RESUMEN
Titanium and its alloys, especially Ti-6Al-4V, are widely studied in implantology for their favorable characteristics. However, challenges remain, such as the high modulus of elasticity and concerns about cytotoxicity. To resolve these issues, research focuses on ß-type titanium alloys that incorporate elements such as Mo, Nb, Sn, and Ta to improve corrosion resistance and obtain a lower modulus of elasticity compatible with bone. This review comprehensively examines current ß titanium alloys, evaluating their mechanical properties, in particular the modulus of elasticity, and corrosion resistance. To this end, a systematic literature search was carried out, where 81 articles were found to evaluate these outcomes. In addition, this review also covers the formation of the alloy, processing methods such as arc melting, and its physical, mechanical, electrochemical, tribological, and biological characteristics. Because ß-Ti alloys have a modulus of elasticity closer to that of human bone compared to other metal alloys, they help reduce stress shielding. This is important because the alloy allows for a more even distribution of forces by having a modulus of elasticity more similar to that of bone. In addition, these alloys show good corrosion resistance due to the formation of a noble titanium oxide layer, facilitated by the incorporation of ß stabilizers. These alloys also show significant improvements in mechanical strength and hardness. Finally, they also have lower cytotoxicity and bacterial adhesion, depending on the ß stabilizer used. However, there are persistent challenges that require detailed research in critical areas, such as optimizing the composition of the alloy to achieve optimal properties in different clinical applications. In addition, it is crucial to study the long-term effects of implants on the human body and to advance the development of cutting-edge manufacturing techniques to guarantee the quality and biocompatibility of implants.
Asunto(s)
Aleaciones , Implantes Dentales , Titanio , Titanio/química , Humanos , Aleaciones/química , Aleaciones/farmacología , Corrosión , Ensayo de MaterialesRESUMEN
Among external stimuli-responsive therapy approaches, those using near infrared (NIR) light irradiation have attracted significant attention to treat bone-related diseases and bone tissue regeneration. Therefore, the development of metallic biomaterials sensitive to NIR stimuli is an important area of research in orthopaedics. In this study, we have generated in situ prism-shaped silver nanoparticles (p-AgNPs) in a biomorphic nano-holed TiO2 coating on a Ti6Al4V alloy (a-Ti6Al4V). Insertion of p-AgNPs does not disturb the periodically arranged sub-wavelength-sized unit cell on the a-Ti6Al4V dielectric structure, while they exacerbate its peculiar optical response, which results in a higher NIR reflectivity and high efficiency of NIR photothermal energy conversion suitable to bacterial annihilation. Together, these results open a promising path toward strategic bone therapeutic procedures, providing novel insights into precision medicine.
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Aleaciones , Antibacterianos , Rayos Infrarrojos , Nanopartículas del Metal , Plata , Propiedades de Superficie , Titanio , Titanio/química , Titanio/farmacología , Aleaciones/química , Aleaciones/farmacología , Plata/química , Plata/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Nanopartículas del Metal/química , Staphylococcus aureus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Escherichia coli/efectos de los fármacos , Tamaño de la PartículaRESUMEN
This study aimed to characterize the immobilization of the novel JIChis-2 peptide on the Ti-6Al-4V alloy, widely used in the biomedical sector. The antimicrobial activity of JIChis-2 was evaluated in the Gram-negative bacterium E. coli. Its immobilization occurred by inducing the formation of covalent bonds between the N-terminus of the peptides and the surface previously submitted to acrylic acid polymerization via the PECVD technique. Coated and uncoated surfaces were characterized by FTIR, AFM, SEM and EDX. Studies of global and localized corrosion were carried out, seeking to explore the effects triggered by surface treatment in an aggressive environment. Additionally, the ability of the functionalized material to prevent E. coli biofilm formation evidenced that the strategy to immobilize JIChis-2 in the Ti-6Al-4V alloy via PECVD of acrylic acid resulted in the development of a functional material with antibiofilm properties.
