Cleaning of biomaterial surfaces: protein removal by different solvents.

Science.gov (United States)

Kratz, Fabian; Grass, Simone; Umanskaya, Natalia; Scheibe, Christian; Müller-Renno, Christine; Davoudi, Neda; Hannig, Matthias; Ziegler, Christiane

2015-04-01

The removal of biofilms or protein films from biomaterials is still a challenging task. In particular, for research investigations on real (applied) surfaces the reuse of samples is of high importance, because reuse allows the comparison of the same sample in different experiments. The aim of the present study was to evaluate the cleaning efficiency of different solvents (SDS, water, acetone, isopropanol, RIPA-buffer and Tween-20) on five different biomaterials (titanium, gold, PMMA (no acetone used), ceramic, and PTFE) with different wettability which were covered by layers of two different adsorbed proteins (BSA and lysozyme). The presence of a protein film after adsorption was confirmed by transmission electron microscopy (TEM). After treatment of the surfaces with the different solvents, the residual proteins on the surface were determined by BCA-assay (bicinchoninic acid assay). Data of the present study indicate that SDS is an effective solvent, but for several protein-substrate combinations it does not show the cleaning efficiency often mentioned in literature. RIPA-buffer and Tween-20 were more effective. They showed very low residual protein amounts after cleaning on all examined material surfaces and for both proteins, however, with small differences for the respective substrate-protein combinations. RIPA-buffer in combination with ultrasonication completely removed the protein layer as confirmed by TEM. Copyright © 2015 Elsevier B.V. All rights reserved.

Deposition of silver nanoparticles on titanium surface for antibacterial effect

Directory of Open Access Journals (Sweden)

Liao Juan

2010-04-01

Full Text Available Liao Juan1, Zhu Zhimin3, Mo Anchun1,2, Li Lei1, Zhang Jingchao11State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, PR China; 2Department of Dental Implant, West China Stomatology Hospital, Sichuan University, Chengdu 610041, PR China; 3Department of Prosthodontics, West China Stomatology Hospital, Sichuan University, Chengdu 610041, PR ChinaAbstract: Microbial colonization on implanted devices and biofilm formation is a recurrent complication in implant surgery and may result in loss of implants. The aim of this study was to deposit silver nanoparticles on a titanium surface to obtain antibacterial properties. In the present study, we prepared a silver nanoparticle-modified titanium (Ti-nAg surface using silanization method. The morphology and chemical components of the Ti-nAg surface were characterized by scanning electron microscopy (SEM equipped with energy-dispersive spectroscopy (EDS. Two species of bacteria, Staphylococcus aureus and Escherichia coli, were utilized to test the antibacterial effect of the Ti-nAg treated surface. The SEM examination revealed that a small quantity of silver nanoparticles was sparsely deposited on the titanium surface. The diameter of these nanoparticles ranged from ten to several hundred nm. EDS analyses revealed that there was 4.26% of Ag present on the surface. After a 24-hour incubation, 94% of Staphylococcus aureus and over 95% of Escherichia coli had been killed on the Ti-nAg surface, and the SEM examination of anti-adhesive efficacy test showed that there were less bacteria attached to Ti-nAg surface than to a control surface of untreated Titanium. These data suggest that silver nanoparticle-modified titanium is a promising material with an antibacterial property that may be used as an implantable biomaterial.Keywords: nano-silver, titanium, antibacterial activity, silanization method

Additively manufactured metallic porous biomaterials based on minimal surfaces

DEFF Research Database (Denmark)

Bobbert, F. S. L.; Lietaert, K.; Eftekhari, Ali Akbar

2017-01-01

Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different...... of bone properties is feasible, biomaterials that could simultaneously mimic all or most of the relevant bone properties are rare. We used rational design and additive manufacturing to develop porous metallic biomaterials that exhibit an interesting combination of topological, mechanical, and mass...

Antibacterial Behavior of Additively Manufactured Porous Titanium with Nanotubular Surfaces Releasing Silver Ions.

Science.gov (United States)

Amin Yavari, S; Loozen, L; Paganelli, F L; Bakhshandeh, S; Lietaert, K; Groot, J A; Fluit, A C; Boel, C H E; Alblas, J; Vogely, H C; Weinans, H; Zadpoor, A A

2016-07-13

Additive manufacturing (3D printing) has enabled fabrication of geometrically complex and fully interconnected porous biomaterials with huge surface areas that could be used for biofunctionalization to achieve multifunctional biomaterials. Covering the huge surface area of such porous titanium with nanotubes has been already shown to result in improved bone regeneration performance and implant fixation. In this study, we loaded TiO2 nanotubes with silver antimicrobial agents to equip them with an additional biofunctionality, i.e., antimicrobial behavior. An optimized anodizing protocol was used to create nanotubes on the entire surface area of direct metal printed porous titanium scaffolds. The nanotubes were then loaded by soaking them in three different concentrations (i.e., 0.02, 0.1, and 0.5 M) of AgNO3 solution. The antimicrobial behavior and cell viability of the developed biomaterials were assessed. As far as the early time points (i.e., up to 1 day) are concerned, the biomaterials were found to be extremely effective in preventing biofilm formation and decreasing the number of planktonic bacteria particularly for the middle and high concentrations of silver ions. Interestingly, nanotubes not loaded with antimicrobial agents also showed significantly smaller numbers of adherent bacteria at day 1, which may be attributed to the bactericidal effect of high aspect ratio nanotopographies. The specimens with the highest concentrations of antimicrobial agents adversely affected cell viability at day 1, but this effect is expected to decrease or disappear in the following days as the rate of release of silver ions was observed to markedly decrease within the next few days. The antimicrobial effects of the biomaterials, particularly the ones with the middle and high concentrations of antimicrobial agents, continued until 2 weeks. The potency of the developed biomaterials in decreasing the number of planktonic bacteria and hindering the formation of biofilms make

Modified titanium surface with gelatin nano gold composite increases osteoblast cell biocompatibility

International Nuclear Information System (INIS)

Lee, Young-Hee; Bhattarai, Govinda; Aryal, Santosh; Lee, Nan-Hee; Lee, Min-Ho; Kim, Tae-Gun; Jhee, Eun-Chung; Kim, Hak-Yong; Yi, Ho-Keun

2010-01-01

This study examined the gelatin nano gold (GnG) composite for surface modification of titanium in addition to insure biocompatibility on dental implants or biomaterials. The GnG composite was constructed by gelatin and hydrogen tetrachloroaurate in presence of reducing agent, sodium borohydrate (NabH 4 ). The GnG composite was confirmed by UV-VIS spectroscopy and transmission electron microscopy (TEM). A dipping method was used to modify the titanium surface by GnG composite. Surface was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The MC-3T3 E1 cell viability was assessed by trypan blue and the expression of proteins to biocompatibility were analyzed by Western blotting. The GnG composite showed well dispersed character, the strong absorption at 530 nm, roughness, regular crystal and clear C, Na, Cl, P, and Au signals onto titanium. Further, this composite allowed MC-3T3 E1 growth and viability compared to gelatin and pure titanium. It induced ERK activation and the expression of cell adherent molecules, FAK and SPARC, and growth factor, VEGF. However, GnG decreased the level of SAPK/JNK. This shows that GnG composite coated titanium surfaces have a good biocompatibility for osteoblast growth and attachment than in intact by simple and versatile dipping method. Furthermore, it offers good communication between cell and implant surfaces by regulating cell signaling and adherent molecules, which are useful to enhance the biocompatibility of titanium surfaces.

Development of titanium alloys and surface treatments to increase the implants lifetime

Directory of Open Access Journals (Sweden)

Joan Lario-Femenía

2016-12-01

Full Text Available The population aging together with increase of life expectancy forces the development of new prosthesis which may present a higher useful life. The clinical success of implants is based on the osseointegration achievement. Therefore, metal implants must have a mechanical compatibility with the substituted bone, which is achieved through a combination of low elastic modulus, high flexural and fatigue strength. The improvement, in the short and long term, of the osseointegration depends on several factors, where the macroscopic design and dimensional, material and implant surface topography are of great importance. This article is focused on summarizing the advantages that present the titanium and its alloys to be used as biomaterials, and the development that they have suffered in recent decades to improve their biocompatibility. Consequently, the implants evolution has been recapitulated and summarized through three generations. In the recent years the interest on the surface treatments for metallic prostheses has been increased, the main objective is achieve a lasting integration between implant and bone tissue, in the shortest time possible. On this article various surface treatments currently used to modify the surface roughness or to obtain coatings are described it; it is worthy to mention the electrochemical oxidation with post-heat treated to modify the titanium oxide crystalline structure. After the literature review conducted for prepare this article, the ? titanium alloys, with a nanotubes surface of obtained by electrochemical oxidation and a subsequent step of heat treatment to obtain a crystalline structure are the future option to improve long term biocompatibility of titanium prostheses.

Biomaterials for artificial organs

CERN Document Server

Lysaght, Michael J

2010-01-01

The worldwide demand for organ transplants far exceeds available donor organs. Consequently some patients die whilst waiting for a transplant. Synthetic alternatives are therefore imperative to improve the quality of, and in some cases, save people's lives. Advances in biomaterials have generated a range of materials and devices for use either outside the body or through implantation to replace or assist functions which may have been lost through disease or injury. Biomaterials for artificial organs reviews the latest developments in biomaterials and investigates how they can be used to improve the quality and efficiency of artificial organs. Part one discusses commodity biomaterials including membranes for oxygenators and plasmafilters, titanium and cobalt chromium alloys for hips and knees, polymeric joint-bearing surfaces for total joint replacements, biomaterials for pacemakers, defibrillators and neurostimulators and mechanical and bioprosthetic heart valves. Part two goes on to investigate advanced and ...

In vitro biocompatibility of titanium after plasma surface alloying with boron

Energy Technology Data Exchange (ETDEWEB)

Kaczmarek, Mariusz, E-mail: markacz@ump.edu.pl [Department of Immunology, Chair of Clinical Immunology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Mieczysława U. [Division Mother' s and Child' s Health, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan (Poland); Miklaszewski, Andrzej [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland); Paszel-Jaworska, Anna; Romaniuk, Aleksandra; Lipińska, Natalia [Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355 Poznan (Poland); Żurawski, Jakub [Department of Immunobiochemistry, Chair of Biology and Environmental Sciences, Poznan University of Medical Sciences, Rokietnicka 8, 60-806 Poznan (Poland); Urbaniak, Paulina [Department of Cell Biology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Karolina [Department of Conservative Dentistry and Periodontology, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznan (Poland)

2016-12-01

Recently, the effect of different sizes of precursor powders during surface plasma alloying modification on the properties of titanium surface was studied. In this work we show in vitro test results of the titanium (α-Ti) after plasma surface alloying with boron (B). Ti-B nanopowders with 2 and 10 wt% B were deposited onto microcrystalline Ti substrate. The in vitro cytocompatibility of these biomaterials was evaluated and compared with a conventional microcrystalline Ti. During the studies, established cell line of human gingival fibroblasts and osteoblasts were cultured in the presence of tested materials, and its survival rate and proliferation activity were examined. For this purpose, MTT assay, flow cytometric and fluorescent microscopic evaluation were made. Biocompatibility tests carried out indicate that the Ti after plasma surface alloying with B could be a possible candidate for dental implants and other medicinal applications. Plasma alloying is a promising method for improving the properties of titanium, thus increasing the field of its applications. - Highlights: • this is first article carried out on the titanium after plasma surface alloying with different contents of boron; • microcrystalline titanium modified with boron changes the physicochemical features of conventional material; • Ti modified by boron is proper in terms of effects on survival and proliferative activity of cells of dental alveoli; • precursors with different content of boron in different ways influence the intensity and stability of cell growth;.

Bone bonding at natural and biomaterial surfaces.

Science.gov (United States)

Davies, John E

2007-12-01

Bone bonding is occurring in each of us and all other terrestrial vertebrates throughout life at bony remodeling sites. The surface created by the bone-resorbing osteoclast provides a three-dimensionally complex surface with which the cement line, the first matrix elaborated during de novo bone formation, interdigitates and is interlocked. The structure and composition of this interfacial bony matrix has been conserved during evolution across species; and we have known for over a decade that this interfacial matrix can be recapitulated at a biomaterial surface implanted in bone, given appropriate healing conditions. No evidence has emerged to suggest that bone bonding to artificial materials is any different from this natural biological process. Given this understanding it is now possible to explain why bone-bonding biomaterials are not restricted to the calcium-phosphate-based bioactive materials as was once thought. Indeed, in the absence of surface porosity, calcium phosphate biomaterials are not bone bonding. On the contrary, non-bonding materials can be rendered bone bonding by modifying their surface topography. This paper argues that the driving force for bone bonding is bone formation by contact osteogenesis, but that this has to occur on a sufficiently stable recipient surface which has micron-scale surface topography with undercuts in the sub-micron scale-range.

Improvement of Functional Properties by Sever Plastic Deformation on Parts of Titanium Biomaterials

Science.gov (United States)

Czán, Andrej; Babík, Ondrej; Daniš, Igor; Martikáň, Pavol; Czánová, Tatiana

2017-12-01

Main task of materials for invasive implantology is their biocompatibility with the tissue but also requirements for improving the functional properties of given materials are increasing constantly. One of problems of materials biocompatibility is the impossibility to improve of functional properties by change the percentage of the chemical elements and so it is necessary to find other innovative methods of improving of functional properties such as mechanical action in the form of high deformation process. This paper is focused on various methods of high deformation process such as Equal Channel Angular Pressing (ECAP) when rods with record strength properties were obtained.The actual studies of the deformation process properties as tri-axial compress stress acting on workpiece with high speed of deformation shows effects similar to results obtained using the other methods, but in lower levels of stress. Hydrostatic extrusion (HE) is applying for the purpose of refining the structure of the commercially pure titanium up to nano-scale. Experiments showed the ability to reduce the grain size below 100 nm. Due to the significant change in the performance of the titanium materials by severe plastic deformation is required to identify the processability of materials with respect to the identification of created surfaces and monitoring the surface integrity, where the experimental results show ability of SPD technologies application on biomaterials.

Surface characterization and cytotoxicity analysis of plasma sprayed coatings on titanium alloys

Energy Technology Data Exchange (ETDEWEB)

Rahman, Zia ur; Shabib, Ishraq [School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI 48859 (United States); Science of Advanced Materials, Central Michigan University, Mount Pleasant, MI 48859 (United States); Haider, Waseem, E-mail: haide1w@cmich.edu [School of Engineering and Technology, Central Michigan University, Mount Pleasant, MI 48859 (United States); Science of Advanced Materials, Central Michigan University, Mount Pleasant, MI 48859 (United States)

2016-10-01

In the realm of biomaterials, metallic materials are widely used for load bearing joints due to their superior mechanical properties. Despite the necessity for long term metallic implants, there are limitations to their prolonged use. Naturally, oxides of titanium have low solubilities and form passive oxide film spontaneously. However, some inclusion and discontinuity spots in oxide film make implant to adopt the decisive nature. These defects heighten the dissolution of metal ions from the implant surface, which results in diminishing bio-integration of titanium implant. To increase the long-term metallic implant stability, surface modifications of titanium alloys are being carried out. In the present study, biomimetic coatings of plasma sprayed hydroxyapatite and titanium were applied to the surface of commercially pure titanium and Ti6Al4V. Surface morphology and surface chemistry were studied using scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Cyclic potentiodynamic polarization and electrochemical impedance spectroscopy were carried out in order to study their electrochemical behavior. Moreover, cytotoxicity analysis was conducted for osteoblast cells by performing MTS assay. It is concluded that both hydroxyapatite and titanium coatings enhance corrosion resistance and improve cytocompatibility. - Highlights: • Surface morphology and surface chemistry were studied using scanning electron microscopy and X-ray photoelectron spectroscopy. • The cyclic polarization tests revealed noticeable improvement towards the positive potentials for both Tip coatings. • CpTi-Hap and Ti6Al4V-Hap both demonstrate similar corrosion rate. • High cytotoxicity was observed for Mp when compared with Tip and Hap after 21 days of immersion. • Both Tip and Hap coatings promoted the osteoblast cell adhesion and exhibited stellar morphology.

The development of peptide-based interfacial biomaterials for generating biological functionality on the surface of bioinert materials.

Science.gov (United States)

Meyers, Steven R; Khoo, Xiaojuan; Huang, Xin; Walsh, Elisabeth B; Grinstaff, Mark W; Kenan, Daniel J

2009-01-01

Biomaterials used in implants have traditionally been selected based on their mechanical properties, chemical stability, and biocompatibility. However, the durability and clinical efficacy of implantable biomedical devices remain limited in part due to the absence of appropriate biological interactions at the implant interface and the lack of integration into adjacent tissues. Herein, we describe a robust peptide-based coating technology capable of modifying the surface of existing biomaterials and medical devices through the non-covalent binding of modular biofunctional peptides. These peptides contain at least one material binding sequence and at least one biologically active sequence and thus are termed, "Interfacial Biomaterials" (IFBMs). IFBMs can simultaneously bind the biomaterial surface while endowing it with desired biological functionalities at the interface between the material and biological realms. We demonstrate the capabilities of model IFBMs to convert native polystyrene, a bioinert surface, into a bioactive surface that can support a range of cell activities. We further distinguish between simple cell attachment with insufficient integrin interactions, which in some cases can adversely impact downstream biology, versus biologically appropriate adhesion, cell spreading, and cell survival mediated by IFBMs. Moreover, we show that we can use the coating technology to create spatially resolved patterns of fluorophores and cells on substrates and that these patterns retain their borders in culture.

Biomaterials surface science

CERN Document Server

Taubert, Andreas; Rodriguez-Cabello, José Carlos

2013-01-01

The book provides an overview of the highly interdisciplinary field of surface science in the context of biological and biomedical applications. The covered topics range from micro- and nanostructuring for imparting functionality in a top-down manner to the bottom-up fabrication of gradient surfaces by self-assembly, from interfaces between biomaterials and living matter to smart, stimuli-responsive surfaces, and from cell and surface mechanics to the elucidation of cell-chip interactions in biomedical devices.

Antimicrobial and Osseointegration Properties of Nanostructured Titanium Orthopaedic Implants.

Science.gov (United States)

Jäger, Marcus; Jennissen, Herbert P; Dittrich, Florian; Fischer, Alfons; Köhling, Hedda Luise

2017-11-13

The surface design of titanium implants influences not only the local biological reactions but also affects at least the clinical result in orthopaedic application. During the last decades, strong efforts have been made to improve osteointegration and prevent bacterial adhesion to these surfaces. Following the rule of "smaller, faster, cheaper", nanotechnology has encountered clinical application. It is evident that the hierarchical implant surface micro- and nanotopography orchestrate the biological cascades of early peri-implant endosseous healing or implant loosening. This review of the literature gives a brief overview of nanostructured titanium-base biomaterials designed to improve osteointegration and prevent from bacterial infection.

Titanium implants with modified surfaces: Meta-analysis of in vivo osteointegration

Energy Technology Data Exchange (ETDEWEB)

Gasik, Michael, E-mail: michael.gasik@aalto.fi [Aalto University Foundation, School of Chemical Technology, P.O. Box 16200, FIN-00076 AALTO (Finland); Braem, Annabel [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium); Chaudhari, Amol; Duyck, Joke [Department of Prosthetic Dentistry, BIOMAT Research Cluster, KU Leuven, Kapucijnenvoer 7a, B-3000 Leuven (Belgium); Vleugels, Jozef [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44, B-3001 Heverlee (Belgium)

2015-04-01

Titanium-based implants are widely used in modern clinical practice, but their “optimal” properties in terms of porosity and topology, roughness and hydrophilic parameters are being a subject of intensive discussions. Recent in vitro results have shown a possibility to optimize the surface of an implant with maximal repelling of bacteria (Staphylococcus aureus, Staphylococcus epidermidis) and improvement in human osteogenic and endothelial cell adhesion, proliferation and differentiation. In this work, these different grades titanium implants were tested in vivo using the same analytical methodology. In addition to material parameters, key histomorphometrical parameters such a regeneration area, bone adaptation area and bone-to-implant contact were determined after 2 and 4 weeks of implantation in rabbit animal model. Porous implants have more clear differences than non-porous ones, with the best optimum values obtained on hydrothermally treated electrophoretically deposited titanium. These in vivo data correlate well with the optimal prediction made by in vitro tests. - Highlights: • Various titanium specimens were studied in vivo on osteointegration vs their properties. • Non-porous implants had a better performance when coated with bioactive glass. • Porous implants have shown the best results for hydrothermally treated specimens. • Good correlation was found with the previous in vitro tests. • New analysis of the in vivo data has shown benefits to assess biomaterials performance.

Titanium implants with modified surfaces: Meta-analysis of in vivo osteointegration

International Nuclear Information System (INIS)

Gasik, Michael; Braem, Annabel; Chaudhari, Amol; Duyck, Joke; Vleugels, Jozef

2015-01-01

Titanium-based implants are widely used in modern clinical practice, but their “optimal” properties in terms of porosity and topology, roughness and hydrophilic parameters are being a subject of intensive discussions. Recent in vitro results have shown a possibility to optimize the surface of an implant with maximal repelling of bacteria (Staphylococcus aureus, Staphylococcus epidermidis) and improvement in human osteogenic and endothelial cell adhesion, proliferation and differentiation. In this work, these different grades titanium implants were tested in vivo using the same analytical methodology. In addition to material parameters, key histomorphometrical parameters such a regeneration area, bone adaptation area and bone-to-implant contact were determined after 2 and 4 weeks of implantation in rabbit animal model. Porous implants have more clear differences than non-porous ones, with the best optimum values obtained on hydrothermally treated electrophoretically deposited titanium. These in vivo data correlate well with the optimal prediction made by in vitro tests. - Highlights: • Various titanium specimens were studied in vivo on osteointegration vs their properties. • Non-porous implants had a better performance when coated with bioactive glass. • Porous implants have shown the best results for hydrothermally treated specimens. • Good correlation was found with the previous in vitro tests. • New analysis of the in vivo data has shown benefits to assess biomaterials performance

Morphological Observations of Mesenchymal Stem Cell Adhesion to a Nanoperiodic-Structured Titanium Surface Patterned Using Femtosecond Laser Processing

Science.gov (United States)

Oya, Kei; Aoki, Shun; Shimomura, Kazunori; Sugita, Norihiko; Suzuki, Kenji; Nakamura, Norimasa; Fujie, Hiromichi

2012-12-01

It is known that the adhesive and anisotropic properties of cell-derived biomaterials are affected by micro- or nanoscale structures processed on culture surfaces. In the present study, the femtosecond laser processing technique was used to scan a laser beam at an intensity of approximately the ablation threshold level on a titanium surface for nanoscale processing. Microscopy observation revealed that the processed titanium exhibited a periodic-patterned groove structure at the surface; the width and depth of the groove were 292 ±50 and 99 ±31 nm, respectively, and the periodic pitch of the groove was 501 ±100 nm. Human synovium-derived mesenchymal stem cells were cultured on the surface at a cell density of 3.0×103 cells/cm2 after 4 cell passages. For comparison, the cells were also cultured on a nonprocessed titanium surface under the condition identical to that of the processed surface. Results revealed that the duration for cell attachment to the surface was markedly reduced on the processed titanium as compared with the nonprocessed titanium. Moreover, on the processed titanium, cell extension area significantly increased while cell orientation was aligned along the direction of the periodic grooves. These results suggest that the femtosecond laser processing improves the adhesive and anisotropic properties of cells by producing the nanoperiodic structure on titanium culture surfaces.

Enhancing anticoagulation and endothelial cell proliferation of titanium surface by sequential immobilization of poly(ethylene glycol) and collagen

International Nuclear Information System (INIS)

Pan, Chang-Jiang; Hou, Yan-Hua; Ding, Hong-Yan; Dong, Yun-Xiao

2013-01-01

In the present study, poly(ethylene glycol) (PEG) and collagen I were sequentially immobilized on the titanium surface to simultaneously improve the anticoagulation and endothelial cell proliferation. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy analysis confirmed that PEG and collagen I were successfully immobilized on the titanium surface. Water contact angle results suggested the excellent hydrophilic surface after the immobilization. The anticoagulation experiments demonstrated that the immobilized PEG and collagen I on the titanium surface could not only obviously prevent platelet adhesion and aggregation but also prolong activated partial thromboplastin time (APTT), leading to the improved blood compatibility. Furthermore, immobilization of collagen to the end of PEG chain did not abate the anticoagulation. As compared to those on the pristine and PEG-modified titanium surfaces, endothelial cells exhibited improved proliferative profiles on the surface modified by the sequential immobilization of PEG and collagen in terms of CCK-8 assay, implying that the modified titanium may promote endothelialization without abating the blood compatibility. Our method may be used to modify the surface of blood-contacting biomaterials such as titanium to promote endothelialization and improve the anticoagulation, it may be helpful for development of the biomedical devices such as coronary stents, where endothelializaton and excellent anticoagulation are required.

Plasma assisted surface treatments of biomaterials.

Science.gov (United States)

Minati, L; Migliaresi, C; Lunelli, L; Viero, G; Dalla Serra, M; Speranza, G

2017-10-01

The biocompatibility of an implant depends upon the material it is composed of, in addition to the prosthetic device's morphology, mechanical and surface properties. Properties as porosity and pore size should allow, when required, cells penetration and proliferation. Stiffness and strength, that depend on the bulk characteristics of the material, should match the mechanical requirements of the prosthetic applications. Surface properties should allow integration in the surrounding tissues by activating proper communication pathways with the surrounding cells. Bulk and surface properties are not interconnected, and for instance a bone prosthesis could possess the necessary stiffness and strength for the application omitting out prerequisite surface properties essential for the osteointegration. In this case, surface treatment is mandatory and can be accomplished using various techniques such as applying coatings to the prosthesis, ion beams, chemical grafting or modification, low temperature plasma, or a combination of the aforementioned. Low temperature plasma-based techniques have gained increasing consensus for the surface modification of biomaterials for being effective and competitive compared to other ways to introduce surface functionalities. In this paper we review plasma processing techniques and describe potentialities and applications of plasma to tailor the interface of biomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

Bone regeneration performance of surface-treated porous titanium.

Science.gov (United States)

Amin Yavari, Saber; van der Stok, Johan; Chai, Yoke Chin; Wauthle, Ruben; Tahmasebi Birgani, Zeinab; Habibovic, Pamela; Mulier, Michiel; Schrooten, Jan; Weinans, Harrie; Zadpoor, Amir Abbas

2014-08-01

The large surface area of highly porous titanium structures produced by additive manufacturing can be modified using biofunctionalizing surface treatments to improve the bone regeneration performance of these otherwise bioinert biomaterials. In this longitudinal study, we applied and compared three types of biofunctionalizing surface treatments, namely acid-alkali (AcAl), alkali-acid-heat treatment (AlAcH), and anodizing-heat treatment (AnH). The effects of treatments on apatite forming ability, cell attachment, cell proliferation, osteogenic gene expression, bone regeneration, biomechanical stability, and bone-biomaterial contact were evaluated using apatite forming ability test, cell culture assays, and animal experiments. It was found that AcAl and AnH work through completely different routes. While AcAl improved the apatite forming ability of as-manufactured (AsM) specimens, it did not have any positive effect on cell attachment, cell proliferation, and osteogenic gene expression. In contrast, AnH did not improve the apatite forming ability of AsM specimens but showed significantly better cell attachment, cell proliferation, and expression of osteogenic markers. The performance of AlAcH in terms of apatite forming ability and cell response was in between both extremes of AnH and AsM. AcAl resulted in significantly larger volumes of newly formed bone within the pores of the scaffold as compared to AnH. Interestingly, larger volumes of regenerated bone did not translate into improved biomechanical stability as AnH exhibited significantly better biomechanical stability as compared to AcAl suggesting that the beneficial effects of cell-nanotopography modulations somehow surpassed the benefits of improved apatite forming ability. In conclusion, the applied surface treatments have considerable effects on apatite forming ability, cell attachment, cell proliferation, and bone ingrowth of the studied biomaterials. The relationship between these properties and the bone

Elaboration de plateformes biomimétiques à base de dopamine pour la fonctionnalisation du titane Elaboration of biomimetic dopamine platforms for the functionalization of titanium surfaces

Directory of Open Access Journals (Sweden)

Laure William

2013-11-01

Full Text Available L'étude concerne la fonctionnalisation de surfaces à base de titane à partir d'une ancre chimique biomimétique modifiable chimiquement, la dopamine, dans le but de concevoir des biomatériaux utilisables en tant que dispositifs implantables. Deux approches différentes de greffage par la stratégie «graft to» sont proposées. La première consiste en la synthèse et l'immobilisation sur les surfaces de titane de polymères parfaitement définis et stimulables fonctionnalisés par un motif catéchol en extrémité de chaîne. La seconde propose de modifier préalablement la surface par une ancre chimique spécifique intégrant un motif catéchol d'une part et un motif furane ou maléimide d'autre part permettant d'engager sur demande une réaction réversible de cycloaddition de type Diels Alder (DA avec une large gamme de molécules ou polymères fonctionnalisés par l'entité complémentaire. The aim of this study concerns the functionalization of titanium surfaces by using versatile dopamine based on biomimetic anchors. This general concept was exploited to design new biomaterials which might be used as medical implants. In this context, two different grafting strategies based onto the “grafting to” approach were developed. The first one consisted on the synthesis and the immobilization of well-defined catechol end-functionalized polymers onto titanium surfaces. The second strategy was based on the functionalization of titanium surfaces by using dopamine derivates containing, on the one hand, a catechol unit for surface attachment and, on the other hand, a furan or a maleimide moiety able to react, on demand, through reversible Diels Alder (DA reaction.

A new titanium based alloy Ti-27Nb-13Zr produced by powder metallurgy with biomimetic coating for use as a biomaterial.

Science.gov (United States)

Mendes, Marcio W D; Ágreda, Carola G; Bressiani, Ana H A; Bressiani, José C

2016-06-01

Titanium alloys are widely used in biomedical applications due to their excellent properties such as high strength, good corrosion resistance and biocompatibility. Titanium alloys with alloying elements such as Nb and Zr are biocompatible and have Young's modulus close to that of human bone. To increase the bioactivity of titanium alloy surfaces is used chemical treatment with NaOH followed by immersion in simulated body fluid (SBF). The purpose of this study was to produce the alloy Ti-27Nb-13Zr with low Young's modulus by powder metallurgy using powders produced by the HDH process. The formation of biomimetic coatings on samples immersed in SBF for 3, 7, 11 and 15 days was evaluated. Characterization of the coating was performed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and scanning electron microscope. The microstructure and composition of the alloy were determined using SEM and XRD, while the mechanical properties were evaluated by determining the elastic modulus and the Vickers microhardness. The sintered alloys were composed of α and β phases, equiaxed grains and with density around 97.8% of its theoretical density. The Vickers microhardness and elasticity modulus of the alloy were determined and their values indicate that this alloy can be used as a biomaterial. Analysis of the coating revealed the presence of calcium phosphate layers on samples immersed for >3 days in the SBF solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Silk film biomaterials for ocular surface repair

Science.gov (United States)

Lawrence, Brian David

Current biomaterial approaches for repairing the cornea's ocular surface upon injury are partially effective due to inherent material limitations. As a result there is a need to expand the biomaterial options available for use in the eye, which in turn will help to expand new clinical innovations and technology development. The studies illustrated here are a collection of work to further characterize silk film biomaterials for use on the ocular surface. Silk films were produced from regenerated fibroin protein solution derived from the Bombyx mori silkworm cocoon. Methods of silk film processing and production were developed to produce consistent biomaterials for in vitro and in vivo evaluation. A wide range of experiments was undertaken that spanned from in vitro silk film material characterization to in vivo evaluation. It was found that a variety of silk film properties could be controlled through a water-annealing process. Silk films were then generated that could be use in vitro to produce stratified corneal epithelial cell sheets comparable to tissue grown on the clinical standard substrate of amniotic membrane. This understanding was translated to produce a silk film design that enhanced corneal healing in vivo on a rabbit injury model. Further work produced silk films with varying surface topographies that were used as a simplified analog to the corneal basement membrane surface in vitro. These studies demonstrated that silk film surface topography is capable of directing corneal epithelial cell attachment, growth, and migration response. Most notably epithelial tissue development was controllably directed by the presence of the silk surface topography through increasing cell sheet migration efficiency at the individual cellular level. Taken together, the presented findings represent a comprehensive characterization of silk film biomaterials for use in ocular surface reconstruction, and indicate their utility as a potential material choice in the

Relationship between surface properties (roughness, wettability) of titanium and titanium alloys and cell behaviour

International Nuclear Information System (INIS)

Ponsonnet, L.; Reybier, K.; Jaffrezic, N.; Comte, V.; Lagneau, C.; Lissac, M.; Martelet, C.

2003-01-01

Cell attachment and spreading to titanium-based alloy surfaces is a major parameter in implant technology. In this paper, substratum surface hydrophobicity, surface free energy, interfacial free energy and surface roughness were investigated to ascertain which of these parameters is predominant in human fibroblast spreading. Two methods for contact angle measurement were compared: the sessile drop method and the captive bubble two-probe method. The relationship between surface roughness and the sessile drop contact angles of various engineered titanium surfaces such as commercial pure titanium (cp-Ti), titanium-aluminium-vanadium alloy (Ti-6Al-4V), and titanium-nickel (NiTi), was shown. Surface free energy (SFE) calculations were performed from contact angles obtained on smooth samples based on the same alloys in order to eliminate the roughness effect. SFE of the surfaces have been calculated using the Owens-Wendt (OW) and Van Oss (VO) approaches with the sessile drop method. The OW calculations are used to obtain the dispersive (γ d ) and polar (γ p ) component of SFE, and the VO approach allows to reach the apolar (γ LW ) and the polar acid-base component (γ ab ) of the surface. From captive bubble contact angle experiments (air or octane bubble under water), the interfacial free energy of the different surfaces in water was obtained. A relationship between cell spreading and the polar component of SFE was found. Interfacial free energy values were low for all the investigated surfaces indicating good biocompatibility for such alloys

Surface modification of polyester biomaterials for tissue engineering

International Nuclear Information System (INIS)

Jiao Yanpeng; Cui Fuzhai

2007-01-01

Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

Microarrays for the evaluation of cell-biomaterial surface interactions

Science.gov (United States)

Thissen, H.; Johnson, G.; McFarland, G.; Verbiest, B. C. H.; Gengenbach, T.; Voelcker, N. H.

