Dissertations / Theses on the topic 'Titanium biomedical implants'

Magnesium has been identified as a promising biodegradable implant material because it does not cause systemic toxicity and can reduce stress shielding. However, it corrodes too quickly in the body. Titanium, which is already used ubiquitously for implants, was chosen as the alloying element because of its proven biocompatibility and corrosion resistance in physiological environments. Thus, alloying magnesium with titanium is expected to improve the corrosion resistance of magnesium. Mg-Ti alloys with a titanium content ranging from 5 to 35 at.-% were successfully synthesized by mechanical alloying. Spark plasma sintering was identified as a processing route to consolidate the alloy powders made by ball-milling into bulk material without destroying the alloy structure. This is an important finding as this metastable Mg-Ti alloy can only be heated up to max. 200C° for a limited time without reaching the stable state of separated magnesium and titanium. The superior corrosion behavior of Mg80-Ti20 alloy in a simulated physiological environment was shown through hydrogen evolution tests, where the corrosion rate was drastically reduced compared to pure magnesium and electrochemical measurements revealed an increased potential and resistance compared to pure magnesium. Cytotoxicity tests on murine pre-osteoblastic cells in vitro confirmed that supernatants made from Mg-Ti alloy were no more cytotoxic than supernatants prepared with pure magnesium. Mg and Mg-Ti alloys can also be used to make novel polymer-metal composites, e.g., with poly(lactic-co-glycolic acid) (PLGA) to avoid the polymer’s detrimental pH drop during degradation and alter its degradation pattern. Thus, Mg-Ti alloys can be fabricated and consolidated while achieving improved corrosion resistance and maintaining cytocompatibility. This work opens up the possibility of using Mg-Ti alloys for fracture fixation implants and other biomedical applications.

The purpose of this study was to determine the effects of local delivery ofthe bisphosphonate alendronic acid (AA) on bone formation around, withinand on porous titanium implants. Cylindrical rods 9mm in diameter and90mm in length were coated with either 0.2mg or 1.0mg of AA prior tobilateral surgical implantation into the femoral intramedullary canals of 10experimental canines. Twelve weeks after surgery the femora wereharvested and scanned with micro computed tomography (microCT) prior toprocessing for undecalcified thin section histology and analysis withbackscattered scanning electron microscopy (BSEM). MicroCT analysisshowed that both levels of AA significantly enhanced peri-implant boneformation around the coated implants compared with controls, with the 1.0mg AA dose resulting in a 3.5-fold greater increase than 0.2mg AA. BSEManalysis of peri-implant bone formation correlated very well the microCTanalysis in a direct comparison of matched microCT and histologic sections.BSEM analysis showed no significant effect of either 0.2mg AA or 1.0mg AAon bone-implant apposition or the extent of bone growth into the implantporous coating. This thesis provided valuable guidance on the doseresponse to locally delivered AA and its potential for enhancing the fixationof orthopaedic implants by increasing the amount of bone that forms withinthe immediate peri-implant space.
L'objectif de cette étude était de déterminer les effets d'une administration localedu biphosphonate acide alendronique (AA) sur la formation osseuse sur, autour età l'intérieur d'implants poreux en titanium. Des tiges cyclindriques de 9mm dediamètre et de 90mm de longueur ont été enduites avec 0.2mg ou 1.0mg de AApréalablement à leur implantation chirurgicale bilatérale dans les canaux fémorauxintramédullaires sur 10 canins expérimentaux. Douze semaines après lachirurgie, les fémurs ont été prélevés et scannés par tomodensitométrie (microCT)avant l'histologie de sections minces décalcifiées et l'analyse par microscopie àbalayage d'électrons rétrodiffusés (BSEM). Les analyses microCT ont montréque les deux doses de AA amélioraient significativement la formation osseuse périimplantautour des implants enduits comparativement aux implants contrôles ; ladose de 1.0mg de AA résultant en une augmentation 3.5 fois supérieure à celleobtenue avec la dose de 0.2mg de AA. Les analyses BSEM de la formationosseuse péri-implant ont montré une bonne corrélation avec les analyses microCTpar une comparaison directe des sections correspondantes microCT ethistologiques. Les analyses BSEM n'ont montré d'effet significatif ni de la dose0.2mg ou 1.0mg AA sur l'apposition os-implant ou sur le niveau de croissanceosseuse dans l'implant poreux enduit. Cette thèse a permis de fournir desdonnées utiles sur la dose réponse pour une administration locale de AA ainsi quesur son potentiel pour améliorer la fixation d'implants orthopédiques en accroissantla quantité osseuse qui se forme aux environs immédiats de la zone péri-implant.