Asunto(s)
Péptidos Antimicrobianos , Escherichia coli , Ensayo de Materiales , Polimerizacion , Biopelículas , Titanio/farmacología , Titanio/química , Aleaciones/farmacología , Aleaciones/químicaRESUMEN
The development of bioactivity in bioinert metallic alloys is a field of interest aiming to improve some aspects of these materials for implant applications. New Co63 Cr28 W9-x Tax alloys with different Ta concentrations (x = 0, 2, 4, 6, and 9% w/w) were synthesized in the work reported here. The alloys were characterized by x-ray diffraction, volumetric density, Vickers microhardness, atomic force microscopy, scanning electron microscopy (SEM), and energy-dispersion x-ray spectroscopy (EDS). Bioactivity properties were evaluated by in vitro tests with simulated body fluid (SBF). In vivo assays were performed to assess biocompatibility. The influence of surface thermochemical treatment and Ta insertion on the bioactive properties of the alloys was investigated. The results showed that the alloy structure comprises εCo and αCo phases, with cobalt as a matrix with Cr, W, and Ta as a solid solution. TaCo2 phase is observed in the alloys with 4, 6, and 9% w/w of Ta, and its amount increase as Ta concentration increases. Volumetric density is reduced (from 8.78 ± 0.06 to 8.56 ± 0.09 g/cm3 ) as Ta concentration increases (from 0% to 9% w/w) mainly due to the lower density of the tantalum compared to the tungsten metal. On the other hand, the TaCo2 phase contributes to the increase of Vickers's hardness by ~17.6% for the alloy with 9% Ta (394.7 ± 8.1 HV) compared with Co63 Cr28 W9 (336 ± 5 HV). The topographic analysis showed increased roughness and adhesion due to the nucleation of Ta1.1 O1.05 and Ca2 Ta2 O7 crystals after surface thermochemical treatment. The roughness and adhesion increase from 16.9 ± 0.6 nm and 8.3 ± 1.8 nN (untreated surface) to 255.7 ± 17.7 nm and 24.1 ± 12.6 nN (treated surface), respectively, for the Co63 Cr28 Ta9 alloy. These results suggest that thermochemical treatment provides surface conditions favorable to hydroxyapatite (HA) nucleation. The SEM and EDS data showed the nucleation of spongy structures, consistent with HA, composed mainly of Ca and P, indicating that oxides tantalum promoted a bioactive response on the sample's surface. The biological assay corroborated the alloy's safety and applicability, highlighting its potential in biomedical application since no harmful effects were observed.
Asunto(s)
Aleaciones , Tantalio , Aleaciones/farmacología , Tantalio/farmacología , Durapatita/química , Metales , Prótesis e Implantes , Propiedades de Superficie , Ensayo de MaterialesRESUMEN
The titanium alloy composition and microdesign affect the dynamic interplay between the bone cells and titanium surface in the osseointegration process. The current study aimed to evaluate the surface physicochemical properties, electrochemical stability, and the metabolic response of the MC3T3-E1 cells (pre-osteoblast cell line) cultured onto titanium-15molybdenum (Ti-15Mo) discs treated with phosphoric acid (H3PO4) and sodium hydroxide (NaOH) and/or strontium-loading by the hydrothermal method. The x-ray dispersive energy spectroscopy (EDS) and x-ray diffraction (XRD) analysis showed no trace of impurities and the possible formation of hydrated strontium oxide (H2O2Sr), respectively. The confocal laser microscopy (CLSM) analysis indicated that titanium samples treated with strontium (Sr) showed greater surface roughness. The acid/alkali treatment prior to the hydrothermal Sr deposition improved the surface free energy and resistance to corrosion of the Ti-15Mo alloy. The acid/alkali treatment also provided greater retention of the Sr particles on the Ti-15Mo surfaces accordingly with inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. The AlamarBlue and fluorescence analysis indicated noncytotoxic effects against the MC3T3-E1 cells, which allowed cells' adhesion and proliferation, with greater cells' spreading in the Sr-loaded Ti-15Mo samples. These findings suggest that Sr deposition by the hydrothermal method has the potential to enhance the physicochemical properties of the Ti-15Mo previously etched with H3PO4and NaOH, and also improve the initial events related to cell-mediated bone deposition.