2007-01-01

The evaluation of cell-material surface interactions is important for the design of novel biomaterials which are used in a variety of biomedical applications. While traditional in vitro test methods have routinely used samples of relatively large size, microarrays representing different biomaterials offer many advantages, including high throughput and reduced sample handling. Here, we describe the simultaneous cell-based testing of matrices of polymeric biomaterials, arrayed on glass slides with a low cell-attachment background coating. Arrays were constructed using a microarray robot at 6 fold redundancy with solid pins having a diameter of 375 μm. Printed solutions contained at least one monomer, an initiator and a bifunctional crosslinker. After subsequent UV polymerisation, the arrays were washed and characterised by X-ray photoelectron spectroscopy. Cell culture experiments were carried out over 24 hours using HeLa cells. After labelling with CellTracker ® Green for the final hour of incubation and subsequent fixation, the arrays were scanned. In addition, individual spots were also viewed by fluorescence microscopy. The evaluation of cell-surface interactions in high-throughput assays as demonstrated here is a key enabling technology for the effective development of future biomaterials.

Decreased bacteria activity on Si3N4 surfaces compared with PEEK or titanium

Directory of Open Access Journals (Sweden)

Puckett S

2012-09-01

Full Text Available Deborah Gorth,1 Sabrina Puckett,1 Batur Ercan,1 Thomas J Webster,1 Mohamed Rahaman,2 B Sonny Bal31School of Engineering and Department of Orthopaedics, Brown University, Providence, RI, 2Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO, 3Department of Orthopaedic Surgery, School of Medicine, University of Missouri, Columbia, MO, USAAbstract: A significant need exists for orthopedic implants that can intrinsically resist bacterial colonization. In this study, three biomaterials that are used in spinal implants – titanium (Ti, poly-ether-ether-ketone (PEEK, and silicon nitride (Si3N4 – were tested to understand their respective susceptibility to bacterial infection with Staphylococcus epidermidis, Staphlococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus. Specifically, the surface chemistry, wettability, and nanostructured topography of respective biomaterials, and the effects on bacterial biofilm formation, colonization, and growth were investigated. Ti and PEEK were received with as-machined surfaces; both materials are hydrophobic, with net negative surface charges. Two surface finishes of Si3N4 were examined: as-fired and polished. In contrast to Ti and PEEK, the surface of Si3N4 is hydrophilic, with a net positive charge. A decreased biofilm formation was found, as well as fewer live bacteria on both the as-fired and polished Si3N4. These differences may reflect differential surface chemistry and surface nanostructure properties between the biomaterials tested. Because protein adsorption on material surfaces affects bacterial adhesion, the adsorption of fibronectin, vitronectin, and laminin on Ti, PEEK, and Si3N4 were also examined. Significantly greater amounts of these proteins adhered to Si3N4 than to Ti or PEEK. The findings of this study suggest that surface properties of biomaterials lead to differential adsorption of physiologic proteins, and that this

Effect of applied voltage on surface properties of anodised titanium in mixture of β-glycerophosphate (β-GP) and calcium acetate (CA)

Energy Technology Data Exchange (ETDEWEB)

Chuan, Lee Te, E-mail: gd130079@siswa.uthm.edu.my; Rathi, Muhammad Fareez Mohamad, E-mail: cd110238@siswa.uthm.edu.my; Abidin, Muhamad Yusuf Zainal, E-mail: cd110221@siswa.uthm.edu.my; Abdullah, Hasan Zuhudi, E-mail: hasan@uthm.edu.my; Idris, Maizlinda Izwana, E-mail: izwana@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

2015-07-22

Anodic oxidation is a surface modification method which combines electric field driven metal and oxygen ion diffusion for formation of oxide layer on the anode surface. This method has been widely used to modify the surface morphology of biomaterial especially titanium. This study aimed to investigate the effect of applied voltage on titanium. Specifically, the titanium foil was anodised in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA) with different applied voltage (50-350 V), electrolyte concentration (0.04 M β-GP + 0.4 M CA), anodising time (10minutes) and current density (50 and 70 mA.cm{sup −2}) at room temperature. Surface oxide properties of anodised titanium were characterised by digital single-lens reflex camera (DSLR camera), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM). At lower applied voltage (≤150 V), surface of titanium foils were relatively smooth. With increasing applied voltage (≥250 V), the oxide layer became more porous and donut-shaped pores were formed on the surface of titanium foils. The AFM results indicated that the surface roughness of anodised titanium increases with increasing of applied voltage. The porous and rough surface is able to promote the osseointegration and reduce the suffering time of patient.

Novel peptide-based platform for the dual presentation of biologically active peptide motifs on biomaterials.

Science.gov (United States)

Mas-Moruno, Carlos; Fraioli, Roberta; Albericio, Fernando; Manero, José María; Gil, F Javier

2014-05-14

Biofunctionalization of metallic materials with cell adhesive molecules derived from the extracellular matrix is a feasible approach to improve cell-material interactions and enhance the biointegration of implant materials (e.g., osseointegration of bone implants). However, classical biomimetic strategies may prove insufficient to elicit complex and multiple biological signals required in the processes of tissue regeneration. Thus, newer strategies are focusing on installing multifunctionality on biomaterials. In this work, we introduce a novel peptide-based divalent platform with the capacity to simultaneously present distinct bioactive peptide motifs in a chemically controlled fashion. As a proof of concept, the integrin-binding sequences RGD and PHSRN were selected and introduced in the platform. The biofunctionalization of titanium with this platform showed a positive trend towards increased numbers of cell attachment, and statistically higher values of spreading and proliferation of osteoblast-like cells compared to control noncoated samples. Moreover, it displayed statistically comparable or improved cell responses compared to samples coated with the single peptides or with an equimolar mixture of the two motifs. Osteoblast-like cells produced higher levels of alkaline phosphatase on surfaces functionalized with the platform than on control titanium; however, these values were not statistically significant. This study demonstrates that these peptidic structures are versatile tools to convey multiple biofunctionality to biomaterials in a chemically defined manner.

Bone substitute biomaterials

CERN Document Server

Mallick, K

2014-01-01

Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

Low-temperature plasma techniques in surface modification of biomaterials

International Nuclear Information System (INIS)

Feng Xiangfen; Xie Hankun; Zhang Jing

2002-01-01

Since synthetic polymers usually can not meet the biocompatibility and bio-functional demands of the human body, surface treatment is a prerequisite for them to be used as biomaterials. A very effective surface modification method, plasma treatment, is introduced. By immobilizing the bio-active molecules with low temperature plasma, polymer surfaces can be modified to fully satisfy the requirements of biomaterials

A new method using insert-based systems (IBS) to improve cell behavior study on flexible and rigid biomaterials.

Science.gov (United States)

Grenade, Charlotte; Moniotte, Nicolas; Rompen, Eric; Vanheusden, Alain; Mainjot, Amélie; De Pauw-Gillet, Marie-Claire

2016-12-01

In vitro studies about biomaterials biological properties are essential screening tests. Yet cell cultures encounter difficulties related to cell retention on material surface or to the observation of both faces of permeable materials. The objective of the present study was to develop a reliable in vitro method to study cell behavior on rigid and flexible/permeable biomaterials elaborating two specific insert-based systems (IBS-R and IBS-F respectively). IBS-R was designed as a specific cylindrical polytetrafluoroethylene (PTFE) system to evaluate attachment, proliferation and morphology of human gingival fibroblasts (HGFs) on grade V titanium and lithium disilicate glass-ceramic discs characteristics of dental prostheses. The number of cells, their covering on discs and their morphology were determined from MTS assays and microscopic fluorescent images after 24, 48 and 72 h. IBS-F was developed as a two components system to study HGFs behavior on guided bone regeneration polyester membranes. The viability and the membrane barrier effect were evaluated by metabolic MTS assays and by scanning electron microscopy. IBS-R and IBS-F were shown to promote (1) easy and rapid handling; (2) cell retention on biomaterial surface; (3) accurate evaluation of the cellular proliferation, spreading and viability; (4) use of non-toxic material. Moreover IBS-F allowed the study of the cell migration through degradable membranes, with an access to both faces of the biomaterial and to the bottom of culture wells for medium changing.

Cellular Performance Comparison of Biomimetic Calcium Phosphate Coating and Alkaline-Treated Titanium Surface

Directory of Open Access Journals (Sweden)

Xiaohua Yu

2013-01-01

Full Text Available The influence of biomimetic calcium phosphate coating on osteoblasts behavior in vitro is not well established yet. In this study, we investigated the behavior of osteoblastic rat osteosarcoma 17/2.8 cells (ROS17/2.8 on two groups of biomaterial surfaces: alkaline-treated titanium surface (ATT and biomimetic calcium phosphate coated ATT (CaP. The cell attachment, proliferation, differentiation, and morphology on these surfaces were extensively evaluated to reveal the impact of substrate surface on osteoblastic cell responses. It was found that the ROS17/2.8 cells cultured on the ATT surface had higher attachment and proliferation rates compared to those on the CaP surface. Our results also showed that the calcium phosphate coatings generated in this work have an inhibiting effect on osteoblast adhesion and further influenced the proliferation and differentiation of osteoblast compared to the ATT surface in vitro. Cells on the ATT surface also exhibited a higher alkaline phosphatase activity than on the CaP surface after two weeks of culture. Immunofluorescence staining and scanning electron microscopy results showed that the cells adhered and spread faster on the ATT surface than on the CaP surface. These results collectively suggested that substrate surface properties directly influence cell adhesion on different biomaterials, which would result in further influence on the cell proliferation and differentiation.

Surface-MALDI mass spectrometry in biomaterials research

DEFF Research Database (Denmark)

Griesser, H.J.; Kingshott, P.; McArthur, S.L.

2004-01-01

Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) has been used for over a decade for the determination of purity and accurate molecular masses of macromolecular analytes, such as proteins, in solution. In the last few years the technique has been adapted to become a new...... surfaces and detecting their molecular ions with high mass resolution and at levels much below monolayer coverage. Thus, Surface-MALDI-MS offers unique means of addressing biomaterial surface analysis needs, such as identification of the proteins and lipids that adsorb from multicomponent biological...... solutions in vitro and in vivo, the study of interactions between biomaterial surfaces and biomolecules, and identification of surface-enriched additives and contaminants. Surface-MALDI-MS is rapid, experimentally convenient, overcomes limitations in mass resolution and sensitivity of established...

Modification of titanium surfaces by adding antibiotic-loaded PHB spheres and PEG for biomedical applications.

Science.gov (United States)

Rodríguez-Contreras, Alejandra; Marqués-Calvo, María Soledad; Gil, Francisco Javier; Manero, José María

2016-08-01

Novel researches are focused on the prevention and management of post-operative infections. To avoid this common complication of implant surgery, it is preferable to use new biomaterials with antibacterial properties. Therefore, the aim of this work is to develop a method of combining the antibacterial properties of antibiotic-loaded poly(3-hydroxybutyrate) (PHB) nano- and micro-spheres and poly(ethylene glycol) (PEG) as an antifouling agent, with titanium (Ti), as the base material for implants, in order to obtain surfaces with antibacterial activity. The Ti surfaces were linked to both PHB particles and PEG by a covalent bond. This attachment was carried out by firstly activating the surfaces with either Oxygen plasma or Sodium hydroxide. Further functionalization of the activated surfaces with different alkoxysilanes allows the reaction with PHB particles and PEG. The study confirms that the Ti surfaces achieved the antibacterial properties by combining the antibiotic-loaded PHB spheres, and PEG as an antifouling agent.

Self-assembly of protein-based biomaterials initiated by titania nanotubes.

Science.gov (United States)

Forstater, Jacob H; Kleinhammes, Alfred; Wu, Yue

2013-12-03

Protein-based biomaterials are a promising strategy for creating robust highly selective biocatalysts. The assembled biomaterials must sufficiently retain the near-native structure of proteins and provide molecular access to catalytically active sites. These requirements often exclude the use of conventional assembly techniques, which rely on covalent cross-linking of proteins or entrapment within a scaffold. Here we demonstrate that titania nanotubes can initiate and template the self-assembly of enzymes, such as ribonuclease A, while maintaining their catalytic activity. Initially, the enzymes form multilayer thick ellipsoidal aggregates centered on the nanotube surface; subsequently, these nanosized entities assemble into a micrometer-sized enzyme material that has enhanced enzymatic activity and contains as little as 0.1 wt % TiO2 nanotubes. This phenomenon is uniquely associated with the active anatase (001)-like surface of titania nanotubes and does not occur on other anatase nanomaterials, which contain significantly fewer undercoordinated Ti surface sites. These findings present a nanotechnology-enabled mechanism of biomaterial growth and open a new route for creating stable protein-based biomaterials and biocatalysts without the need for chemical modification.

Hydration behaviors of calcium silicate-based biomaterials.

Science.gov (United States)

Lee, Yuan-Ling; Wang, Wen-Hsi; Lin, Feng-Huie; Lin, Chun-Pin

2017-06-01

Calcium silicate (CS)-based biomaterials, such as mineral trioxide aggregate (MTA), have become the most popular and convincing material used in restorative endodontic treatments. However, the commercially available CS-based biomaterials all contain different minor additives, which may affect their hydration behaviors and material properties. The purpose of this study was to evaluate the hydration behavior of CS-based biomaterials with/without minor additives. A novel CS-based biomaterial with a simplified composition, without mineral oxides as minor additives, was produced. The characteristics of this biomaterial during hydration were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectrometry. The hydration behaviors of commercially available gray and white MTAs with mineral oxide as minor additives were also evaluated for reference. For all three test materials, the XRD analysis revealed similar diffraction patterns after hydration, but MTAs presented a significant decrease in the intensities of Bi 2 O 3 -related peaks. SEM results demonstrated similar porous microstructures with some hexagonal and facetted crystals on the outer surfaces. In addition, compared to CS with a simplified composition, the FTIR plot indicated that hydrated MTAs with mineral oxides were better for the polymerization of calcium silicate hydrate (CSH), presenting Si-O band shifting to higher wave numbers, and contained more water crystals within CSH, presenting sharper bands for O-H bending. Mineral oxides might not result in significant changes in the crystal phases or microstructures during the hydration of CS-based biomaterials, but these compounds affected the hydration behavior at the molecular level. Copyright © 2016. Published by Elsevier B.V.

The influence of surface integrin binding patterns on specific biomaterial-cell interactions

Science.gov (United States)

Beranek, Maggi Marie

As the future of biomaterials progresses toward bioactivity, the biomaterial surface must control non-specific protein adsorption and encourage selective protein and cell adsorption. Integrins alphavbeta3, alpha 1beta1, alpha5beta1 and alpha Mbeta2 are expressed on cells involved in endothelialization, inflammation, and intimal hyperplasia. These cellular events play a vital role in biomaterial biocompatibility, especially in the vascular environment. The overall hypothesis of these studies is that biomaterial surfaces exhibit selective integrin binding, which then specifies differential cell binding. To test this hypothesis, four specific aims were developed. The first aim was designed to determine whether metal and polymeric biomaterials exhibit selective integrin binding. The tested materials included 316L stainless steel, nitinol, gold, Elgiloy RTM, poly(D, L-lactide-co-glycolide), polycarbonate urethane and expanded polytetrafluoroethylene. Discrete integrin binding patterns were detected microscopically using integrin specific fluorescent antibodies. Stainless steel exhibited high level integrin alpha1beta 1 and low level integrin alphaMbeta2 binding pattern. This suggests that this metal surface should selectively encourage endothelial cell to inflammatory cell binding. In contrast, gold bound ten times the amount of integrin alphaMbeta2 compared to integrin alpha1beta1, which should encourage inflammatory cell adhesion. The 65/35 poly(D, L-lactide-co-glycolide) was the only polymeric biomaterial tested that had integrin binding levels comparable to metal biomaterials. Based on these observations, a combinational biomaterial with a surface pattern of 65/35 poly(D, L-lactide-co-glycolide) dots on a 316L stainless steel background was created. A pattern of high level integrin alpha1beta1 binding and low level integrin alpha Mbeta2 binding on this combinational surface indicates that this surface should selectively favor endothelial cell binding. In the second

Cell Attachment Following Instrumentation with Titanium and Plastic Instruments, Diode Laser, and Titanium Brush on Titanium, Titanium-Zirconium, and Zirconia Surfaces.

Science.gov (United States)

Lang, Melissa S; Cerutis, D Roselyn; Miyamoto, Takanari; Nunn, Martha E

2016-01-01

The aim of this study was to evaluate the surface characteristics and gingival fibroblast adhesion of disks composed of implant and abutment materials following brief and repeated instrumentation with instruments commonly used in procedures for implant maintenance, stage-two implant surgery, and periimplantitis treatment. One hundred twenty disks (40 titanium, 40 titaniumzirconium, 40 zirconia) were grouped into treatment categories of instrumentation by plastic curette, titanium curette, diode microlaser, rotary titanium brush, and no treatment. Twenty strokes were applied to half of the disks in the plastic and titanium curette treatment categories, while half of the disks received 100 strokes each to simulate implant maintenance occurring on a repetitive basis. Following analysis of the disks by optical laser profilometry, disks were cultured with human gingival fibroblasts. Cell counts were conducted from scanning electron microscopy (SEM) images. Differences in surface roughness across all instruments tested for zirconia disks were negligible, while both titanium disks and titaniumzirconium disks showed large differences in surface roughness across the spectrum of instruments tested. The rotary titanium brush and the titanium curette yielded the greatest overall mean surface roughness, while the plastic curette yielded the lowest mean surface roughness. The greatest mean cell counts for each disk type were as follows: titanium disks with plastic curettes, titanium-zirconium disks with titanium curettes, and zirconia disks with the diode microlaser. Repeated instrumentation did not result in cumulative changes in surface roughness of implant materials made of titanium, titanium-zirconium, or zirconia. Instrumentation with plastic implant curettes on titanium and zirconia surfaces appeared to be more favorable than titanium implant curettes in terms of gingival fibroblast attachment on these surfaces.

Wettability and surface free energy of polarised ceramic biomaterials

International Nuclear Information System (INIS)

Nakamura, Miho; Hori, Naoko; Namba, Saki; Yamashita, Kimihiro; Toyama, Takeshi; Nishimiya, Nobuyuki

2015-01-01

The surface modification of ceramic biomaterials used for medical devices is expected to improve osteoconductivity through control of the interfaces between the materials and living tissues. Polarisation treatment induced surface charges on hydroxyapatite, β-tricalcium phosphate, carbonate-substituted hydroxyapatite and yttria-stabilized zirconia regardless of the differences in the carrier ions participating in the polarisation. Characterization of the surfaces revealed that the wettability of the polarised ceramic biomaterials was improved through the increase in the surface free energies compared with conventional ceramic surfaces. (note)

Effect of cathodic polarization on coating doxycycline on titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Geißler, Sebastian; Tiainen, Hanna; Haugen, Håvard J., E-mail: h.j.haugen@odont.uio.no

2016-06-01

Cathodic polarization has been reported to enhance the ability of titanium based implant materials to interact with biomolecules by forming titanium hydride at the outermost surface layer. Although this hydride layer has recently been suggested to allow the immobilization of the broad spectrum antibiotic doxycycline on titanium surfaces, the involvement of hydride in binding the biomolecule onto titanium remains poorly understood. To gain better understanding of the influence this immobilization process has on titanium surfaces, mirror-polished commercially pure titanium surfaces were cathodically polarized in the presence of doxycycline and the modified surfaces were thoroughly characterized using atomic force microscopy, electron microscopy, secondary ion mass spectrometry, and angle-resolved X-ray spectroscopy. We demonstrated that no hydride was created during the polarization process. Doxycycline was found to be attached to an oxide layer that was modified during the electrochemical process. A bacterial assay using bioluminescent Staphylococcus epidermidis Xen43 showed the ability of the coating to reduce bacterial colonization and planktonic bacterial growth. - Highlights: • Titanium hydride was found not to be involved in immobilization of doxycycline. • Doxycycline coating was strongly bound to a modified surface oxide layer. • Effect of coatings tested using a dynamic bacteria assay based on bioluminescence. • Topmost layer of adsorbed doxycycline was shown to have strong antibacterial effect.

Electrodeposition of amine-terminatedpoly(ethylene glycol) to titanium surface

International Nuclear Information System (INIS)

Tanaka, Yuta; Doi, Hisashi; Iwasaki, Yasuhiko; Hiromoto, Sachiko; Yoneyama, Takayuki; Asami, Katsuhiko; Imai, Hachiro; Hanawa, Takao

2007-01-01

The immobilization of poly(ethylene glycol), PEG, to a solid surface is useful to functionalize the surface, e.g., to prevent the adsorption of proteins. No successful one-stage technique for the immobilization of PEG to base metals has ever been developed. In this study, PEG in which both terminals or one terminal had been modified with amine bases was immobilized onto a titanium surface using electrodeposition. PEG was dissolved in a NaCl solution, and electrodeposition was carried out at 310 K with - 5 V for 300 min. The thickness of the deposited PEG layer was evaluated using ellipsometry, and the bonding manner of PEG to the titanium surface was characterized using X-ray photoelectron spectroscopy after electrodeposition. The results indicated that a certain amount of PEG was adsorbed on titanium through both electrodeposition and immersion when PEG was terminated by amine. However, terminated amines existed at the surface of titanium and were combined with titanium oxide as N-HO by electrodeposition, while amines randomly existed in the molecule and showed an ionic bond with titanium oxide by immersion. The electrodeposition of PEG was effective for the inhibition of albumin adsorption. This process is useful for materials that have electroconductivity and a complex morphology

Surface modification of titanium and titanium alloys by ion implantation.

Science.gov (United States)

Rautray, Tapash R; Narayanan, R; Kwon, Tae-Yub; Kim, Kyo-Han

2010-05-01

Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, to improve the biological, chemical, and mechanical properties, surface modification is often performed. In view of this, the current review casts new light on surface modification of titanium and titanium alloys by ion beam implantation. (c) 2010 Wiley Periodicals, Inc.

TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium

Directory of Open Access Journals (Sweden)

Iwasa F

2011-06-01

Full Text Available Fuminori Iwasa1, Naoki Tsukimura1, Yoshihiko Sugita1, Rajita Kodali Kanuru1, Katsutoshi Kubo1, Hafiz Hasnain1, Wael Att1,2, Takahiro Ogawa11Laboratory of Bone and Implant Sciences (LBIS, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA; 2Department of Prosthodontics, Dental School, Albert-Ludwigs University, Freiburg, GermanyAbstract: Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO2 nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow–derived osteoblasts were cultured on fresh disks (immediately after UV treatment, 3-day-old disks (disks stored for 3 days after UV treatment, and 7-day-old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%–50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano-hybrid surfaces became hydrorepellent

A new titanium based alloy Ti–27Nb–13Zr produced by powder metallurgy with biomimetic coating for use as a biomaterial

Energy Technology Data Exchange (ETDEWEB)

Mendes, Marcio W.D., E-mail: mwdmendes@ipen.com; Ágreda, Carola G.; Bressiani, Ana H.A.; Bressiani, José C.

2016-06-01

Titanium alloys are widely used in biomedical applications due to their excellent properties such as high strength, good corrosion resistance and biocompatibility. Titanium alloys with alloying elements such as Nb and Zr are biocompatible and have Young's modulus close to that of human bone. To increase the bioactivity of titanium alloy surfaces is used chemical treatment with NaOH followed by immersion in simulated body fluid (SBF). The purpose of this study was to produce the alloy Ti–27Nb–13Zr with low Young's modulus by powder metallurgy using powders produced by the HDH process. The formation of biomimetic coatings on samples immersed in SBF for 3, 7, 11 and 15 days was evaluated. Characterization of the coating was performed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and scanning electron microscope. The microstructure and composition of the alloy were determined using SEM and XRD, while the mechanical properties were evaluated by determining the elastic modulus and the Vickers microhardness. The sintered alloys were composed of α and β phases, equiaxed grains and with density around 97.8% of its theoretical density. The Vickers microhardness and elasticity modulus of the alloy were determined and their values indicate that this alloy can be used as a biomaterial. Analysis of the coating revealed the presence of calcium phosphate layers on samples immersed for > 3 days in the SBF solution. - Highlights: • The alloy is classified as α + β and the milling time influences the formation of these phases. • Dissolution of Nb is related to the mechanical properties of the alloy. • It's possible to form apatite on all samples immersed in SBF from 3 days. • The alloy can be used in orthopedic applications or in dental applications.

Biomaterial-based regional chemotherapy: Local anticancer drug delivery to enhance chemotherapy and minimize its side-effects.

Science.gov (United States)

Krukiewicz, Katarzyna; Zak, Jerzy K

2016-05-01

Since the majority of anticancer pharmacological agents affect not only cancer tissue but also normal cells, chemotherapy is usually accompanied with severe side effects. Regional chemotherapy, as the alternative version of conventional treatment, leads to the enhancement of the therapeutic efficiency of anticancer drugs and, simultaneously, reduction of toxic effects to healthy tissues. This paper provides an insight into different approaches of local delivery of chemotherapeutics, such as the injection of anticancer agents directly into tumor tissue, the use of injectable in situ forming drug carriers or injectable platforms in a form of implants. The wide range of biomaterials used as reservoirs of anticancer drugs is described, i.e. poly(ethylene glycol) and its copolymers, polyurethanes, poly(lactic acid) and its copolymers, poly(ɛ-caprolactone), polyanhydrides, chitosan, cellulose, cyclodextrins, silk, conducting polymers, modified titanium surfaces, calcium phosphate based biomaterials, silicone and silica implants, as well as carbon nanotubes and graphene. To emphasize the applicability of regional chemotherapy in cancer treatment, the commercially available products approved by the relevant health agencies are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantification of susceptibility artifacts in 0.5, 1.5 and 3.0 tesla magnetic resonance imaging produced from various biomaterials

International Nuclear Information System (INIS)

Matsuura, Hideki

2002-01-01

Several studies have examined various biomaterials to minimize susceptibility artifacts using low magnetic fields such as 0.5 Tesla or 1.5 Tesla, but no work has been done with high magnetic field. The purpose of the present study was to quantify the susceptibility artifacts produced from various biomaterials for neurosurgical implants in 0.5, 1.5 and 3.0 Tesla MR scanner. We performed MR imaging of six kinds of ceramics, two kinds of Co-based alloys with different combination, pure titanium, titanium alloy and stainless steel. Images were transferred to computer and analyzed. On all biomaterials, susceptibility artifacts developed parallel to the direction of the main magnetic field at both ends. Ceramics had considerably smaller artifact diameter compared with other biomaterials. Among ceramics, the artifact diameter of zirconia was the smallest. There were few differences between the artifact diameter of pure titanium and that of titanium alloy. Ceramics are promising biomaterials for minimum artifacts in higher field MR system. Although it is necessary to carry out degradation tests or retention force evaluation of the ceramics, we considered the ceramics are the most suitable biomaterials for the artifacts in MR imaging. (author)

Quantitative analysis of magnetic resonance imaging susceptibility artifacts caused by neurosurgical biomaterials. Comparison of 0.5, 1.5, and 3.0 tesla magnetic fields

International Nuclear Information System (INIS)

Matsuura, Hideki; Inoue, Takashi; Ogasawara, Kuniaki; Sasaki, Makoto; Konno, Hiromu; Kuzu, Yasutaka; Nishimoto, Hideaki; Ogawa, Akira

2005-01-01

Magnetic resonance (MR) imaging is an important diagnostic tool for neurosurgical diseases but susceptibility artifacts caused by biomaterial instrumentation frequently causes difficulty in visualizing postoperative changes. The susceptibility artifacts caused by neurosurgical biomaterials were compared quantitatively by 0.5, 1.5, and 3.0 Tesla MR imaging. MR imaging of uniform size and shape of pieces ceramic (zirconia), pure titanium, titanium alloy, and cobalt-based alloy was performed at 0.5, 1.5, and 3.0 Tesla. A linear region of interest was defined across the center of the biomaterial in the transverse direction, and the susceptibility artifact diameter was calculated. Susceptibility artifacts developed around all biomaterials at all magnetic field strengths. The artifact diameters caused by pure titanium, titanium alloy, and cobalt-based alloy increased in the order of 0.5, 1.5, to 3.0 Tesla magnetic fields. The artifact diameter of ceramic was not influenced by magnetic field strength, and was the smallest of all biomaterials at all magnetic field strengths. The artifacts caused by biomaterials except ceramic increase with the magnetic field strength. Ceramic instrumentation will minimize artifacts in all magnetic fields. (author)

Surface modification of biomaterials and biomedical devices using additive manufacturing.

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Bose, Susmita; Robertson, Samuel Ford; Bandyopadhyay, Amit

2018-01-15

The demand for synthetic biomaterials in medical devices, pharmaceutical products and, tissue replacement applications are growing steadily due to aging population worldwide. The use for patient matched devices is also increasing due to availability and integration of new technologies. Applications of additive manufacturing (AM) or 3D printing (3DP) in biomaterials have also increased significantly over the past decade towards traditional as well as innovative next generation Class I, II and III devices. In this review, we have focused our attention towards the use of AM in surface modified biomaterials to enhance their in vitro and in vivo performances. Specifically, we have discussed the use of AM to deliberately modify the surfaces of different classes of biomaterials with spatial specificity in a single manufacturing process as well as commented on the future outlook towards surface modification using AM. It is widely understood that the success of implanted medical devices depends largely on favorable material-tissue interactions. Additive manufacturing has gained traction as a viable and unique approach to engineered biomaterials, for both bulk and surface properties that improve implant outcomes. This review explores how additive manufacturing techniques have been and can be used to augment the surfaces of biomedical devices for direct clinical applications. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Albumin grafting on biomaterial surfaces using gamma-irradiation

International Nuclear Information System (INIS)

Kamath, K.R.

1993-01-01

Surface modification has been used extensively in various fields to introduce desirable surface properties without affecting the bulk properties of the material. In the area of biomaterials, the approach of surface modification offers an effective alternative to the synthesis of new biomaterials. The specific objective of this study was to modify different biomaterial surfaces by albumin grafting to improve their blood compatibility. The modified surfaces were characterized for surface-induced platelet activation and thrombus formation. This behavior was correlated with the conditions used for grafting. In particular, albumin was functionalized to introduce pendant double bonds into the molecule. The functionalized albumin was covalently attached to various surfaces, such as dimethyldichlorosilane-coated glass, polypropylene, polycarbonate, poly(vinyl chloride), and polyethylene by gamma-irradiation. Platelet adhesion and activation on these surfaces was examined using video microscopy and scanning electron microscopy. The extent of grafting was found to be dependent on the albumin concentration used for adsorption and the gamma-irradiation time. Release of the grafted albumin during exposure to blood was minimal. The albumin-grafted fibers maintained their thromboresistant properties even after storage at elevated temperatures for prolonged time periods. Finally, the approach was used to graft albumin on the PLEXUS Adult Hollow Fiber Oxygenators (Shiley). The blood compatibility of the grafted oxygenators improved significantly when compared to controls

Structure-related antibacterial activity of a titanium nanostructured surface fabricated by glancing angle sputter deposition

International Nuclear Information System (INIS)

Sengstock, Christina; Borgmann, Anna; Schildhauer, Thomas A; Köller, Manfred; Lopian, Michael; Motemani, Yahya; Khare, Chinmay; Buenconsejo, Pio John S; Ludwig, Alfred

2014-01-01

The aim of this study was to reproduce the physico-mechanical antibacterial effect of the nanocolumnar cicada wing surface for metallic biomaterials by fabrication of titanium (Ti) nanocolumnar surfaces using glancing angle sputter deposition (GLAD). Nanocolumnar Ti thin films were fabricated by GLAD on silicon substrates. S. aureus as well as E. coli were incubated with nanostructured or reference dense Ti thin film test samples for one or three hours at 37 °C. Bacterial adherence, morphology, and viability were analyzed by fluorescence staining and scanning electron microscopy and compared to human mesenchymal stem cells (hMSCs). Bacterial adherence was not significantly different after short (1 h) incubation on the dense or the nanostructured Ti surface. In contrast to S. aureus the viability of E. coli was significantly decreased after 3 h on the nanostructured film compared to the dense film and was accompanied by an irregular morphology and a cell wall deformation. Cell adherence, spreading and viability of hMSCs were not altered on the nanostructured surface. The results show that the selective antibacterial effect of the cicada wing could be transferred to a nanostructured metallic biomaterial by mimicking the natural nanocolumnar topography. (papers)

Reproducible Biofilm Cultivation of Chemostat-Grown Escherichia coli and Investigation of Bacterial Adhesion on Biomaterials Using a Non-Constant-Depth Film Fermenter

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Lüdecke, Claudia; Jandt, Klaus D.; Siegismund, Daniel; Kujau, Marian J.; Zang, Emerson; Rettenmayr, Markus; Bossert, Jörg; Roth, Martin

2014-01-01

Biomaterials-associated infections are primarily initiated by the adhesion of microorganisms on the biomaterial surfaces and subsequent biofilm formation. Understanding the fundamental microbial adhesion mechanisms and biofilm development is crucial for developing strategies to prevent such infections. Suitable in vitro systems for biofilm cultivation and bacterial adhesion at controllable, constant and reproducible conditions are indispensable. This study aimed (i) to modify the previously described constant-depth film fermenter for the reproducible cultivation of biofilms at non-depth-restricted, constant and low shear conditions and (ii) to use this system to elucidate bacterial adhesion kinetics on different biomaterials, focusing on biomaterials surface nanoroughness and hydrophobicity. Chemostat-grown Escherichia coli were used for biofilm cultivation on titanium oxide and investigating bacterial adhesion over time on titanium oxide, poly(styrene), poly(tetrafluoroethylene) and glass. Using chemostat-grown microbial cells (single-species continuous culture) minimized variations between the biofilms cultivated during different experimental runs. Bacterial adhesion on biomaterials comprised an initial lag-phase I followed by a fast adhesion phase II and a phase of saturation III. With increasing biomaterials surface nanoroughness and increasing hydrophobicity, adhesion rates increased during phases I and II. The influence of materials surface hydrophobicity seemed to exceed that of nanoroughness during the lag-phase I, whereas it was vice versa during adhesion phase II. This study introduces the non-constant-depth film fermenter in combination with a chemostat culture to allow for a controlled approach to reproducibly cultivate biofilms and to investigate bacterial adhesion kinetics at constant and low shear conditions. The findings will support developing and adequate testing of biomaterials surface modifications eventually preventing biomaterial

Combining 3D human in vitro methods for a 3Rs evaluation of novel titanium surfaces in orthopaedic applications.