The performance of bone (osseous) implants is critically dependent on the interactions of the implant surface with the surrounding osseous tissue. Correlating surface topography with bioperformance is essential for the optimized design of osseous implants. The goal of this thesis is to develop a robust methodology for the measurement and analysis of aperiodic surface topographies, such as those encountered on bone implants, over multiple length scales. Two widely used measurement techniques, namely, Atomic Force Microscopy (AFM) and White-Light Interferometry (WLI), are compared and contrasted. A custom-designed MATLAB-based program is developed to analyze the images from both tools, and to extract fourteen different statistical topography parameters. The errors associated with measurement and image analysis are identified, and guidelines are suggested to minimize their effect. This methodology is then applied to measure the topographies of two commonly-used titanium implant surfaces. Previous studies have shown that both surfaces have similar average (root-mean-square) roughness but elicit significantly different bioresponses. Here, it is demonstrated that the two surfaces differ in several other topography parameters, most significantly in surface slope, peak curvature, and developed interfacial area, and crucially, that these differences are strongly scale dependent. These findings form the basis for devising robust quantitative topography-performance correlations for titanium bone implants.
La performance des implants osseux dépend de façon critique de l'interaction entre la surface de l'implant et le tissu osseux environment. Le but de cette thèse est de développer une méthodologie fiable pour mesurer et analyser la topographie de surfaces non périodiques à différentes échelles. Ainsi, deux techniques de mesure extrêmement utilisées, la microscopie à force atomique et l'interférométrie à lumière blanche ont été comparées et confrontées. Un programme développé sur le logiciel MATLAB a été conçu pour analyser les images obtenues par ses deux instruments et en extraire quatorze différents paramètres topographiques statistiques. Les erreurs associées à la mesure et à l'analyse d'image ont été ensuite identifiées et des recommandations ont été suggérées pour minimiser leurs effets. Cette méthodologie a été ensuite appliquée pour mesurer les topographies de deux implants en titane communément utilisés. Il apparaît que ces deux surfaces ont une moyenne quadratique similaire pour la rugosité, mais présentent néanmoins des réponses biologiques différentes. Dans cette recherche, il a été démontré que les deux surfaces présentent, en plus, plusieurs différences pour d'autres paramètres topographiques, notamment de façon significative, pour l'inclinaison des surfaces, la courbure des pics et l'aire interraciale développée. Ces différences dépendent fortement d'un facteur d'échelle, et forment la base pour d'autres études afin de développer des relations quantitatives entre la topologie de la surface et les réponses biologiques associées.

Thesis (M.S.)--Biomedical Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Boyan, Barbara; Committee Member: Eskin, Suzanne; Committee Member: Lobachev, Kirill; Committee Member: Schwartz, Zvi. Part of the SMARTech Electronic Thesis and Dissertation Collection.