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Estroncio , Titanio , Aleaciones/farmacología , Proliferación Celular , Hidróxido de Sodio/farmacología , Estroncio/química , Estroncio/farmacología , Propiedades de Superficie , Titanio/química , Titanio/farmacologíaRESUMEN
Organic-inorganic hybrid coatings deposited on different types of metallic alloys have shown outstanding anticorrosive performance. The incorporation of osteoconductive additives such as hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) into organic-inorganic hybrid coatings is promising to improve the osseointegration and corrosion resistance of Ti6Al4V alloys, which are the most widely used metallic orthopedic and dental implant materials today. Therefore, this study evaluated the capability of poly(methyl methacrylate) (PMMA)-TiO2 and PMMA-ZrO2 hybrid coatings modified with HA and ß-TCP to act as bioactive and corrosion protection coatings for Ti6Al4V alloys. In terms of cell growth and mineralization, osteoblast viability, Ca+2 deposition and alkaline phosphatase assays revealed a significant improvement for the HA and ß-TCP modified coatings, compared to the bare alloy. This can be explained by an increase in nanoscale roughness and associated higher surface free energy, which lead to enhanced protein adsorption to promote osteoblast attachment and functions on the coatings. The effect of HA and ß-TCP additives on the anticorrosive efficiency was studied by electrochemical impedance spectroscopy (EIS) in a simulated body fluid (SBF) solution. The coatings presented a low-frequency impedance modulus of up to 430 GΩ cm2, 5 decades higher than the bare Ti6Al4V alloy. These findings provide clear evidence of the beneficial role of HA and ß-TCP modified hybrid coatings, improving both the biocompatibility and corrosion resistance of the Ti6Al4V alloy.
Asunto(s)
Materiales Biocompatibles Revestidos , Durapatita , Polimetil Metacrilato , Aleaciones/farmacología , Fosfatos de Calcio , Materiales Biocompatibles Revestidos/farmacología , Corrosión , Ensayo de Materiales , Propiedades de Superficie , TitanioRESUMEN
Biological effects of titanium (Ti) alloys were analyzed on biofilms of Candida albicans, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, and Streptococcus sanguinis, as well as on osteoblast-like cells (MG63) and murine macrophages (RAW 264.7). Standard samples composed of aluminum and vanadium (Ti-6Al-4V), and sample containing niobium (Ti-35Nb) and zirconium (Ti-13Nb-13Zr) were analyzed. Monomicrobial biofilms were formed on the Ti alloys. MG63 cells were grown with the alloys and the biocompatibility (MTT), total protein (TP) level, alkaline phosphatase (ALP) activity, and mineralization nodules (MN) formation were verified. Levels of interleukins (IL-1ß and IL-17), tumor necrosis factor alpha (TNF-α), and oxide nitric (NO) were checked, from RAW 264.7 cells supernatants. Data were statically analyzed by one-way analysis of variance (ANOVA) and Tukey's test, or T-test (P ≤ 0.05). Concerning the biofilm formation, Ti-13Nb-13Zr alloy showed the best inhibitory effect on E. faecalis, P. aeruginosa, and S. aureus. And, it also acted similarly to the Ti-6Al-4V alloy on C. albicans and Streptococcus spp. Both alloys were biocompatible and similar to the Ti-6Al-4V alloy. Additionally, Ti-13Nb-13Zr alloy was more effective for cell differentiation, as observed in the assays of ALP and MN. Regarding the stimulation for release of IL-1ß and TNF-α, Ti-35Nb and Ti-13Nb-13Zr alloys inhibited similarly the synthesis of these molecules. However, both alloys stimulated the production of IL-17. Additionally, all Ti alloys showed the same effect for NO generation. Thus, Ti-13Nb-13Zr alloy was the most effective for inhibition of biofilm formation, cell differentiation, and stimulation for release of immune mediators.
Asunto(s)
Aleaciones/farmacología , Materiales Biocompatibles/farmacología , Biopelículas/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Titanio/farmacología , Aleaciones/química , Animales , Materiales Biocompatibles/química , Biopelículas/crecimiento & desarrollo , Candida albicans/efectos de los fármacos , Candida albicans/fisiología , Células Cultivadas , Ensayo de Materiales , Ratones , Pruebas de Sensibilidad Microbiana , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Osteoblastos/fisiología , Pseudomonas/efectos de los fármacos , Pseudomonas/fisiología , Células RAW 264.7 , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Streptococcus/efectos de los fármacos , Streptococcus/fisiología , Propiedades de Superficie , Titanio/químicaRESUMEN
The objective of this work was a systemic evaluation of the anodizing treatment in a ß-type Ti-15Mo alloy to grow a TiO2 nanostructured layer for osseointegration improvement. The technical viability of the surface modification was assessed based on the resistance to mechanical fatigue, electrochemical corrosion, and biological response. By using an organic solution of NH4 F in ethylene glycol, a well-organized array of 90 nm diameter nanotubes was obtained with a potential of 40 V for 6 h, while undefined nanotubes of 25 nm diameter were formed with a potential of 20 V for 1 h. Nevertheless, the production of the 90 nm diameter nanotubes was followed by micrometer pits that significantly reduced the fatigue performance. The undefined nanotubes of 25 nm diameter, besides the greater cell viability and improved osteoblastic cell differentiation in comparison to the as-polished surface, were not deleterious to the fatigue and corrosion properties. This result strengthens the necessity of an overall evaluation of the anodizing treatment, particularly the fatigue resistance, before suggesting it for the design of implants. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 86-96, 2019.