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Stevenson, G; Rehman, S; Draper, E; Hernández-Nava, E; Hunt, J; Haycock, J W

2016-07-01

In this study, we report on a group of complementary human osteoblast in vitro test methods for the preclinical evaluation of 3D porous titanium surfaces. The surfaces were prepared by additive manufacturing (electron beam melting [EBM]) and plasma spraying, allowing the creation of complex lattice surface geometries. Physical properties of the surfaces were characterized by SEM and profilometry and 3D in vitro cell culture using human osteoblasts. Primary human osteoblast cells were found to elicit greater differences between titanium sample surfaces than an MG63 osteoblast-like cell line, particularly in terms of cell survival. Surface morphology was associated with higher osteoblast metabolic activity and mineralization on rougher titanium plasma spray coated surfaces than smoother surfaces. Differences in osteoblast survival and metabolic activity on titanium lattice structures were also found, despite analogous surface morphology at the cellular level. 3D confocal microscopy identified osteoblast organization within complex titanium surface geometries, adhesion, spreading, and alignment to the biomaterial strut geometries. Mineralized nodule formation throughout the lattice structures was also observed, and indicative of early markers of bone in-growth on such materials. Testing methods such as those presented are not traditionally considered by medical device manufacturers, but we suggest have value as an increasingly vital tool in efficiently translating pre-clinical studies, especially in balance with current regulatory practice, commercial demands, the 3Rs, and the relative merits of in vitro and in vivo studies. Biotechnol. Bioeng. 2016;113: 1586-1599. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

Laser processing of metallic biomaterials: An approach for surface patterning and wettability control

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Razi, Sepehr; Mollabashi, Mahmoud; Madanipour, Khosro

2015-12-01

Q -switched Nd:YAG laser is used to manipulate the surface morphology and wettability characteristic of 316L stainless steel (SS) and titanium biomaterials. Water and glycerol are selected as wettability testing liquids and the sessile drop method is used for the contact angle measurements. Results indicate that on both of the metals, wettability toward water improves significantly after the laser treatment. Different analyses including the study of the surface morphology, free energy and oxidation are assessed in correlation with wettability. Beside the important role of the laser-induced surface patterns, the increase in the surface roughness, oxygen content and the polar component of the surface energy, are detected as the most important physical and chemical phenomena controlling the improvement in the wettability. However, all the processed hydrophilic surfaces that are exposed to air become hydrophobic over time. The time dependency of the surface wettability is related to the chemical activities on the treated surfaces and the reduction of oxygen/carbon (O/C) ratio on them. The behavior is further studied with investigating the effect of the keeping environment and changes of the components of the surface tension. Results show that the pulsed laser treatment is a versatile approach to create either hydrophobic or super hydrophilic surfaces for industrial and medical applications.

Rough surfaces of titanium and titanium alloys for implants and prostheses

International Nuclear Information System (INIS)

Conforto, E.; Aronsson, B.-O.; Salito, A.; Crestou, C.; Caillard, D.

2004-01-01

Titanium and titanium alloys for dental implants and hip prostheses were surface-treated and/or covered by metallic or ceramic rough layers after being submitted to sand blasting. The goal of these treatments is to improve the surface roughness and consequently the osteointegration, the fixation, and the stability of the implant. The microstructure of titanium and titanium alloys submitted to these treatments has been studied and correlated to their mechanical behavior. As-treated/covered and mechanically tested surfaces were characterized by scanning electron microscopy (SEM). Structural analyses performed by transmission electron microscopy (TEM), mainly in cross-section, reveal the degree of adherence and cohesion between the surface layer and the substrate (implant). We observed that, although the same convenient surface roughness was obtained with the two types of process, many characteristics as structural properties and mechanical behavior are very different

Integrated Circuit-Based Biofabrication with Common Biomaterials for Probing Cellular Biomechanics.

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Sung, Chun-Yen; Yang, Chung-Yao; Yeh, J Andrew; Cheng, Chao-Min

2016-02-01

Recent advances in bioengineering have enabled the development of biomedical tools with modifiable surface features (small-scale architecture) to mimic extracellular matrices and aid in the development of well-controlled platforms that allow for the application of mechanical stimulation for studying cellular biomechanics. An overview of recent developments in common biomaterials that can be manufactured using integrated circuit-based biofabrication is presented. Integrated circuit-based biofabrication possesses advantages including mass and diverse production capacities for fabricating in vitro biomedical devices. This review highlights the use of common biomaterials that have been most frequently used to study cellular biomechanics. In addition, the influence of various small-scale characteristics on common biomaterial surfaces for a range of different cell types is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Manufacture of nanosized apatite coatings on titanium with different surface treatments using a supersaturated calcification solution

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Adrian Paz Ramos

Full Text Available The biomimetic method is used for the deposition of calcium phosphate coatings (Ca - P on the surface of different biomaterials. However, the application of this method requires long exposure times in order to obtain a suitable layer thickness for its use in medical devices. In this paper, we present a fast approach to obtain apatite coatings on titanium, using a combination of supersaturated calcification solution (SCS with chemical modification of the titanium surface. Also, it was evaluated the effect of four different surface treatments on the apatite deposition rate. Commercially pure titanium plates were activated by chemical or thermochemical treatments. Then, the activated samples were immersed in a solution with high content of calcium and phosphate ions at 37 ºC for 24 h, mimicking the physiological conditions. The coatings were studied by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, scanning electron microscopy (SEM and energy dispersive X-ray spectroscopy (EDX. The use of SCS solutions allowed the formation of crystalline hydroxyapatite coatings within a period of 24 h with a thickness between 1 and 5.3 µm. Besides, precipitates of hydroxyapatite nanoparticles with a globular configuration, forming aggregates with submicrometer size, were found in SCS solutions.

Antibacterial Surface Design of Titanium-Based Biomaterials for Enhanced Bacteria-Killing and Cell-Assisting Functions Against Periprosthetic Joint Infection.

Science.gov (United States)

Wang, Jiaxing; Li, Jinhua; Qian, Shi; Guo, Geyong; Wang, Qiaojie; Tang, Jin; Shen, Hao; Liu, Xuanyong; Zhang, Xianlong; Chu, Paul K

2016-05-04

Periprosthetic joint infection (PJI) is one of the formidable and recalcitrant complications after orthopedic surgery, and inhibiting biofilm formation on the implant surface is considered crucial to prophylaxis of PJI. However, it has recently been demonstrated that free-floating biofilm-like aggregates in the local body fluid and bacterial colonization on the implant and peri-implant tissues can coexist and are involved in the pathogenesis of PJI. An effective surface with both contact-killing and release-killing antimicrobial capabilities can potentially abate these concerns and minimize PJI caused by adherent/planktonic bacteria. Herein, Ag nanoparticles (NPs) are embedded in titania (TiO2) nanotubes by anodic oxidation and plasma immersion ion implantation (PIII) to form a contact-killing surface. Vancomycin is then incorporated into the nanotubes by vacuum extraction and lyophilization to produce the release-killing effect. A novel clinical PJI model system involving both in vitro and in vivo use of methicillin-resistant Staphylococcus aureus (MRSA) ST239 is established to systematically evaluate the antibacterial properties of the hybrid surface against planktonic and sessile bacteria. The vancomycin-loaded and Ag-implanted TiO2 nanotubular surface exhibits excellent antimicrobial and antibiofilm effects against planktonic/adherent bacteria without appreciable silver ion release. The fibroblasts/bacteria cocultures reveal that the surface can help fibroblasts to combat bacteria. We first utilize the nanoarchitecture of implant surface as a bridge between the inorganic bactericide (Ag NPs) and organic antibacterial agent (vancomycin) to achieve total victory in the battle of PJI. The combination of contact-killing and release-killing together with cell-assisting function also provides a novel and effective strategy to mitigate bacterial infection and biofilm formation on biomaterials and has large potential in orthopedic applications.

Application of ion beams for polymeric carbon based biomaterials

International Nuclear Information System (INIS)

Evelyn, A.L.

2001-01-01

Ion beams have been shown to be quite suitable for the modification and analysis of carbon based biomaterials. Glassy polymeric carbon (GPC), made from cured phenolic resins, has a high chemical inertness that makes it useful as a biomaterial in medicine for drug delivery systems and for the manufacture of heart valves and other prosthetic devices. Low and high-energy ion beams have been used, with both partially and fully cured phenolic resins, to enhance biological cell/tissue growth on, and to increase tissue adhesion to GPC surfaces. Samples bombarded with energetic ion beams in the keV to MeV range exhibited increased surface roughness, measured using optical microscopy and atomic force microscopy. Ion beams were also used to perform nuclear reaction analyses of GPC encapsulated drugs for use in internal drug delivery systems. The results from the high energy bombardment were more dramatic and are shown in this paper. The interaction of energetic ions has demonstrated the useful application of ion beams to enhance the properties of carbon-based biomaterials

Alkaline phosphatase binds tenaciously to titanium; implications for biological surface evaluation following bone implant retrieval.

Science.gov (United States)

Mansell, J P; Shiel, A I; Harwood, C; Stephens, D

2017-07-01

Enhancing the performance and longevity of titanium (Ti) implants continues to be a significant developmental theme in contemporary biomaterials design. Our specific focus pertains to the surface functionalisation of Ti using the bioactive lipid, lysophosphatidic acid (LPA) and certain phosphatase-resistant analogues of LPA. Coating survivorship to a plethora of testing regimens is required to align with due regulatory process before novel biomaterials can enter clinical trials. One of the key acceptance criteria is coating retention to the physical stresses experienced during implantation. In assessing coating stability to insertion into porcine bone we found that a subsequent in vitro assessment to confirm coating persistence was masked by abundant alkaline phosphatase (ALP) contamination adsorbed to the metal surface. Herein we report that ALP can bind to Ti in a matter of minutes by simply immersing Ti samples in aqueous solutions of the enzyme. We strongly discourage the in vitro monitoring of osteoblast and stromal cell ALP expression when assessing bioactive coating survivorship following Ti implant retrieval form native bone tissue. Copyright © 2017 Elsevier B.V. All rights reserved.

Immobilization of poly(MPC) brushes onto titanium surface by combining dopamine self-polymerization and ATRP: Preparation, characterization and evaluation of hemocompatibility in vitro

Energy Technology Data Exchange (ETDEWEB)

Ma, Wenyong; Yang, Ping; Li, Jingan; Li, Shiqi; Li, Peichuang; Zhao, Yuancong, E-mail: Zhaoyc7320@163.com; Huang, Nan

2015-09-15

Graphical abstract: The functional surface containing rich amino and hydroxyl groups was obtained by simple and easily dopamine self-polymerization. Poly (MPC) brushes were successfully immobilized on titanium surface by combining acylation reaction and ATRP. This chemical and biomimetic modified titanium surface effectively inhibits platelet adhesion and activation. - Highlights: • Polydopamine coating provides amino and hydroxyl groups for second reactivity. • Poly(MPC) brushes covalently immobilized on coating by surface initiated ATRP. • In vitro hemocompatibility of biomimetic modified Ti was better than unmodified. - Abstract: Poly(2-methacryloyloxyethyl phosphorylcholine(MPC)) has been studied in many biomedical fields because of good biocompatibility, such as hemocompatibility, inhibiting protein adhesion, antifouling, and so on. To achieve good hemocompatibility of titanium (Ti) surface, bio-inspired poly(MPC) brushes were grafted from Ti substrate covalently. In this work, the surface of Ti was first coated with polydopamine, and got a surface bearing −NH{sub 2} and −OH groups which could be bridged with poly(MPC) via atom transfer radical polymerization. Water contact angle decreased to 51.3° when titanium grafted with poly(MPC) brushes. The data of Infrared Spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that poly(MPC) was successfully grafted onto the surface of titanium. Platelet-rich plasma (PRP) adhesion test and lactate dehydrogenase (LDH) assay showed that the number of platelets adhered on the surface of modified-titanium was much less than that of unmodified titanium and platelets did not aggregate and distort. Thus, the simple and chemical method of immobilization of poly(MPC) brushes has potential application for improving hemocompatibility for cardiovascular stent and some other biomaterials.

Antibacterial iodine-supported titanium implants.

Science.gov (United States)

Shirai, T; Shimizu, T; Ohtani, K; Zen, Y; Takaya, M; Tsuchiya, H

2011-04-01

Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I(2)) and its impact on post-implant infection, as well as determining the potential suitability of Ti-I(2) as a biomaterial. External fixation pins were used in this experiment as trial implants because of the ease of making the septic models. The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to Ti-I(2) vs. stainless steel and titanium controls. Ti-I(2) clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation. Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I(2) pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I(2) and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I(2) has antimicrobial activity and exhibits cytocompatibility. Therefore, Ti-I(2) substantially reduces the incidence of implant infection and shows particular promise as a biomaterial. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Repositioning Titanium: An In Vitro Evaluation of Laser-Generated Microporous, Microrough Titanium Templates As a Potential Bridging Interface for Enhanced Osseointegration and Durability of Implants

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Daniel Tang

2017-12-01

Full Text Available Although titanium alloys remain the preferred biomaterials for the manufacture of biomedical implants today, such devices can fail within 15 years of implantation due to inadequate osseointegration. Furthermore, wear debris toxicity due to alloy metal ion release has been found to cause side-effects including neurotoxicity and chronic inflammation. Titanium, with its known biocompatibility, corrosion resistance, and high elastic modulus, could if harnessed in the form of a superficial scaffold or bridging device, resolve such issues. A novel three-dimensional culture approach was used to investigate the potential osteoinductive and osseointegrative capabilities of a laser-generated microporous, microrough medical grade IV titanium template on human skeletal stem cells (SSCs. Human SSCs seeded on a rough 90-µm pore surface of ethylene oxide-sterilized templates were observed to be strongly adherent, and to display early osteogenic differentiation, despite their inverted culture in basal conditions over 21 days. Limited cellular migration across the template surface highlighted the importance of high surface wettability in maximizing cell adhesion, spreading and cell-biomaterial interaction, while restricted cell ingrowth within the conical-shaped pores underlined the crucial role of pore geometry and size in determining the extent of osseointegration of an implant device. The overall findings indicate that titanium only devices, with appropriate optimizations to porosity and surface wettability, could yet play a major role in improving the long-term efficacy, durability, and safety of future implant technology.

Nanoscale Topography on Black Titanium Imparts Multi-biofunctional Properties for Orthopedic Applications

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Hasan, Jafar; Jain, Shubham; Chatterjee, Kaushik

2017-01-01

We have developed a chlorine based reactive ion etching process to yield randomly oriented anisotropic nanostructures that render the titanium metal surface ‘black’ similar to that of black silicon. The surface appears black due to the nanostructures in contrast to the conventional shiny surface of titanium. The nanostructures were found to kill bacteria on contact by mechanically rupturing the cells as has been observed previously on wings of certain insects. The etching was optimized to yield nanostructures of ≈1 μm height for maximal bactericidal efficiency without compromising cytocompatibility. Within 4 hours of contact with the black titanium surface, 95% ± 5% of E. coli, 98% ± 2% of P. aeruginosa, 92% ± 5% of M. smegmatis and 22% ± 8% of S. aureus cells that had attached were killed. The killing efficiency for the S. aureus increased to 76% ± 4% when the cells were allowed to adhere up to 24 hours. The black titanium supported the attachment and proliferation of human mesenchymal stem cells and augmented osteogenic lineage commitment in vitro. Thus, the bioinspired nanostructures on black titanium impart multi-biofunctional properties toward engineering the next-generation biomaterials for orthopedic implants.

Lysophosphatidic acid-functionalised titanium as a superior surface for supporting human osteoblast (MG63 maturation

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JP Mansell

2012-05-01

Full Text Available Covalent modifications of titanium with small molecules known to promote human osteoblast maturation are especially attractive in developing superior biomaterials. An important step in securing competent bone formation at implant sites is promoting the formation of mature osteoblasts, either from committed pre-osteoblasts or from their mesenchymal progenitors. To this end our research has focussed on identifying molecules that enhance human osteoblast formation and maturation and to develop ways of covalently attaching these molecules to implant surfaces so that they are more likely to withstand the rigors of the implantation process whilst still retaining their bioactivity. Herein we report the novel production of lipid-functionalised titanium using lysophosphatidic acid or a related compound, (3S 1-fluoro-3-hydroxy-4-butyl-1-phosphonate. Both lipids were especially effective at co-operating with calcitriol to promote human osteoblast maturation at these modified Ti surfaces in vitro. The novel findings presented offer enticing new developments towards the fabrication of next-generation implant devices with the potential to significantly enhance the osseointegration process and with it improvements in future prosthesis performance and longevity.

Comparison of surface modified zirconia implants with commercially available zirconium and titanium implants: a histological study in pigs.

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Gredes, Tomasz; Kubasiewicz-Ross, Pawel; Gedrange, Tomasz; Dominiak, Marzena; Kunert-Keil, Christiane

2014-08-01

New biomaterials and their various surface modifications should undergo in vitro and in vivo evaluation before clinical trials. The objective of our in vivo study was to evaluate the biocompatibility of newly created zirconium implant surfaces after implantation in the lower jaw of pigs and compare the osseointegration of these dental implants with commercially available zirconium and titanium implants. After a healing period of 12 weeks, a histological analysis of the soft and hard tissues and a histomorphometric analysis of the bone-implant contact (BIC) were performed. The implant surfaces showed an intimate connection to the adjacent bone for all tested implants. The 3 newly created zirconium implant surfaces achieved a BIC of 45% on average in comparison with a BIC of 56% from the reference zirconium implants and 35% from titanium implants. Furthermore, the new zirconium implants had a better attachment to gingival and bone tissues in the range of implant necks as compared with the reference implants. The results suggest that the new implants comparably osseointegrate within the healing period, and they have a good in vivo biocompatibility.

Calcium phosphate thin films enhance the response of human mesenchymal stem cells to nanostructured titanium surfaces

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Mura M McCafferty

2014-05-01

Full Text Available The development of biomaterial surfaces possessing the topographical cues that can promote mesenchymal stem cell recruitment and, in particular, those capable of subsequently directing osteogenic differentiation is of increasing importance for the advancement of tissue engineering. While it is accepted that it is the interaction with specific nanoscale topography that induces mesenchymal stem cell differentiation, the potential for an attendant bioactive chemistry working in tandem with such nanoscale features to enhance this effect has not been considered to any great extent. This article presents a study of mesenchymal stem cell response to conformal bioactive calcium phosphate thin films sputter deposited onto a polycrystalline titanium nanostructured surface with proven capability to directly induce osteogenic differentiation in human bone marrow–derived mesenchymal stem cells. The sputter deposited surfaces supported high levels of human bone marrow–derived mesenchymal stem cell adherence and proliferation, as determined by DNA quantification. Furthermore, they were also found to be capable of directly promoting significant levels of osteogenic differentiation. Specifically, alkaline phosphatase activity, gene expression and immunocytochemical localisation of key osteogenic markers revealed that the nanostructured titanium surfaces and the bioactive calcium phosphate coatings could direct the differentiation towards an osteogenic lineage. Moreover, the addition of the calcium phosphate chemistry to the topographical profile of the titanium was found to induce increased human bone marrow–derived mesenchymal stem cell differentiation compared to that observed for either the titanium or calcium phosphate coating without an underlying nanostructure. Hence, the results presented here highlight that a clear benefit can be achieved from a surface engineering strategy that combines a defined surface topography with an attendant, conformal

Plant Products for Innovative Biomaterials in Dentistry

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Elena M. Varoni

2012-07-01

Full Text Available Dental biomaterials and natural products represent two of the main growing research fields, revealing plant-derived compounds may play a role not only as nutraceuticals in affecting oral health, but also in improving physico-chemical properties of biomaterials used in dentistry. Therefore, our aim was to collect all available data concerning the utilization of plant polysaccharides, proteins and extracts rich in bioactive phytochemicals in enhancing performance of dental biomaterials. Although compelling evidences are suggestive of a great potential of plant products in promoting material-tissue/cell interface, to date, only few authors have investigated their use in development of innovative dental biomaterials. A small number of studies have reported plant extract-based titanium implant coatings and periodontal regenerative materials. To the best of our knowledge, this review is the first to deal with this topic, highlighting a general lack of research findings in an interesting field which still needs to be investigated.

Surface properties, crystallinity and optical properties of anodised titanium in mixture of β-glycerophosphate (β-GP) and calcium acetate (CA)

Energy Technology Data Exchange (ETDEWEB)

Chuan, Lee Te, E-mail: gd130079@siswa.uthm.edu.my; Abdullah, Hasan Zuhudi, E-mail: hasan@uthm.edu.my; Idris, Maizlinda Izwana, E-mail: izwana@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

2015-07-22

Anodic oxidation is an electrochemical method for the production of ceramic films on a metallic substrate. It had been widely used to deposit the ceramic coatings on the metals surface. This method has been widely used in surface modification of biomaterials especially for dental implants. In this study, the surface morphology, crystallinity and optical properties of titanium foil was modified by anodising in mixture of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA). The experiments were carried out at high voltage (350 V), different anodising time (5 and 10 minutes) and current density (10-70 mA.cm{sup −2}) at room temperature. Anodised titanium was characterised by using field emission scanning electron microscopy (FESEM), X-ray diffractometer (XRD), and UV-Vis spectrometry. The result of the experiment showed that surface morphology, crystallinity and optical properties depended strongly on the current density and anodising time. More porous surface and large amount of anatase and rutile was produced at higher current density and longer anodising time. Apart from that, it is also revealed that the energy band gap of anodised titanium increases as the increase in current density due to the presence of anatase and rutile TiO{sub 2}.

Adhesion force of staphylococcus aureus on various biomaterial surfaces.

Science.gov (United States)

Alam, Fahad; Balani, Kantesh

2017-01-01

Staphylococcus comprises of more than half of all pathogens in orthopedic implant infections and they can cause major bone infection which can result in destruction of joint and bone. In the current study, adhesion force of bacteria on the surface of various biomaterial surfaces is measured using atomic force microscope (AFM). Staphylococcus aureus was immobilized on an AFM tipless cantilever as a force probe to measure the adhesion force between bacteria and biomaterials (viz. ultra-high molecular weight poly ethylene (UHMWPE), stainless steel (SS), Ti-6Al-4V alloy, hydroxyapatite (HA)). At the contact time of 10s, UHMWPE shows weak adhesion force (~4nN) whereas SS showed strong adhesion force (~15nN) due to their surface energy and surface roughness. Bacterial retention and viability experiment (3M™ petrifilm test, agar plate) dictates that hydroxyapatite shows the lowest vaibility of bacteria, whereas lowest bacterial retention is observed on UHMWPE surface. Similar results were obtained from live/dead staining test, where HA shows 65% viability, whereas on UHMWPE, SS and Ti-6Al-4V, the bacterial viability is 78%, 94% and 97%, respectively. Lower adhesion forces, constrained pull-off distance (of bacterial) and high antibacterial resistance of bioactive-HA makes it a potential biomaterial for bone-replacement arthroplasty. Copyright © 2016 Elsevier Ltd. All rights reserved.

A chlorhexidine-releasing epoxy-based coating on titanium implants prevents Staphylococcus aureus experimental biomaterial-associated infection

NARCIS (Netherlands)

Riool, M.; Dirks, A. J.; Jaspers, V.; de Boer, L.; Loontjens, T. J.; van der Loos, C. M.; Florquin, S.; Apachitei, I.; Rijk, L. N.; Keul, H. A.; Zaat, S. A.

2017-01-01

Prevention of biomaterial-associated infections (BAI) remains a challenging problem, in particular due to the increased risk of resistance development with the current antibiotic-based strategies. Metallic orthopaedic devices, such as non-cemented implants, are often inserted under high mechanical

Application of bone marrow and adipose-derived mesenchymal stem cells for testing the biocompatibility of metal-based biomaterials functionalized with ascorbic acid

International Nuclear Information System (INIS)

Marycz, Krzysztof; Śmieszek, Agnieszka; Grzesiak, Jakub; Donesz-Sikorska, Anna; Krzak-Roś, Justyna

2013-01-01

In this study, metal-based biomaterials were functionalized with ascorbic acid (LAA). Two types of substrates were used: austenitic steel 316L and titanium Ti6Al4V. Coatings were prepared with the sol–gel method and applied on metal surfaces using the dip-coating technique. Ascorbic acid was delivered with SiO 2 -coating at concentrations of 0.1 and 0.4 M. The morphology of the surfaces and coatings was determined using scanning electron microscope (SEM), whereas their elemental composition by SEM-EDX. Immobilization of ascorbic acid in the coatings was confirmed with Raman spectroscopy. The biocompatibility of the materials obtained was tested in vitro using both bone marrow- and adipose-derived mesenchymal stem cells (BMMSC and ADMSC, respectively). Proliferation rate and morphology of cells cultured in the presence of designed biomaterials were monitored after 24, 48, 120 and 168 h of propagation. The results obtained indicated that silica coatings doped with 0.4 M LAA had a positive effect on the proliferation rate of investigated cells, and in some cases on the growth pattern of culture. (paper)

Surface characterization of titanium based dental implants; Caracterizacao de implantes odontologicos a base de titanio

Energy Technology Data Exchange (ETDEWEB)

Castilho, Guilherme Augusto Alcaraz

2006-07-01

Dental implantology uses metallic devices made of commercially pure titanium in order to replace lost teeth. Titanium presents favorable characteristics as bio material and modern implants are capable of integrate, witch is the union between bone and implant without fibrous tissue development. Three of the major Brazilian implant manufacturers were chosen to join the study. A foreign manufacturer participated as standard. The manufacturers had three specimens of each implant with two different surface finishing, as machined and porous, submitted to analysis. Surface chemical composition and implant morphology were analyzed by X-ray photoelectron spectroscopy (XP S), scanning electron microscopy (SEM) and microprobe. Implant surface is mainly composed of titanium, oxygen and carbon. Few contaminants commonly present on implant surface were found on samples. Superficial oxide layer is basically composed of titanium dioxide (TiO{sub 2}), another oxides as Ti O and Ti{sub 2}O{sub 3} were also found in small amount. Carbon on implant surface was attributed to manufacturing process. Nitrogen, Phosphorous and Silicon appeared in smaller concentration on surface. There was no surface discrepancy among foreign and Brazilian made implants. SEM images were made on different magnification, 35 X to 3500 X, and showed similarity among as machined implants. Porous surface finishing implants presented distinct morphology. This result was attributed to differences on manufacturing process. Implant bioactivity was accessed through immersion on simulated body solution (SBF) in order to verify formation of an hydroxyapatite (HA) layer on surface. Samples were divided on three groups according to immersion time: G1 (7 days), G2 (14 days), G3 (21 days), and deep in SBF solution at 37 deg C. After being removed from solution, XPS analyses were made and then implants have been submitted to microprobe analysis. XPS showed some components of SBF solution on sample surface but microprobe

Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

International Nuclear Information System (INIS)

Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

2012-01-01

Highlights: ► Cell-adhesive molecules were covalently immobilized on a Ti surface. ► Immobilized cell-adhesive molecules maintained native function on the Ti surface. ► Immobilized collagen enhanced adhesion of periodontal ligament cells to the Ti. - Abstract: A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface

Creating nanoshell on the surface of titanium hydride bead

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PAVLENKO Vyacheslav Ivanovich

2016-12-01

Full Text Available The article presents data on the modification of titanium hydride bead by creating titanium nanoshell on its surface by ion-plasma vacuum magnetron sputtering. To apply titanium nanoshell on the titanium hydride bead vacuum coating plant of multifunctional nanocomposite coatings QVADRA 500 located in the center of high technology was used. Analysis of the micrographs of the original surface of titanium hydride bead showed that the microstructure of the surface is flat, smooth, in addition the analysis of the microstructure of material surface showed the presence of small porosity, roughness, mainly cavities, as well as shallow longitudinal cracks. The presence of oxide film in titanium hydride prevents the free release of hydrogen and fills some micro-cracks on the surface. Differential thermal analysis of both samples was conducted to determine the thermal stability of the initial titanium hydride bead and bead with applied titanium nanoshell. Hydrogen thermal desorption spectra of the samples of the initial titanium hydride bead and bead with applied titanium nanoshell show different thermal stability of compared materials in the temperature range from 550 to 860о C. Titanium nanoshells applied in this way allows increasing the heat resistance of titanium hydride bead – the temperature of starting decomposition is 695о C and temperature when decomposition finishes is more than 1000о C. Modified in this way titanium hydride bead can be used as a filler in the radiation protective materials used in the construction or upgrading biological protection of nuclear power plants.

A review of the biomaterials technologies for infection-resistant surfaces.

Science.gov (United States)

Campoccia, Davide; Montanaro, Lucio; Arciola, Carla Renata

2013-11-01

Anti-infective biomaterials need to be tailored according to the specific clinical application. All their properties have to be tuned to achieve the best anti-infective performance together with safe biocompatibility and appropriate tissue interactions. Innovative technologies are developing new biomaterials and surfaces endowed with anti-infective properties, relying either on antifouling, or bactericidal, or antibiofilm activities. This review aims at thoroughly surveying the numerous classes of antibacterial biomaterials and the underlying strategies behind them. Bacteria repelling and antiadhesive surfaces, materials with intrinsic antibacterial properties, antibacterial coatings, nanostructured materials, and molecules interfering with bacterial biofilm are considered. Among the new strategies, the use of phages or of antisense peptide nucleic acids are discussed, as well as the possibility to modulate the local immune response by active cytokines. Overall, there is a wealth of technical solutions to contrast the establishment of an implant infection. Many of them exhibit a great potential in preclinical models. The lack of well-structured prospective multicenter clinical trials hinders the achievement of conclusive data on the efficacy and comparative performance of anti-infective biomaterials. © 2013 Elsevier Ltd. All rights reserved.

[The surface roughness analysis of the titanium casting founding by a new titanium casting investment material].

Science.gov (United States)

Liang, Qin-ye; Wu, Xia-yi; Lin, Xue-feng

2012-04-01

To investigate the surface roughness property of the titanium castings cast in a new investment for titanium casting. Six wax patterns (20 mm × 20 mm × 0.5 mm) were invested using two investments: three in a new titanium investment material and three in the control material (Rematitan Plus). Six titanium specimens were obtained by conventional casting. After casting, surface roughness of the specimens were evaluated with a surface profilometer. The surface roughness of the specimens cast in new titanium investment material was (1.72 ± 0.08) µm, which was much smaller than that from Rematitan Plus [(1.91 ± 0.15) µm, P cast using these two investment materials are both smooth enough to fulfill the demand of the titanium precision-casting for prosthodontic clinical use.

The surface nanostructures of titanium alloy regulate the proliferation of endothelial cells

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Min Lai

2014-02-01

Full Text Available To investigate the effect of surface nanostructures on the behaviors of human umbilical vein endothelial cells (HUVECs, surface nanostructured titanium alloy (Ti-3Zr2Sn-3Mo-25Nb, TLM was fabricated by surface mechanical attrition treatment (SMAT technique. Field emission scanning electron microscopy (FE-SEM, atomic force microscopy (AFM, transmission electron microscopy (TEM and X-ray diffraction (XRD were employed to characterize the surface nanostructures of the TLM, respectively. The results demonstrated that nano-crystalline structures with several tens of nanometers were formed on the surface of TLM substrates. The HUVECs grown onto the surface nanostructured TLM spread well and expressed more vinculin around the edges of cells. More importantly, HUVECs grown onto the surface nanostructured TLM displayed significantly higher (p < 0.01 or p < 0.05 cell adhesion and viabilities than those of native titanium alloy. HUVECs cultured on the surface nanostructured titanium alloy displayed significantly higher (p < 0.01 or p < 0.05 productions of nitric oxide (NO and prostacyclin (PGI2 than those of native titanium alloy, respectively. This study provides an alternative for the development of titanium alloy based vascular stents.

Assessment of Surface Area Characteristics of Dental Implants with Gradual Bioactive Surface Treatment

Science.gov (United States)

Czan, Andrej; Babík, Ondrej; Miklos, Matej; Záušková, Lucia; Mezencevová, Viktória

2017-10-01

Since most of the implant surface is in direct contact with bone tissue, shape and integrity of said surface has great influence on successful osseointegration. Among other characteristics that predetermine titanium of different grades of pureness as ideal biomaterial, titanium shows high mechanical strength making precise miniature machining increasingly difficult. Current titanium-based implants are often anodized due to colour coding. This anodized layer has important functional properties for right usage and also bio-compatibility of dental implants. Physical method of anodizing and usage of anodizing mediums has a significant influence on the surface quality and itself functionality. However, basic requirement of the dental implant with satisfactory properties is quality of machined surface before anodizing. Roughness, for example, is factor affecting of time length of anodizing operation and so whole productivity. The paper is focused on monitoring of surface and area characteristics, such as roughness or surface integrity after different cutting conditions of miniature machining of dental implants and their impact on suitability for creation of satisfactory anodized layer with the correct biocompatible functional properties.

Tribocorrosion studies of metallic biomaterials: The effect of plasma nitriding and DLC surface modifications.

Science.gov (United States)

Zhao, Guo-Hua; Aune, Ragnhild E; Espallargas, Nuria

2016-10-01

The medical grade pure titanium, stainless steel and CoCrMo alloy have been utilized as biomaterials for load-bearing orthopedic prosthesis. The conventional surgery metals suffer from a combined effect of wear and corrosion once they are implanted, which may significantly accelerate the material degradation process. In this work, the tribocorrosion performance of the metallic biomaterials with different surface modifications was studied in the simulated body fluid for the purpose of investigating the effect of the surface treatments on the tribocorrosion performance and eventually finding the most suitable implantation materials. The metals were subjected to surface modifications by plasma nitriding in different treatment temperatures or physical vapor deposition (PVD) to produce diamond-like carbon (DLC) coating, respectively. The dry wear and tribocorrosion properties of the samples were evaluated by using a reciprocating ball-on-disc tribometer equipped with an electrochemical cell. Prior to the tribocorrosion tests, their electrochemical behavior was measured by the potentiodynamic polarization in phosphate buffer saline (PBS) solution at room temperature. Both stainless steel and CoCrMo after low temperature nitriding kept their passive nature by forming an expanded austenite phase. The DLC coated samples presented the low anodic corrosion current due to the chemical inertness of the carbon layer. During the tribocorrosion tests at open circuit potential, the untreated and low temperature nitrided samples exhibited significant potential drop towards the cathodic direction, which was a result of the worn out of the passive film. Galvanic coupling was established between the depassivated (worn) area and the still passive (unworn) area, making the materials suffered from wear-accelerated corrosion. The DLC coating performed as a solid lubricant in both dry wear and tribocorrosion tests, and the resulting wear after the tests was almost negligible. Copyright �

Tribological investigations of perfluoroalkylsilanes monolayers deposited on titanium surface

International Nuclear Information System (INIS)

Cichomski, Michał

2012-01-01

Therefore the present work reports a systematic study of titanium modification by fluoroalkylsilanes and surface characterization from the tribological point of view. The vapor phase deposition method was used to modify titanium surfaces by fluoroalkylsilanes and the influence of the used modifier on the tribological properties is presented. The modification procedure efficiency, surface structure and morphology were characterized by secondary ion mass spectrometry, infrared spectroscopy and atomic force microscopy. The effectiveness of modification of the titanium surface was monitored by the measurement of the wetting contact angle and the surface free energy. The increase of surface hydrophobicity was observed upon the modification by increasing the wetting contact angle and reducing the surface free energy. The tribological performance of various perfluoroalkylsilanes films on the titanium surface was investigated in mili- and nano-newton load ranges. Dependence of the adhesive force and coefficient of friction values obtained in nano- and micro-scale on fluoroalkyl chain length was observed. Nano- and micro-tribological measurements show that titanium modified by fluoroalkylsilanes has lower adhesion and coefficient of friction than unmodified one. The investigation also indicates a decrease of the friction coefficient with increasing fluoric alkyl chain length. It was found that the titanium modified by fluoroalkylsilanes with longer alkyl chains is a prime candidate for practical use as a lubricant in biomedical and electronic applications. -- Highlights: ► Titanium surface modification by perfluoroalkylsilanes was investigated. ► The effectiveness of modification was monitored by the surface free energy. ► The modification procedure correctness was characterized by ToF-SIMS, AFM, FT-IR measurements. ► The tribological performance of modified titanium in differed scale was studied.