One of the many promising applications of metal/ceramic joining is in biomedical implantable devices. This work is focused on vacuum brazing of C.P titanium to 96% alumina ceramic using pure gold as the filler metal. A novel method of brazing is developed where resistance heating of C.P titanium is done inside a thermal evaporator using a Ta heating electrode. The design of electrode is optimized using Ansys resistive heating simulations. The materials chosen in this study are biocompatible and have prior history in implantable devices approved by FDA. This research is part of Boston Retinal implant project to make a biocompatible implantable device (www.bostonretina.org). Pure gold braze has been used in the construction of single terminal feedthrough in low density hermetic packages utilizing a single platinum pin brazed to an alumina or sapphire ceramic donut ( brazed to a titanium case or ferrule for many years in implantable pacemakers. Pure gold (99.99%) brazing of 96% alumina ceramic with CP titanium has been performed and evaluated in this dissertation. Brazing has been done by using electrical resistance heating. The 96% alumina ceramic disk was manufactured by high temperature cofired ceramic (HTCC) processing while the Ti ferrule and gold performs were purchased from outside. Hermetic joints having leak rate of the order of 1.6 X 10-8 atm-cc/ sec on a helium leak detector were measured. Alumina ceramics made by HTCC processing were centreless grounded utilizing 800 grit diamond wheel to provide a smooth surface for sputtering of a thin film of Nb. Since pure alumina demonstrates no adhesion or wetting to gold, an adhesion layer must be used on the alumina surface. Niobium (Nb), Tantalum (Ta) and Tungsten (W) were chosen for evaluation since all are refractory (less dissolution into molten gold), all form stable oxides (necessary for adhesion to alumina) and all are readily thin film deposited as metals. Wetting studies are also performed to determine the wetting angle of pure gold to Ti, Ta, Nb and W substrates. Nano tribological scratch testing of thin film of Nb (which demonstrated the best wetting properties towards gold) on polished 96% alumina ceramic is performed to determine the adhesion strength of thin film to the substrate. The wetting studies also determined the thickness of the intermetallic compounds layers formed between Ti and gold, reaction microstructure and the dissolution of the metal into the molten gold.

Thesis (MScEng) -- Stellenbosch University, 2014.
ENGLISH ABSTRACT: In this study, commercially pure titanium foam was produced using space holder powder metallurgy techniques. Titanium foam is attractive as a scaffolding material for bone replacement and implants in the body. The porous morphology of the foam promotes osteogenesis, while the mechanical behaviour of the foam is closer to that of bone, which has an elastic moduli range of 5 - 40 GPa. Titanium foam was manufactured from powder mixtures of commercially pure titanium (CPTi) powder mixed with 41.4 wt% ammonium bicarbonate (ABC) powder and 1.45 wt% polyethyl glycol (PEG) powder. In this study, two CPTi powders with different particle size distributions, < 75 μm (-200 mesh, designated TiAA) and < 200 μm (-100 mesh, designated TiG), were mixed with the space holder ABC powder, that had been sieved into specified particle size ranges. The size ranges of space holder material studied were: 0 - 710, 250 - 425, 425 - 560, and 560 - 710 μm. This allowed foams with different large or macropore distributions to be produced from the different mixtures. The mixtures were uniaxially compacted at 100 MPa into transverse rupture bars. The ABC and PEG was then removed by thermal debinding in air for 5 hours at 100 °C and 1 hour at 330 °C each, consecutively. The debound samples are then sintered under high (10-6 mbar) vacuum on yttria-stabilised zirconia substrates, heating at 5 °C/min to 1200 °C, with a 2 hour hold at temperature. The microstructures of the different foams were evaluated by examining the polished samples using light optical microscopy. Three point bend tests were conducted on the sintered bars in order to determine the flexural strength and flexural modulus of the different foams. The produced foams had a relative density range between 37.5 - 62.5 % and average macro pore size range between 300 - 500 μm. The foams were found to have an elastic modulus similar to that of bone, 2 - 7 GPa. Finally, the mechanical properties of the foams were compared to known open foam mechanical models and other research projects. It was found that: (i) changes in either metal or space holder powder influences the sintering behaviour of metal foams, (ii) sintered titanium foams with similar densities but different macro/micropore size distributions have different mechanical responses to stress and (iii) the Ashby-Gibson model, based on foam density alone, gives a rough estimate of mechanical properties for the titanium foams studied, but does not capture variations due to pore size distribution.
