Paclitaxel/hydroxyapatite composite coatings on titanium alloy for biomedical applications

Mg alloys are promising biomedical metal due to their natural degradability, good processability, and favorable mechanical properties. However, the poor corrosion resistance limits their further clinical applications. In this study, the combined strategies of surface chemical treatment and layer-by-layer self-assembly were used to prepare composite coatings on Mg alloys to improve the biocorrosion resistance. Specially, alkalized AZ91 Mg alloy generated chemical linkage with silane via Si–O–Mg covalent bond at the interface. Subsequently, Si–OH group from silane formed a crosslinked silane layer by Si–O–Si network. Further chemical assembly with graphene oxide (GO), lengthened the diffusion pathway of corrosive medium. The chemically assembled composite coatings could firmly bond to Mg alloy substrate, which persistently and effectively acted as compact barriers against corrosion propagation. Improved biocorrosion resistance of AZ91 Mg alloy with self-assembly composite coatings of silane/GO was subsequently confirmed by immersion tests. Besides, the Mg alloy exhibited good wear resistance due to outside layer of GO with a lubricant effect. Cell viability of higher than 75% had also been found for the alloy with self-assembly composite coatings, which showed good cytocompatibility.

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Biocompatible Ceramic-Biopolymer Coatings Obtained by Electrophoretic Deposition on Electron Beam Structured Titanium Alloy Surfaces

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.1552 ◽

2016 ◽

Vol 879 ◽

pp. 1552-1557

Author(s):

C. Ramskogler ◽

L. Cordero ◽

Fernando Warchomicka ◽

A.R. Boccaccini ◽

Christof Sommitsch

Keyword(s):

Titanium Alloy ◽

Surface Modification ◽

Electron Beam ◽

Electrophoretic Deposition ◽

Composite Coatings ◽

Substrate Surface ◽

3D Structure ◽

Titania Nanoparticles ◽

Structured Surfaces ◽

Major Interest

An area of major interest in biomedical engineering is currently the development of improved materials for medical implants. Research efforts are being focused on the investigation of surface modification methods for metallic prostheses due to the fundamental bioinert character of these materials and the possible ion release from their surfaces, which could potentially induce the interfacial loosening of devices after implantation. Electron beam (EB) structuring is a novel technique to control the surface topography in metals. Electrophoretic deposition (EPD) offers the feasibility to deposit at room temperature a variety of materials on conductive substrates from colloidal suspensions under electric fields. In this work single layers of chitosan composite coatings containing titania nanoparticles (n-TiO2) were deposit by EPD on electron beam (EB) structured Ti6Al4V titanium alloy. Surface structures were designed following different criteria in order to develop specific topography on the Ti6Al4V substrate. n-TiO2 particles were used as a model particle in order to demonstrate the versatility of the proposed technique for achieving homogenous chitosan based coatings on structured surfaces. A linear relation between EPD time and deposition yield on different patterned Ti6Al4V surfaces was determined under constant voltage conditions, obtaining homogeneous EPD coatings which replicate the 3D structure (pattern) of the substrate surface. The present results show that a combination of both techniques can be considered a promising surface modification approach for metallic implants, which should lead to improved interaction between the implant surface and the biological environment for orthopaedic applications.

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Bioactive Surface Modification of Newly Developed β-Type Titanium Alloy for Biomedical Applications by Electrochemical Treatment

Journal of the Japan Institute of Metals and Materials ◽

10.2320/jinstmet.70.304 ◽

2006 ◽

Vol 70 (4) ◽

pp. 304-313

Author(s):

Mitsuo Niinomi ◽

Toshikazu Akahori ◽

Hiroyuki Toda ◽

Daisuke Iizuka ◽

Hisao Fukui ◽

...

Keyword(s):

Titanium Alloy ◽

Surface Modification ◽

Biomedical Applications ◽

Electrochemical Treatment ◽

Bioactive Surface Modification

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Electrodeposition of MgO/Calcium Phosphate Composite Coatings on Titanium for Biomedical Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.785-786.872 ◽

2013 ◽

Vol 785-786 ◽

pp. 872-876

Author(s):

Yong Huang ◽

Shu Guang Han ◽

Ya Jing Yan ◽

Xiao Feng Pang

Keyword(s):

Corrosion Resistance ◽

Phase Composition ◽

Calcium Phosphate ◽

Biomedical Applications ◽

Lower Layer ◽

Composite Coatings ◽

Polarization Test ◽

Coated Surface ◽

Bare Titanium ◽

Superior Corrosion Resistance

This work elucidated corrosion resistance of the electrodeposited MgO/calcium phosphate (Ca-P/MgO) films on titanium (Ti). The microstructure, phase composition, and corrosion resistance of the films were studied. Results revealed that The Ca-P/MgO composite coatings were rough and inhomogeneous, the upper layer was floral-like crystals or flakes agglomerates morphology, and the lower layer was needle-like crystals which were mutually cross linked. The coating was very dense, and the content of Mg was about 0.3 wt%. Potentiodynamic polarization test manifested that the Ca-P/MgO-coated surface exhibited superior corrosion resistance than the bare titanium.

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