Effect of Superhydrophobic Surface of Titanium on Staphylococcus aureus Adhesion

Directory of Open Access Journals (Sweden)

Peifu Tang

2011-01-01

Full Text Available Despite the systemic antibiotics prophylaxis, orthopedic implants still remain highly susceptible to bacterial adhesion and resulting in device-associated infection. Surface modification is an effective way to decrease bacterial adhesion. In this study, we prepared surfaces with different wettability on titanium surface based on TiO2 nanotube to examine the effect of bacterial adhesion. Firstly, titanium plates were calcined to form hydrophilic TiO2 nanotube films of anatase phase. Subsequently, the nanotube films and inoxidized titaniums were treated with 1H, 1H, 2H, 2H-perfluorooctyl-triethoxysilane (PTES, forming superhydrophobic and hydrophobic surfaces. Observed by SEM and contact angle measurements, the different surfaces have different characteristics. Staphylococcus aureus (SA adhesion on different surfaces was evaluated. Our experiment results show that the superhydrophobic surface has contact angles of water greater than 150∘ and also shows high resistance to bacterial contamination. It is indicated that superhydrophobic surface may be a factor to reduce device-associated infection and could be used in clinical practice.

A fundamental approach to adhesion: Synthesis, surface analysis, thermodynamics and mechanics. [acid-base properties of titanium 6-4 surfaces

Science.gov (United States)

Siriwardane, R.; Wightman, J. P.

1980-01-01

The acid-base properties of titanium 6-4 plates (low surface area) were investigated after three different pretreatments, namely Turco, phosphate-fluoride and Pasa-Jell. A series of indicators was used and color changes were detected using diffuse reflectance visible spectroscopy. Electron spectroscopy for chemical analysis was used to examine the indicator on the Ti 6-4 surface. Specular reflectance infra-red spectroscopy was used to study the adsorption of stearic acid from cyclohexane solutions on the Ti 6-4 surface.

Research progress on laser surface modification of titanium alloys

International Nuclear Information System (INIS)

Tian, Y.S.; Chen, C.Z.; Li, S.T.; Huo, Q.H.

2005-01-01

Recent developments on laser surface modification of titanium and its alloys are reviewed. Due to the intrinsic properties of high coherence and directionality, laser beam can be focus onto metallic surface to perform a broad range of treatments such as remelting, alloying and cladding, which are used to improve the wear and corrosion resistance of titanium alloys. In addition, the fabrication of bioactive films on the surface of titanium alloys to improve their biocompatibility can be performed by the method of laser ablation deposition. The effect of some laser processing parameters on the resulting surface properties of titanium alloys is discussed. The problems to be solved and the prospects in the field of laser modification of titanium and its alloys are elucidated

Surface characterization of nickel titanium orthodontic arch wires

Science.gov (United States)

Krishnan, Manu; Seema, Saraswathy; Tiwari, Brijesh; Sharma, Himanshu S.; Londhe, Sanjay; Arora, Vimal

2015-01-01

Background Surface roughness of nickel titanium orthodontic arch wires poses several clinical challenges. Surface modification with aesthetic/metallic/non metallic materials is therefore a recent innovation, with clinical efficacy yet to be comprehensively evaluated. Methods One conventional and five types of surface modified nickel titanium arch wires were surface characterized with scanning electron microscopy, energy dispersive analysis, Raman spectroscopy, Atomic force microscopy and 3D profilometry. Root mean square roughness values were analyzed by one way analysis of variance and post hoc Duncan's multiple range tests. Results Study groups demonstrated considerable reduction in roughness values from conventional in a material specific pattern: Group I; conventional (578.56 nm) > Group V; Teflon (365.33 nm) > Group III; nitride (301.51 nm) > Group VI (i); rhodium (290.64 nm) > Group VI (ii); silver (252.22 nm) > Group IV; titanium (229.51 nm) > Group II; resin (158.60 nm). It also showed the defects with aesthetic (resin/Teflon) and nitride surfaces and smooth topography achieved with metals; titanium/silver/rhodium. Conclusions Resin, Teflon, titanium, silver, rhodium and nitrides were effective in decreasing surface roughness of nickel titanium arch wires albeit; certain flaws. Findings have clinical implications, considering their potential in lessening biofilm adhesion, reducing friction, improving corrosion resistance and preventing nickel leach and allergic reactions. PMID:26843749

Adhesion of osteoblasts to a nanorough titanium implant surface

Directory of Open Access Journals (Sweden)

Gongadze E

2011-08-01

Full Text Available Ekaterina Gongadze1, Doron Kabaso2, Sebastian Bauer3, Tomaž Slivnik2, Patrik Schmuki3, Ursula van Rienen1, Aleš Iglič21Institute of General Electrical Engineering, University of Rostock, Rostock, Germany; 2Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia; 3Department of Materials Science, Friedrich-Alexander University of Erlangen-Nurenberg, Erlangen, GermanyAbstract: This work considers the adhesion of cells to a nanorough titanium implant surface with sharp edges. The basic assumption was that the attraction between the negatively charged titanium surface and a negatively charged osteoblast is mediated by charged proteins with a distinctive quadrupolar internal charge distribution. Similarly, cation-mediated attraction between fibronectin molecules and the titanium surface is expected to be more efficient for a high surface charge density, resulting in facilitated integrin mediated osteoblast adhesion. We suggest that osteoblasts are most strongly bound along the sharp convex edges or spikes of nanorough titanium surfaces where the magnitude of the negative surface charge density is the highest. It is therefore plausible that nanorough regions of titanium surfaces with sharp edges and spikes promote the adhesion of osteoblasts.Keywords: osteoblasts, nanostructures, adhesion, titanium implants, osteointegration

The promotion of osseointegration of titanium surfaces by coating with silk protein sericin.

Science.gov (United States)

Nayak, Sunita; Dey, Tuli; Naskar, Deboki; Kundu, Subhas C

2013-04-01

A promising strategy to influence the osseointegration process around orthopaedic titanium implants is the immobilization of bioactive molecules. This recruits appropriate interaction between the surface and the tissue by directing cells adhesion, proliferation, differentiation and active matrix remodelling. In this study, we aimed to investigate the functionalization of metallic implant titanium with silk protein sericin. Titanium surface was immobilized with non-mulberry Antheraea mylitta sericin using glutaraldehyde as crosslinker. To analyse combinatorial effects the sericin immobilized titanium was further conjugated with integrin binding peptide sequence Arg-Gly-Asp (RGD) using ethyl (dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling agents. The surface of sericin immobilized titanium was characterized biophysically. Osteoblast-like cells were cultured on sericin and sericin/RGD functionalized titanium and found to be more viable than those on pristine titanium. The enhanced adhesion, proliferation, and differentiation of osteoblast cells were observed. RT-PCR analysis showed that mRNA expressions of bone sialoprotein, osteocalcin and alkaline phosphatase were upregulated in osteoblast cells cultured on sericin and sericin/RGD immobilized titanium substrates. Additionally, no significant amount of pro-inflammatory cytokines TNF-α, IL-1β and nitric oxide production were recorded when macrophages cells and osteoblast-macrophages co culture cells were grown on sericin immobilized titanium. The findings demonstrate that the sericin immobilized titanium surfaces are potentially useful bioactive coated materials for titanium-based medical implants. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Corrosion resistant properties of different anodized microtopographies on titanium surfaces].

Science.gov (United States)

Fangjun, Huo; Li, Xie; Xingye, Tong; Yueting, Wang; Weihua, Guo; Weidong, Tian

2015-12-01

To investigate the corrosion resistant properties of titanium samples prepared by anodic oxidation with different surface morphologies. Pure titanium substrates were treated by anodic oxidation to obtain porous titanium films in micron, submicron, and micron-submicron scales. The surface morphologies, coating cross-sectional morphologies, crystalline structures, and surface roughness of these samples were characterized. Electrochemical technique was used to measure the corrosion potential (Ecorr), current density of corrosion (Icorr), and polarization resistance (Rp) of these samples in a simulated body fluid. Pure titanium could be modified to exhibit different surface morphologies by the anodic oxidation technique. The Tafel curve results showed that the technique can improve the corrosion resistance of pure titanium. Furthermore, the corrosion resistance varied with different surface morphologies. The submicron porous surface sample demonstrated the best corrosion resistance, with maximal Ecorr and Rp and minimal Icorr. Anodic oxidation technology can improve the corrosion resistance of pure titanium in a simulated body fluid. The submicron porous surface sample exhibited the best corrosion resistance because of its small surface area and thick barrier layer.

Tribological Characteristic of Titanium Alloy Surface Layers Produced by Diode Laser Gas Nitriding

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Lisiecki A.

2016-06-01

Full Text Available In order to improve the tribological properties of titanium alloy Ti6Al4V composite surface layers Ti/TiN were produced during laser surface gas nitriding by means of a novel high power direct diode laser with unique characteristics of the laser beam and a rectangular beam spot. Microstructure, surface topography and microhardness distribution across the surface layers were analyzed. Ball-on-disk tests were performed to evaluate and compare the wear and friction characteristics of surface layers nitrided at different process parameters, base metal of titanium alloy Ti6Al4V and also the commercially pure titanium. Results showed that under dry sliding condition the commercially pure titanium samples have the highest coefficient of friction about 0.45, compared to 0.36 of titanium alloy Ti6Al4V and 0.1-0.13 in a case of the laser gas nitrided surface layers. The volume loss of Ti6Al4V samples under such conditions is twice lower than in a case of pure titanium. On the other hand the composite surface layer characterized by the highest wear resistance showed almost 21 times lower volume loss during the ball-on-disk test, compared to Ti6Al4V samples.

Surface bioactivity modification of titanium by CO 2 plasma treatment and induction of hydroxyapatite: In vitro and in vivo studies

Science.gov (United States)

Hu, Xixue; Shen, Hong; Shuai, Kegang; Zhang, Enwei; Bai, Yanjie; Cheng, Yan; Xiong, Xiaoling; Wang, Shenguo; Fang, Jing; Wei, Shicheng

2011-01-01

Since metallic biomaterials used for orthopedic and dental implants possess a paucity of reactive functional groups, bioactivity modification of these materials is challenging. In the present work, the titanium discs and rods were treated with carbon dioxide plasma and then incubated in a modified simulated body fluid 1.5SBF to obtain a hydroxyapatite layer. Surface hydrophilicity of samples, changes of surface chemistry, surface morphologies of samples, and structural analysis of formed hydroxyapatite were investigated by contact angle to water, X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The results demonstrated that hydrophilicity of titanium surface was improved and hydroxyl groups increased after modification with carbon dioxide plasma treatment. The hydroxyl groups on the surface of titanium were the richest after carbon dioxide plasma treatment under the condition of 20 W for less than 30 s. The hydroxyapatite formability of titanium surface was enhanced by carbon dioxide plasma pretreatment, which was attributed to the surface chemistry. MC3T3-E1 cell as a model cell was cultured on the Ti, CPT-Ti and CPT/SBF-Ti discs in vitro, and the results of the morphology and differentiation of the cell showed that CPT/SBF-Ti was the highest bioactive. The relative parameters of the new bone around the Ti and CPT/SBF-Ti rods including bone mineral density (BMD), a ratio of bone volume to total volume (BV/TV), trabecular thickness (Tb.Th.) and trabecular number (Tb.N.) were analyzed by a micro-computed tomography (micro-CT) after 4-, 8- and 12-week implantation periods in vivo. The results indicated that the CPT/SBF-Ti was more advantageous for new bone formation.

Collagen based Biomaterials from CLRI: An Inspiration from the ...

Indian Academy of Sciences (India)

Collagen-based Smart Biomaterials · Smart materials: As smart people see them · Some Biomaterials based on Collagen in Human Health care · Questions of Value to this presentation ... Collagen based biomaterials · COLLAGEN IN VISION CARE · Slide 57 · Bandage lens: A smart device · Work at CLRI: In summary.

Osteoblastic response to pectin nanocoating on titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Gurzawska, Katarzyna, E-mail: kagu@sund.ku.dk [Research Center for Ageing and Osteoporosis, Departments of Medicine and Diagnostics, Copenhagen University Hospital Glostrup, Ndr. Ringvej 57, 2600 Glostrup (Denmark); Institute of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Nørre Allé 20, 2200 Copenhagen N (Denmark); Svava, Rikke [Department of Plant Environment Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Copenhagen Center for Glycomics, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N (Denmark); Yihua, Yu; Haugshøj, Kenneth Brian [Microtechnology and Surface Analysis, Danish Technological Institute, Gregersensvej 8, 2630 Taastrup (Denmark); Dirscherl, Kai [Dansk Fundamental Metrologi A/S, Matematiktorvet 307, 2800 Lyngby (Denmark); Levery, Steven B. [Copenhagen Center for Glycomics, Institute for Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N (Denmark); Byg, Inge [Department of Plant Environment Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Damager, Iben [Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd (Denmark); Nielsen, Martin W. [Department of Systems Biology, Technical University of Denmark, Matematiktorvet, Building 301, Kgs. Lyngby DK-2800 (Denmark); Jørgensen, Bodil [Department of Plant Environment Sciences, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Jørgensen, Niklas Rye [Research Center for Ageing and Osteoporosis, Departments of Medicine and Diagnostics, Copenhagen University Hospital Glostrup, Ndr. Ringvej 57, 2600 Glostrup (Denmark); and others

2014-10-01

Osseointegration of titanium implants can be improved by organic and inorganic nanocoating of the surface. The aim of our study was to evaluate the effect of organic nanocoating of titanium surface with unmodified and modified pectin Rhamnogalacturonan-Is (RG-Is) isolated from potato and apple with respect to surface properties and osteogenic response in osteoblastic cells. Nanocoatings on titanium surfaces were evaluated by scanning electron microscopy, contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy. The effect of coated RG-Is on cell adhesion, cell viability, bone matrix formation and mineralization was tested using SaOS-2 cells. Nanocoating with pectin RG-Is affected surface properties and in consequence changed the environment for cellular response. The cells cultured on surfaces coated with RG-Is from potato with high content of linear 1.4-linked galactose produced higher level of mineralized matrix compared with control surfaces and surfaces coated with RG-I with low content of linear 1.4-linked galactose. The study showed that the pectin RG-Is nanocoating not only changed chemical and physical titanium surface properties, but also specific coating with RG-Is containing high amount of galactan increased mineralized matrix formation of osteoblastic cells in vitro. - Highlights: • Surface nanocoating with plant-derived Rhamnogalacturonan-I (RG-I) is proposed. • Titanium surface became more hydrophilic after RG-Is nanocoating. • RG-Is with high galactose content resulted in high level of mineralized matrix. • RG-I is a new candidate for improvement of bone healing and osseointegration.

Calcium-based biomaterials for diagnosis, treatment, and theranostics.

Science.gov (United States)

Qi, Chao; Lin, Jing; Fu, Lian-Hua; Huang, Peng

2018-01-22

Calcium-based (CaXs) biomaterials including calcium phosphates, calcium carbonates, calcium silicate and calcium fluoride have been widely utilized in the biomedical field owing to their excellent biocompatibility and biodegradability. In recent years, CaXs biomaterials have been strategically integrated with imaging contrast agents and therapeutic agents for various molecular imaging modalities including fluorescence imaging, magnetic resonance imaging, ultrasound imaging or multimodal imaging, as well as for various therapeutic approaches including chemotherapy, gene therapy, hyperthermia therapy, photodynamic therapy, radiation therapy, or combination therapy, even imaging-guided therapy. Compared with other inorganic biomaterials such as silica-, carbon-, and gold-based biomaterials, CaXs biomaterials can dissolve into nontoxic ions and participate in the normal metabolism of organisms. Thus, they offer safer clinical solutions for disease theranostics. This review focuses on the state-of-the-art progress in CaXs biomaterials, which covers from their categories, characteristics and preparation methods to their bioapplications including diagnosis, treatment, and theranostics. Moreover, the current trends and key problems as well as the future prospects and challenges of CaXs biomaterials are also discussed at the end.

The effect of simulated inflammatory conditions on the surface properties of titanium and stainless steel and their importance as biomaterials

International Nuclear Information System (INIS)

Fonseca-García, Abril; Pérez-Alvarez, J.; Barrera, C.C.; Medina, J.C.; Almaguer-Flores, A.; Sánchez, R. Basurto

2016-01-01

This work compares the surface modifications induced by the immersion in solutions that simulate inflammatory conditions of pure titanium (cpTi) and medical grade stainless steel (SS). The inflammatory conditions were simulated using a mixture of Hartman solution and 50 mM of hydrogen peroxide (H_2O_2) at pH = 5.2. The samples were immersed by 7 days refreshing the solution every day to keep the reactivity of the H_2O_2. The surface characteristics that were investigated were: elemental composition by X-ray photoelectron spectroscopy (XPS); topography by atomic force microscopy (AFM) and profilometry; wettability and surface energy by sessile drop contact angle and point of zero charge by titration. Moreover, the variations in the electrochemical response were evaluated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) performed before and after the treatment using the Hartman solution as the electrolyte. The XPS results indicated that for both metallic samples, oxidation of the surface was promoted and/or the oxide layer was thicker after the immersion. The roughness and the solid-liquid surface energy were increased; the samples showed a more hydrophilic character after the treatment. However, the surface energy of the solid estimated using the Van Oss–Chaudhury–Good approach showed different trends between the cpTi and the SS surfaces; the polar component decreased for cpTi, while it increased for SS. Finally, the electrochemical results indicated that the corrosion resistance (R_c_o_r) and the pore resistance (R_p_o) significantly decreased for cpTi, while both resistances were not significantly different for the SS. This is indicative of a higher dissolution of the cpTi compared to SS and the lower R_p_o means that the species are easily transported through the surface layer, which can be explained in terms of the formation of a porous TiO_x layer, not observed on the SS. The cpTi surface

The effect of simulated inflammatory conditions on the surface properties of titanium and stainless steel and their importance as biomaterials

Energy Technology Data Exchange (ETDEWEB)

Fonseca-García, Abril [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México, México (Mexico); Pérez-Alvarez, J. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México (Mexico); Barrera, C.C. [Posgrado en Ciencias Médicas, Odontológicas y de la Salud, Universidad Nacional Autónoma de México, México (Mexico); Medina, J.C. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, México (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México, México (Mexico); Almaguer-Flores, A. [Facultad de Odontología, Universidad Nacional Autónoma de México, México (Mexico); Sánchez, R. Basurto [Instituto Nacional de Investigaciones Nucleares, México (Mexico); and others

2016-09-01

This work compares the surface modifications induced by the immersion in solutions that simulate inflammatory conditions of pure titanium (cpTi) and medical grade stainless steel (SS). The inflammatory conditions were simulated using a mixture of Hartman solution and 50 mM of hydrogen peroxide (H{sub 2}O{sub 2}) at pH = 5.2. The samples were immersed by 7 days refreshing the solution every day to keep the reactivity of the H{sub 2}O{sub 2}. The surface characteristics that were investigated were: elemental composition by X-ray photoelectron spectroscopy (XPS); topography by atomic force microscopy (AFM) and profilometry; wettability and surface energy by sessile drop contact angle and point of zero charge by titration. Moreover, the variations in the electrochemical response were evaluated by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) performed before and after the treatment using the Hartman solution as the electrolyte. The XPS results indicated that for both metallic samples, oxidation of the surface was promoted and/or the oxide layer was thicker after the immersion. The roughness and the solid-liquid surface energy were increased; the samples showed a more hydrophilic character after the treatment. However, the surface energy of the solid estimated using the Van Oss–Chaudhury–Good approach showed different trends between the cpTi and the SS surfaces; the polar component decreased for cpTi, while it increased for SS. Finally, the electrochemical results indicated that the corrosion resistance (R{sub cor}) and the pore resistance (R{sub po}) significantly decreased for cpTi, while both resistances were not significantly different for the SS. This is indicative of a higher dissolution of the cpTi compared to SS and the lower R{sub po} means that the species are easily transported through the surface layer, which can be explained in terms of the formation of a porous TiO{sub x} layer, not

Surface-Induced Hybridization between Graphene and Titanium

Energy Technology Data Exchange (ETDEWEB)

Hsu, Allen L. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States).; Koch, Roland J. [Technische Universitat, Chemnitz (Germany); Ong, Mitchell T. [Stanford Univ., CA (United States); Fang, Wenjing [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Hofmann, Mario [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Kim, Ki Kang [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States).; Seyller, Thomas [Technische Universitat, Chemnitz (Germany); Dresselhaus, Mildred S. [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Reed, Evan J. [Stanford Univ., CA (United States); Kong, Jing [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Palacios, Tomás [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)

2014-08-26

Carbon-based materials such as graphene sheets and carbon nanotubes have inspired a broad range of applications ranging from high-speed flexible electronics all the way to ultrastrong membranes. However, many of these applications are limited by the complex interactions between carbon-based materials and metals. In this work, we experimentally investigate the structural interactions between graphene and transition metals such as palladium (Pd) and titanium (Ti), which have been confirmed by density functional simulations. We find that the adsorption of titanium on graphene is more energetically favorable than in the case of most metals, and density functional theory shows that a surface induced p-d hybridization occurs between atomic carbon and titanium orbitals. This strong affinity between the two materials results in a short-range ordered crystalline deposition on top of graphene as well as chemical modifications to graphene as seen by Raman and X-ray photoemission spectroscopy (XPS). This induced hybridization is interface-specific and has major consequences for contacting graphene nanoelectronic devices as well as applications toward metal-induced chemical functionalization of graphene.

Multiscale electrochemical analysis of the corrosion of titanium and nitinol for implant applications

International Nuclear Information System (INIS)

Izquierdo, J.; González-Marrero, M.B.; Bozorg, M.; Fernández-Pérez, B.M.; Vasconcelos, H.C.; Santana, J.J.; Souto, R.M.

2016-01-01

Highlights: • Direct screening of differences in the surface reactivity of the passive layers formed on pure titanium and nitinol. • Distinct effect of polarization on the passive layers. • Detection of nickel soluble species released from corrosion pits. - Abstract: Surface electrochemical activity of titanium and nitinol biomaterials in naturally aerated Ringer’s physiological solution was investigated using potentiodynamic polarization and scanning electrochemical microscopy (SECM) techniques. SECM was operated in feedback and redox competition modes as a function of potential applied to the substrate. The kinetics of the electron transfer rate on both materials was characterized by mathematical modelling of the Z-approach curves monitored under feedback conditions. The rate constant values greatly depended on the characteristics of the passive layers formed over the metals under potentiostatic control. A more insulating film was found on nitinol when biased at low polarizations, resulting in smaller tip current increments during tip approach to the investigated surface under positive feedback and competition operation modes. However, at higher anodic polarizations, nitinol passive layers experience breakdown, and therefore tip current values reflect the release of metal cations from the biomaterial surface.

Trends in prosthetic biomaterials in implant dentistry

Directory of Open Access Journals (Sweden)

Saranjit Singh Bhasin

2015-01-01

Full Text Available The most important criterion for the success of dental implants is the selection of a suitable implant biomaterial. To improve the biologic performance of an implant, it is necessary to select a material that does not elicit any negative biological response and at the same time maintains adequate function. It is mandatory for a dentist to have a comprehensive knowledge of various biomaterials used for dental implants. The material of choice for fabrication of the dental implant till date is titanium. With the advancements in the field of implants, zirconia seems to be propitious in the future. However, more advanced in vitro and in vivo studies are required before reaching any such conclusion. To increase the success of zirconia implants, care should be taken to reduce the incidence of mechanical failures. Such failures can be taken care of by having a thorough technical knowledge of implant designing and manufacturing defects. This article attempts to compare the advantages and disadvantages of various dental implant biomaterials. Focus is placed on the recent advances in this field with the recently introduced zirconia and its comparison to conventional titanium.

Osteoblast growth behavior on porous-structure titanium surface

Energy Technology Data Exchange (ETDEWEB)

Tian Yuan; Ding Siyang; Peng Hui; Lu Shanming; Wang Guoping [Research Institute of Stomatology, Nanjing Medical University, Nanjing 210029 (China); Xia Lu, E-mail: shelueia@yahoo.com.cn [Research Institute of Stomatology, Nanjing Medical University, Nanjing 210029 (China); Wang Peizhi, E-mail: wangpzi@sina.com [Research Institute of Stomatology, Nanjing Medical University, Nanjing 210029 (China)

2012-11-15

Highlights: Black-Right-Pointing-Pointer Micro-arc oxidation technology formed a porous feature on titanium surface. Black-Right-Pointing-Pointer This porous surface accelerated adhesion, proliferation and differentiation compared with smooth surface. Black-Right-Pointing-Pointer Osteogenesis-related proteins and genes were up regulated by this porous surface. Black-Right-Pointing-Pointer It is anticipated that micro-arc oxidation surface could enhance osteoblastic activity and bone regeneration. - Abstract: A bioavailable surface generated by nano-technology could accelerate implant osteointegration, reduce healing time and enable implants to bear early loading. In this study, a nano-porous surface of titanium wafers was modified using micro-arc oxidation technique; surface of smooth titanium was used as control group. Surface characteristic was evaluated by investigating morphology, roughness and hydrophilicity of titanium wafers. In vitro studies, osteoblastic adhesion, proliferation and ALP activity, as well as gene and protein expressions relative to mineralization were assayed. Our results showed that a crater-liked nano-porous surface with greater roughness and better hydrophilicity were fabricated by micro-arc oxidation. It was further indicated that nano-porous surface could enhance adhesion, proliferation and ALP activity of osteoblasts compared with smooth surfaces. In addition, gene and protein expression of collagen-I, osteocalcin and osteopontin were also obviously increased. In summary, micro-arc oxidized techniques could form an irregular nano-porous morphology on implant surface which is favorable to improve osteoblastic function and prospected to be a potent modification of dental implant.

Osteoblast growth behavior on porous-structure titanium surface

International Nuclear Information System (INIS)

Tian Yuan; Ding Siyang; Peng Hui; Lu Shanming; Wang Guoping; Xia Lu; Wang Peizhi

2012-01-01

Highlights: ► Micro-arc oxidation technology formed a porous feature on titanium surface. ► This porous surface accelerated adhesion, proliferation and differentiation compared with smooth surface. ► Osteogenesis-related proteins and genes were up regulated by this porous surface. ► It is anticipated that micro-arc oxidation surface could enhance osteoblastic activity and bone regeneration. - Abstract: A bioavailable surface generated by nano-technology could accelerate implant osteointegration, reduce healing time and enable implants to bear early loading. In this study, a nano-porous surface of titanium wafers was modified using micro-arc oxidation technique; surface of smooth titanium was used as control group. Surface characteristic was evaluated by investigating morphology, roughness and hydrophilicity of titanium wafers. In vitro studies, osteoblastic adhesion, proliferation and ALP activity, as well as gene and protein expressions relative to mineralization were assayed. Our results showed that a crater-liked nano-porous surface with greater roughness and better hydrophilicity were fabricated by micro-arc oxidation. It was further indicated that nano-porous surface could enhance adhesion, proliferation and ALP activity of osteoblasts compared with smooth surfaces. In addition, gene and protein expression of collagen-I, osteocalcin and osteopontin were also obviously increased. In summary, micro-arc oxidized techniques could form an irregular nano-porous morphology on implant surface which is favorable to improve osteoblastic function and prospected to be a potent modification of dental implant.

In vitro characterization of two different atmospheric plasma jet chemical functionalizations of titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Mussano, F., E-mail: federico.mussano@unito.it [CIR Dental School, Department of Surgical Sciences UNITO, via Nizza 230, 10126, Turin (Italy); Genova, T. [CIR Dental School, Department of Surgical Sciences UNITO, via Nizza 230, 10126, Turin (Italy); Department of Life Sciences and Systems Biology, UNITO, via Accademia Albertina 13, 10123, Turin (Italy); Verga Falzacappa, E. [Department of Molecular Science and Nanosystems, UNIVE, Via Torino 155, 30170, Venezia (Italy); Nadir srl, Via Torino 155, 30170 Venezia (Italy); Scopece, P. [Nadir srl, Via Torino 155, 30170 Venezia (Italy); Munaron, L. [Department of Life Sciences and Systems Biology, UNITO, via Accademia Albertina 13, 10123, Turin (Italy); Centre for Nanostructured Interfaces and Surfaces (NIS) (Italy); Rivolo, P.; Mandracci, P. [Politecnico di Torino, Department of Applied Science and Technology, Materials and Microsoystems Laboratory (ChiLab), Corso Duca degli Abruzzi 24, 10129, Torino (Italy); Benedetti, A. [Department of Molecular Science and Nanosystems, UNIVE, Via Torino 155, 30170, Venezia (Italy); Carossa, S. [CIR Dental School, Department of Surgical Sciences UNITO, via Nizza 230, 10126, Turin (Italy); Patelli, A. [Department of Physics and Astronomy, UNIPD, via Marzolo 8, 35122 Padova (Italy)

2017-07-01

Highlights: • NH{sub 2}-Ti and COOH/R-Ti obtained via atmospheric plasma jet RF-APPJ portable equipment. • Higher quantity of adsorbed proteins and improved cell adhesion on treated surfaces. • More tapered and elongated cells on NH{sub 2}-Ti compared to COOH/R-Ti. • Higher osteocalcin expression on NH{sub 2}-Ti. - Abstract: Plasma surface activation and plasma polymers deposition are promising technologies capable to modulate biologically relevant surface features of biomaterials. The purpose of this study was to evaluate the biological effects of two different surface modifications, i.e. amine (NH{sub 2}-Ti) and carboxylic/esteric (COOH/R-Ti) functionalities obtained from 3-aminopropyltriethoxysilane (3-APTES) and methylmethacrylate (MMA) precursors, respectively, through an atmospheric plasma jet RF-APPJ portable equipment. The coatings were characterized by Scanning Electron Microscopy, FT-IR spectroscopy, XPS and surface energy calculations. Stability in water and after UV sterilization were also verified. The pre-osteoblastic murine cell line MC3T3-E1 was used to perform the in-vitro tests. The treated samples showed a higher quantity of adsorbed proteins and improved osteoblast cells adhesion on the surfaces compared to the pristine titanium, in particular the COOH/R-Ti led to a nearly two-fold improvement. Cell proliferation on coated samples was initially (at 24 h) lower than on titanium control, while, at 48 h, COOH/R-Ti reached the proliferation rate of pristine titanium. Cells grown on NH{sub 2}-Ti were more tapered and elongated in shape with lower areas than on COOH/R-Ti enriched surfaces. Finally, NH{sub 2}-Ti significantly enhanced osteocalcin production, starting from 14 days, while COOH/R-Ti had this effect only from 21 days. Notably, NH{sub 2}-Ti was more efficient than COOH/R-Ti at 21 days. The amine functionality elicited the most relevant osteogenic effect in terms of osteocalcin expression, thus establishing an interesting correlation

Investigation of biomaterials by human epithelial gingiva cells: an in vitro study

Directory of Open Access Journals (Sweden)

Neunzehn Jörg

2012-12-01

Full Text Available Abstract Introduction In modern medicine and dentistry the use of biomaterials is a fast developing field of increasing interest. Especially in dentistry the interaction between biomaterials like implant materials and the soft tissue in the oral cavity is in the focus of daily research. In this context the high importance of testing materials and their surfaces concerning their biocompatibility towards corresponding cells is very likely. For this purpose this study investigates cells derived from human gingival biopsies on different materials and surfaces. Methods Cells in this study were cultivated out of human biopsies by a grow out explant technique and were sub cultivated on titanium, zirconium dioxide and collagen membrane specimens. To characterise the cells on the material surfaces used in this study immunohistochemical and histological staining techniques as well as different methods of microscopy (light microscopy and SEM were applied. Results With the aid of the explant technique and the chosen cell cultivation method it was possible to investigate the human gingiva derived cells on different materials. The data of the present study show that the human gingival cells attach and proliferate on all three tested materials by exhibiting characteristic gingival keratinocyte protein expression even after long periods of culture e.g. up to 70 days. Conclusions It could be shown that the three tested materials titanium, zirconium dioxide and collagen membrane (and their special surfaces are good candidates for the application as materials in the dental gingival environment or, in the case of the collagen membrane as scaffold/cell-carrier for human gingival cells in tissue engineering.

Nanocoating of titanium implant surfaces with organic molecules. Polysaccharides including glycosaminoglycans

DEFF Research Database (Denmark)

Gurzawska, Katarzyna Aleksandra; Svava, Rikke; Jørgensen, Niklas Rye

2012-01-01

Long-term stability of titanium implants are dependent on a variety of factors. Nanocoating with organic molecules is one of the method used to improve osseointegration. Nanoscale modification of titanium implants affects surface properties, such as hydrophilicity, biochemical bonding capacity...... and roughness. This influences cell behaviour on the surface such as adhesion, proliferation and differentiation of cells as well as the mineralization of the extracellular matrix at the implant surfaces. The aim of the present systematic review was to describe organic molecules used for surface nanocoating...... nanocoatings. The included in vivo studies, showed improvement of bone interface reactions measured as increased Bone-to-Implant Contact length and Bone Mineral Density adjacent to the polysaccharide coated surfaces. Based on existing literature, surface modification with polysaccharide and glycosaminoglycans...

Surface Modification of Porous Titanium Granules for Improving Bioactivity.