AFRIKAANSE OPSOMMING: In hierdie studie is kommersiële suiwer titaanskuim geproduseer met behulp van ruimtehouer poeier metallurgie tegnieke. Titaanskuim is aantreklik as 'n raamwerkmateriaal vir beenvervanging en -inplantings in die liggaam. Die poreuse morfologie van die skuim bevorder osteogenese, terwyl die meganiese gedrag van die skuim naby aan dié van been is, met ‘n elasticiteitsmodulus tussen 5 - 40 GPa. Titaanskuim is vervaardig van ‘n poeier mengsel van kommersiële suiwer titaan (CPTi) poeier gemeng met 41,4 gew% ammonium bikarbonaat (ABC) poeier en 1.45 gew% poli-etileenglikol (PEG) poeier. In hierdie studie is twee tipes CPTi poeiers met verskillende deeltjiegrootteverspreiding, < 75 μm (-200 stofdigtheid, TiAA genoem) en <200 μm (-100 stofdigtheid, TiG genoem), met die ruimtehouer ABC-poeier, wat in bepaalde deeltjiegroottereekse gesif is, gemeng. Die wisselende groottes van ruimtehouer wat bestudeer is, was: 0 - 710, 250 - 425, 425 - 560, 560 - 710 μm. Dit het die vervaardiging van skuim met verskillende groot of macroporeuse vanaf die verskillende mengsels toegelaat. Die mengsel is teen 100 MPa in een rigting gekompakteer. Die ABC en PEG is dan verwyder word deur termiese ontbinding in lug vir 5 uur by 100 °C en 1 uur by 330 °C elk, onderskeidelik. Die ontbinde monsters is dan onder hoë (10-6 mbar) leemte op yttrium-gestabiliseer zirconia-substraat, met verwarming teen 5 °C/min tot 1200 °C met 'n verdere 2 uur by 1200 °C, gesinterd. Die mikrostrukture van die verskillende skuim is geëvalueer deur gepoleerde monsters met behulp van ‘n ligmikroskopie te ondersoek . Driepunt draaitoetse is op die gesinterd stawe uitgevoer om die buigsterkte en buigmodulus van die verskillende skuime te bepaal. Die vervaardigde skuime se relatiewe digtheid het tussen 37,5 - 62,5 % gewissel en die gemiddelde makroporiegrootte tussen 300 - 500 μm gewissel. Die skuim het 'n elastisiteitsmodulus soortgelyk aan dié van been getoon, 2 – 7 GPa. Ten slotte is die meganiese eienskappe van die skuim met bekende oop skuim meganiese modelle en ander navorsingsprojekte vergelyk. Daar is bevind dat: (i) veranderinge in óf metaal of ruimtehouer poeier beïnvloed die sinteringgedrag van metaalskuime, (ii) gesinterd titaniumskuim met soortgelyke digthede, maar verskillende makro / mikroporeuse verdelings, toon verskillende meganiese reaksies op stres en die Ashby-Gibson model, gebaseer op die skuimdigtheid alleen, (iii) wat 'n rowwe skatting van die meganiese eienskappe vir die bestudeerde titaniumskuime gee, maar nie die variasies ingrootteverspreiding van porieë ondervang nie.