Asunto(s)
Aleaciones , Materiales Biocompatibles Revestidos , Técnicas Electroquímicas , Ensayo de Materiales , Nanotubos/química , Osteoblastos/metabolismo , Titanio , Aleaciones/química , Aleaciones/farmacología , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Corrosión , Humanos , Osteoblastos/citología , Titanio/química , Titanio/farmacologíaRESUMEN
Perform a physicochemical and morphological characterization of a Ti-15Mo alloy surface modified by laser beam irradiation and to evaluate in vitro the morphological response and proliferation of osteoblastic cells seeded onto this alloy. Disks were made of two different metals, Ti-15Mo alloy and cpTi, used as control. A total of four groups were evaluated: polished cpTi (cpTi-pol), laser-irradiated cpTi (cpTi-L), polished Ti-15Mo alloy (Ti-15Mo-pol), and laser-irradiated Ti-15Mo alloy (Ti-15Mo-L). Before and after laser irradiation of the surfaces, physicochemical and morphological analyses were performed: scanning electron microscopy (FEG-SEM), energy-dispersive spectroscopy (EDX), and X-ray diffraction (XRD). The wettability of the samples was evaluated by contact angle measurement. Murine preosteoblastic cells MC3T3-E1 were cultured onto the experimental disks for cell proliferation, morphology, and spreading analyses. Laser groups presented irregular-shaped cavities on its surface and a typical microstructured surface with large depressions (FEG-SEM). The contact angle for both laser groups was 0°, whereas for the polished groups was ≈ 77 and ≈ 78 for cpTi-pol and Ti-15Mo-pol, respectively. Cell proliferation analysis demonstrated a higher metabolic activity in the laser groups (p < 0.05). From the fluorescence microscopy, Ti-15Mo-L surface seems to induce greater cellular differentiation compared to the cpTi-L surface. The preliminary biological in vitro analyses suggested possible advantages of laser surface treatment in the Ti-15Mo alloy regarding cell proliferation and maturation.
Asunto(s)
Aleaciones/química , Aleaciones/farmacología , Rayos Láser , Animales , Línea Celular , Proliferación Celular/efectos de los fármacos , Proliferación Celular/efectos de la radiación , Forma de la Célula/efectos de los fármacos , Forma de la Célula/efectos de la radiación , Fluorescencia , Ratones , Microscopía Electrónica de Rastreo , Espectrometría por Rayos X , Propiedades de Superficie , Difracción de Rayos XRESUMEN
Significant health concerns have been raised by the high levels of Cr and Co ions into whole blood as resulted of corrosion process released from biomedical implants, but very little is known about their biological behavior in governing cell metabolism. Thus, we prompted to address this issue by exploring the effects of CoCr enriched medium on both fibroblast and preosteoblast (pre-Ob) cells. First, we showed there is a significant difference in Co and Cr releasing dependent on engineered surface, it being even more released in dual acid-etching treating surface (named w/DAE) than the machined surfaces (named wo/DAE). Thereafter, we showed CoCr affects pre-osteoblast and fibroblast metabolism by dynamically modulating integrin-based downstream signaling (FAK, Src, Rac1, and Cofilin). Specifically on this matter, we have shown there is dynamic ß1-integrin gene activation up 24 h in both preosteoblast and fibroblast. Our analysis showed also that both pre-Ob and fibroblast are important resource of proinflammatory cytokines when responding to CoCr enriched medium. In addition, survival-related signaling pathway was also affected interfering on survival and proliferating signal, mainly affecting CDK2, mapk-Erk and mapk-p38 phosphorylations, while AKT/PKB-related gene remained active. In addition, during cell adhesion PP2A (an important Ser/Thr phosphatase) was inactive in both cell lineages and it seems be a CoCr's molecular fingerprint, regulating specific metabolic pathways involved with cytoskeleton rearrangement. Altogether, our results showed for the first time CoCr affects cellular performance in vitro by modulating integrin activation-based downstream signaling and requiring a reprograming of inflammatory genes activations in vitro. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 839-849, 2018.
