http://sistemas.eel.usp.br/docentes/arquivos/2166002/1234Nb/Geetha-review2009.pdf

Ti based biomaterials, the ultimate choice for orthopaedic implants – A review

Electrophoretic deposition (EPD) is attracting increasing attention as an effective technique for the processing of biomaterials, specifically bioactive coatings and biomedical nanostructures. The well-known advantages of EPD for the production of a wide range of microstructures and nanostructures as well as unique and complex material combinations are being exploited, starting from well-dispersed suspensions of biomaterials in particulate form (microsized and nanoscale particles, nanotubes, nanoplatelets). EPD of biological entities such as enzymes, bacteria and cells is also being investigated. The review presents a comprehensive summary and discussion of relevant recent work on EPD describing the specific application of the technique in the processing of several biomaterials, focusing on (i) conventional bioactive (inorganic) coatings, e.g. hydroxyapatite or bioactive glass coatings on orthopaedic implants, and (ii) biomedical nanostructures, including biopolymer–ceramic nanocomposites, carbon nanotube coatings, tissue engineering scaffolds, deposition of proteins and other biological entities for sensors and advanced functional coatings. It is the intention to inform the reader on how EPD has become an important tool in advanced biomaterials processing, as a convenient alternative to conventional methods, and to present the potential of the technique to manipulate and control the deposition of a range of nanomaterials of interest in the biomedical and biotechnology fields.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsif.2010.0156.focus

Electrophoretic deposition of biomaterials

With an ageing population, war, and sports related injuries there is an ever-expanding requirement for hard tissue replacement such as bone. Engineered artificial scaffold biomaterials with appropriate mechanical properties, surface chemistry and surface topography are in a great demand for enhancing cell attachment, cell growth and tissue formation at such defect sites. Most of these engineering techniques are aimed at mimicking the natural organization of the bone tissues and thereby create a conducive environment for bone regeneration. As the interaction between the cells and tissues with biomaterials at the tissue–implant interface is a surface phenomenon, surface properties play a major role in determining both the biological response to implants and the material response to the physiological condition. Hence surface engineering of biomaterials is aimed at modifying the material and biological responses through changes in surface properties while still maintaining the bulk mechanical properties of the implant. Therefore, there has been a great thrust towards development of Ca–P-based surface coatings on various metallic and nonmetallic substrates for load bearing implant applications such as hip joint prosthesis, knee joint prosthesis and dental implants. Typical coating methodologies like ion beam assisted deposition, plasma spray deposition, pulsed laser physical vapor deposition, magnetron sputtering, sol–gel derived coatings, electrodeposition, micro-arc oxidation and laser deposition are extensively studied at laboratory scale. In the present article, attempts are made to give an overview of the basic principles behind the coating techniques as well as advantageous features such as bioactivity and biocompatibility associated with these coatings. A strong emphasis will be given on laser-induced textured and bioactive coatings obtained by the author's research group [A. Kurella, N.B. Dahotre, Journal of Biomedical Applications 20 (2005) 5–50; A. Kurella, N.B. Dahotre, Acta Biomaterialia 2 (2006) 677–688; A. Kurella, N.B. Dahotre, Journal of Minerals, Metals and Materials Society (JOM) 58 (2006) 64–66; A. Kurella, N.B. Dahotre, Journal of Materials Science: Materials in Medicine 17 (2006) 565–572; P.G. Engleman, A. Kurella, A. Samant, C.A. Blue, N.B. Dahotre, Journal of Minerals, Metals and Materials Society (JOM) 57 (2005) 46–50; R. Singh, A. Kurella, N.B. Dahotre, Journal of Biomaterials Applications 21 (2006) 46–72; S.R. Paital, N.B. Dahotre, Biomedical Materials 2 (2007) 274–281; S.R. Paital, N.B. Dahotre, 2009, Acta Biomaterialia, doi:10.1016/j.actbio.2009.03.004 ; R. Singh, N.B. Dahotre, Journal of Materials Science: Materials in Medicine 18 (2007) 725–751.]. Since cells are sensitive to topographical features ranging from mesoscale to nanoscale, formation of these features by both pulsed and continuous wave Nd:YAG laser system will be highlighted. This can also be regarded as advancement towards third generation biomaterials which are bioinert, bioactive and which once implanted will stimulate cell adhesion, proliferation and growth at the interface. Further, an overview of various bio-implants and bio-devices and materials used for these kinds of devices, performance factors such as mechanical and corrosion behavior and surface science associated with these materials are also explained. As the present article is aimed at describing the multidisciplinary nature of this exciting field it also provides a common platform to understand this subject in a simple way for students, researchers, teachers and engineers in the fields ranging from medicine, dentistry, biology, materials science, biomedicine, biomechanics to physics.

Calcium phosphate coatings for bio-implant applications: Materials, performance factors, and methodologies

Corrosion and surface modification on biocompatible metals: A review.

Passive film on orthopaedic TiAlV alloy formed in physiological solution investigated by X-ray photoelectron spectroscopy

Preparation and characterisation of electrophoretically deposited hydroxyapatite coatings on type 316L stainless steel

Sintering atmosphere and temperature effects on hydroxyapatite coated type 316L stainless steel

Electrochemical behaviour of hydroxyapatite-coated stainless steel implants

Nitrogen ion implantation was carried out to modify the surface of a Ti6A14 alloy for improving its corrosion resistance in a simulated body fluid environment. Ion implantation was carried out at 70 keV energy at the dose of 7 x 10 20 ions/m 2 . The implanted surface was electrochemically passivated at 1.0 V for I h. X-ray photoelectron spectroscopy (XPS) was used to identify the concentration and chemical state of the elements present in the passivated film. The change in the nature and composition of the passive film of the implanted-passivated specimen was compared with the unimplanted-passivated and as-implanted specimens. Open Circuit Potential (OCP)-time measurement and cyclic polarization studies were additionally carried out to understand the nature of the passive film. The results showed that the implanted specimen exhibited enhanced corrosion resistance than the unimplanted specimen (one order of magnitude) due to the presence of oxynitride along with oxide in the passive film.

Surface Characterization of Electrochemically Formed Passive Film on Nitrogen Ion Implanted Ti6Al4V Alloy

Nitrogen ion implanted type 316L stainless steel orthopaedic implant devices showed three fold improvement in the localized corrosion (pitting, crevice) resistance in a simulated human body environment compared to unimplantated condition. Also, the nitrogen ion implanted 316L SS specimens indicated that the release of iron, chromium, and nickel ions were considerably reduced compared to unimplanted specimen. XPS studies of the nitrogen ion implanted specimen showed the presence of nitrogen in solid solution, and nitrides along with oxides which are attributed to the enhanced corrosion resistance. SIMS depth profiling results indicated that implanted nitrogen is present in the surface along with the oxide layers. Residual stress measurement results showed an increase in the compressive residual stresses in the nitrogen implanted layer which was due to the implantation process. The formation of high density nitrides may attributed to the improvement in localized corrosion resistance of nitrogen implanted specimens.

M. Subbaiyan

Papers

Preparation and characterisation of electrophoretically deposited hydroxyapatite coatings on type 316L stainless steel

Sintering atmosphere and temperature effects on hydroxyapatite coated type 316L stainless steel

Electrochemical behaviour of hydroxyapatite-coated stainless steel implants

Surface Characterization of Electrochemically Formed Passive Film on Nitrogen Ion Implanted Ti6Al4V Alloy

Improvements in Localized Corrosion Resistance of Nitrogen Ion Implanted Type 316L Stainless Steel Orthopaedic Implant Devices