Thesis (Ph.D)--Materials Science and Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Barbara Boyan; Committee Member: Andres Garcia; Committee Member: Anthony Norman; Committee Member: Nael McCarty; Committee Member: Zvi Schwartz. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Cell adhesion to the extracellular matrix through cell-surface integrin receptors is essential to development, wound healing, and tissue remodeling and therefore represents a central theme in the design of bioactive surfaces that successfully interface with the body. This is especially significant in the areas of integrative implant coatings since adhesion triggers signals that regulate cell cycle progression and differentiation in multiple cellular systems. The interactions of osteoblasts with their surrounding extracellular matrix are essential for skeletal development and homeostasis and the maintenance of the mature osteoblastic phenotype. Our objective was to engineer integrin-specific bioactive surfaces that support osteoblastic differentiation and promote osseointegration by mimicking these interactions. We target two specific integrins essential to osteoblast differentiation the type I collagen receptor alpha2beta1 and the fibronectin receptor alpha5beta1. The central hypothesis of this project was that the controlled presentation of type I collagen and fibronectin binding domains onto well-defined substrates would result in integrin-specific bioadhesive surfaces that support osteoblastic differentiation, matrix mineralization, and osseointegration. We have demonstrated that these biomimetic peptides enhance bone formation and mechanical osseointegration on titanium implants in a rat tibia cortical bone model. We have also shown that the presentation of multiple integrin-binding ligands synergize to enhance intracellular signaling and proliferation. Finally, we demonstrate the advantage of the short biomimetic peptides over the native ECM proteins. This research is significant because it addresses current orthopaedic implant limitations by specifically targeting cellular responses that are critical to osteoblastic differentiation and bone formation. This biomolecular approach provides a versatile and robust strategy for developing bioactive surfaces that enhance bone repair and osseointegration of orthopaedic implants.

O câncer de cabeça e pescoço tem maior prevalência em homens, predominantemente de meia ou terceira idade, caracterizando um grupo de indivíduos com grande probabilidade em ter realizado implantes dentários ósseointegrados. A maior parte desses implantes é feito de titânio e a interação dos fótons de raios X com esse material de alto número atômico e elevada densidade eletrônica gera grande espalhamento de radiação e perturbação de dose nas suas interfaces, gerando incertezas dosimétricas nos tratamentos de radioterapia de cabeça e pescoço. O objetivo desse estudo é avaliar a influência dosimétrica dos implantes dentários de titânio em VMAT de cabeça e pescoço. Para isso, foi realizada irradiação de um fantoma de água sólida com a presença de um implante dentário de titânio por campo direto e com a aplicação adaptada para VMAT dos testes CShape Easy e Head and Neck, propostos pelo TG 119. O planejamento desses casos foi realizado conforme critérios determinados pela AAPM, com o software Monaco 5.0, e a execução do tratamento em Acelerador Linear Synergy, da Elekta. As medidas foram realizadas com câmara de ionização Semiflex e eletrômetro UNIDOS PTW, filme radiocrômico GafChromic EBT3 com varredura no scanner Epson Expression XL e análise com o software VeriSoft 6.0. Os resultados da distribuição e perfis de dose encontrados na irradiação de campo direto comprovam que a presença de implante dentário de titânio causa perturbações de dose significativas. Em decorrência da presença do material, também foi aumentada a diferença entre dose calculada e medida, quando comparada à irradiação de fantoma homogêneo. Porém na dosimetria dos casos do TG 119 essa diferença foi irrelevante. A dose calculada pelo software e a medida com a câmara de ionização tiveram diferenças insignificantes, assim como a concordância do critério gamma para os casos com e sem a presença do implante dentário de titânio. Os resultados encontrados são satisfatórios e compatíveis com testes de outros autores em irradiações de fantomas homogêneos. O impacto da presença do implante dentário de titânio pode ser minimizado através do delineamento manual do objeto metálico e do artefato gerado por ele e através da atribuição de valores de densidade eletrônica corrigidos a eles, além de incluí-los como órgãos com restrição de dose na otimização do planejamento. A partir da aplicação dos testes CShape Easy e Head and Neck do TG 119 da AAPM, foi comprovado que seguindo as recomendações descritas, o sistema de planejamento Monaco 5.0 com é capaz de realizar cálculos de dose com elevado grau de exatidão para VMAT de cabeça e pescoço em pacientes com implante dentário de titânio.