Asunto(s)
Cromo/farmacología , Cobalto/farmacología , Inflamación/genética , Integrinas/metabolismo , Transducción de Señal , Factores Despolimerizantes de la Actina/metabolismo , Aleaciones/farmacología , Animales , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Medios de Cultivo/química , Citocinas/metabolismo , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Mediadores de Inflamación/metabolismo , Ratones , Células 3T3 NIH , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Fosforilación/efectos de los fármacosRESUMEN
Bone is a complexly structured tissue and hierarchically organized from macro to nano levels of dimensions. Biomaterial devices developed to replace and interact with bone tissues have been designed from the macro to nano perspective to provide suitable performance in acquiring primary and biological stability. Macro level designed features provide mechanical interlock and primary stability to implants inside the bone. Surface micro and nano structures influence cells behavior to promote the secondary or biological stability, reaching successful osseointegration.
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Aleaciones/química , Aleaciones/farmacología , Huesos/efectos de los fármacos , Prótesis e Implantes , Titanio/química , Titanio/farmacología , Humanos , Oseointegración/efectos de los fármacos , Propiedades de SuperficieRESUMEN
The development of Ti alloys to manufacture dental implants has emerged in recent years due to the increased failure of commercially pure titanium (cpTi) implants. Thus, this study reviews existing information about the mechanical, chemical, electrochemical, and biological properties of the main Ti alloys developed over the past few years to provide scientific evidence in favor of using Ti-based alloys as alternative to cpTi. Ti alloys may be considered viable substitutes in the fabrication of dental implants. Such evidence is given by the enhanced properties of alloys, such as a low elastic modulus, high tensile strength, satisfactory biocompatibility, and good corrosion and wear resistances. In addition, Ti alloys may be modified at the structural, chemical, and thermomechanical levels, which allows the development of materials in accordance with the demands of several situations encountered in clinical practice. Although several in vitro studies have established the superiority of Ti alloys over cpTi, mainly in terms of their mechanical properties, there is no scientific evidence that supports the total replacement of this material in vivo. This review demonstrates the superiority of ß-type alloys. However, it is evident that in vivo studies are encouraged to test new alloys to consolidate their use as substitutes for cpTi.
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Aleaciones , Implantes Dentales , Titanio , Aleaciones/química , Aleaciones/farmacología , Animales , Humanos , Titanio/química , Titanio/farmacologíaRESUMEN
Magneto-elastic materials (ME) have important advantages when applied as biosensors due to the possibility of wireless monitoring. Commercial Metglas 2826MB3™ (FeNiMoB) is widely used, however sensor stabilization is an important factor for biosensor performance. This study compared the effects of biocompatibility and degradation of the Metglas 2826MB3™ alloy, covered or not with a gold layer, when in contact with cell culture medium. Strips of amorphous Metglas 2826MB3™ were cut and coated with thin layers of Cr and Au, as verified by Rutherford Backscattering Spectroscopy (RBS). Using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), the presence of metals in the culture medium was quantitatively determined for up to seven days after alloy exposure. Biocompatibility of fibroblast Chinese Hamster Ovary (CHO) cultures was tested and cytotoxicity parameters were investigated by indirect means of reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) at 1, 2 and 7 days. Cell death was further evaluated through in situ analysis using Acridine Orange/Ethidium Bromide (AO/EB) staining and images were processed with ImageJ software. Ions from Metglas(®) 2826MB3™ induced a degradation process in living organisms. The cytotoxicity assay showed a decrease in the percentage of live cells compared to control for the ME strip not coated with gold. AO/EB in situ staining revealed that most of the cells grown on top of the gold-covered sensor presented a normal morphology (85.46%). Covering ME sensors with a gold coating improved their effectiveness by generating protection of the transducer by reducing the release of ions and promoting a significant cell survival.
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Aleaciones/farmacología , Técnicas Biosensibles , Materiales Biocompatibles Revestidos/farmacología , Oro/farmacología , Aleaciones/química , Animales , Células CHO , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cromo/química , Cromo/farmacología , Materiales Biocompatibles Revestidos/química , Cricetulus , Oro/química , Espectrofotometría AtómicaRESUMEN
This work is focused on the processes occurring at the bioabsorbable metallic biomaterial/cell interfaces that may lead to toxicity. A critical analysis of the results obtained when degradable metal disks (pure Mg and rare earth-containing alloys (ZEK100 alloys)) are in direct contact with cell culture and those obtained with indirect methods such as the use of metal salts and extracts was made. Viability was assessed by Acridine Orange dye, neutral red and clonogenic assays. The effects of concentration of corrosion products and possible joint effects of the binary and ternary combinations of La, Zn and Mg ions, as constituents of ZEK alloys, were evaluated on a mammalian cell culture. In all cases more detrimental effects were found for pure Mg than for the alloys. Experiments with disks showed that gradual alterations in pH and in the amount of corrosion products were better tolerated by cells and resulted in higher viability than abrupt changes. In addition, viability was dependent on the distance from the source of ions. Experiments with extracts showed that the effect of insoluble degradation products was highly detrimental. Indirect tests with Zn ions revealed that harmful effects may be found at concentrations ≥ 150 µM and at ≥ 100 µM in mixtures with Mg. These mixtures lead to more deleterious effects than single ions. Results highlight the need to develop a battery of tests to evaluate the biocompatibility of bioabsorbable biomaterials.