Science.gov (United States)

Karaji, Zahra Gorgin; Houshmand, Behzad; Faghihi, Shahab

The highly porous titanium granules are currently being used as bone substitute material and for bone tissue augmentation. However, they suffer from weak bone bonding ability. The aim of this study was to create a nanostructured surface oxide layer on irregularly shaped titanium granules to improve their bioactivity. This could be achieved using optimized electrochemical anodic oxidation (anodizing) and heat treatment processes. The anodizing process was done in an ethylene glycol-based electrolyte at an optimized condition of 60 V for 3 hours. The anodized granules were subsequently annealed at 450°C for 1 hour. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) were used to characterize the surface structure and morphology of the granules. The in vitro bioactivity of the samples was evaluated by immersion of specimens in simulated body fluid (SBF) for 1, 2, and 3 weeks. The human osteoblastic sarcoma cell line, MG63, was used to evaluate cell viability on the samples using dimethylthiazol-diphenyl tetrazolium bromide (MTT) assay. The results demonstrated the formation of amorphous nanostructured titanium oxide after anodizing, which transformed to crystalline anatase and rutile phases upon heat treatment. After immersion in SBF, spherical aggregates of amorphous calcium phosphate were formed on the surface of the anodized sample, which turned into crystalline hydroxyapatite on the surface of the anodized annealed sample. No cytotoxicity was detected among the samples. It is suggested that anodic oxidation followed by heat treatment could be used as an effective surface treatment procedure to improve bioactivity of titanium granules implemented for bone tissue repair and augmentation.

A review of the clinical implications of anti-infective biomaterials and infection-resistant surfaces.

Science.gov (United States)

Campoccia, Davide; Montanaro, Lucio; Arciola, Carla Renata

2013-11-01

Infection is currently regarded as the most severe and devastating complication associated to the use of biomaterials. The important social, clinical and economic impacts of implant-related infections are promoting the efforts to obviate these severe diseases. In this context, the development of anti-infective biomaterials and of infection-resistant surfaces is being regarded as the main strategy to prevent the establishment of implant colonisation and biofilm formation by bacteria. In this review, the attention is focused on the biomaterial-associated infections, from which the need for anti-infective biomaterials originates. Biomaterial-associated infections differ markedly for epidemiology, aetiology and severity, depending mainly on the anatomic site, on the time of biomaterial application, and on the depth of the tissues harbouring the prosthesis. Here, the diversity and complexity of the different scenarios where medical devices are currently utilised are explored, providing an overview of the emblematic applicative fields and of the requirements for anti-infective biomaterials. © 2013 Elsevier Ltd. All rights reserved.

In vitro Evaluation of Calcium Phosphate Precipitation on Possibly Bioactive Titanium Surfaces in the Presence of Laminin

Directory of Open Access Journals (Sweden)

Kostas Bougas

2011-07-01

Full Text Available Objectives: The aim of the present study was to evaluate calcium phosphate precipitation and the amount of precipitated protein on three potentially bioactive surfaces when adding laminin in simulated body fluid.Material and Methods: Blasted titanium discs were prepared by three different techniques claimed to provide bioactivity: alkali and heat treatment (AH, anodic oxidation (AO or hydroxyapatite coating (HA. A blasted surface incubated in laminin-containing simulated body fuid served as a positive control (B while a blasted surface incubated in non laminin-containing simulated body fuid served as a negative control (B-. The immersion time was 1 hour, 24 hours, 72 hours and 1 week. Surface topography was investigated by interferometry and morphology by Scanning Electron Microscopy (SEM. Analysis of the precipitated calcium and phosphorous was performed by Energy Dispersive X-ray Spectroscopy (EDX and the adsorbed laminin was quantified by iodine (125I labeling.Results: SEM demonstrated that all specimens except for the negative control were totally covered with calcium phosphate (CaP after 1 week. EDX revealed that B- demonstrated lower sum of Ca and P levels compared to the other groups after 1 week. Iodine labeling demonstrated that laminin precipitated in a similar manner on the possibly bioactive surfaces as on the positive control surface.Conclusions: Our results indicate that laminin precipitates equally on all tested titanium surfaces and may function as a nucleation center thus locally elevating the calcium concentration. Nevertheless further studies are required to clarify the role of laminin in the interaction of biomaterials with the host bone tissue.

Effect of surface reaction layer on grindability of cast titanium alloys.

Science.gov (United States)

Ohkubo, Chikahiro; Hosoi, Toshio; Ford, J Phillip; Watanabe, Ikuya

2006-03-01

The purpose of this study was to investigate the effect of the cast surface reaction layer on the grindability of titanium alloys, including free-machining titanium alloy (DT2F), and to compare the results with the grindability of two dental casting alloys (gold and Co-Cr). All titanium specimens (pure Ti, Ti-6Al-4V and DT2F) were cast using a centrifugal casting machine in magnesia-based investment molds. Two specimen sizes were used to cast the titanium metals so that the larger castings would be the same size as the smaller gold and Co-Cr alloy specimens after removal of the surface reaction layer (alpha-case). Grindability was measured as volume loss ground from a specimen for 1 min using a handpiece engine with a SiC abrasive wheel at 0.1 kgf and four circumferential wheel speeds. For the titanium and gold alloys, grindability increased as the rotational speed increased. There was no statistical difference (p>0.05) in grindability for all titanium specimens either with or without the alpha-case. Of the titanium metals tested, Ti-6 Al-4V had the greatest grindability at higher speeds, followed by DT2F and CP Ti. The grindability of the gold alloy was similar to that of Ti-6 Al-4V, whereas the Co-Cr alloy had the lowest grindability. The results of this study indicated that the alpha-case did not significantly affect the grindability of the titanium alloys. The free-machining titanium alloy had improved grindability compared to CP Ti.

Surface Texture-Based Surface Treatments on Ti6Al4V Titanium Alloys for Tribological and Biological Applications: A Mini Review

Directory of Open Access Journals (Sweden)

Naiming Lin

2018-03-01

Full Text Available Surface texture (ST has been confirmed as an effective and economical surface treatment technique that can be applied to a great range of materials and presents growing interests in various engineering fields. Ti6Al4V which is the most frequently and successfully used titanium alloy has long been restricted in tribological-related operations due to the shortcomings of low surface hardness, high friction coefficient, and poor abrasive wear resistance. Ti6Al4V has benefited from surface texture-based surface treatments over the last decade. This review begins with a brief introduction, analysis approaches, and processing methods of surface texture. The specific applications of the surface texture-based surface treatments for improving surface performance of Ti6Al4V are thoroughly reviewed from the point of view of tribology and biology.

Strategies For Immobilization Of Bioactive Organic Molecules On Titanium Implant Surfaces – A Review

Directory of Open Access Journals (Sweden)

Panayotov Ivan V.

2015-03-01

Full Text Available Numerous approaches have been used to improve the tissue-implant interface of titanium (Ti and titanium alloy (Ti6Al4V. They all aim at increasing cell migration and attachment to the metal, preventing unspecific protein adsorption and improving post-implantation healing process. Promising methods for titanium and titanium alloy surface modification are based on the immobilization of biologically active organic molecules. New and interesting biochemical approaches to such surface modification include layer-by-layer deposition of polyelectrolyte films, phage display-selected surface binding peptides and self-assembled DNA monolayer systems. The present review summarizes the scientific information about these methods, which are at in vitro or in vivo development stages, and hopes to promote their future application in dental implantology and in oral and maxillofacial surgery.

Oligoaniline-based conductive biomaterials for tissue engineering.

Science.gov (United States)

Zarrintaj, Payam; Bakhshandeh, Behnaz; Saeb, Mohammad Reza; Sefat, Farshid; Rezaeian, Iraj; Ganjali, Mohammad Reza; Ramakrishna, Seeram; Mozafari, Masoud

2018-05-01

The science and engineering of biomaterials have improved the human life expectancy. Tissue engineering is one of the nascent strategies with an aim to fulfill this target. Tissue engineering scaffolds are one of the most significant aspects of the recent tissue repair strategies; hence, it is imperative to design biomimetic substrates with suitable features. Conductive substrates can ameliorate the cellular activity through enhancement of cellular signaling. Biocompatible polymers with conductivity can mimic the cells' niche in an appropriate manner. Bioconductive polymers based on aniline oligomers can potentially actualize this purpose because of their unique and tailoring properties. The aniline oligomers can be positioned within the molecular structure of other polymers, thus painter acting with the side groups of the main polymer or acting as a comonomer in their backbone. The conductivity of oligoaniline-based conductive biomaterials can be tailored to mimic the electrical and mechanical properties of targeted tissues/organs. These bioconductive substrates can be designed with high mechanical strength for hard tissues such as the bone and with high elasticity to be used for the cardiac tissue or can be synthesized in the form of injectable hydrogels, particles, and nanofibers for noninvasive implantation; these structures can be used for applications such as drug/gene delivery and extracellular biomimetic structures. It is expected that with progress in the fields of biomaterials and tissue engineering, more innovative constructs will be proposed in the near future. This review discusses the recent advancements in the use of oligoaniline-based conductive biomaterials for tissue engineering and regenerative medicine applications. The tissue engineering applications of aniline oligomers and their derivatives have recently attracted an increasing interest due to their electroactive and biodegradable properties. However, no reports have systematically reviewed

Cell spreading on titanium dioxide film formed and modified with aerosol beam and femtosecond laser

International Nuclear Information System (INIS)

Shinonaga, Togo; Tsukamoto, Masahiro; Nagai, Akiko; Yamashita, Kimihiro; Hanawa, Takao; Matsushita, Nobuhiro; Xie, Guoqiang; Abe, Nobuyuki

2014-01-01

Titanium (Ti) is widely used in biomaterials because of its excellent anti-corrosion properties and high strength. However, Ti has no biological function, so its bioactivity must be improved. Coating a titanium dioxide (TiO 2 ) film on a Ti plate surface has been shown to improve the biocompatibility of Ti plates. If periodic nanostructures were formed on the film surface, the direction of cell spreading might be controlled by the direction of the grooves. Controlling cell spreading on biomaterials would contribute to the creation of advanced biomaterials. In this paper, a TiO 2 film was formed on a Ti plate with an aerosol beam composed of sub micron-sized TiO 2 particles and helium gas. Periodic nanostructures, lying perpendicular to the laser electric field polarization vector, were formed on the film by scanning the femtosecond laser focusing spot. The period and height of the periodic nanostructures were about 230 nm and 150 nm, respectively. In a cell test, cell spreading was observed along the grooves of the periodic nanostructures; in contrast, cell spreading did not show a definite direction on TiO 2 a film without periodic nanostructures. These results suggest that the direction of cell spreading on the film can be controlled by periodic nanostructure formation generated using a femtosecond laser.

Characterization of biomaterials

CERN Document Server

Jaffe, M; Tolias, P; Arinzeh, T

2012-01-01

Biomaterials and medical devices must be rigorously tested in the laboratory before they can be implanted. Testing requires the right analytical techniques. Characterization of biomaterials reviews the latest methods for analyzing the structure, properties and behaviour of biomaterials. Beginning with an introduction to microscopy techniques for analyzing the phase nature and morphology of biomaterials, Characterization of biomaterials goes on to discuss scattering techniques for structural analysis, quantitative assays for measuring cell adhesion, motility and differentiation, and the evaluation of cell infiltration and tissue formation using bioreactors. Further topics considered include studying molecular-scale protein-surface interactions in biomaterials, analysis of the cellular genome and abnormalities, and the use of microarrays to measure cellular changes induced by biomaterials. Finally, the book concludes by outlining standards and methods for assessing the safety and biocompatibility of biomaterial...

Surface modification of porous titanium with rice husk as space holder

Science.gov (United States)

Wang, Xinsheng; Hou, Junjian; Liu, Yanpei

2018-06-01

Porous titanium was characterized after its surface modification by acid and alkali solution immersion. The results show that the acid surface treatment caused the emergence of flocculent sodium titanate and induced apatite formation. The surface modification of porous titanium promotes biological activation, and the application of porous titanium is also improved as an implant material because of the existence of C and Si.

Trends in biomedical engineering: focus on Smart Bio-Materials and Drug Delivery.

Science.gov (United States)

Tanzi, Maria Cristina; Bozzini, Sabrina; Candiani, Gabriele; Cigada, Alberto; De Nardo, Luigi; Farè, Silvia; Ganazzoli, Fabio; Gastaldi, Dario; Levi, Marinella; Metrangolo, Pierangelo; Migliavacca, Francesco; Osellame, Roberto; Petrini, Paola; Raffaini, Giuseppina; Resnati, Giuseppe; Vena, Pasquale; Vesentini, Simone; Zunino, Paolo

2011-01-01

The present article reviews on different research lines, namely: drug and gene delivery, surface modification/modeling, design of advanced materials (shape memory polymers and biodegradable stents), presently developed at Politecnico di Milano, Italy. For gene delivery, non-viral polycationic-branched polyethylenimine (b-PEI) polyplexes are coated with pectin, an anionic polysaccharide, to enhance the polyplex stability and decrease b-PEI cytotoxicity. Perfluorinated materials, specifically perfluoroether, and perfluoro-polyether fluids are proposed as ultrasound contrast agents and smart agents for drug delivery. Non-fouling, self-assembled PEG-based monolayers are developed on titanium surfaces with the aim of drastically reducing cariogenic bacteria adhesion on dental implants. Femtosecond laser microfabrication is used for selectively and spatially tuning the wettability of polymeric biomaterials and the effects of femtosecond laser ablation on the surface properties of polymethylmethacrylate are studied. Innovative functionally graded Alumina-Ti coatings for wear resistant articulating surfaces are deposited with PLD and characterized by means of a combined experimental and computational approach. Protein adsorption on biomaterials surfaces with an unlike wettability and surface-modification induced by pre-adsorbed proteins are studied by atomistic computer simulations. A study was performed on the fabrication of porous Shape Memory Polymeric structures and on the assessment of their potential application in minimally invasive surgical procedures. A model of magnesium (alloys) degradation, in a finite element framework analysis, and a bottom-up multiscale analysis for modeling the degradation mechanism of PLA matrices was developed, with the aim of providing valuable tools for the design of bioresorbable stents.

Effects of applied stress ratio on the fatigue behavior of additively manufactured porous biomaterials under compressive loading.

Science.gov (United States)

de Krijger, Joep; Rans, Calvin; Van Hooreweder, Brecht; Lietaert, Karel; Pouran, Behdad; Zadpoor, Amir A

2017-06-01

Additively manufactured (AM) porous metallic biomaterials are considered promising candidates for bone substitution. In particular, AM porous titanium can be designed to exhibit mechanical properties similar to bone. There is some experimental data available in the literature regarding the fatigue behavior of AM porous titanium, but the effect of stress ratio on the fatigue behavior of those materials has not been studied before. In this paper, we study the effect of applied stress ratio on the compression-compression fatigue behavior of selective laser melted porous titanium (Ti-6Al-4V) based on the diamond unit cell. The porous titanium biomaterial is treated as a meta-material in the context of this work, meaning that R-ratios are calculated based on the applied stresses acting on a homogenized volume. After morphological characterization using micro computed tomography and quasi-static mechanical testing, the porous structures were tested under cyclic loading using five different stress ratios, i.e. R = 0.1, 0.3, 0.5, 0.7 and 0.8, to determine their S-N curves. Feature tracking algorithms were used for full-field deformation measurements during the fatigue tests. It was observed that the S-N curves of the porous structures shift upwards as the stress ratio increases. The stress amplitude was the most important factor determining the fatigue life. Constant fatigue life diagrams were constructed and compared with similar diagrams for bulk Ti-6Al-4V. Contrary to the bulk material, there was limited dependency of the constant life diagrams to mean stress. The notches present in the AM biomaterials were the sites of crack initiation. This observation and other evidence suggest that the notches created by the AM process cause the insensitivity of the fatigue life diagrams to mean stress. Feature tracking algorithms visualized the deformation during fatigue tests and demonstrated the root cause of inclined (45°) planes of specimen failure. In conclusion, the R

New Ti-Alloys and Surface Modifications to Improve the Mechanical Properties and the Biological Response to Orthopedic and Dental Implants: A Review

Science.gov (United States)

Kirmanidou, Yvoni; Sidira, Margarita; Drosou, Maria-Eleni; Bennani, Vincent; Bakopoulou, Athina; Tsouknidas, Alexander; Michailidis, Nikolaos; Michalakis, Konstantinos

2016-01-01

Titanium implants are widely used in the orthopedic and dentistry fields for many decades, for joint arthroplasties, spinal and maxillofacial reconstructions, and dental prostheses. However, despite the quite satisfactory survival rates failures still exist. New Ti-alloys and surface treatments have been developed, in an attempt to overcome those failures. This review provides information about new Ti-alloys that provide better mechanical properties to the implants, such as superelasticity, mechanical strength, and corrosion resistance. Furthermore, in vitro and in vivo studies, which investigate the biocompatibility and cytotoxicity of these new biomaterials, are introduced. In addition, data regarding the bioactivity of new surface treatments and surface topographies on Ti-implants is provided. The aim of this paper is to discuss the current trends, advantages, and disadvantages of new titanium-based biomaterials, fabricated to enhance the quality of life of many patients around the world. PMID:26885506

Evidence of antibacterial activity on titanium surfaces through nanotextures

Energy Technology Data Exchange (ETDEWEB)

Seddiki, O.; Harnagea, C. [INRS – Centre Énergie, Matériaux et Télécommunications, Boulevard Lionel-Boulet, Varennes, Québec J3X 1S2 (Canada); Levesque, L.; Mantovani, D. [Laboratory for Biomaterials and Bioengineering (CRC-I), Dept Min-Met-Materials Engineering and Research Center CHU-Quebec, Laval University, Quebec City (Canada); Rosei, F., E-mail: rosei@emt.inrs.ca [INRS – Centre Énergie, Matériaux et Télécommunications, Boulevard Lionel-Boulet, Varennes, Québec J3X 1S2 (Canada); Center for Self-Assembled Chemical Structures, McGill University, H3A 2K6 Montreal, Quebec (Canada)

2014-07-01

Nosocomial infections (Nis) are a major concern for public health. As more and more of the pathogens responsible for these infections are antibiotic resistant, finding new ways to overcome them is a major challenge for biomedical research. We present a method to reduce Nis spreading by hindering bacterial adhesion in its very early stage. This is achieved by reducing the contact interface area between the bacterium and the surface by nanoengineering the surface topography. In particular, we studied the Escheria Coli adhesion on titanium surfaces exhibiting different morphologies, that were obtained by a combination of mechanical polishing and chemical etching. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) characterization revealed that the titanium surface is modified at both micro- and nano-scale. X-ray Photoelectron Spectroscopy (XPS) revealed that the surfaces have the same composition before and after piranha treatment, consisting mainly of TiO{sub 2}. Adhesion tests showed a significant reduction in bacterial accumulation on nanostructured surfaces that had the lowest roughness over large areas. SEM images acquired after bacterial culture on different titanium substrates confirmed that the polished titanium surface treated one hour in a piranha solution at a temperature of 25 °C has the lowest bacterial accumulation among all the surfaces tested. This suggests that the difference observed in bacterial adhesion between the different surfaces is due primarily to surface topography.

Evidence of antibacterial activity on titanium surfaces through nanotextures

International Nuclear Information System (INIS)

Seddiki, O.; Harnagea, C.; Levesque, L.; Mantovani, D.; Rosei, F.

2014-01-01

Nosocomial infections (Nis) are a major concern for public health. As more and more of the pathogens responsible for these infections are antibiotic resistant, finding new ways to overcome them is a major challenge for biomedical research. We present a method to reduce Nis spreading by hindering bacterial adhesion in its very early stage. This is achieved by reducing the contact interface area between the bacterium and the surface by nanoengineering the surface topography. In particular, we studied the Escheria Coli adhesion on titanium surfaces exhibiting different morphologies, that were obtained by a combination of mechanical polishing and chemical etching. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) characterization revealed that the titanium surface is modified at both micro- and nano-scale. X-ray Photoelectron Spectroscopy (XPS) revealed that the surfaces have the same composition before and after piranha treatment, consisting mainly of TiO 2 . Adhesion tests showed a significant reduction in bacterial accumulation on nanostructured surfaces that had the lowest roughness over large areas. SEM images acquired after bacterial culture on different titanium substrates confirmed that the polished titanium surface treated one hour in a piranha solution at a temperature of 25 °C has the lowest bacterial accumulation among all the surfaces tested. This suggests that the difference observed in bacterial adhesion between the different surfaces is due primarily to surface topography.

Additively manufactured metallic porous biomaterials based on minimal surfaces : A unique combination of topological, mechanical, and mass transport properties

NARCIS (Netherlands)

Bobbert, F S L; Lietaert, K; Eftekhari, A A; Pouran, B; Ahmadi, S M; Weinans, H; Zadpoor, A A

2017-01-01

Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different

Narrow titanium oxide nanowires induced by femtosecond laser pulses on a titanium surface

Energy Technology Data Exchange (ETDEWEB)

Li, Hui; Li, Xian-Feng [Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China); Zhang, Cheng-Yun [School of Physics and Electronic Engineering, Guangzhou University, Guangzhou 510006 (China); Tie, Shao-Long [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Lan, Sheng, E-mail: slan@scnu.edu.cn [Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China)

2017-02-28

Highlights: • Titanium oxide nanowires with a feature width as narrow as ∼20 nm were induced on a titanium surface by using femtosecond laser pulses at 400 nm. • An evolution of the surface structure from a high spatial frequency laser-induced periodic structure parallel to the laser polarization to a low spatial frequency one perpendicular to the laser polarization was observed with increasing irradiation pulse number. • The formation of the titanium oxide nanowires was confirmed by the energy dispersive spectroscopy measurements and the evolution of the surface structure was successfully interpreted by using the efficacy factor theory. - Abstract: The evolution of the nanostructure induced on a titanium (Ti) surface with increasing irradiation pulse number by using a 400-nm femtosecond laser was examined by using scanning electron microscopy. High spatial frequency periodic structures of TiO{sub 2} parallel to the laser polarization were initially observed because of the laser-induced oxidation of the Ti surface and the larger efficacy factor of TiO{sub 2} in this direction. Periodically aligned TiO{sub 2} nanowires with featured width as small as 20 nm were obtained. With increasing pulse number, however, low spatial frequency periodic structures of Ti perpendicular to the laser polarization became dominant because Ti possesses a larger efficacy factor in this direction. The competition between the high- and low-spatial frequency periodic structures is in good agreement with the prediction of the efficacy factor theory and it should also be observed in the femtosecond laser ablation of other metals which are easily oxidized in air.

Electrochemical surface modification of titanium in dentistry.

Science.gov (United States)

Kim, Kyo-Han; Ramaswamy, Narayanan

2009-01-01

Titanium and its alloys have good biocompatibility with body cells and tissues and are widely used for implant applications. However, clinical procedures place more stringent and tough requirements on the titanium surface necessitating artificial surface treatments. Among the many methods of titanium surface modification, electrochemical techniques are simple and cheap. Anodic oxidation is the anodic electrochemical technique while electrophoretic and cathodic depositions are the cathodic electrochemical techniques. By anodic oxidation it is possible to obtain desired roughness, porosity and chemical composition of the oxide. Anodic oxidation at high voltages can improve the crystallinity of the oxide. The chief advantage of this technique is doping of the coating of the bath constituents and incorporation of these elements improves the properties of the oxide. Electrophoretic deposition uses hydroxyapatite (HA) powders dispersed in a suitable solvent at a particular pH. Under these operating conditions these particles acquire positive charge and coatings are obtained on the cathodic titanium by applying an external electric field. These coatings require a post-sintering treatment to improve the coating properties. Cathodic deposition is another type of electrochemical method where HA is formed in situ from an electrolyte containing calcium and phosphate ions. It is also possible to alter structure and/or chemistry of the obtained deposit. Nano-grained HA has higher surface energy and greater biological activity and therefore emphasis is being laid to produce these coatings by cathodic deposition.

Maggot excretions inhibit biofilm formation on biomaterials.

Science.gov (United States)

Cazander, Gwendolyn; van de Veerdonk, Mariëlle C; Vandenbroucke-Grauls, Christina M J E; Schreurs, Marco W J; Jukema, Gerrolt N

2010-10-01

Biofilm-associated infections in trauma surgery are difficult to treat with conventional therapies. Therefore, it is important to develop new treatment modalities. Maggots in captured bags, which are permeable for larval excretions/secretions, aid in healing severe, infected wounds, suspect for biofilm formation. Therefore we presumed maggot excretions/secretions would reduce biofilm formation. We studied biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella oxytoca, Enterococcus faecalis, and Enterobacter cloacae on polyethylene, titanium, and stainless steel. We compared the quantities of biofilm formation between the bacterial species on the various biomaterials and the quantity of biofilm formation after various incubation times. Maggot excretions/secretions were added to existing biofilms to examine their effect. Comb-like models of the biomaterials, made to fit in a 96-well microtiter plate, were incubated with bacterial suspension. The formed biofilms were stained in crystal violet, which was eluted in ethanol. The optical density (at 595 nm) of the eluate was determined to quantify biofilm formation. Maggot excretions/secretions were pipetted in different concentrations to (nonstained) 7-day-old biofilms, incubated 24 hours, and finally measured. The strongest biofilms were formed by S. aureus and S. epidermidis on polyethylene and the weakest on titanium. The highest quantity of biofilm formation was reached within 7 days for both bacteria. The presence of excretions/secretions reduced biofilm formation on all biomaterials. A maximum of 92% of biofilm reduction was measured. Our observations suggest maggot excretions/secretions decrease biofilm formation and could provide a new treatment for biofilm formation on infected biomaterials.

Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein.

Directory of Open Access Journals (Sweden)

Andreas Baranowski

Full Text Available Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP has been shown to enhance bone formation when coated onto titanium femoral implants and in rat calvarial defect models. However, the most appropriate method of BSP coating, the necessary level of BSP coating, and the effect of BSP coating on cell behavior remain largely unknown. In this study, BSP was covalently coupled to titanium surfaces via an aminosilane linker (APTES, and its properties were compared to BSP applied to titanium via physisorption and untreated titanium. Cell functions were examined using primary human osteoblasts (hOBs and L929 mouse fibroblasts. Gene expression of specific bone turnover markers at the RNA level was detected at different intervals. Cell adhesion to titanium surfaces treated with BSP via physisorption was not significantly different from that of untreated titanium at any time point, whereas BSP application via covalent coupling caused reduced cell adhesion during the first few hours in culture. Cell migration was increased on titanium disks that were treated with higher concentrations of BSP solution, independent of the coating method. During the early phases of hOB proliferation, a suppressive effect of BSP was observed independent of its concentration, particularly when BSP was applied to the titanium surface via physisorption. Although alkaline phosphatase activity was reduced in the BSP-coated titanium groups after 4 days in culture, increased calcium deposition was observed after 21 days. In particular, the gene expression level of RUNX2 was upregulated by BSP. The increase in calcium deposition and the stimulation of cell differentiation induced by BSP highlight its potential as a surface modifier that could enhance the osseointegration of orthopedic implants

Friction and Wear Behavior of Ti-6Al-7Nb Biomaterial Alloy

OpenAIRE

FELLAH , Mamoun; ASSALA , Omar; LABAÏZ , Mohamed; DEKHIL , Leila; IOST , Alain

2013-01-01

Titanium and its alloys have been used as implant materials due to their very good mechanical and corrosion resistance and biocompatibility [1,2]. The most used biomaterials were commercially pure titanium (CP-Ti} issued in clinics, although CP- Ti has been pointed out to have disadvantages of low strength, difficulty for polishing, and poor wear resistance. Therefore, Titanium is still insufficient for high-stress applications ; e.g., long spanned fixed prostheses and the fr...

Enhanced Hydrophilicity and Protein Adsorption of Titanium Surface by Sodium Bicarbonate Solution

Directory of Open Access Journals (Sweden)

Shengnan Jia

2015-01-01

Full Text Available The aim of this study was to investigate a novel and convenient method of chemical treatment to modify the hydrophilicity of titanium surfaces. Sand-blasted and acid-etched (SLA titanium surfaces and machined titanium surfaces were treated with sodium bicarbonate (NaHCO3 solution. The wetting behavior of both kinds of surfaces was measured by water contact angle (WCA test. The surface microstructure was assessed with scanning electron microscopy (SEM and three-dimensional (3D optical microscopy. The elemental compositions of the surfaces were analyzed by X-ray photoelectron spectroscopy (XPS. The protein adsorption analysis was performed with fibronectin. Results showed that, after 1 M NaHCO3 treatment, the hydrophilicity of both SLA and machined surfaces was enhanced. No significant microstructural change presented on titanium surfaces after NaHCO3 treatment. The deprotonation and ion exchange activities might cause the enhanced hydrophilicity of titanium surfaces. The increased protein adsorption of NaHCO3-treated SLA surfaces might indicate their improved tissue-integration in clinical use.

Simulation of the Electric Field Distribution Near a Topographically Nanostructured Titanium-Electrolyte Interface: Influence of the Passivation Layer

Directory of Open Access Journals (Sweden)

Andreas Körtge

2013-01-01

Full Text Available A major challenge in biomaterials research is the regulation of protein adsorption at metallic implant surfaces. Recently, a number of studies have shown that protein adsorption can be influenced by metallic nanotopographies, which are discussed to increase electric field strengths near sharp edges and spikes. Since many metallic biomaterials form a native passivation layer with semiconducting properties, we have analyzed the influence of this layer on the near-surface electric field distribution of a nanostructure using finite element simulations. The Poisson-Boltzmann equation was solved for a titanium nanostructure covered by a TiO2 passivation layer in contact with a physiological NaCl solution (bulk concentration 0.137 mol/L. In contrast to a purely metallic nanostructure, the electric field strengths near sharp edges and spikes can be lower than in planar regions if a passivation layer is considered. Our results demonstrate that the passivation layer has a significant influence on the near-surface electric field distribution and must be considered for theoretical treatments of protein adsorption on passivated metals like titanium.

Functionalized Surface Geometries Induce: “Bone: Formation by Autoinduction”

Directory of Open Access Journals (Sweden)

Ugo Ripamonti

2018-02-01

Full Text Available The induction of tissue formation, and the allied disciplines of tissue engineering and regenerative medicine, have flooded the twenty-first century tissue biology scenario and morphed into high expectations of a fulfilling regenerative dream of molecularly generated tissues and organs in assembling human tissue factories. The grand conceptualization of deploying soluble molecular signals, first defined by Turing as forms generating substances, or morphogens, stemmed from classic last century studies that hypothesized the presence of morphogens in several mineralized and non-mineralized mammalian matrices. The realization of morphogens within mammalian matrices devised dissociative extractions and chromatographic procedures to isolate, purify, and finally reconstitute the cloned morphogens, found to be members of the transforming growth factor-β (TGF-β supergene family, with insoluble signals or substrata to induce de novo tissue induction and morphogenesis. Can we however construct macroporous bioreactors per se capable of inducing bone formation even without the exogenous applications of the osteogenic soluble molecular signals of the TGF-β supergene family? This review describes original research on coral-derived calcium phosphate-based macroporous constructs showing that the formation of bone is independent of the exogenous application of the osteogenic soluble signals of the TGF-β supergene family. Such signals are the molecular bases of the induction of bone formation. The aim of this review is to primarily describe today's hottest topic of biomaterials' science, i.e., to construct and define osteogenetic biomaterials' surfaces that per se, in its own right, do initiate the induction of bone formation. Biomaterials are often used to reconstruct osseous defects particularly in the craniofacial skeleton. Edentulism did spring titanium implants as tooth replacement strategies. No were else that titanium surfaces require functionalized

Biofunctionalization of Titanium Granules with Simvastatin for Improving Osteogenic Activity and Antibacterial Properties (Ex Vivo Study).

Science.gov (United States)

Karaji, Zahra Gorgin; Houshmand, Behzad; Abbasi, Shahsanam; Shafiei, Sara; Faghihi, Shahab

Titanium-based biomaterials present good biocompatibility, while their osseointegration and antibacterial properties need to be improved. This study aimed to enhance the bone-bonding ability of titanium-based granules, which are intended to be used as bone graft. The titanium granules were anodized in ethylene glycol-based electrolyte and subsequently annealed to be loaded separately with simvastatin. The samples were then inspected with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) for drug loading. The release of simvastatin from titanium granule samples was measured after soaking samples in phosphate-buffered saline (PBS) for 30 days using ultraviolet-visible (UV/Vis) spectroscopy. The alkaline phosphatase (ALP) activity of MG63 osteosarcoma-loaded samples was measured, and microbroth dilution assay was performed to evaluate the antibacterial potential of drug-loaded and nonloaded titanium granule samples for bacterial growth. The results expressed the gradual and constant release of simvastatin within the duration of the examination. ALP of the samples showed improved activity of anodized and annealed granules, while the antibacterial test illustrated no significant improvement in their bactericidal effects. However, the simvastatin-loaded samples showed an improved antibacterial effect compared with nonloaded samples. It is assumed that anodizing, annealing, and subsequent simvastatin loading of titanium granules could be used as surface modification to improve osseointegration and restrain bacterial growth and adhesion. It is fair to believe that the results of this study could be used to treat titanium granules as bone graft substitute materials for dental and orthopedic applications.

Biomimetic approaches to modulate cellular adhesion in biomaterials: A review.

Science.gov (United States)

Rahmany, Maria B; Van Dyke, Mark

2013-03-01

Natural extracellular matrix (ECM) proteins possess critical biological characteristics that provide a platform for cellular adhesion and activation of highly regulated signaling pathways. However, ECM-based biomaterials can have several limitations, including poor mechanical properties and risk of immunogenicity. Synthetic biomaterials alleviate the risks associated with natural biomaterials but often lack the robust biological activity necessary to direct cell function beyond initial adhesion. A thorough understanding of receptor-mediated cellular adhesion to the ECM and subsequent signaling activation has facilitated development of techniques that functionalize inert biomaterials to provide a biologically active surface. Here we review a range of approaches used to modify biomaterial surfaces for optimal receptor-mediated cell interactions, as well as provide insights into specific mechanisms of downstream signaling activation. In addition to a brief overview of integrin receptor-mediated cell function, so-called "biomimetic" techniques reviewed here include (i) surface modification of biomaterials with bioadhesive ECM macromolecules or specific binding motifs, (ii) nanoscale patterning of the materials and (iii) the use of "natural-like" biomaterials. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Enhancing Surface Finish of Additively Manufactured Titanium and Cobalt Chrome Elements Using Laser Based Finishing

Science.gov (United States)

Gora, Wojciech S.; Tian, Yingtao; Cabo, Aldara Pan; Ardron, Marcus; Maier, Robert R. J.; Prangnell, Philip; Weston, Nicholas J.; Hand, Duncan P.

Additive manufacturing (AM) offers the possibility of creating a complex free form object as a single element, which is not possible using traditional mechanical machining. Unfortunately the typically rough surface finish of additively manufactured parts is unsuitable for many applications. As a result AM parts must be post-processed; typically mechanically machined and/or and polished using either chemical or mechanical techniques (both of which have their limitations). Laser based polishing is based on remelting of a very thin surface layer and it offers potential as a highly repeatable, higher speed process capable of selective area polishing, and without any waste problems (no abrasives or liquids). In this paper an in-depth investigation of CW laser polishing of titanium and cobalt chrome AM elements is presented. The impact of different scanning strategies, laser parameters and initial surface condition on the achieved surface finish is evaluated.