The head and neck cancer is more prevalent in men, predominantly middle or elderly age, featuring a group of individuals with high probability of having done osseointegrated dental implants. Most of these implants are made of titanium and the interaction of X-ray photons with this high atomic number material and high electron density generates scattering and disturbance on radiation dose in their interfaces, generating dosimetric uncertainties in the head and neck radiotherapy treatments. The aim of this study is to assess the dosimetric impact of dental implants of titanium in head and neck VMAT. For this, irradiation of phantom was performed in the presence of a titanium dental implant for direct field and with application of CShape Easy and Head and Neck tests proposed by the TG 119, adapted to VMAT. The planning of these cases was conducted according to criteria determined by the AAPM, with Monaco 5.0 software, and the treatment is in Linear Accelerator Synergy Elekta. The measurements were performed with Semiflex ionization chamber and electrometer US PTW, radiochromic film GafChromic EBT3 scanned with the Epson Expression XL scanner and analysis with the software VeriSoft 6.0. The results of the distribution and dose profiles found in direct irradiation field show that the presence of titanium dental implant causes significant dose disturbance. Due to the presence of the material was also increased the difference between the calculated and the measured dose when compared to irradiation of the homogeneous phantom. But in the dosimetry of TG 119 cases this difference was irrelevant. The dose calculated by the software and the measure with the ionization chamber had negligible differences, as well as the consent of the gamma criterion for cases with and without the presence of dental titanium implant. The results are satisfactory and consistent with other author’s tests in homogeneous phantoms. The impact of dental titanium implant presence can be minimized through the manual delimitation of the metal object and artifact generated and by assigning the electron density values corrected them, and include them as organs with dose constraints on optimization planning. From the testing CShape Easy and Head and Neck TG 119 of the AAPM, we have verified that following the recommendations described, the planning system Monaco 5.0 is capable of performing dose calculations with high degree of accuracy for head and neck VMAT in patients with titanium dental implant.

Ceramics are distinguished from metals and polymers by their inorganic nature and lack of metallic properties. They can be highly crystalline to amorphous, and their physical and chemical properties can vary widely. Ceramics can, for instance, be made to resemble the mineral phase in bone and are therefore an excellent substitute for damaged hard tissue. They can also be made porous, surface active, chemically inert, mechanically strong, optically transparent or biologically resorbable, and all these properties are of interest in the development of new materials intended for a wide variety of applications. In this thesis, the focus was on the development of different ceramics for use in the controlled release of drugs and ions. These concepts were developed to obtain improved therapeutic effects from orally administered opioid drugs, and to reduce the number of implant-related infections as well as to improve the stabilization of prosthetic implants in bone. Geopolymers were used to produce mechanically strong and chemically inert formulations intended for oral administration of opioids. The carriers were developed to allow controlled release of the drugs over several hours, in order to improve the therapeutic effect of the substances in patients with severe chronic pain. The requirement for a stable carrier is a key feature for these drugs, as the rapid release of the entire dose, due to mechanical or chemical damage to the carrier, could have lethal effects on the patient because of the narrow therapeutic window of opioids. It was found that it was possible to profoundly retard drug release and to achieve almost linear release profiles from mesoporous geopolymers when the aluminum/silicon ratio of the precursor particles and the curing temperature were tuned. Ceramic implant coatings were produced via a biomimetic mineralization process and used as carriers for various drugs or as an ion reservoir for local release at the site of the implant. The formation and characteristics of these coatings were examined before they were evaluated as potential drug carriers. It was demonstrated that these coatings were able to carry antibiotics, bisphosphonates and bone morphogenetic proteins to obtain a sustained local effect, as they were slowly released from the coatings.

Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 710

For many decades, the implantation of Ti based biomedical implants has been extensively utilized to improve and restore the patients’ quality of life. However, despite advances in technology, failures of the implant do occur. In many cases, the failed Ti implants require immediate removal or correction through surgical operation, which, apart from the substantial economic impact on patients and governments, would cause prolonged suffering for patients. Moreover, the rapid increase in the population’s life expectancy necessitates the fabrication and engineering of more reliable orthopaedic implants based on Ti and its allosys for the aged population to address the current issues associated with implant failure. Several factors are involved in bone implant failures, such as bacterial infection and inflammation and poor integration of the bone with the implant surface. Among them, the infection problem requires special attention, as almost two-thirds of the infected implants are not treatable and eventually fail. The emergence of multi-drug resistant (MDR) bacteria is another horrifying issue, which poses a real threat to humankind and is responsible for high mortality rates among vulnerable patients. Fortunately, the emerging advances in nanotechnology and surface engineering can be a promising solution to this crisis. The ideal bone implant should possess antibacterial properties as well as the high bioactivity required for osseointegration improvement. In this regard, novel surface modification treatments such as the plasma electrolytic oxidation technique (PEO) has proven to be effective in the bioactivity improvement of titanium-based implants. However, the development of the PEO treated surface with antibacterial properties is still challenging. This study aims to implement innovative approaches to address the critical factors associated with titanium implant failure by applying post-PEO treatments such as hydrothermal process and functionalizing the surface with novel 2D materials. This thesis is presented in eight chapters, including a comprehensive literature review and several published, under review or confidential unpublished papers. In brief, the significant contributions of this work fall into four categories as follows: •Engineering of nanostructured titania surfaces with tunable and mixed topography (paper 1). • Optimal fabrication of antibacterial titania nanostructures, a combined approach of plasma electrolytic oxidation and hydrothermal treatment (paper 2). • Antibacterial development of titania surface with the application of graphene oxide and PEO-EPD technique (paper 3). • Comparative antibacterial activity of 2D materials coated on the porous-titania against gram-positive (S. aureus) and gram-negative (E.coli) bacteria (paper 4).
Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering and Advanced Materials, 2021

碩士
南臺科技大學
機械工程系
105
This study adopts the use of selected vacuum plasma spray (VPS) as the coating process because it produces fewer oxides and has a stable crystalline nature and excellent adhesion during cladding. Titanium alloy (Ti-6Al-4V) was chosen as the substrate and Ta powder as the coating material. Spraying was carried out in three layers. The melting rate of Ta powder was controlled by applying fine, medium, and coarse powder particle diameters to the inner, middle, and outer layer respectively to form a coating that increases porosity from inside out. In addition, the substrate was preheated at 650 ° C to enhance the interface fusing effect. After the completing of Ta powder coating, it was examined by mechanical property test and biomedical property test. Experimental results exhibited that Ta powder coating has a good cohesion with Ti-6Al-4V substrate interface. The average porosity of the coating surface is about 13%, the average roughness is about Ra: 22.2 μm, the average porosity of the cross-section (about 380 μm thick) is increased from 0.6 % of the inner layer to 7.6 % of the outer layer, and the corresponding hardness and elastic modulus (E) are decreased from 240 to 167 HV0.1 and from 148.3 to 123.1GPa, respectively. It then helps reduce the stress shielding effect of the coating and reduce the risk of coats flaking. In addition, the average bonding strength of the coating to the substrate is up to 54.5±2 MPa and the failure mode is in the coating surface and the tensile bar of the glue. In biomedical property test, when the coating was immersed in the simulated body fluid (SBF) for 3 days after alkali-(1M NaOH) and heat- treatment (300 ° C), the surface was almost full of apatite, which increases according to the soaking time, and the bioactivity is significantly higher than the non- alkali- and heat- treatment term. However, when the test items were cultured in MG-63 cells, the cells had started to spread to the surroundings 3 hours later for both with alkali- and heat- treatment and without alkali-heat treatment. The longer the cultivating time is, the greater the area expands. The two test items showed excellent biocompatibility. The results of the whole study indicate that the coating formed by Ta coating on Ti-6Al-4V substrate by VPS process can obtain excellent bonding quality and biocompatibility, and the bioactivity can be improved by alkali- and heat- treatment.