A modified porous titanium sheet prepared by plasma activated sintering for biomedical applications

This study aimed to develop a contamination free porous titanium scaffold by a plasma activated sintering within an originally developed TiN coated graphite mold. The surface of porous titanium sheet with or without a coated graphite mold was characterized. The cell adhesion property of porous titanium sheet was also evaluated in this study. The peak of TiC was detected on the titanium sheet processed with the graphite mold without a TiN coating. Since the titanium fiber elements were directly in contact with the carbon graphite mold during processing, surface contamination was unavoidable event in this condition. The TiC peak was not detectable on the titanium sheet processed within the TiN coated carbon graphite mold. This modified plasma activated sintering with the TiN coated graphite mold would be useful to fabricate a contamination free titanium sheet. The number of adherent cells on the modified titanium sheet was greater than that of the bare titanium plate. Stress fiber formation and the extension of the cells were observed on the titanium sheets. This modified titanium sheet is expected to be a new tissue engineering material in orthopedic bone repair.Comment: 5 pages, 4 figure

Titanium dioxide nanotubes for production and delivery of nitric oxide and methods for production thereof

The present disclosure describes compositions operable for releasing nitric oxide under photochemical conditions. The compositions include a titanium dioxide nanomaterial and a nitric oxide-releasing compound deposited on the titanium dioxide nanomaterial that is operable to release nitric oxide under photochemical conditions. Titanium dioxide nanomaterials include, for example, titanium dioxide nanotubes. To facilitate the photochemical release of nitric oxide, some embodiments of the compositions further include a semiconductor that is deposited on the titanium dioxide nanotubes. Both the semiconductor and the nitric oxide-releasing compound may be deposited on the interior surface, exterior surface, or both of the titanium dioxide nanotubes. A polymer may wrap the titanium dioxide nanotubes to protect the nitric oxide-releasing compounds from moisture. Also disclosed herein are methods for producing such compositions and medical devices obtained therefrom.Board of Regents, University of Texas Syste

Microstructural Characterization of Shrouded Plasma-Sprayed Titanium Coatings

Titanium and its alloys are often used for corrosion protection because they are able to offer high chemical resistance against various corrosive media. In this paper, shrouded plasma spray technology was applied to produce titanium coatings. A solid shroud with an external shrouding gas was used to plasma spray titanium powder feedstock with aim of reducing the oxide content in the as-sprayed coatings. The titanium coatings were assessed by optical microscope, scanning electron microscopy, X-ray diffraction, LECO combustion method and Vickers microhardness testing. The results showed that the presence of the shroud and the external shrouding gas led to a dense microstructure with a low porosity in the plasma-sprayed titanium coatings. The oxygen and nitrogen contents in the titanium coating were kept at a low level due to the shielding effect of the shroud attachment and the external shrouding gas. The dominant phase in the shrouded titanium coatings was mainly composed of α-Ti phase, which was very similar to the titanium feedstock powders. The shrouded plasma-sprayed titanium coatings had a Vickers microhardness of 404.2 ± 103.2 HV

Porosity and Micro-Hardness of Shrouded Plasma Sprayed Titanium Coatings

Titanium and its alloys are often used as key materials for corrosion protection. A promising approach to optimize both mechanical properties and corrosion resistance is the use of coating technologies. In this paper, shrouded plasma spray was used as a useful technology to produce low oxide containing titanium coatings. A solid shroud was used to plasma spray titanium coatings to reduce the oxide content. The titanium coatings were assessed by optical microscope, scanning electron microscopy and Vickers microhardness testing. The results showed that the shrouded titanium coatings exhibited an enhanced microstructure. The presence of the shroud and shroud gas flow led to a significant reduction in coating porosity because the reduction in air entrainment with the shroud resulted in better heating of the particles. The shrouded titanium coatings had a lower value of Vickers microhardness and a relative lower standard deviation than the air plasma sprayed titanium coatings

Porosity and Micro-Hardness of Shrouded Plasma Sprayed Titanium Coatings

Titanium and its alloys are often used as key materials for corrosion protection. A promising approach to optimize both mechanical properties and corrosion resistance is the use of coating technologies. In this paper, shrouded plasma spray was used as a useful technology to produce low oxide containing titanium coatings. A solid shroud was used to plasma spray titanium coatings to reduce the oxide content. The titanium coatings were assessed by optical microscope, scanning electron microscopy and Vickers microhardness testing. The results showed that the shrouded titanium coatings exhibited an enhanced microstructure. The presence of the shroud and shroud gas flow led to a significant reduction in coating porosity because the reduction in air entrainment with the shroud resulted in better heating of the particles. The shrouded titanium coatings had a lower value of Vickers microhardness and a relative lower standard deviation than the air plasma sprayed titanium coatings