LASER SURFACE MODIFICATION OF TITANIUM ALLOYS — A REVIEW

OpenAIRE

Y. S. TIAN; C. Z. CHEN; D. Y. WANG; T. Q. LEI

2005-01-01

Recent developments of laser surface modification of titanium alloys for increasing their corrosion, wear and oxidation resistance are introduced. The effects of laser processing parameters on the resulting surface properties of titanium alloys are reviewed. The problems to be solved and the prospects in the field of laser modification of Ti alloys are discussed. Due to the intrinsic properties, a laser beam can be focused onto the metallic surface to produce a broad range of treatments depen...

Cell spreading on titanium dioxide film formed and modified with aerosol beam and femtosecond laser

Energy Technology Data Exchange (ETDEWEB)

Shinonaga, Togo, E-mail: togo@jwri.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tsukamoto, Masahiro [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Nagai, Akiko; Yamashita, Kimihiro; Hanawa, Takao [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Matsushita, Nobuhiro [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Xie, Guoqiang [Institute for Materials Research, Tohoku University, 2-1-1 Karahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Abe, Nobuyuki [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

2014-01-01

Titanium (Ti) is widely used in biomaterials because of its excellent anti-corrosion properties and high strength. However, Ti has no biological function, so its bioactivity must be improved. Coating a titanium dioxide (TiO{sub 2}) film on a Ti plate surface has been shown to improve the biocompatibility of Ti plates. If periodic nanostructures were formed on the film surface, the direction of cell spreading might be controlled by the direction of the grooves. Controlling cell spreading on biomaterials would contribute to the creation of advanced biomaterials. In this paper, a TiO{sub 2} film was formed on a Ti plate with an aerosol beam composed of sub micron-sized TiO{sub 2} particles and helium gas. Periodic nanostructures, lying perpendicular to the laser electric field polarization vector, were formed on the film by scanning the femtosecond laser focusing spot. The period and height of the periodic nanostructures were about 230 nm and 150 nm, respectively. In a cell test, cell spreading was observed along the grooves of the periodic nanostructures; in contrast, cell spreading did not show a definite direction on TiO{sub 2} a film without periodic nanostructures. These results suggest that the direction of cell spreading on the film can be controlled by periodic nanostructure formation generated using a femtosecond laser.

The precipitation behavior of titanium carbide on the surface of SUS 321 stainless steel

International Nuclear Information System (INIS)

Yoshihara, Kazuhiro; Nii, Kazuyoshi

1982-01-01

The surface composition of SUS 321 stainless steel at high temperatures was observed in vacuum with Auger electron spectroscopy. The precipitation of titanium carbide was found on the surface of SUS 321. The thickness of precipitated titanium carbide layer increased in proportion to the square root of annealing time and became about 0.05 μm after heated at 1100 K for 432 ks. The precipitated titanium carbide was not replaced by the most surface active element sulfur, and remained stable on the surface. The precipitated layer, however, was not even and had many holes about 1 μm in diameter. The bottom of a hole was SUS 321, on which phosphorus, oxygen and sulfur segregated. As the annealing time was prolonged, these segregants were replaced one by one in the order of the surface activity, and finally the most surface active element, sulfur, remained on the bottom of the hole. Moreover, sulfur diffused over the outside of the hole. The precipitation of titanium carbide on the surface occurred according to the following processes: (1) The titanium and carbon which had been dissolved in the bulk diffused onto the surface of the stainless steel. (2) The titanium carbide which had been precipitated in the bulk dissolved because the concentration of titanum and carbon fell under their solubility limits in the bulk. (3) The titanium and carbon diffused onto the surface which was exposed to vacuum. (4) The titanium and carbon recombined into titanium carbide and precipitated on the surface. The growth rate of the thickness of the precipitated layer was controlled by the diffusion of titanium and carbon in the precipitated titanium carbide. (J.P.N.)

Effect of alkali treatment on surface morphology of titanium

Energy Technology Data Exchange (ETDEWEB)

Tan, K. J., E-mail: gd130056@siswa.uthm.edu.my; Wahab, M. A. A., E-mail: cd110006@siswa.uthm.edu.my; Mahmod, S., E-mail: cd110201@siswa.uthm.edu.my; Idris, M. I., E-mail: izwana@uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

2015-07-22

Alkali and heat treatments were first introduced by Kim et al. to prepare a bioactive surface on titanium. This method has been proven very effective and widely used in other studies to promote titanium osteointegration. This study aims to investigate further the effect of alkali treatment on surface morphology of high purity titanium. High purity titanium foils were immersed in NaOH aqueous solutions of 0.5 M, 5 M and 15 M at 60°C and 80 °C for 1, 3 and 7 days. The surface morphology was examined using Field Emission Scanning Electron Microscope (FESEM). The obtained phases were analysed using Fourier Transform Infrared Spectroscopy (FTIR) in the spectra range of 4000-600 cm{sup −1} at 4 cm{sup −1} resolution and 50 scans. At the same soaking temperature and soaking time, a thicker porous network was observed with increasing concentration of NaOH. At the same soaking temperature, a much porous structure was observed with increasing soaking time. At constant alkali concentration, more homogenously distributed porous surface structure was observed with increasing soaking temperature.

Biofilm and Dental Biomaterials

Directory of Open Access Journals (Sweden)

Marit Øilo

2015-05-01

Full Text Available All treatment involving the use of biomaterials in the body can affect the host in positive or negative ways. The microbiological environment in the oral cavity is affected by the composition and shape of the biomaterials used for oral restorations. This may impair the patients’ oral health and sometimes their general health as well. Many factors determine the composition of the microbiota and the formation of biofilm in relation to biomaterials such as, surface roughness, surface energy and chemical composition, This paper aims to give an overview of the scientific literature regarding the association between the chemical, mechanical and physical properties of dental biomaterials and oral biofilm formation, with emphasis on current research and future perspectives.

Silk-based biomaterials.

Science.gov (United States)

Altman, Gregory H; Diaz, Frank; Jakuba, Caroline; Calabro, Tara; Horan, Rebecca L; Chen, Jingsong; Lu, Helen; Richmond, John; Kaplan, David L

2003-02-01

Silk from the silkworm, Bombyx mori, has been used as biomedical suture material for centuries. The unique mechanical properties of these fibers provided important clinical repair options for many applications. During the past 20 years, some biocompatibility problems have been reported for silkworm silk; however, contamination from residual sericin (glue-like proteins) was the likely cause. More recent studies with well-defined silkworm silk fibers and films suggest that the core silk fibroin fibers exhibit comparable biocompatibility in vitro and in vivo with other commonly used biomaterials such as polylactic acid and collagen. Furthermore, the unique mechanical properties of the silk fibers, the diversity of side chain chemistries for 'decoration' with growth and adhesion factors, and the ability to genetically tailor the protein provide additional rationale for the exploration of this family of fibrous proteins for biomaterial applications. For example, in designing scaffolds for tissue engineering these properties are particularly relevant and recent results with bone and ligament formation in vitro support the potential role for this biomaterial in future applications. To date, studies with silks to address biomaterial and matrix scaffold needs have focused on silkworm silk. With the diversity of silk-like fibrous proteins from spiders and insects, a range of native or bioengineered variants can be expected for application to a diverse set of clinical needs.

Biological Behavior of Osteoblast Cell and Apatite Forming Ability of the Surface Modified Ti Alloys.

Science.gov (United States)

Zhao, Jingming; Hwang, K H; Choi, W S; Shin, S J; Lee, J K

2016-02-01

Titanium as one kind of biomaterials comes in direct contact with the body, making evaluation of biocompatibility an important aspect to biomaterials development. Surface chemistry of titanium plays an important role in osseointegration. Different surface modification alters the surface chemistry and result in different biological response. In this study, three kinds of mixed acid solutions were used to treat Ti specimens to induce Ca-P formation. Following a strong mixed acid activation process, Ca-P coating successfully formed on the Ti surfaces in simulated body fluid. Strong mixed acid increased the roughness of the metal surface, because the porous and rough surface allows better adhesion between Ca-P coatings and substrates. After modification of titanium surface by mixed acidic solution and subsequently H2O2/HCL treatment evaluation of biocompatibility was conducted from hydroxyapatite formation by biomimetic process and cell viability on modified titanium surface. Nano-scale modification of titanium surfaces can alter cellular and tissue responses, which may benefit osseointegration and dental implant therapy. Results from this study indicated that surface treatment methods affect the surface morphology, type of TiO2 layer formed and subsequent apatite deposition and biological responses. The thermo scientific alamarblue cell viability assay reagent is used to quantitatively measure the viability of mammalian cell lines, bacteria and fungi by incorporating a rapid, sensitive and reliable fluorometric/colorimetric growth indicator, without any toxic and side effect to cell line. In addition, mixed acid treatment uses a lower temperature and shorter time period than widely used alkali treatment.

Laser bioengineering of glass-titanium implants surface

Science.gov (United States)

Lusquiños, F.; Arias-González, F.; Penide, J.; del Val, J.; Comesaña, R.; Quintero, F.; Riveiro, A.; Boutinguiza, M.; Pascual, M. J.; Durán, A.; Pou, J.

2013-11-01

Osseointegration is the mean challenge when surgical treatments fight against load-bearing bone diseases. Absolute bone replacement by a synthetic implant has to be completed not only from the mechanics point of view, but also from a biological approach. Suitable strength, resilience and stress distribution of titanium alloy implants are spoiled by the lack of optimal biological characteristics. The inert quality of extra low interstitial titanium alloy, which make it the most attractive metallic alloy for biomedical applications, oppose to an ideal surface with bone cell affinity, and capable to stimulate bone attachment bone growth. Diverse laser treatments have been proven as effective tools to modify surface properties, such as wettability in contact to physiological fluids, or osteoblast guided and slightly enhanced attachment. The laser surface cladding can go beyond by providing titanium alloy surfaces with osteoconduction and osteoinduction properties. In this research work, the laser radiation is used to produce bioactive glass coatings on Ti6Al4V alloy substrates. Specific silicate bioactive glass compositions has been investigated to achieve suitable surface tension and viscosity temperature behavior during processing, and to provide with the required release of bone growth gene up regulation agents in the course of resorption mediated by physiological fluids. The produced coatings and interfaces, the surface osteoconduction properties, and the chemical species release in simulated physiological fluid were characterized by scanning electron microscopy (SEM), hot stage microscopy (HSM), X-ray diffraction (XRD), X ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR).

Characterization of poly(Sodium Styrene Sulfonate) Thin Films Grafted from Functionalized Titanium Surfaces

Science.gov (United States)

Zorn, Gilad; Baio, Joe E.; Weidner, Tobias; Migonney, Veronique; Castner, David G.

2011-01-01

Biointegration of titanium implants in the body is controlled by their surface properties. Improving surface properties by coating with a bioactive polymer is a promising approach to improve the biological performance of titanium implants. To optimize the grafting processes, it is important to fully understand the composition and structure of the modified surfaces. The main focus of this study is to provide a detailed, multi-technique characterization of a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film grafted from titanium surfaces via a two-step procedure. Thin titanium films (~50 nm thick with an average surface roughness of 0.9±0.2nm) prepared by evaporation onto silicon wafers were used as smooth model substrates. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) showed that the titanium film was covered with a TiO2 layer that was at least 10nm thick and contained hydroxyl groups present at the outermost surface. These hydroxyl groups were first modified with a 3-methacryloxypropyltrimethoxysilane (MPS) cross linker. XPS and ToF-SIMS showed that a monolayer of the MPS molecules were successfully attached onto the titanium surfaces. The pNaSS film was grafted from the MPS modified titanium through atom transfer radical polymerization. Again, XPS and ToF-SIMS were used to verify that the pNaSS molecules were successfully grafted onto the modified surfaces. Atomic force microscopy analysis showed that the film was smooth and uniformly covered the surface. Fourier transform infrared spectroscopy indicated an ordered array of grafted NaSS molecules were present on the titanium surfaces. Sum frequency generation vibration spectroscopy and near edge X-ray absorption fine structure spectroscopy illustrated that the NaSS molecules were grafted onto the titanium surface with a substantial degree of orientational order in the styrene rings. PMID:21892821

Photographic-Based Optical Evaluation of Tissues and Biomaterials Used for Corneal Surface Repair: A New Easy-Applied Method.

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Miguel Gonzalez-Andrades

Full Text Available Tissues and biomaterials used for corneal surface repair require fulfilling specific optical standards prior to implantation in the patient. However, there is not a feasible evaluation method to be applied in clinical or Good Manufacturing Practice settings. In this study, we describe and assess an innovative easy-applied photographic-based method (PBM for measuring functional optical blurring and transparency in corneal surface grafts.Plastic compressed collagen scaffolds (PCCS and multilayered amniotic membranes (AM samples were optically and histologically evaluated. Transparency and image blurring measures were obtained by PBM, analyzing photographic images of a standardized band pattern taken through the samples. These measures were compared and correlated to those obtained applying the Inverse Adding-Doubling (IAD technique, which is the gold standard method.All the samples used for optical evaluation by PBM or IAD were histological suitable. PCCS samples presented transmittance values higher than 60%, values that increased with increasing wavelength as determined by IAD. The PBM indicated that PCCS had a transparency ratio (TR value of 80.3 ± 2.8%, with a blurring index (BI of 50.6 ± 4.2%. TR and BI obtained from the PBM showed a high correlation (ρ>|0.6| with the diffuse transmittance and the diffuse reflectance, both determined using the IAD (p<0.005. The AM optical properties showed that there was a largely linear relationship between the blurring and the number of amnion layers, with more layers producing greater blurring.This innovative proposed method represents an easy-applied technique for evaluating transparency and blurriness of tissues and biomaterials used for corneal surface repair.

Ultrasonic Surface Treatment of Titanium Alloys. The Submicrocrystalline State

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Klimenov, V. A.; Vlasov, V. A.; Borozna, V. Y.; Klopotov, A. A.

2015-09-01

The paper presents the results of the research on improvement of physical-and- mechanical properties of titanium alloys VT1-0 and VT6 by modification of surfaces using ultrasonic treatment, and a comprehensive study of the microstructure and mechanical properties of modified surface layers. It has been established that exposure to ultrasonic treatment leads to formation in the surface layer of a structure with an average size of elements 50 - 100 nm, depending on the brand of titanium alloy.

Biocomposites and hybrid biomaterials based on calcium orthophosphates

Science.gov (United States)

Dorozhkin, Sergey V.

2011-01-01

The state-of-the-art of biocomposites and hybrid biomaterials based on calcium orthophosphates that are suitable for biomedical applications is presented in this review. Since these types of biomaterials offer many significant and exciting possibilities for hard tissue regeneration, this subject belongs to a rapidly expanding area of biomedical research. Through successful combinations of the desired properties of matrix materials with those of fillers (in such systems, calcium orthophosphates might play either role), innovative bone graft biomaterials can be designed. Various types of biocomposites and hybrid biomaterials based on calcium orthophosphates, either those already in use or being investigated for biomedical applications, are extensively discussed. Many different formulations, in terms of the material constituents, fabrication technologies, structural and bioactive properties as well as both in vitro and in vivo characteristics, have already been proposed. Among the others, the nanostructurally controlled biocomposites, those containing nanodimensional compounds, biomimetically fabricated formulations with collagen, chitin and/or gelatin as well as various functionally graded structures seem to be the most promising candidates for clinical applications. The specific advantages of using biocomposites and hybrid biomaterials based on calcium orthophosphates in the selected applications are highlighted. As the way from the laboratory to the hospital is a long one, and the prospective biomedical candidates have to meet many different necessities, this review also examines the critical issues and scientific challenges that require further research and development. PMID:23507726

Preparation and mechanical property of polymer-based biomaterials

International Nuclear Information System (INIS)

Zhang, P; Chen, G; Zheng, X F

2010-01-01

The porous polymer-based biomaterial has been synthesized from PLGA, dioxane and tricalcium phosphate (TCP) by low-temperature deposition process. The deformation behaviours and fracture mechanism of polymer-based biomaterials were investigated using the compression test and the finite element (FE) simulation. The results show that the stress-strain curve of compression process includes linear elastic stage I, platform stage II and densification stage III, and the fracture mechanism can be considered as brittle fracture.

Pheochromocytoma (PC12 Cell Response on Mechanobactericidal Titanium Surfaces

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Jason V. Wandiyanto

2018-04-01

Full Text Available Titanium is a biocompatible material that is frequently used for making implantable medical devices. Nanoengineering of the surface is the common method for increasing material biocompatibility, and while the nanostructured materials are well-known to represent attractive substrata for eukaryotic cells, very little information has been documented about the interaction between mammalian cells and bactericidal nanostructured surfaces. In this study, we investigated the effect of bactericidal titanium nanostructures on PC12 cell attachment and differentiation—a cell line which has become a widely used in vitro model to study neuronal differentiation. The effects of the nanostructures on the cells were then compared to effects observed when the cells were placed in contact with non-structured titanium. It was found that bactericidal nanostructured surfaces enhanced the attachment of neuron-like cells. In addition, the PC12 cells were able to differentiate on nanostructured surfaces, while the cells on non-structured surfaces were not able to do so. These promising results demonstrate the potential application of bactericidal nanostructured surfaces in biomedical applications such as cochlear and neuronal implants.

From acid etching treatments to tribocorrosive properties of dental implants: do some experimental results on surface treatments have an influence on the tribocorrosion behaviour of dental implants?

International Nuclear Information System (INIS)

Geringer, Jean; Demanget, Nicolas; Pellier, Julie

2013-01-01

Surface treatments of dental implants aim at promoting osseointegration, i.e. the anchorage of the metallic part. Titanium-, grade II–V, based material is used as a bulk material for dental implants. For promoting the anchorage of this metallic biomaterial in human jaw, some strategies have been applied for improving the surface state, i.e. roughness, topography and coatings. A case study, experimental study, is described with the method of acid etching on titanium grade 4, CpTi. The main goal is to find the right proportion in a mixture of two acids in order to obtain the best surface state. Finally, a pure theoretical prediction is quite impossible and some experimental investigations are necessary to improve the surface state. The described acid etching is compared with some other acid etching treatments and some coatings available on dental implants. Thus, the discussion is focused on the tribocorrosion behaviour of titanium-based materials. The purpose of the coating is that the lifetime under tribocorrosion is limited. Moreover, the surgery related to the implantation has a huge impact on the stability of dental implants. Thus, the performance of dental implants depends on factors related to surgery (implantation) that are difficult to predict from the biomaterial characteristics. From the tribocorrosion point of view, i.e. during the mastication step, the titanium material is submitted to some deleterious factors that cause the performance of dental implants to decrease. (paper)

In-vitro responses of T lymphocytes to poly(butylene succinate) based biomaterials.

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Toso, Montree; Patntirapong, Somying; Janvikul, Wanida; Singhatanadgit, Weerachai

2017-04-01

Polybutylene succinate (PBSu) and PBSu/β-tricalcium phosphate (TCP) composites are biocompatible and good candidates as bone graft materials. However, little is known about the responses of T lymphocytes to these biomaterials, which play an important role in the success of bone grafting. Activated T lymphocytes were cultured onto 32 mm diameter films (PBSu/TCP films), that had previously been placed in 6-well culture plates, for 8, 24 and 72 hours. A plastic-well culture plate was used as a control surface. The effects of PBSu-based biomaterials on T lymphocytes were examined by the using flow cytometry and reverse-transcription polymerase chain reaction. These biomaterials were non-toxic to T lymphocytes, allowing their normal DNA synthesis and activation. All materials induced only transient activation of T lymphocytes, which existed no longer than 72 hours. Proportions of four main CD4/CD8 T lymphocyte subpopulations were not affected by these biomaterials. Moreover, PBSu and PBSu/TCP significantly suppressed the expression of IL-1β and IL-6 genes by 15-35% and 21-26%, respectively. In contrast, a PBSu/TCP composite (at PBSu:TCP=60:40) significantly stimulated the expression of IL-10 and IL-13 genes by 17% and 19%, respectively. PBSu and PBSu/TCP composites were non-toxic to T lymphocytes and did not induce unfavorable responses of T lymphocytes. The tested biomaterials down-regulated key proinflammatory cytokine genes and up-regulated anti-inflammatory cytokine genes in T lymphocytes. These suggest that the biomaterials studied are good candidates as bone graft materials.

Influence of surface modification on friction coefficient of the titanium-elastomer couple.

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Chladek, Wiesław; Hadasik, Eugeniusz; Chladek, Grzegorz

2007-01-01

This paper presents the results of a study of the friction coefficient of titanium-elastomer couple. The study was carried out with a view to potential future utilization of its results for constructing retentive elements of implanted prostheses. Changes in the friction force were recorded while removing titanium specimens placed between two silicone counter specimens made of Ufi Gel. The influence of the titanium specimen movement speed in relation that of to the counter specimens and the influence of clamping force on the friction force were assessed. Additionally, the surface roughness of titanium specimens differed; in one case, titanium was coated with polyethylene. The effect of introducing artificial saliva between the cooperating surfaces on the friction force and friction coefficient was analyzed as well. Based on the characteristics recorded, the possibilities of shaping the friction coefficient have been assessed, since it is the friction coefficient that determines effective operation of a friction couple through increasing the titanium specimen roughness. The artificial saliva being introduced between the specimens reduces considerably the friction coefficient through a change of the phenomenon model. An increase in the pressure force for the specimens of high roughness entails a reduction of the friction coefficient. The study carried out allows us to identify the roughness parameters, which in turn will enable obtaining the prescribed retention force for friction/membrane couplings.

Modification of the Surface Topography and Composition of Ultrafine and Coarse Grained Titanium by Chemical Etching.

Science.gov (United States)

Nazarov, Denis V; Zemtsova, Elena G; Solokhin, Alexandr Yu; Valiev, Ruslan Z; Smirnov, Vladimir M

2017-01-13

In this study, we present the detailed investigation of the influence of the etching medium (acidic or basic Piranha solutions) and the etching time on the morphology and surface relief of ultrafine grained (UFG) and coarse grained (CG) titanium. The surface relief and morphology have been studied by means of scanning electron microscopy (SEM), atomic force microscopy (AFM), and the spectral ellipsometry. The composition of the samples has been determined by X-ray fluorescence analysis (XRF) and X-ray Photoelectron Spectroscopy (XPS). Significant difference in the etching behavior of UFG and CG titanium has been found. UFG titanium exhibits higher etching activity independently of the etching medium. Formed structures possess higher homogeneity. The variation of the etching medium and time leads to micro-, nano-, or hierarchical micro/nanostructures on the surface. Significant difference has been found between surface composition for UFG titanium etched in basic and acidic Piranha solution. Based on the experimental data, the possible reasons and mechanisms are considered for the formation of nano- and microstructures. The prospects of etched UFG titanium as the material for implants are discussed.

Influence of octacalcium phosphate coating on osteoinductive properties of biomaterials

NARCIS (Netherlands)

Habibovic, Pamela; van der Valk, C.M.; van Blitterswijk, Clemens; de Groot, K.

2004-01-01

In this study, we investigated the influence of octacalcium phosphate (OCP) coating on osteoinductive behaviour of the biomaterials. Porous titanium alloy (Ti6Al4V), hydroxyapatite (HA), biphasic calcium phosphate (BCP) and polyethylene glyco terephtalate/polybuthylene terephtalate (PEGT–PBT)

Particles induced surface nanoroughness of titanium surface and its influence on adhesion of osteoblast-like MG-63 cells

Science.gov (United States)

Solař, P.; Kylián, O.; Marek, A.; Vandrovcová, M.; Bačáková, L.; Hanuš, J.; Vyskočil, J.; Slavínská, D.; Biederman, H.

2015-01-01

Titanium is one of the most common materials employed for production of implants, which is due to its good biocompatibility. However, the colonization of titanium surface by osteoblast cells may be influenced by its roughness and therefore precise control of roughness of titanium surface as well as identification of its optimal value for growth of cells is of high importance. In this study the nanorough titanium surfaces were prepared on polished disks of TiAlV by two step method of deposition. In the first step TiAlV were coated by nanoparticles generated by gas aggregation sources. Such prepared films of nanoparticles were subsequently covered with a titanium overlayer. Different values of surface roughness in the range 1-100 nm were achieved by variation of the size and number of the nanoparticles. Such prepared surfaces were subsequently used for investigation of influence of roughness of titanium surfaces on the adhesion of human osteoblast-like MG-63 cells. It was found out that 7 days after seeding the highest number of adhering cells was observed for samples with root-mean-square roughness of 30 nm.

Corrosion and surface modification on biocompatible metals: A review.

Science.gov (United States)

Asri, R I M; Harun, W S W; Samykano, M; Lah, N A C; Ghani, S A C; Tarlochan, F; Raza, M R

2017-08-01

Corrosion prevention in biomaterials has become crucial particularly to overcome inflammation and allergic reactions caused by the biomaterials' implants towards the human body. When these metal implants contacted with fluidic environments such as bloodstream and tissue of the body, most of them became mutually highly antagonistic and subsequently promotes corrosion. Biocompatible implants are typically made up of metallic, ceramic, composite and polymers. The present paper specifically focuses on biocompatible metals which favorably used as implants such as 316L stainless steel, cobalt-chromium-molybdenum, pure titanium and titanium-based alloys. This article also takes a close look at the effect of corrosion towards the implant and human body and the mechanism to improve it. Due to this corrosion delinquent, several surface modification techniques have been used to improve the corrosion behavior of biocompatible metals such as deposition of the coating, development of passivation oxide layer and ion beam surface modification. Apart from that, surface texturing methods such as plasma spraying, chemical etching, blasting, electropolishing, and laser treatment which used to improve corrosion behavior are also discussed in detail. Introduction of surface modifications to biocompatible metals is considered as a "best solution" so far to enhanced corrosion resistance performance; besides achieving superior biocompatibility and promoting osseointegration of biocompatible metals and alloys. Copyright © 2017 Elsevier B.V. All rights reserved.

Additively Manufactured Macroporous Titanium with Silver-Releasing Micro-/Nanoporous Surface for Multipurpose Infection Control and Bone Repair - A Proof of Concept.

Science.gov (United States)

Jia, Zhaojun; Xiu, Peng; Xiong, Pan; Zhou, Wenhao; Cheng, Yan; Wei, Shicheng; Zheng, Yufeng; Xi, Tingfei; Cai, Hong; Liu, Zhongjun; Wang, Caimei; Zhang, Weiping; Li, Zhijiang

2016-10-26

Restoring large-scale bone defects, where osteogenesis is slow while infections lurk, with biomaterials represents a formidable challenge in orthopedic clinics. Here, we propose a scaffold-based multipurpose anti-infection and bone repairing strategy to meet such restorative needs. To do this, personalized multifunctional titanium meshes were produced through an advanced additive manufacturing process and dual "TiO 2 -poly(dopamine)/Ag (nano)" post modifications, yielding macroporous constructs with micro-/nanoporous walls and nanosilver bullets immobilized/embedded therein. Ultrahigh loading capacity and durable release of Ag + were accomplished. The scaffolds were active against planktonic/adherent bacteria (Gram-negative and positive) for up to 12 weeks. Additionally, they not only defended themselves from biofilm colonization but also helped destroy existing biofilms, especially in combination with antibiotics. Further, the osteoblasts/bacteria coculture study displayed that the engineered surfaces aided MG-63 cells to combat bacterial invasion. Meanwhile, the scaffolds elicited generally acceptable biocompatibility (cell adhesion, proliferation, and viability) and hastened osteoblast differentiation and maturation (alkaline phosphatase production, matrix secretion, and calcification), by synergy of micro-/nanoscale topological cues and bioactive catecholamine chemistry. Although done ex vivo, these studies reveal that our three-in-one strategy (infection prophylaxis, infection fighting, and bone repair) has great potential to simultaneously prevent/combat infections and bridge defected bone. This work provides new thoughts to the use of enabling technologies to design biomaterials that resolve unmet clinical needs.

Effect of Nanosheet Surface Structure of Titanium Alloys on Cell Differentiation

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Satoshi Komasa

2014-01-01

Full Text Available Titanium alloys are the most frequently used dental implants partly because of the protective oxide coating that spontaneously forms on their surface. We fabricated titania nanosheet (TNS structures on titanium surfaces by NaOH treatment to improve bone differentiation on titanium alloy implants. The cellular response to TNSs on Ti6Al4V alloy was investigated, and the ability of the modified surfaces to affect osteogenic differentiation of rat bone marrow cells and increase the success rate of titanium implants was evaluated. The nanoscale network structures formed by alkali etching markedly enhanced the functions of cell adhesion and osteogenesis-related gene expression of rat bone marrow cells. Other cell behaviors, such as proliferation, alkaline phosphatase activity, osteocalcin deposition, and mineralization, were also markedly increased in TNS-modified Ti6Al4V. Our results suggest that titanium implants modified with nanostructures promote osteogenic differentiation, which may improve the biointegration of these implants into the alveolar bone.

Novel nanostructured biomaterials: implications for coronary stent thrombosis

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Karagkiozaki V

2012-12-01

Full Text Available Varvara Karagkiozaki,1,2 Panagiotis G Karagiannidis,1 Nikolaos Kalfagiannis,1 Paraskevi Kavatzikidou,1 Panagiotis Patsalas,3 Despoina Georgiou,1 Stergios Logothetidis11Lab for Thin Films – Nanosystems and Nanometrology (LTFN, Physics Department, Aristotle University of Thessaloniki, Thessaloniki, 2AHEPA Hospital, Aristotle University of Thessaloniki, Thessaloniki, 3Department of Materials Science and Engineering, University of Ioannina, Ioannina, Epirus, GreeceBackground: Nanomedicine has the potential to revolutionize medicine and help clinicians to treat cardiovascular disease through the improvement of stents. Advanced nanomaterials and tools for monitoring cell–material interactions will aid in inhibiting stent thrombosis. Although titanium boron nitride (TiBN, titanium diboride, and carbon nanotube (CNT thin films are emerging materials in the biomaterial field, the effect of their surface properties on platelet adhesion is relatively unexplored.Objective and methods: In this study, novel nanomaterials made of amorphous carbon, CNTs, titanium diboride, and TiBN were grown by vacuum deposition techniques to assess their role as potential stent coatings. Platelet response towards the nanostructured surfaces of the samples was analyzed in line with their physicochemical properties. As the stent skeleton is formed mainly of stainless steel, this material was used as reference material. Platelet adhesion studies were carried out by atomic force microscopy and scanning electron microscopy observations. A cell viability study was performed to assess the cytocompatibility of all thin film groups for 24 hours with a standard immortalized cell line.Results: The nanotopographic features of material surface, stoichiometry, and wetting properties were found to be significant factors in dictating platelet behavior and cell viability. The TiBN films with higher nitrogen contents were less thrombogenic compared with the biased carbon films and control

Biocompatibility and Toxicity of Nano biomaterials 2014

International Nuclear Information System (INIS)

Li, X.; Lee, S.Ch.; Zhang, Sh.; Akasaka, T.

2014-01-01

It is well known that nano materials have developed rapidly over the past few decades. Based on their unique physicochemical properties and special mechanical properties, nano materials have provided application possibility in many different fields. Currently, as nano biomaterials, they are widely used in various biomedical applications, such as drug delivery systems, tissue engineering, dental/bone implant, and biosensors. For example, nano biomaterials have been used in tissue engineering because of their satisfactory bioactivity, high mechanical properties, and large surface area to adsorb specific proteins. Many kinds of nano biomaterials are used to prepare composite scaffolds to get better biocompatibility and higher ability in repairing specific tissues. Several antibacterial metallic nano biomaterials are used to coat implant surfaces to improve the speed of healing fractures. In addition, lots of nano biomaterials have the potential to break the limitations of the traditional delivery systems. They can load larger amount of drugs and provide stable drug release for long time at the targeted sites, such as tumors. Moreover, they can combine with polymers to furnish simultaneous drug delivery systems with the controllable release rate. Besides these applications, more and more nano biomaterials show great potential to be applied as highly sensitive biosensors because they have higher ability in loading firmly or interacting completely with recognition aptamers.

Antibacterial effect of hydrogen peroxide-titanium dioxide suspensions in the decontamination of rough titanium surfaces.

Science.gov (United States)

Wiedmer, David; Petersen, Fernanda Cristina; Lönn-Stensrud, Jessica; Tiainen, Hanna

2017-07-01

The chemical decontamination of infected dental implants is essential for the successful treatment of peri-implantitis. The aim of this study was to assess the antibacterial effect of a hydrogen peroxide-titanium dioxide (H 2 O 2 -TiO 2 ) suspension against Staphylococcus epidermidis biofilms. Titanium (Ti) coins were inoculated with a bioluminescent S. epidermidis strain for 8 h and subsequently exposed to H 2 O 2 with and without TiO 2 nanoparticles or chlorhexidine (CHX). Bacterial regrowth, bacterial load and viability after decontamination were analyzed by continuous luminescence monitoring, live/dead staining and scanning electron microscopy. Bacterial regrowth was delayed on surfaces treated with H 2 O 2 -TiO 2 compared to H 2 O 2 . H 2 O 2 -based treatments resulted in a lower bacterial load compared to CHX. Few viable bacteria were found on surfaces treated with H 2 O 2 and H 2 O 2 -TiO 2 , which contrasted with a uniform layer of dead bacteria for surfaces treated with CHX. H 2 O 2 -TiO 2 suspensions could therefore be considered an alternative approach in the decontamination of dental implants.

Histomorphometric and histologic evaluation of titanium-zirconium (aTiZr) implants with anodized surfaces.

Science.gov (United States)

Sharma, Ajay; McQuillan, A James; Shibata, Yo; Sharma, Lavanya A; Waddell, John Neil; Duncan, Warwick John

2016-05-01

The choice of implant surface has a significant influence on osseointegration. Modification of TiZr surface by anodization is reported to have the potential to modulate the osteoblast cell behaviour favouring more rapid bone formation. The aim of this study is to investigate the effect of anodizing the surface of TiZr discs with respect to osseointegration after four weeks implantation in sheep femurs. Titanium (Ti) and TiZr discs were anodized in an electrolyte containing DL-α-glycerophosphate and calcium acetate at 300 V. The surface characteristics were analyzed by scanning electron microscopy, electron dispersive spectroscopy, atomic force microscopy and goniometry. Forty implant discs with thickness of 1.5 and 10 mm diameter (10 of each-titanium, titanium-zirconium, anodized titanium and anodized titanium-zirconium) were placed in the femoral condyles of 10 sheep. Histomorphometric and histologic analysis were performed 4 weeks after implantation. The anodized implants displayed hydrophilic, porous, nano-to-micrometer scale roughened surfaces. Energy dispersive spectroscopy analysis revealed calcium and phosphorous incorporation into the surface of both titanium and titanium-zirconium after anodization. Histologically there was new bone apposition on all implanted discs, slightly more pronounced on anodised discs. The percentage bone-to-implant contact measurements of anodized implants were higher than machined/unmodified implants but there was no significant difference between the two groups with anodized surfaces (P > 0.05, n = 10). The present histomorphometric and histological findings confirm that surface modification of titanium-zirconium by anodization is similar to anodised titanium enhances early osseointegration compared to machined implant surfaces.

