angles of the silver-containing hydroxyapatite coatings were smaller than the hydroxyapatite coating. The improvement of hydrophilicity for the silver-containing hydroxyapatite coating could be beneficial to the cells proliferation on its surface. It can be concluded that the addition of silver in the hydroxyapatite coating endowed the coating with antibacterial property while maintaining its excellent cytocompatibility.
Authors: Rubens Lincoln Santana Blazutti Marçal, Jose Ricardo Muniz Ferreira, Luis Henrique Leme Louro, Andrea Machado Costa, Daniel Navarro da Rocha, José Brant de Campos, Marcelo Henrique Prado da Silva
Abstract: In this work a two-step thermochemical deposition of calcium phosphate from ostrich eggshell on titanium surface was performed. After the deposition, the coatings were immersed into 0,1M KOH solution in order to favoring HA precipitation. The coatings were characterized by scanning electron microscope with field emission gun (FEG-SEM), and X-ray diffraction (XRD) analysis. Bioactivity assessment was performed in cell culture media, McCoy 5A medium, for 14 days. XRD patterns showed brushite/monetite as the phases present at first deposition step; in the second deposition step XRD patterns indicated HA phase peaks on titanium surface. After 14 days on McCoy 5A medium, brushite/monetite coatings revealed bone-like apatite precipitation, showing bioactivity; hydroxyapatite coatings showed a surface modification but no significant bone-like apatite precipitation, thus lower bioactivity. The use of ostrich eggshells as an alternative source to obtain bioactive calcium phosphate coatings showed to be effective.
Authors: Yun Cang Li, Jian Yu Xiong, C.S. Wong, Peter D. Hodgson, Cui E Wen
Abstract: In the present study, titanium (Ti) samples were surface-modified by titania (TiO2), silica (SiO2) and hydroxyapatite (HA) coatings using a sol-gel process. The bioactivity of the film-coated Ti samples was investigated by cell attachment and morphology study using human osteoblast-like SaOS-2 cells. Results of the cell attachment indicated that the densities of cell attachment on the surfaces of Ti samples were significantly increased by film coatings; the density of cell attachment on HA film-coated surface was higher than those on TiO2 and SiO2 film-coated surfaces. Cell morphology study showed that the cells attached, spread and grew well on the three kinds of film-coated surfaces. It can be concluded that the three kinds of film coatings can bioactivate the surfaces of Ti samples effectively. Overall, Ti sample with HA film-coated surface exhibited the best bioactivity.
Authors: Ying Chun Wang, Yu Yong Yang, Mei Chun Wang
Abstract: Laser cladding technology was adopted to fabricate hydroxyapatite(HAP) and calcium phosphate compound coating according to the feature that a metallurgical bonding can be formed by laser cladding process. Compared with CO2 laser, Nd-YAG laser has different wavelength(the former is 1.06μm and the latter is 10.06μm). Metal and ceramic material has quite different absorbance ability towards them and thus they can generate different laser cladding products by these two laser surface processings with different wavelength. This paper presents a new process and mechanism analysis to obtain bioceramic composite coating on Ti6Al4V substrate by Nd-YAG laser cladding. A bioceramic composite coating including HAP,Ca2P2O7,Ca3(PO4)2 and calcium titanates and was successfully obtained by Nd-YAG laser cladding with pre-depositing mixed powders of CaHPO4•2H2O and CaCO3 directly on Ti6Al4V substrate. Nd-YAG laser transmits mixed powders of CaHPO4•2H2O and CaCO3 and the laser power is absorbed by Ti6Al4V substrate to produce a thin layer of molten region. There are mainly two kinds of chemical reaction systems in the coating during laser cladding processing. When CaHPO4•2H2O and CaCO3 react together, they make calcium phosphate bioceramic products; The microstructure of the bioceramic composite coating is even and minute because of the rapid solidification in laser processing. A chemical metallergical bonding is formed between the boceramic composite coating and Ti6Al4V substrate. It can also be expected that Nd-YAG laser cladding technology can be used as a further modification procedure to enhance HAp/metal interface property.
Authors: Mamoru Omori, A. Okubo, M. Otsubo, Toshiyuki Hashida, K. Tohji
Authors: Lei Zhang, Wen Tao Zhang, Hu Qiang Li, Wei Qiang Geng, Yong Ji Bao
Abstract: A novel cold spraying system for fabricating hydroxyapatite coatings on titanium and titanium alloy substrates is introduced in this paper. A description of the system components is presented. It is expected that the system could provide an effective method to improve deposition efficiency and compactness of hydroxyapatite coating. The addition of substrate heater helps to create dense and adherent coatings. It is found that the system could make feedstock hydroxyapatite particles be accelerated to high impact velocity. Hydroxyapatite coatings that preserve the chemical composition and microstructure of feedstock hydroxyapatite powders are obtained.
Authors: Mohd Amin Farhan Zaludin, Zul Azhar Zahid Jamal, Mochd Nazree B. Derman, Mohd Zaheruddin Kasmuin
Abstract: Magnesium corrosion has been identified as the main challenge that limits the implementation of this material into various applications, including biomaterials. Simple chemical conversion coatings have been employed in order to minimize the corrosion problems. In this paper, hydroxyapatite-coated magnesium were fabricated by using chemical conversion coatings and the corrosion behaviour of the coated samples were evaluated inside different corrosion media (Ringers, SBF, and PBS) by using electrochemical impedance spectroscopy (EIS). EIS reveals the electrical properties of the coatings towards corrosion attack by the corrosion media. The corrosiveness of the tested solutions was given by (from least to the most aggressive): PBS ˂ SBF ˂ Ringers.
Authors: M. Demircioğlu, A. Pasinli, N. Arda, İ. Özdemir, Seda Aksoy, H. Yıldız
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