Asunto(s)
Implantes Absorbibles , Aleaciones/química , Magnesio/química , Aleaciones/farmacología , Animales , Células CHO , Supervivencia Celular/efectos de los fármacos , Corrosión , Cricetinae , Cricetulus , Iones , Magnesio/farmacologíaRESUMEN
STATEMENT OF PROBLEM: Although the use of titanium has increased, casting difficulties limit routine use. PURPOSE: The purpose of the present study was to compare the mechanical properties and biocompatibility of the experimental titanium alloys titanium-5-zirconium, titanium-5-tantalum, and titanium-5-tantalum-5-zirconium (in wt%) with those of commercially pure titanium. MATERIAL AND METHODS: Specimens of titanium alloys and commercially pure titanium were cast by using plasma. Their modulus of elasticity and ultimate tensile strength were determined in a universal testing machine. Biocompatibility was evaluated with SCC9 cells. In periods of 1, 4, 7, 10, and 14 days, cell proliferation was evaluated by the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction assay, and cell viability was evaluated in the 7-day period. Cell morphology was evaluated at 2, 12, and 24 hours. Modulus of elasticity, ultimate tensile strength, and cell viability were analyzed by 1-way ANOVA and the Bonferroni test; cell proliferation data were compared by 2-way ANOVA (alloy versus time) and by the Bonferroni test; and the cell morphology data were analyzed by split-plot design. All statistical tests were performed at the 95% confidence level (P<.05). RESULTS: Titanium-5-tantalum presented the lowest modulus of elasticity and ultimate tensile strength, whereas titanium-5-zirconium and titanium-5-tantalum-5-zirconium were statistically similar to commercially pure titanium. Cell proliferation and viability were not affected by any alloy being similar to those observed for commercially pure titanium. No noticeably differences were found in the morphology of cells cultured on any alloy and commercially pure titanium. CONCLUSION: Experimental alloys, especially titanium-5-zirconium and titanium-5-tantalum-5-zirconium, presented promising mechanical results for future studies and clinical applications. In addition, these alloys, evaluated by cell proliferation, viability, and morphology, were found to be biocompatible in vitro.
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Materiales Dentales/química , Titanio/química , Aleaciones/química , Aleaciones/farmacología , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Aleaciones Dentales/química , Aleaciones Dentales/farmacología , Técnica de Colado Dental , Materiales Dentales/farmacología , Análisis del Estrés Dental/instrumentación , Módulo de Elasticidad , Humanos , Ensayo de Materiales , Fenómenos Mecánicos , Microscopía Electrónica de Rastreo , Gases em Plasma , Docilidad , Tantalio/química , Tantalio/farmacología , Resistencia a la Tracción , Sales de Tetrazolio , Tiazoles , Factores de Tiempo , Titanio/farmacologíaRESUMEN
Use of occluder devices for a patent ductus arteriosus (PDA) closure is restricted to small diameter PDAs and involves high device costs. The objective of this study was to develop a new nitinol implant for the closure of a PDA and to evaluate its safety and efficacy in an animal model. The design consists of a device that promotes thrombus formation in the PDA. The device has a double-cone shape with their vertices joined. The cones are made of a nitinol wire helix with dacron fibers attached. The proximal end of the helix can be screwed to a conventional catheter release wire. In vitro testing was performed to verify the effectiveness of the implantation of the device and its releasing system; all trials (n = 30) were successful, showing accurate placement and release of the device. Complete and successful implantation of the device was achieved in all in vivo experiments (n = 5). There was one case of embolization due to premature detachment; a second device was successfully implanted. Histological evaluation after 42.3 +/- 3.1 days demonstrated complete PDA occlusion. The retrieved PDA showed total closure of the defect, endothelization of the PDA outlets and proper lodging of the device.