Improved stability of titanium based boron-doped chemical vapor deposited diamond thin-film electrode by modifying titanium substrate surface

International Nuclear Information System (INIS)

Lim, P.Y.; Lin, F.Y.; Shih, H.C.; Ralchenko, V.G.; Varnin, V.P.; Pleskov, Yu.V.; Hsu, S.F.; Chou, S.S.; Hsu, P.L.

2008-01-01

The film quality and electrochemical properties of BDD (boron-doped diamond) thin films grown by hot-filament chemical vapor deposition technique on titanium substrates that had been subjected to a range of pre-treatment processes were evaluated. The pre-roughened Ti-substrates are shown to support more adherent BDD films. It is evident that acid-etching the Ti-substrate involves surface hydrogenation that enhances nucleation and formation of diamond thereon. The prepared BDD film exhibits wide potential window and electrochemical reversibility. It also demonstrated a better long-term electrochemical stability based on the low variation in voltametric background current upon the exposing of the electrodes to repeated cycles of electrochemical metal deposition/stripping process

Sensitivity of surface roughness parameters to changes in the density of scanning points in multi-scale AFM studies. Application to a biomaterial surface

International Nuclear Information System (INIS)

Mendez-Vilas, A.; Bruque, J.M.; Gonzalez-Martin, M.L.

2007-01-01

In the field of biomaterials surfaces, the ability of the atomic force microscope (AFM) to access the surface structure at unprecedented spatial (vertical and lateral) resolution, is helping in a better understanding on how topography affects the overall interaction of biological cells with the material surface. Since cells in a wide range of sizes are in contact with the biomaterial surface, a quantification of the surface structure in such a wide range of dimensional scales is needed. With the advent of the AFM, this can be routinely done in the lab. In this work, we show that even when it is clear that such a scale-dependent study is needed, AFM maps of the biomaterial surface taken at different scanning lengths are not completely consistent when they are taken at the same scanning resolution, as it is usually done: AFM images of different scanning areas have different point-to-point physical distances. We show that this effect influences the quantification of the average (R a ) and rms (R q ) roughness parameters determined at different length scales. This is the first time this inconsistency is reported and should be taken into account when roughness is measured in this way. Since differences will be in general in the range of nanometres, this is especially interesting for those processes involving the interaction of the biomaterial surface with small biocolloids as bacteria, while this effect should not represent any problems for larger animal cells

Temperature effect on surface oxidation of titanium

International Nuclear Information System (INIS)

Vaquilla, I.; Barco, J.L. del; Ferron, J.

1990-01-01

The effect of temperature on the first stages of the superficial oxidation of polycrystalline titanium was studied using both Auger electron spectroscopy (AES) and emission shreshold (AEAPS). The number of compounds present on the surface was determined by application of the factor analysis technique. Reaction evolution was followed through the relative variation of Auger LMM and LMV transitions which are characteristic of titanium. Also the evolution of the chemical shift was determined by AEAPS. The amount of oxygen on the surface was quantified using transition KLL of oxygen. It was found that superficial oxidation depends on temperature. As much as three different compounds were determined according to substrate temperature and our exposure ranges. (Author). 7 refs., 5 figs

Streptococcus mutans attachment on a cast titanium surface

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Sicknan Soares da Rocha

2009-03-01

Full Text Available This study examined by means of scanning electron microscopy (SEM, the attachment of Streptococcus mutans and the corrosion of cast commercially pure titanium, used in dental dentures. The sample discs were cast in commercially pure titanium using the vacuum-pressure machine (Rematitan System. The surfaces of each metal were ground and polished with sandpaper (#300-4000 and alumina paste (0.3 µm. The roughness of the surface (Ra was measured using the Surfcorder rugosimeter SE 1700. Four coupons were inserted separately into Falcon tubes contained Mueller Hinton broth inoculated with S. mutans ATCC 25175 (10(9 cuf and incubated at 37 °C. The culture medium was changed every three days during a 365-day period, after which the falcons were prepared for observations by SEM. The mean Ra value of CP Ti was 0.1527 µm. After S. mutans biofilm removal, pits of corrosion were observed. Despite the low roughness, S. mutans attachment and biofilm formation was observed, which induced a surface corrosion of the cast pure titanium.

The pathology of the foreign body reaction against biomaterials.

Science.gov (United States)

Klopfleisch, R; Jung, F

2017-03-01

The healing process after implantation of biomaterials involves the interaction of many contributing factors. Besides their in vivo functionality, biomaterials also require characteristics that allow their integration into the designated tissue without eliciting an overshooting foreign body reaction (FBR). The targeted design of biomaterials with these features, thus, needs understanding of the molecular mechanisms of the FBR. Much effort has been put into research on the interaction of engineered materials and the host tissue. This elucidated many aspects of the five FBR phases, that is protein adsorption, acute inflammation, chronic inflammation, foreign body giant cell formation, and fibrous capsule formation. However, in practice, it is still difficult to predict the response against a newly designed biomaterial purely based on the knowledge of its physical-chemical surface features. This insufficient knowledge leads to a high number of factors potentially influencing the FBR, which have to be analyzed in complex animal experiments including appropriate data-based sample sizes. This review is focused on the current knowledge on the general mechanisms of the FBR against biomaterials and the influence of biomaterial surface topography and chemical and physical features on the quality and quantity of the reaction. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 927-940, 2017. © 2016 Wiley Periodicals, Inc.

Tribological Properties of Surface-Textured and Plasma-Nitrided Pure Titanium Under Oil Lubrication Condition

Science.gov (United States)

Zhang, Baosen; Dong, Qiangsheng; Ba, Zhixin; Wang, Zhangzhong; Shi, Hancheng; Xue, Yanting

2018-01-01

Plasma nitriding was conducted as post-treatment for surface texture on pure titanium to obtain a continuous nitriding layer. Supersonic fine particles bombarding (SFPB) was carried out to prepare surface texture. The surface morphologies and chemical composition were analyzed using scanning electron microscope and energy disperse spectroscopy. The microstructures of modified layers were characterized by transmission electron microscope. The tribological properties of surface-textured and duplex-treated pure titanium under oil lubrication condition were systematically investigated in the ball-on-plate reciprocating mode. The effects of applied load and sliding velocity on the tribological behavior were analyzed. The results show that after duplex treatments, the grains size in modified layer becomes slightly larger, and hardness is obviously improved. Wear resistance of duplex-treated pure titanium is significantly improved referenced to untreated and surface-textured pure titanium, which is 3.22 times as much as untreated pure titanium and 2.15 times of that for surface-textured pure titanium, respectively.

Facile design of biomaterials by 'click' chemistry

DEFF Research Database (Denmark)

Hvilsted, Søren

2012-01-01

The advent of the so‐called ‘click chemistry’ a decade ago has significantly improved the chemical toolbox for producing novel biomaterials. This review focuses primarily on the application of Cu(I)‐catalysed azide–alkyne 1,3‐cycloadditon in the preparation of numerous, diverse biomaterials...... chemistry is elaborated. The present state of creating functional and biologically active surfaces by click chemistry is presented. Finally, conducting surfaces based on an azide‐functionalized polymer with prospective biological sensor potential are introduced. Copyright © 2012 Society of Chemical Industry...

Chitosan patterning on titanium alloys

OpenAIRE

Gilabert Chirivella, Eduardo; Pérez Feito, Ricardo; Ribeiro, Clarisse; Ribeiro, Sylvie; Correia, Daniela; González Martin, María Luisa; Manero Planella, José María; Lanceros Méndez, Senentxu; Gallego Ferrer, Gloria; Gómez Ribelles, José Luis

2017-01-01

Titanium and its alloys are widely used in medical implants because of their excellent properties. However, bacterial infection is a frequent cause of titanium-based implant failure and also compromises its osseointegration. In this study, we report a new simple method of providing titanium surfaces with antibacterial properties by alternating antibacterial chitosan domains with titanium domains in the micrometric scale. Surface microgrooves were etched on pure titanium disks at i...

Improved antibacterial behavior of titanium surface with torularhodin–polypyrrole film

International Nuclear Information System (INIS)

Ungureanu, Camelia; Popescu, Simona; Purcel, Gabriela; Tofan, Vlad; Popescu, Marian; Sălăgeanu, Aurora; Pîrvu, Cristian

2014-01-01

The problem of microorganisms attaching and proliferating on implants and medical devices surfaces is still attracting interest in developing research on different coatings based on antibacterial agents. The aim of this work is centered on modifying titanium (Ti) based implants surfaces through incorporation of a natural compound with antimicrobial effect, torularhodin (T), by means of a polypyrrole (PPy) film. This study tested the potential antimicrobial activity of the new coating against a range of standard bacterial strains: Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and Pseudomonas aeruginosa. The morphology, physical and electrochemical properties of the synthesized films were assessed by SEM, AFM, UV–Vis, FTIR and cyclic voltammetry. In addition, biocompatibility of this new coating was evaluated using L929 mouse fibroblast cells. The results showed that PPy–torularhodin composite film acts as a corrosion protective coating with antibacterial activity and it has no harmful effect on cell viability. - Highlights: • Modification of titanium surfaces by incorporating a natural compound • new PPy - torularhodin corrosion protective composite coatings • antibacterial activity for the new PPy - torularhodin coating • cytocompatibility of new coating was demonstrated using mouse fibroblast cells

Improved antibacterial behavior of titanium surface with torularhodin–polypyrrole film

Energy Technology Data Exchange (ETDEWEB)

Ungureanu, Camelia; Popescu, Simona; Purcel, Gabriela [University POLITEHNICA of Bucharest, 1-7 Polizu, 011061 Bucharest (Romania); Tofan, Vlad [“Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, 103 Splaiul Independentei, Sector 5, 050096 Bucharest (Romania); Popescu, Marian [University POLITEHNICA of Bucharest, 1-7 Polizu, 011061 Bucharest (Romania); National Institute for Research and Development in Microtechnologies, 126A, Erou Iancu Nicolae Street, 077190 Bucharest (Romania); Sălăgeanu, Aurora [“Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, 103 Splaiul Independentei, Sector 5, 050096 Bucharest (Romania); Pîrvu, Cristian, E-mail: c_pirvu@chim.pub.ro [University POLITEHNICA of Bucharest, 1-7 Polizu, 011061 Bucharest (Romania)

2014-09-01

The problem of microorganisms attaching and proliferating on implants and medical devices surfaces is still attracting interest in developing research on different coatings based on antibacterial agents. The aim of this work is centered on modifying titanium (Ti) based implants surfaces through incorporation of a natural compound with antimicrobial effect, torularhodin (T), by means of a polypyrrole (PPy) film. This study tested the potential antimicrobial activity of the new coating against a range of standard bacterial strains: Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and Pseudomonas aeruginosa. The morphology, physical and electrochemical properties of the synthesized films were assessed by SEM, AFM, UV–Vis, FTIR and cyclic voltammetry. In addition, biocompatibility of this new coating was evaluated using L929 mouse fibroblast cells. The results showed that PPy–torularhodin composite film acts as a corrosion protective coating with antibacterial activity and it has no harmful effect on cell viability. - Highlights: • Modification of titanium surfaces by incorporating a natural compound • new PPy - torularhodin corrosion protective composite coatings • antibacterial activity for the new PPy - torularhodin coating • cytocompatibility of new coating was demonstrated using mouse fibroblast cells.

Electrochemical Characterization of Surface Reactions on Biomedical Titanium alloys

OpenAIRE

Alkhateeb, Emad Hashim

2008-01-01

Titanium and its alloys are successfully used as implant materials for dental, orthopedic and osteosynthesis applications. The processes that take place at the implant tissue interface are important for the acceptance and integration of the implant. This thesis is divided into two parts: the first part deals with surface modification of titanium to improve the osseointegration, and the second part studies metastable pitting of titanium and its alloys. The weakly attached layer of a bone-like ...

Surface treatment of a titanium implant using low temperature atmospheric pressure plasmas

Science.gov (United States)

Lee, Hyun-Young; Tang, Tianyu; Ok, Jung-Woo; Kim, Dong-Hyun; Lee, Ho-Jun; Lee, Hae June

2015-09-01

During the last two decades, atmospheric pressure plasmas(APP) are widely used in diverse fields of biomedical applications, reduction of pollutants, and surface treatment of materials. Applications of APP to titanium surface of dental implants is steadily increasing as it renders surfaces wettability and modifies the oxide layer of titanium that hinders the interaction with cells and proteins. In this study, we have treated the titanium surfaces of screw-shaped implant samples using a plasma jet which is composed of a ceramic coaxial tube of dielectrics, a stainless steel inner electrode, and a coper tube outer electrode. The plasma ignition occurred with Ar gas flow between two coaxial metal electrodes and a sinusoidal bias voltage of 3 kV with a frequency of 20 kHz. Titanium materials used in this study are screw-shaped implants of which diameter and length are 5 mm and 13 mm, respectively. Samples were mounted at a distance of 5 mm below the plasma source, and the plasma treatment time was set to 3 min. The wettability of titanium surface was measured by the moving speed of water on its surface, which is enhanced by plasma treatment. The surface roughness was also measured by atomic force microscopy. The optimal condition for wettability change is discussed.

Modification of the Surface Topography and Composition of Ultrafine and Coarse Grained Titanium by Chemical Etching

Directory of Open Access Journals (Sweden)

Denis V. Nazarov

2017-01-01

Full Text Available In this study, we present the detailed investigation of the influence of the etching medium (acidic or basic Piranha solutions and the etching time on the morphology and surface relief of ultrafine grained (UFG and coarse grained (CG titanium. The surface relief and morphology have been studied by means of scanning electron microscopy (SEM, atomic force microscopy (AFM, and the spectral ellipsometry. The composition of the samples has been determined by X-ray fluorescence analysis (XRF and X-ray Photoelectron Spectroscopy (XPS. Significant difference in the etching behavior of UFG and CG titanium has been found. UFG titanium exhibits higher etching activity independently of the etching medium. Formed structures possess higher homogeneity. The variation of the etching medium and time leads to micro-, nano-, or hierarchical micro/nanostructures on the surface. Significant difference has been found between surface composition for UFG titanium etched in basic and acidic Piranha solution. Based on the experimental data, the possible reasons and mechanisms are considered for the formation of nano- and microstructures. The prospects of etched UFG titanium as the material for implants are discussed.

Difference in surface reactions between titanium and zirconium in Hanks' solution to elucidate mechanism of calcium phosphate formation on titanium using XPS and cathodic polarization

International Nuclear Information System (INIS)

Tsutsumi, Y.; Nishimura, D.; Doi, H.; Nomura, N.; Hanawa, T.

2009-01-01

Titanium and zirconium were immersed in Hanks' solution with and without calcium and phosphate ions, and the surfaces were characterized with X-ray photoelectron spectroscopy (XPS) to determine the mechanism of calcium phosphate formation on titanium in simulated body fluids and in a living body. In addition, they were cathodically polarized in the above solutions. XPS characterization and cathodic polarization revealed differences in the surface properties in the ability of calcium phosphate formation between titanium and zirconium. The surface oxide film on titanium is not completely oxidized and is relatively reactive; that on zirconium is more passive and protective than that on titanium. Neither calcium nor phosphate stably exists alone on titanium, and calcium phosphate is naturally formed on it; calcium phosphate formed on titanium is stable and protective. On the other hand, calcium is never incorporated on zirconium, while zirconium phosphate, which is easily formed on zirconium, is highly stable and protective. Our study presents new information regarding the surface property of titanium and demonstrates that the characteristics of titanium and zirconium may be applied to various medical devices and new surface modification techniques.

Evaluation of Antibacterial Activity of Titanium Surface Modified by PVD/PACVD Process.

Science.gov (United States)

Ji, Min-Kyung; Lee, Min-Joo; Park, Sang-Won; Lee, Kwangmin; Yun, Kwi-Dug; Kim, Hyun-Seung; Oh, Gye-Jeong; Kim, Ji-Hyun; Lim, Hyun-Pil

2016-02-01

The aim of this study was to evaluate the response of Streptococcus mutans (S. mutans) via crystal violet staining assay on titanium surface modified by physical vapor deposition/plasma assisted chemical vapor deposition process. Specimens were divided into the following three groups: polished titanium (control group), titanium modified by DC magnetron sputtering (group TiN-Ti), and titanium modified by plasma nitriding (group N-Ti). Surface characteristics of specimens were observed by using nanosurface 3D optical profiler and field emission scanning electron microscope. Group TiN-Ti showed TiN layer of 1.2 microm in thickness. Group N-Ti was identified as plasma nitriding with X-ray photoelectron spectroscopy. Roughness average (Ra) of all specimens had values 0.05). Within the process condition of this study, modified titanium surfaces by DC magnetron sputtering and plasma nitriding did not influence the adhesion of S. mutans.

Graded/Gradient Porous Biomaterials

Directory of Open Access Journals (Sweden)

Xigeng Miao

2009-12-01

Full Text Available Biomaterials include bioceramics, biometals, biopolymers and biocomposites and they play important roles in the replacement and regeneration of human tissues. However, dense bioceramics and dense biometals pose the problem of stress shielding due to their high Young’s moduli compared to those of bones. On the other hand, porous biomaterials exhibit the potential of bone ingrowth, which will depend on porous parameters such as pore size, pore interconnectivity, and porosity. Unfortunately, a highly porous biomaterial results in poor mechanical properties. To optimise the mechanical and the biological properties, porous biomaterials with graded/gradient porosity, pores size, and/or composition have been developed. Graded/gradient porous biomaterials have many advantages over graded/gradient dense biomaterials and uniform or homogenous porous biomaterials. The internal pore surfaces of graded/gradient porous biomaterials can be modified with organic, inorganic, or biological coatings and the internal pores themselves can also be filled with biocompatible and biodegradable materials or living cells. However, graded/gradient porous biomaterials are generally more difficult to fabricate than uniform or homogenous porous biomaterials. With the development of cost-effective processing techniques, graded/gradient porous biomaterials can find wide applications in bone defect filling, implant fixation, bone replacement, drug delivery, and tissue engineering.

Surface Modification of Titanium with Heparin-Chitosan Multilayers via Layer-by-Layer Self-Assembly Technique

International Nuclear Information System (INIS)

Shu, Y.; Zou, J.; Ou, G.; Wang, L.; Li, Q.

2011-01-01

Extracellular matrix (ECM), like biomimetic surface modification of titanium implants, is a promising method for improving its biocompatibility. In this paper chitosan (Chi) and heparin (Hep) multilayer was coated on pure titanium using a layer-by-layer (LbL) self-assembly technique. The Hep-Chi multilayer growth was carried out by first depositing a single layer of positively charged poly-L-lysine (PLL) on the NaOH-treated titanium substrate (negatively charged surface), followed by alternate deposition of negatively charged Hep and positively charged Chi, and terminated by an outermost layer of Chi. The multilayer was characterized by DR-FTIR, SEM, and AFM, and osteoblasts were cocultured with the modified titanium and untreated titanium surfaces, respectively, to evaluate their cytocompatibility in vitro. The results confirmed that Hep-Chi multilayer was fabricated gradually on the titanium surface. The Hep-Chi multilayer-coated titanium improved the adhesion, proliferation and differentiation of osteoblasts. Thus, the approach described here may provide a basis for the preparation of modified titanium surfaces for use in dental or orthopedic implants

Highly antibacterial UHMWPE surfaces by implantation of titanium ions

Energy Technology Data Exchange (ETDEWEB)

Delle Side, D., E-mail: domenico.delleside@le.infn.it [LEAS, Dipartimento di Matematica e Fisica “Ennio de Giorgi”, Università del Salento, Lecce (Italy); Istituto Nazionale di Fisica Nucleare – Sezione di Lecce, Lecce (Italy); Nassisi, V.; Giuffreda, E.; Velardi, L. [LEAS, Dipartimento di Matematica e Fisica “Ennio de Giorgi”, Università del Salento, Lecce (Italy); Istituto Nazionale di Fisica Nucleare – Sezione di Lecce, Lecce (Italy); Alifano, P.; Talà, A.; Tredici, S.M. [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce (Italy)

2014-07-15

The spreading of pathogens represents a serious threat for human beings. Consequently, efficient antimicrobial surfaces are needed in order to reduce risks of contracting severe diseases. In this work we present the first evidences of a new technique to obtain a highly antibacterial Ultra High Molecular Weight Polyethylene (UHMWPE) based on a non-stoichiometric titanium oxide coating, visible-light responsive, obtained through ion implantation.

Highly antibacterial UHMWPE surfaces by implantation of titanium ions

Science.gov (United States)

Delle Side, D.; Nassisi, V.; Giuffreda, E.; Velardi, L.; Alifano, P.; Talà, A.; Tredici, S. M.

2014-07-01

The spreading of pathogens represents a serious threat for human beings. Consequently, efficient antimicrobial surfaces are needed in order to reduce risks of contracting severe diseases. In this work we present the first evidences of a new technique to obtain a highly antibacterial Ultra High Molecular Weight Polyethylene (UHMWPE) based on a non-stoichiometric titanium oxide coating, visible-light responsive, obtained through ion implantation.

In vitro evaluation of three different biomaterials as scaffolds for canine mesenchymal stem cells

Directory of Open Access Journals (Sweden)

Oduvaldo Câmara Marques Pereira-Junior

2013-05-01

Full Text Available PURPOSE: To evaluate in vitro ability the of three different biomaterials - purified hydroxyapatite, demineralized bone matrix and castor oil-based polyurethane - as biocompatible 3D scaffolds for canine bone marrow mesenchymal stem cell (MSC intending bone tissue engineering. METHODS: MSCs were isolated from canine bone marrow, characterized and cultivated for seven days with the biomaterials. Cell proliferation and adhesion to the biomaterial surface were evaluated by scanning electron microscopy while differentiation into osteogenic lineage was evaluated by Alizarin Red staining and Sp7/Osterix surface antibody marker. RESULTS: The biomaterials allowed cellular growth, attachment and proliferation. Osteogenic differentiation occurred in the presence of hydroxyapatite, and matrix deposition commenced in the presence of the castor oil-based polyurethane. CONCLUSION: All the tested biomaterials may be used as mesenchymal stem cell scaffolds in cell-based orthopedic reconstructive therapy.

Titanium. Properties, raw datum surface, physicochemical basis and fabrication technique

International Nuclear Information System (INIS)

Garmata, V.A.; Petrun'ko, A.N.; Galitskij, N.V.; Olesov, Yu.G.; Sandler, R.A.

1983-01-01

On the nowadays science and technology achievements the complex of titanium metallurgy problems comprising raw material base, physico-chemical basis and fabrication technique, properties and titanium usage fields is considered for the first time. A particular attention is given to raw material base, manufacturing titanium concentrates and titanium tetrachloride, metallothermal reduction, improvement of metal quality. Data on titanium properties are given, processes of titanium powder metallurgy, scrap and waste processing, problems of economics and complex raw material use are considered

Effects of different titanium zirconium implant surfaces on initial supragingival plaque formation.

Science.gov (United States)

John, Gordon; Becker, Jürgen; Schwarz, Frank

2017-07-01

The aim of the current study was the evaluation of biofilm development on different implant surfaces. Initial biofilm formation was investigated on five different implant surfaces, machined titanium (MTi), modified machined acid-etched titanium (modMATi), machined titanium zirconium (MTiZr), modified machined and acid-etched titanium zirconium (modMATiZr) and sandblasted large grid and acid-etched titanium zirconium surface (SLATiZr) for 24 and 48 h. Biocompatibility was tested after tooth brushing of the samples via cell viability testing with human gingival fibroblasts. After 24 h of biofilm collection, mean plaque surface was detected in the following descending order: After 24 h: MTiZr > MTi > SLATiZr > modMATiZr > modMATi. Both M surfaces showed significant higher biofilm formation than the other groups. After 48 h: MTiZr > MTi > SLATiZr > modMATiZr > modMATi. After tooth brushing: SLATiZr > modMATi > modMATiZr > MTi > MTiZr. All native samples depicted significant higher cell viability than their corresponding surfaces after biofilm removal procedure. The TiZr groups especially the modMATiZr group showed slower and less biofilm formation. In combination with the good biocompatibility, both modMA surfaces seem to be interesting candidates for surfaces in transgingival implant design. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

In Situ Growth of Mesoporous Silica with Drugs on Titanium Surface and Its Biomedical Applications.

Science.gov (United States)

Wan, Mimi; Zhang, Jin; Wang, Qi; Zhan, Shuyue; Chen, Xudong; Mao, Chun; Liu, Yuhong; Shen, Jian

2017-06-07

Mesoporous silica has been developed for the modification of titanium surfaces that are used as implant materials. Yet, the traditional modification methods failed to effectively construct mesoporous silica on the titanium surface evenly and firmly, in which the interaction between mesoporous silica and titanium was mainly physical. Here, in situ growth of mesoporous silica on a titanium surface was performed using a simple evaporation-induced self-assembly strategy. Meantime, in situ introduction of drugs (heparin and vancomycin) to mesoporous silica was also adopted to improve the drug-loading amount. Both the above-mentioned processes were completed at the same time. Transmission electron microscopy, N 2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, scanning electron microscopy, and water contact angle measurements were used to characterize the structure of the mesoporous silica film. Results indicated that the mesoporous silica film that in situ grew on the titanium surface was smooth, thin, transparent, and stable. Cytotoxicity, proliferation performance of osteoblast cells, and in vitro and in vivo studies of the antibacterial activity of the coating were tested. This is the first study to modify the titanium surface by the in situ growth of a mesoporous silica coating with two kinds of drugs. The stability of the mesoporous silica coating can be attributed to the chemical bonding between dopamine and silicon hydroxyl of the mesoporous silica coating, and the smooth surface of mesoporous silica is a result of the method of in situ growth. The large amount of drug-loading also could be ascribed to the in situ introduction of drugs during the synthetic process. The strategy proposed in this work will bring more possibilities for the preparation of advanced functional materials based on the combination of mesoporous structure and metallic materials.

Osteoblastic response to pectin nanocoating on titanium surfaces

DEFF Research Database (Denmark)

Gurzawska, Katarzyna; Svava, Rikke; Yihua, Yu

2014-01-01

with respect to surface properties and osteogenic response in osteoblastic cells. Nanocoatings on titanium surfaces were evaluated by scanning electron microscopy, contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy. The effect of coated RG-Is on cell adhesion, cell...

Dimensional accuracy and surface property of titanium casting using gypsum-bonded alumina investment.

Science.gov (United States)

Yan, Min; Takahashi, Hidekazu; Nishimura, Fumio

2004-12-01

The aim of the present study was to evaluate the dimensional accuracy and surface property of titanium casting obtained using a gypsum-bonded alumina investment. The experimental gypsum-bonded alumina investment with 20 mass% gypsum content mixed with 2 mass% potassium sulfate was used for five cp titanium castings and three Cu-Zn alloy castings. The accuracy, surface roughness (Ra), and reaction layer thickness of these castings were investigated. The accuracy of the castings obtained from the experimental investment ranged from -0.04 to 0.23%, while surface roughness (Ra) ranged from 7.6 to 10.3microm. A reaction layer of about 150 microm thickness under the titanium casting surface was observed. These results suggested that the titanium casting obtained using the experimental investment was acceptable. Although the reaction layer was thin, surface roughness should be improved.

Influence of Electropolishing and Magnetoelectropolishing on Corrosion and Biocompatibility of Titanium Implants

Science.gov (United States)

Rahman, Zia ur; Pompa, Luis; Haider, Waseem

2014-11-01

Titanium alloys are playing a vital role in the field of biomaterials due to their excellent corrosion resistance and biocompatibility. These alloys enhance the quality and longevity of human life by replacing or treating various parts of the body. However, as these materials are in constant contact with the aggressive body fluids, corrosion of these alloys leads to metal ions release. These ions leach to the adjacent tissues and result in adverse biological reactions and mechanical failure of implant. Surface modifications are used to improve corrosion resistance and biological activity without changing their bulk properties. In this investigation, electropolishing and magnetoelectropolishing were carried out on commercially pure titanium, Ti6Al4V, and Ti6Al4V-ELI. These surface modifications are known to effect surface charge, chemistry, morphology; wettability, corrosion resistance, and biocompatibility of these materials. In vitro cyclic potentiodynamic polarization tests were conducted in phosphate buffer saline in compliance with ASTM standard F-2129-12. The surface morphology, roughness, and wettability of these alloys were studied using scanning electron microscope, atomic force microscope, and contact angle meter, respectively. Moreover, biocompatibility of titanium alloys was assessed by growing MC3T3 pre-osteoblast cells on them.

Simulation of Protein and Peptide-Based Biomaterials

National Research Council Canada - National Science Library

Daggett, Valerie

2002-01-01

The overall goal of the proposed research is to pursue realistic molecular modeling studies of the stability, dynamics, structure, function, and folding of proteins and protein-based biomaterials in solution...

Corrosion resistance of titanium alloys for dentistry

International Nuclear Information System (INIS)

Laskawiec, J.; Michalik, R.

2001-01-01

Titanium and its alloys belong to biomaterials which the application scope in medicine increases. Some properties of the alloys, such as high mechanical strength, low density, low Young's modulus, high corrosion resistance and good biotolerance decide about it. The main areas of the application of titanium and its alloys are: orthopedics and traumatology, cardiosurgery, faciomaxillary surgery and dentistry. The results of investigations concerning the corrosion resistance of the technical titanium and Ti6Al14V alloy and comparatively a cobalt alloy of the Vitallium type in the artificial saliva is presented in the work. Significantly better corrosion resistance of titanium and the Ti6Al14V than the Co-Cr-Mo alloy was found. (author)

The influence of biomaterials on endothelial cell thrombogenicity

Science.gov (United States)

McGuigan, Alison P.; Sefton, Michael V.

2007-01-01

Driven by tissue engineering and regenerative medicine, endothelial cells are being used in combination with biomaterials in a number of applications for the purpose of improving blood compatibility and host integration. Endothelialized vascular grafts are beginning to be used clinically with some success in some centers, while endothelial seeding is being explored as a means of creating a vasculature within engineered tissues. The underlying assumption of this strategy is that when cultured on artificial biomaterials, a confluent layer of endothelial cells maintain their non-thrombogenic phenotype. In this review the existing knowledge base of endothelial cell thrombogenicity cultured on a number of different biomaterials is summarized. The importance of selecting appropriate endpoint measures that are most reflective of overall surface thrombogenicity is the focus of this review. Endothelial cells inhibit thrombosis through three interconnected regulatory systems (1) the coagulation cascade (2) the cellular components of the blood such as leukocytes and platelets and (3) the complement cascade, and also through effects on fibrinolysis and vascular tone, the latter which influences blood flow. Thus, in order to demonstrate the thromobgenic benefit of seeding a biomaterial with EC, the conditions under which EC surfaces are more likely to exhibit lower thrombogenicity than unseeded biomaterial surfaces need to be consistent with the experimental context. The endpoints selected should be appropriate for the dominant thrombotic process that occurs under the given experimental conditions. PMID:17316788

Host response to bacterially contaminated titanium and titanium alloy surfaces

NARCIS (Netherlands)

Yue, Chongxia

2015-01-01

Biomaterial-implants are frequently used to restore the function and form of human anatomy. However, the presence of implanted biomaterials dramatically elevates infection risk. Their use will increase due to an increasing life expectancy of an ever growing population world-wide. The occurrence of

Modified surface of titanium dioxide nanoparticles-based biosensor for DNA detection

Science.gov (United States)

Nadzirah, Sh.; Hashim, U.; Rusop, M.

2018-05-01

A new technique was used to develop a simple and selective picoammeter DNA biosensor for identification of E. coli O157:H7. This biosensor was fabricated from titanium dioxide nanoparticles that was synthesized by sol-gel method and spin-coated on silicon dioxide substrate via spinner. 3-Aminopropyl triethoxy silane (APTES) was used to modify the surface of TiO2. Simple surface modification approach has been applied; which is single dropping of APTES onto the TiO2 nanoparticles surface. Carboxyl modified probe DNA has been bind onto the surface of APTES/TiO2 without any amplifier element. Electrical signal has been used as the indicator to differentiate each step (surface modification of TiO2 and probe DNA immobilization). The I-V measurements indicate extremely low current (pico-ampere) flow through the device which is 2.8138E-10 A for pure TiO2 nanoparticles, 2.8124E-10 A after APTES modification and 3.5949E-10 A after probe DNA immobilization.

The Effect of Pure Titanium and Titanium Alloy on Osteoblast and Chondrocyte Maturatin In Vitro

National Research Council Canada - National Science Library

Lincks, Jack

1999-01-01

... bone growth at the interface. Based on in vivo and in vitro studies, biomaterial composition, surface energy, surface roughness, and surface topography appear to play a major role in implant success...

Biomaterials for cardiac regeneration

CERN Document Server

Ruel, Marc

2015-01-01

This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

A new method using insert-based systems (IBS) to improve cell behavior study on flexible and rigid biomaterials

OpenAIRE

Grenade, Charlotte; Moniotte, Nicolas; Rompen, Eric; Vanheusden, Alain; Mainjot, Amélie; De Pauw-Gillet, Marie-Claire

2016-01-01

In vitro studies about biomaterials biological properties are essential screening tests. Yet cell cultures encounter difficulties related to cell retention on material surface or to the observation of both faces of permeable materials. The objective of the present study was to develop a reliable in vitro method to study cell behavior on rigid and flexible/permeable biomaterials elaborating two specific insert-based systems (IBS-R and IBS-F respectively). IBS-R was designed as a specific cylin...

Gentamicin-Eluting Titanium Dioxide Nanotubes Grown on the Ultrafine-Grained Titanium.

Science.gov (United States)

Nemati, Sima Hashemi; Hadjizadeh, Afra

2017-08-01

Titanium (Ti)-based materials is the most appropriate choices for the applications as orthopedic and dental implants. In this regard, ultrafine-grained (UFG) titanium with an enhanced mechanical properties and surface energy has attracted more attention. Titanium dioxide (TiO 2 ) nanotubes grown on the titanium could enhance bone bonding, cellular response and are good reservoirs for loading drugs and antibacterial agents. This article investigates gentamicin loading into and release from the TiO 2 nanotubes, grown on the UFG compared to coarse-grained (CG) titanium substrate surfaces. Equal Channel Angular Pressing (ECAP) was employed to produce the UFG structure titanium. TiO 2 nanotubes were grown by the anodizing technique on both UFG and CG titanium substrate surfaces. Scanning electron microscopy (SEM) imaging confirmed TiO 2 nanotube growth on the surface. The UV-vis spectroscopy analysis results show that the amount of gentamicin load-release in the anodized UFG titanium sample is higher than that of CG one which can be explained in terms of thicker TiO 2 nanotube arrays layer formed on UFG sample. Moreover, the anodized UFG titanium samples released the drug in a longer time than CG (1 day for the UFG titanium vs. 3 h for the CG one). Regarding wettability analysis, anodized UFG titanium sample showed more enhanced hydrophilicity than CG counterpart. Therefore, the significantly smaller grain size of pure titanium provided by the ECAP technique coupled with appropriate subsequent anodization treatment not only offers a good combination of biocompatibility and adequate mechanical properties but also it provides a delayed release condition for gentamicin.