Numerical and experimental analysis of cold forming of titanium alloy sheets

Due to an increasing demand for the titanium drawn-parts, mainly from the aerospace and car industries, the demand for expertise in sheet-titanium forming grows. Although titanium combine many valuable features like lightweight with high strength and excellent corrosion resistance, its application is still limited because titanium processing, especially cold forming of titanium sheets poses many problems. In the paper technological problems with forming of titanium sheets is discussed. A special attention is paid to flexible forming. The experimental and numerical simulation results of semi-flexible forming are presented. The numerical analyses are carried out with the ADINA System v. 8.6 basing on the Finite Element Method (FEM). A spherical drawn-part made of Ti6Al4V titanium sheet is analysed. The material data, which are necessary for the numerical calculations, such as tensile strength Rm, yield point Re, R-value and hardening coefficient n were determined experimentally. The numerical calculations show good convergence with the experiment

Biomaterial Properties of Titanium in Dentistry

Background Among various dental materials and their successful restorative uses, titanium provides an excellent example of integrating science and technology involving multiple disciplines of dentistry including biomaterials, prosthodontics and surgical sciences. Titanium and its alloys have emerged as a material of choice for dental implants fulfilling all requirements biologically, chemically and mechanically. Several excellent reviews have discussed the properties of titanium and its surface characteristics that render it biocompatible. However, in most patients, titanium implants are used alongside several other metals. Presence of different metals in the same oral environment can alter the properties of titanium. Other influencing factors include intra-oral pH, salivary content, and effect of fluorides. Highlight This review discusses the effect of the above-mentioned conditions on the properties of titanium and its alloys. An extensive literature search encompassing the properties of titanium in an altered oral environment and its interaction with other restorative materials is presented. Specific conditions that could cause titanium to corrode, specifically due to interaction with other dental materials used in oral rehabilitation, as well as methods that can be employed for passivation of titanium are discussed. Conclusion This review presents an overview of the properties of titanium that are vital for its use in implant dentistry. From a restorative perspective, interaction between implant restoration metals, intra-oral fluorides and pH may cause titanium to corrode. Therefore, in order to avoid the resulting deleterious effects, an understanding of these interactions is important for long-term prognosis of implant restorations

Functionalisation of Ti6Al4V and hydroxyapatite surfaces with combined peptides based on KKLPDA and EEEEEEEE peptides

Surface modifications are usually performed on titanium alloys to improve osteo-integration and surface bioactivity. Modifications such as alkaline and acid etching, or coating with bioactive materials such as hydroxyapatite, have previously been demonstrated. The aim of this work is to develop a peptide with combined titanium oxide and hydroxyapatite binders in order to achieve a biomimetic hydroxyapatite coating on titanium surfaces. The technology would also be applicable for the functionalisation of titanium and hydroxyapatite surfaces for selective protein adsorption, conjugation of antimicrobial peptides, and adsorption of specialised drugs for drug delivery. In this work, functionalisation of Ti6Al4V and hydroxyapatite surfaces was achieved using combined titanium-hydroxyapatite (Ti-Hap) peptides based on titanium binder (RKLPDA) and hydroxyapatite binder (EEEEEEEE) peptides. Homogeneous peptide coatings on Ti6Al4V surfaces were obtained after surface chemical treatments with a 30 wt % aqueous solution of H2O2 for 24 and 48 hours. The treated titanium surfaces presented an average roughness of Sa=197 nm (24 h) and Sa=128 nm (48 h); an untreated mirror polished sample exhibited an Sa of 13 nm. The advancing water contact angle of the titanium oxide layer after 1 hour of exposure to 30 wt % aqueous solution of H2O2 was around 65°, decreasing gradually with time until it reached 35° after a 48 hour exposure, suggesting that the surface hydrophilicity increased over etching time. The presence of a lysine (L) amino acid in the sequence of the titanium binder resulted in fluorescence intensity roughly 16 % higher compared with the arginine (R) amino acid analogue and therefore the lysine containing titanium binder was used in this work. The Ti-Hap peptide KKLPDAEEEEEEEE (Ti-Hap1) was not adsorbed by the treated Ti6Al4V surfaces and therefore was modified. The modifications involved the inclusion of a glycine spacer between the binding terminals (Ti-Hap2) and the addition of a second titanium binder (KKLPDA) (Ti-Hap3 and Ti-Hap4). The Ti-Hap peptide aptamer which exhibited the strongest intensity after the titanium dip coating was KKLPDAKKLPDAEEEEEEEE (Ti-Hap4). On the other hand, hydroxyapatite surfaces, exhibiting an average roughness of Sa=1.42 µm, showed a higher fluorescence for all peptides compared with titanium surfaces

Synthesis of titanium-containing ZSM-48

Titanium-containing ZSM-48 is synthesized with silicon to titanium ratios of 26 or larger; changes in unit cell volume and IR data show that titanium is incorporated into framework positions