Interactions between endothelial progenitor cells (EPC) and titanium implant surfaces.

Science.gov (United States)

Ziebart, Thomas; Schnell, Anne; Walter, Christian; Kämmerer, Peer W; Pabst, Andreas; Lehmann, Karl M; Ziebart, Johanna; Klein, Marc O; Al-Nawas, Bilal

2013-01-01

Endothelial cells play an important role in peri-implant angiogenesis during early bone formation. Therefore, interactions between endothelial progenitor cells (EPCs) and titanium dental implant surfaces are of crucial interest. The aim of our in vitro study was to investigate the reactions of EPCs in contact with different commercially available implant surfaces. EPCs from buffy coats were isolated by Ficoll density gradient separation. After cell differentiation, EPC were cultured for a period of 7 days on different titanium surfaces. The test surfaces varied in roughness and hydrophilicity: acid-etched (A), sand-blasted-blasted and acid-etched (SLA), hydrophilic A (modA), and hydrophilic SLA (modSLA). Plastic and fibronectin-coated plastic surfaces served as controls. Cell numbers and morphology were analyzed by confocal laser scanning microscopy. Secretion of vascular endothelial growth factor (VEGF)-A was measured by enzyme-linked immunosorbent assay and expressions of iNOS and eNOS were investigated by real-time polymerase chain reaction. Cell numbers were higher in the control groups compared to the cells of titanium surfaces. Initially, hydrophilic titanium surfaces (modA and modSLA) showed lower cell numbers than hydrophobic surfaces (A and SLA). After 7 days smoother surfaces (A and modA) showed increased cell numbers compared to rougher surfaces (SLA and modSLA). Cell morphology of A, modA, and control surfaces was characterized by a multitude of pseudopodia and planar cell soma architecture. SLA and modSLA promoted small and plump cell soma with little quantity of pseudopodia. The lowest VEGF level was measured on A, the highest on modSLA. The highest eNOS and iNOS expressions were found on modA surfaces. The results of this study demonstrate that biological behaviors of EPCs can be influenced by different surfaces. The modSLA surface promotes an undifferentiated phenotype of EPCs that has the ability to secrete growth factors in great quantities. In

Injectable silk-based biomaterials for cervical tissue augmentation: an in vitro study.

Science.gov (United States)

Brown, Joseph E; Partlow, Benjamin P; Berman, Alison M; House, Michael D; Kaplan, David L

2016-01-01

Cerclage therapy is an important treatment option for preterm birth prevention. Several patient populations benefit from cerclage therapy including patients with a classic history of cervical insufficiency; patients who present with advanced cervical dilation prior to viability; and patients with a history of preterm birth and cervical shortening. Although cerclage is an effective treatment option in some patients, it can be associated with limited efficacy and procedure complications. Development of an alternative to cerclage therapy would be an important clinical development. Here we report on an injectable, silk protein-based biomaterial for cervical tissue augmentation. The rationale for the development of an injectable biomaterial is to restore the native properties of cervical tissue. While cerclage provides support to the tissue, it does not address excessive tissue softening, which is a central feature of the pathogenesis of cervical insufficiency. Silk protein-based hydrogels, which are biocompatible and naturally degrade in vivo, are suggested as a platform for restoring the native properties of cervical tissue and improving cervical function. We sought to study the properties of an injectable, silk-based biomaterial for potential use as an alternative treatment for cervical insufficiency. These biomaterials were evaluated for mechanical tunability, biocompatibility, facile injection, and in vitro degradation. Silk protein solutions were cross-linked by an enzyme catalyzed reaction to form elastic biomaterials. Biomaterials were formulated to match the native physical properties of cervical tissue during pregnancy. The cell compatibility of the materials was assessed in vitro using cervical fibroblasts, and biodegradation was evaluated using concentrated protease solution. Tissue augmentation or bulking was demonstrated using human cervical tissue from nonpregnant hysterectomy specimens. Mechanical compression tests measured the tissue stiffness as a

The Interface Structure of High-Temperature Oxidation-Resistant Aluminum-Based Coatings on Titanium Billet Surface

Science.gov (United States)

Xu, Zhefeng; Rong, Ju; Yu, Xiaohua; Kun, Meng; Zhan, Zhaolin; Wang, Xiao; Zhang, Yannan

2017-10-01

A new type of high-temperature oxidation-resistant aluminum-based coating, on a titanium billet surface, was fabricated by the cold spray method, at a high temperature of 1050°C, for 8 h, under atmospheric pressure. The microstructure of the exposed surface was analyzed via optical microscopy, the microstructure of the coating and elemental diffusion was analyzed via field emission scanning electron microscopy, and the interfacial phases were identified via x-ray diffraction. The Ti-Al binary phase diagram and Gibbs free energy of the stable phase were calculated by Thermo-calc. The results revealed that good oxidation resistant 50-μm-thick coatings were successfully obtained after 8 h at 1050°C. Two layers were obtained after the coating process: an Al2O3 oxidation layer and a TiAl3 transition layer on the Ti-based substrate. The large and brittle Al2O3 grains on the surface, which can be easily spalled off from the surface after thermal processing, protected the substrate against oxidation during processing. In addition, the thermodynamic calculation results were in good agreement with the experimental data.

Corrosion performance of some titanium-based hard coatings

International Nuclear Information System (INIS)

Matthes, B.; Broszeit, E.; Aromaa, J.; Ronkainen, H.; Hannula, S.P.; Leyland, A.; Matthews, A.

1991-01-01

Tools and machine parts which could benefit from wear-resistant titanium-based hard films are often subject to corrosive environments. Physically vapour-deposited coatings frequently exhibit porosity and even small defects, which can cause rapid local corrosion of the substrate material; there is therefore a requirement for dense and chemically inert coatings. This paper presents corrosion data for titanium-based hard coatings such as TiN, (Ti, Al)N, Ti(B, N) and TiB 2 and also for multilayered structures where additional aluminium-based insulating surface layers (AlN and Al 2 O 3 ) were deposited. The corrosion resistance and porosity of the films were analysed by electrochemical techniques. The degree of metallic bonding can play a significant role in influencing the corrosion resistance of refractory transition-metal-based ceramic coatings. Here we demonstrate that, under potentiodynamic corrosion test conditions, resistance to corrosive attack was relatively poor for TiB 2 , better for (Ti, Al)N and Ti(B, N) and best for TiN. It is also shown that applying the additional protective aluminium-based insulating surface layers on the coating can further improve corrosion resistance. (orig.)

TiO2 micro-nano-hybrid surface to alleviate biological aging of UV-photofunctionalized titanium.

Science.gov (United States)

Iwasa, Fuminori; Tsukimura, Naoki; Sugita, Yoshihiko; Kanuru, Rajita Kodali; Kubo, Katsutoshi; Hasnain, Hafiz; Att, Wael; Ogawa, Takahiro

2011-01-01

Bioactivity and osteoconductivity of titanium degrade over time after surface processing. This time-dependent degradation is substantial and defined as the biological aging of titanium. UV treatment has shown to reactivate the aged surfaces, a process known as photofunctionalization. This study determined whether there is a difference in the behavior of biological aging for titanium with micro-nano-hybrid topography and titanium with microtopography alone, following functionalization. Titanium disks were acid etched to create micropits on the surface. Micro-nano-hybrid surfaces were created by depositioning 300-nm diameter TiO(2) nodules onto the micropits using a previously established self-assembly protocol. These disks were stored for 8 weeks in the dark to allow sufficient aging, then treated with UV light for 48 hours. Rat bone marrow-derived osteoblasts were cultured on fresh disks (immediately after UV treatment), 3-day-old disks (disks stored for 3 days after UV treatment), and 7-day- old disks. The rates of cell attachment, spread, proliferation, and levels of alkaline phosphatase activity, and calcium deposition were reduced by 30%-50% on micropit surfaces, depending on the age of the titanium. In contrast, 7-day-old hybrid surfaces maintained equivalent levels of bioactivity compared with the fresh surfaces. Both micropit and micro-nano-hybrid surfaces were superhydrophilic immediately after UV treatment. However, after 7 days, the micro-nano- hybrid surfaces became hydrorepellent, while the micropit surfaces remained hydrophilic. The sustained bioactivity levels of the micro-nano-hybrid surfaces were nullified by treating these surfaces with Cl(-)anions. A thin TiO(2) coating on the micropit surface without the formation of nanonodules did not result in the prevention or alleviation of the time-dependent decrease in biological activity. In conclusion, the micro-nano-hybrid titanium surfaces may slow the rate of time-dependent degradation of titanium

Conducting polymer-based multilayer films for instructive biomaterial coatings

OpenAIRE

Hardy, John G; Li, Hetian; Chow, Jacqueline K; Geissler, Sydney A; McElroy, Austin B; Nguy, Lindsey; Hernandez, Derek S; Schmidt, Christine E

2015-01-01

Aim: To demonstrate the design, fabrication and testing of conformable conducting biomaterials that encourage cell alignment. Materials & methods: Thin conducting composite biomaterials based on multilayer films of poly (3,4-ethylenedioxythiophene) derivatives, chitosan and gelatin were prepared in a layer-by-layer fashion. Fibroblasts were observed with fluorescence microscopy and their alignment (relative to the dipping direction and direction of electrical current passed through the films)...

Modified Titanium Surface-Mediated Effects on Human Bone Marrow Stromal Cell Response

Directory of Open Access Journals (Sweden)

Amol Chaudhari

2013-11-01

Full Text Available Surface modification of titanium implants is used to enhance osseointegration. The study objective was to evaluate five modified titanium surfaces in terms of cytocompatibility and pro-osteogenic/pro-angiogenic properties for human mesenchymal stromal cells: amorphous microporous silica (AMS, bone morphogenetic protein-2 immobilized on AMS (AMS + BMP, bio-active glass (BAG and two titanium coatings with different porosity (T1; T2. Four surfaces served as controls: uncoated Ti (Ti, Ti functionalized with BMP-2 (Ti + BMP, Ti surface with a thickened titanium oxide layer (TiO2 and a tissue culture polystyrene surface (TCPS. The proliferation of eGFP-fLuc (enhanced green fluorescence protein-firefly luciferase transfected cells was tracked non-invasively by fluorescence microscopy and bio-luminescence imaging. The implant surface-mediated effects on cell differentiation potential was tracked by determination of osteogenic and angiogenic parameters [alkaline phosphatase (ALP; osteocalcin (OC; osteoprotegerin (OPG; vascular endothelial growth factor-A (VEGF-A]. Unrestrained cell proliferation was observed on (unfunctionalized Ti and AMS surfaces, whereas BAG and porous titanium coatings T1 and T2 did not support cell proliferation. An important pro-osteogenic and pro-angiogenic potential of the AMS + BMP surface was observed. In contrast, coating the Ti surface with BMP did not affect the osteogenic differentiation of the progenitor cells. A significantly slower BMP-2 release from AMS compared to Ti supports these findings. In the unfunctionalized state, Ti was found to be superior to AMS in terms of OPG and VEGF-A production. AMS is suggested to be a promising implant coating material for bioactive agents delivery.

New surface modification method of bio-titanium alloy by EB polishing

International Nuclear Information System (INIS)

Okada, Akira; Uno, Yoshiyuki; Iio, Atsuo; Fujiwara, Kunihiko; Doi, Kenji

2008-01-01

A new surface modification for bio-titanium alloy products by electron beam (EB) polishing is proposed. In this EB polishing method, high energy density EB can be irradiated without concentrating the beam. Therefore, large-area EB with a maximum diameter of 60 mm can be used for instantaneously melting or evaporating metal surface. Experimental results made it clear that surface characteristics, such as repellency, corrosion resistance and coefficient of friction could be improved simultaneously with the surface smoothing in a few minutes under a proper condition. Therefore, EB polishing method has a possibility of high efficient surface smoothing and surface modification process for bio-titanium alloy. (author)

In vitro cytotoxicity and surface topography evaluation of additive manufacturing titanium implant materials.

Science.gov (United States)

Tuomi, Jukka T; Björkstrand, Roy V; Pernu, Mikael L; Salmi, Mika V J; Huotilainen, Eero I; Wolff, Jan E H; Vallittu, Pekka K; Mäkitie, Antti A

2017-03-01

Custom-designed patient-specific implants and reconstruction plates are to date commonly manufactured using two different additive manufacturing (AM) technologies: direct metal laser sintering (DMLS) and electron beam melting (EBM). The purpose of this investigation was to characterize the surface structure and to assess the cytotoxicity of titanium alloys processed using DMLS and EBM technologies as the existing information on these issues is scarce. "Processed" and "polished" DMLS and EBM disks were assessed. Microscopic examination revealed titanium alloy particles and surface flaws on the processed materials. These surface flaws were subsequently removed by polishing. Surface roughness of EBM processed titanium was higher than that of DMLS processed. The cytotoxicity results of the DMLS and EBM discs were compared with a "gold standard" commercially available titanium mandible reconstruction plate. The mean cell viability for all discs was 82.6% (range, 77.4 to 89.7) and 83.3% for the control reconstruction plate. The DMLS and EBM manufactured titanium plates were non-cytotoxic both in "processed" and in "polished" forms.

The Role of Oral Cavity Biofilm on Metallic Biomaterial Surface Destruction–Corrosion and Friction Aspects

Science.gov (United States)

Niemirowicz-Laskowska, Katarzyna; Łysik, Dawid; Tokajuk, Grażyna; Dąbrowski, Jan R.; Bucki, Robert

2018-01-01

Metallic biomaterials in the oral cavity are exposed to many factors such as saliva, bacterial microflora, food, temperature fluctuations, and mechanical forces. Extreme conditions present in the oral cavity affect biomaterial exploitation and significantly reduce its biofunctionality, limiting the time of exploitation stability. We mainly refer to friction, corrosion, and biocorrosion processes. Saliva plays an important role and is responsible for lubrication and biofilm formation as a transporter of nutrients for microorganisms. The presence of metallic elements in the oral cavity may lead to the formation of electro-galvanic cells and, as a result, may induce corrosion. Transitional microorganisms such as sulfate-reducing bacteria may also be present among the metabolic microflora in the oral cavity, which can induce biological corrosion. Microorganisms that form a biofilm locally change the conditions on the surface of biomaterials and contribute to the intensification of the biocorrosion processes. These processes may enhance allergy to metals, inflammation, or cancer development. On the other hand, the presence of saliva and biofilm may significantly reduce friction and wear on enamel as well as on biomaterials. This work summarizes data on the influence of saliva and oral biofilms on the destruction of metallic biomaterials. PMID:29509686

The Role of Oral Cavity Biofilm on Metallic Biomaterial Surface Destruction-Corrosion and Friction Aspects.

Science.gov (United States)

Mystkowska, Joanna; Niemirowicz-Laskowska, Katarzyna; Łysik, Dawid; Tokajuk, Grażyna; Dąbrowski, Jan R; Bucki, Robert

2018-03-06

Metallic biomaterials in the oral cavity are exposed to many factors such as saliva, bacterial microflora, food, temperature fluctuations, and mechanical forces. Extreme conditions present in the oral cavity affect biomaterial exploitation and significantly reduce its biofunctionality, limiting the time of exploitation stability. We mainly refer to friction, corrosion, and biocorrosion processes. Saliva plays an important role and is responsible for lubrication and biofilm formation as a transporter of nutrients for microorganisms. The presence of metallic elements in the oral cavity may lead to the formation of electro-galvanic cells and, as a result, may induce corrosion. Transitional microorganisms such as sulfate-reducing bacteria may also be present among the metabolic microflora in the oral cavity, which can induce biological corrosion. Microorganisms that form a biofilm locally change the conditions on the surface of biomaterials and contribute to the intensification of the biocorrosion processes. These processes may enhance allergy to metals, inflammation, or cancer development. On the other hand, the presence of saliva and biofilm may significantly reduce friction and wear on enamel as well as on biomaterials. This work summarizes data on the influence of saliva and oral biofilms on the destruction of metallic biomaterials.

The Role of Oral Cavity Biofilm on Metallic Biomaterial Surface Destruction–Corrosion and Friction Aspects

Directory of Open Access Journals (Sweden)

Joanna Mystkowska

2018-03-01

Full Text Available Metallic biomaterials in the oral cavity are exposed to many factors such as saliva, bacterial microflora, food, temperature fluctuations, and mechanical forces. Extreme conditions present in the oral cavity affect biomaterial exploitation and significantly reduce its biofunctionality, limiting the time of exploitation stability. We mainly refer to friction, corrosion, and biocorrosion processes. Saliva plays an important role and is responsible for lubrication and biofilm formation as a transporter of nutrients for microorganisms. The presence of metallic elements in the oral cavity may lead to the formation of electro-galvanic cells and, as a result, may induce corrosion. Transitional microorganisms such as sulfate-reducing bacteria may also be present among the metabolic microflora in the oral cavity, which can induce biological corrosion. Microorganisms that form a biofilm locally change the conditions on the surface of biomaterials and contribute to the intensification of the biocorrosion processes. These processes may enhance allergy to metals, inflammation, or cancer development. On the other hand, the presence of saliva and biofilm may significantly reduce friction and wear on enamel as well as on biomaterials. This work summarizes data on the influence of saliva and oral biofilms on the destruction of metallic biomaterials.

Titanium Dioxide-Based 64∘ YX LiNbO3 Surface Acoustic Wave Hydrogen Gas Sensors

Directory of Open Access Journals (Sweden)

A. Z. Sadek

2008-01-01

Full Text Available Amorphous titanium dioxide (TiO2 and gold (Au doped TiO2-based surface acoustic wave (SAW sensors have been investigated as hydrogen gas detectors. The nanocrystal-doped TiO2 films were synthesized through a sol-gel route, mixing a Ti-butoxide-based solution with diluted colloidal gold nanoparticles. The films were deposited via spin coating onto 64∘ YX LiNbO3 SAW transducers in a helium atmosphere. The SAW gas sensors were operated at various temperatures between 150 and 310∘C. It was found that gold doping on TiO2 increased the device sensitivity and reduced the optimum operating temperature.

Composite Biomaterials Based on Sol-Gel Mesoporous Silicate Glasses: A Review

Science.gov (United States)

Baino, Francesco; Fiorilli, Sonia; Vitale-Brovarone, Chiara

2017-01-01

Bioactive glasses are able to bond to bone and stimulate the growth of new tissue while dissolving over time, which makes them ideal materials for regenerative medicine. The advent of mesoporous glasses, which are typically synthesized via sol-gel routes, allowed researchers to develop a broad and versatile class of novel biomaterials that combine superior bone regenerative potential (compared to traditional melt-derived glasses) with the ability of incorporating drugs and various biomolecules for targeted therapy in situ. Mesoporous glass particles can be directly embedded as a bioactive phase within a non-porous (e.g., microspheres), porous (3D scaffolds) or injectable matrix, or be processed to manufacture a surface coating on inorganic or organic (macro)porous substrates, thereby obtaining hierarchical structures with multiscale porosity. This review provides a picture of composite systems and coatings based on mesoporous glasses and highlights the challenges for the future, including the great potential of inorganic–organic hybrid sol-gel biomaterials. PMID:28952496

Surface analysis of titanium dental implants with different topographies

Directory of Open Access Journals (Sweden)

Silva M.H. Prado da

2000-01-01

Full Text Available Cylindrical dental implants made of commercially pure titanium were analysed in four different surface finishes: as-machined, Al2O3 blasted with Al2O3 particles, plasma-sprayed with titanium beads and electrolytically coated with hydroxyapatite. Scanning electron microscopy (SEM with Energy Dispersive X-ray Analysis (EDX revealed the topography of the surfaces and provided qualitative results of the chemical composition of the different implants. X-ray Photoelectron Spectroscopy (XPS was used to perform chemical analysis on the surface of the implants while Laser Scanning Confocal Microscopy (LSM produced topographic maps of the analysed surfaces. Optical Profilometry was used to quantitatively characterise the level of roughness of the surfaces. The implant that was plasma-sprayed and the hydroxyapatite coated implant showed the roughest surface, followed by the implant blasted with alumina and the as-machined implant. Some remnant contamination from the processes of blasting, coating and cleaning was detected by XPS.

Microstructural and micromechanical tests of titanium biomaterials intended for prosthetic reconstructions.

Science.gov (United States)

Ryniewicz, Anna M; Bojko, Łukasz; Ryniewicz, Wojciech I

2016-01-01

The aim of the present paper was a question of structural identification and evaluation of strength parameters of Titanium (Ticp - grade 2) and its alloy (Ti6Al4V) which are used to serve as a base for those permanent prosthetic supplements which are later manufactured employing CAD/CAM systems. Microstructural tests of Ticp and Ti6Al4V were conducted using an optical microscope as well as a scanning microscope. Hardness was measured with the Vickers method. Micromechanical properties of samples: microhardness and Young's modulus value, were measured with the Oliver and Pharr method. Based on studies using optical microscopy it was observed that the Ticp from the milling technology had a single phase, granular microstructure. The Ti64 alloy had a two-phase, fine-grained microstructure with an acicular-lamellar character. The results of scanning tests show that titanium Ticp had a single phase structure. On its grain there was visible acicular martensite. The structure of the two phase Ti64 alloy consists of a β matrix as well as released α phase deposits in the shape of extended needles. Micromechanical tests demonstrated that the alloy of Ti64 in both methods showed twice as high the microhardness as Ticp. In studies of Young's modulus of Ti64 alloy DMLS technology have lower value than titanium milling technology. According to the results obtained, the following conclusion has been drawn: when strength aspect is discussed, the DMLS method is a preferred one in manufacturing load structures in dentistry and may be an alternate way for the CAD/CAM system used in decrement processing.

Effect of surface treatment of titanium posts on the tensile bond strength

NARCIS (Netherlands)

Schmage, P; Sohn, J; Ozcan, M; Nergiz, [No Value

Objectives. Retention of composite resins to metal can be improved when metal surfaces are conditioned. The purpose of this investigation was to investigate the effect of two conditioning treatments on the tensile bond strength of four resin-based luting cements and zinc phosphate cement to titanium

Effects of plasma electrolytic oxidation process on the mechanical properties of additively manufactured porous biomaterials.

Science.gov (United States)

Gorgin Karaji, Zahra; Hedayati, Reza; Pouran, Behdad; Apachitei, Iulian; Zadpoor, Amir A

2017-07-01

Metallic porous biomaterials are recently attracting more attention thanks to the additive manufacturing techniques which help produce more complex structures as compared to conventional techniques. On the other hand, bio-functional surfaces on metallic biomaterials such as titanium and its alloys are necessary to enhance the biological interactions with the host tissue. This study discusses the effect of plasma electrolytic oxidation (PEO), as a surface modification technique to produce bio-functional layers, on the mechanical properties of additively manufactured Ti6Al4V scaffolds based on the cubic unit cell. For this purpose, the PEO process with two different oxidation times was applied on scaffolds with four different values of relative density. The effects of the PEO process were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), optical microscopy as well as static and dynamic (fatigue) mechanical testing under compression. SEM results indicated pore formation on the surface of the scaffolds after oxidation with a thickness of 4.85±0.36μm of the oxide layer after 2min and 9.04±2.27μm after 5min oxidation (based on optical images). The static test results showed the high effect of relative density of porous structure on its mechanical properties. However, oxidation did not influence most of the mechanical properties such as maximum stress, yield stress, plateau stress, and energy absorption, although its effect on the elastic modulus was considerable. Under fatigue loading, none of the scaffolds failed even after 10 6 loading cycles at 70% of their yield stress. Copyright © 2017 Elsevier B.V. All rights reserved.

Smart biomaterials

CERN Document Server

Ebara, Mitsuhiro; Narain, Ravin; Idota, Naokazu; Kim, Young-Jin; Hoffman, John M; Uto, Koichiro; Aoyagi, Takao

2014-01-01

This book surveys smart biomaterials, exploring the properties, mechanics and characterization of hydrogels, particles, assemblies, surfaces, fibers and conjugates. Reviews applications such as drug delivery, tissue engineering, bioseparation and more.

Porous titanium obtained by a new powder metallurgy technique: Preliminary results of human osteoblast adhesion on surface polished substrates.

Science.gov (United States)

Biasotto, M; Ricceri, R; Scuor, N; Schmid, C; Sandrucci, M A; Di Lenarda, R; Matteazzi, P

2003-01-01

This study concerns a novel powder metallurgy method for producing porous titanium (pTi) exhibiting high mechanical properties. The preparation procedure consisted of the following stages: first, the preparation of Ti and titanium hydride (TiH2) powder mixtures and their consolidation with a cold isostatic press, followed by a sintering of the green bodies performed with hot isostatic press (HIP) equipment. Thermal decomposition in controlled environment of the TiH2 phase results in the foam structure. The resulting porosity percolates with a volume fraction of approximately 20%. The final material exhibits interesting mechanical properties, comparable to those of full density titanium (between grade 2 and grade 3), with the advantage of a minor density. The samples produced were tested to verify their biological response by studying the effectiveness of osteoblast adhesion and growth. In this preliminary study, osteoblastic cell morphology was investigated and compared to that observed on fully dense commercially pure titanium (Ti-cp) (ASTM, grade 3). The preliminary results were promising regarding cellular adhesion and spreading. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 172-7).

Biocompatibility of the titanium-based implant surfaces: Effect of the calcium dihydrogen phosphate on osteoblast cells

Directory of Open Access Journals (Sweden)

Kaluđerović Milena R.

2016-01-01

Full Text Available The influence of the presence of calcium dihydrogen phosphate in acid media on titanium-based implant surfaces, Ticer, employed in clinics, and its white form (Ticer white, on osteoblast cells was investigated. Novel surfaces M1 and M2 were obtained by immersing Ticer and Ticer white surfaces in calcium dihydrogen phosphate solution at pH 3.5. The surfaces were characterized by SEM, EDS and X-ray diffraction. The results related to interaction of investigated surfaces and human osteoblast cells from indirect biocompatibility (MTT and SRB assays, proliferation (DAPI assay and mode of cell death (acridine orange/ethidium bromide (AO/EB double staining were found to be in good agreement, as well as findings from osteocalcin (OC and bone sialoprotein (BSP expression. Surfaces were obtained by employing anodic plasma-electrochemical oxidation with spark discharges without subsequent surface modifications were found to be more compatible. Soaking of Ticer and Ticer white in phosphate solution gave toxic materials (M1 and M2 which induced apoptosis and secondary necrosis in osteoblast cells.

Effects of storage methods on time-related changes of titanium surface properties and cellular response

International Nuclear Information System (INIS)

Lu Haibin; Zhou Lei; Wan Lei; Li Shaobing; Rong Mingdeng; Guo Zehong

2012-01-01

Titanium implants are sold in the market as storable medical devices. All the implants have a certain shelf life during which they maintain their sterility, but variations of the surface properties through this duration have not been subject to a comprehensive assessment. The aim of this study was to investigate the effects of storage methods on time-related changes of titanium surface properties. Acid-etched titanium discs (Sa = 0.82 µm) were placed in a sealed container (tradition method) or submerged in the ddH 2 O/NaCl solution (0.15 mol L −1 )/CaCl 2 solution (0.15 mol L −1 ), and new titanium discs were used as a control group. SEM and optical profiler showed that surface morphology and roughness did not change within different groups, but the XPS analysis confirmed that the surface chemistry altered by different storage protocols as the storage duration increased, and the contact angle also varied with storage methods. The storage method also affected the protein adsorption capacity and cellular response on the titanium surface. All titanium discs stored in the solution maintained their excellent bioactivity even after four weeks storage time, but titanium discs stored in a traditional manner decreased substantially in an age-dependent manner. Much effort is needed to improve the storage methods in order to maintain the bioactivity of a titanium dental implant. (paper)

Designing protein-based biomaterials for medical applications.

Science.gov (United States)

Gagner, Jennifer E; Kim, Wookhyun; Chaikof, Elliot L

2014-04-01

Biomaterials produced by nature have been honed through billions of years, evolving exquisitely precise structure-function relationships that scientists strive to emulate. Advances in genetic engineering have facilitated extensive investigations to determine how changes in even a single peptide within a protein sequence can produce biomaterials with unique thermal, mechanical and biological properties. Elastin, a naturally occurring protein polymer, serves as a model protein to determine the relationship between specific structural elements and desirable material characteristics. The modular, repetitive nature of the protein facilitates the formation of well-defined secondary structures with the ability to self-assemble into complex three-dimensional architectures on a variety of length scales. Furthermore, many opportunities exist to incorporate other protein-based motifs and inorganic materials into recombinant protein-based materials, extending the range and usefulness of these materials in potential biomedical applications. Elastin-like polypeptides (ELPs) can be assembled into 3-D architectures with precise control over payload encapsulation, mechanical and thermal properties, as well as unique functionalization opportunities through both genetic and enzymatic means. An overview of current protein-based materials, their properties and uses in biomedicine will be provided, with a focus on the advantages of ELPs. Applications of these biomaterials as imaging and therapeutic delivery agents will be discussed. Finally, broader implications and future directions of these materials as diagnostic and therapeutic systems will be explored. Copyright © 2013 Elsevier Ltd. All rights reserved.

Innovative coatings and surface modification of titanium for sea water condenser applications

International Nuclear Information System (INIS)

George, R.P.; Anandkumar, B.; Vanithakumari, S.C.; Kamachi Mudali, U.

2016-01-01

Effectiveness of cooling water systems in various power plants to maintain highest electrical energy output per tonne of fuel is important as part of good energy management. Cooling water systems of nuclear power plants using seawater for cooling comes under constant attack from the marine and sea water environment. Many metallic components and civil structures in the cooling water systems like bridges, intake wells, intake pipes, pump house wells, water boxes, condenser pipes are subjected to severe fouling and corrosion which limits the service life and availability of power plants. The experience with a coastal water cooled power plant at Kalpakkam (MAPS), India, showed that chlorination and screening control macrofouling to a great extend by controlling protozoans, invertebrates, algae and fungi. However 90% of marine bacteria are resistant to such control measures, and they cause microfouling of condenser pipes leading to poor heat transfer and microbially influenced corrosion (MIC) failures. Titanium is used as condenser for Indian nuclear power plants employing sea water cooling, including the PFBR at Kalpakkam. Though titanium is excellent with respect to corrosion behavior under sea water conditions, its biocompatible nature results in biofouling and MIC during service. Therefore innovative antifouling coatings and surface modification techniques for titanium condenser applications in seawater and marine environments are the need of the hour. Extensive investigations were carried out by different methods including nanostructuring of surfaces for making them antibacterial. The microroughness of titanium was produced by repeated pickling and polishing which by itself reduced microbial adhesion. To utilize photocatalytic activity for antibacterial property, anodization of titanium surfaces followed by heat treatment was adopted and this also has controlled microbial fouling. Electroless plating of nanofilm of copper-nickel alloy decreased biofouling of

Failure Surface Analysis of Polyimide/Titanium Notched Coating Adhesion Specimens

Energy Technology Data Exchange (ETDEWEB)

GIUNTA,RACHEL K.; KANDER,RONALD G.

2000-12-18

Adhesively bonded joints of LaRC{trademark} PETI-5, a phenylethynyl-terminated polyimide, with chromic acid anodized titanium were fabricated and debonded interfacially. The adhesive-substrate failure surfaces were investigated using several surface analysis techniques. From Auger spectroscopy, field emission scanning electron microscopy, and atomic force microscopy studies, polymer appears to be penetrating the pores of the anodized substrate to a depth of approximately 100 nm. From x-ray photoelectron spectroscopy data, the polymer penetrating the pores appears to be in electrical contact with the titanium substrate, leading to differential charging. These analyses confirm that the polymer is becoming mechanically interlocked within the substrate surface.

Photon absorption of calcium phosphate-based dental biomaterials

International Nuclear Information System (INIS)

Singh, V. P.; Badiger, N. M.; Tekin, H. O.; Kara, U.; Vega C, H. R.; Fernandes Z, M. A.

2017-10-01

Effective atomic number and mass energy absorption buildup factors for four calcium phosphate-based biomaterials used in dental treatments were calculated for 0.015 to 15 MeV photons. The mass energy absorption coefficients were calculated for 0.5 to 40 mean free paths of photons. In the energy region important for dental radiology the Zeff for all studied biomaterials are larger in comparison to larger energies. In x-rays for dental radiology and the energy absorption buildup factors are low, however CbMDI bio material shows a resonance at 80 keV. (Author)

Studies of the surface of titanium dioxide. IV. The hydrogen-deuterium equilibration reaction

International Nuclear Information System (INIS)

Iwaki, T.; Katsuta, K.; Miura, M.

1981-01-01

The interaction of hydrogen with the surface of titanium dioxide has been studied in connection with the hydrogen-reduction mechanism of titanium dioxide, by means of such measurements as weight decrease, magnetic susceptibility, hydrogen uptake, and electrical conductance. It was postulated in the previous study that the rate-determining step of the hydrogen-reduction reaction may be the formation of surface hydroxyl groups, followed by the rapid removal of water molecules from the surface. In this study, the interactions between hydrogen and the surface of titanium dioxide were investigated by measuring the hydrogen-deuterium equilibration reaction, H 2 + D 2 = 2HD, at temperatures above 200 0 C on both surfaces before and after hydrogen reduction to compare the differences in the reactivities

Deuteriding of thin titanium films: the effect of carbon monoxide surface contamination

International Nuclear Information System (INIS)

Malinowski, M.W.

1976-02-01

The effect of adsorbed CO on the deuteriding of thin titanium films at room temperature was measured at D 2 pressures between 10 to 25 mtorr on films contaminated with CO exposures ranging between approximately 10 -8 torr-seconds (''clean'') to 10 -4 torr-seconds. In all measurements, for deuterium/titanium atom ratios greater than .2, the deuteriding appeared to be initally limited by the sticking of D 2 on the clean or contaminated titanium deuteride surface; the effective sticking coefficient on a clean titanium deuteride surface was approximately 3 x 10 -3 , while on a surface contaminated with 10 -4 torr-seconds of CO, the coefficient was reduced to approximately, 2 x 10 -4 . The pumping speeds of Ti films were dramatically different when the films were evaporated over TiD 2 . These changes were attributed to the presence of deuterium which diffused from the substrate film into the overlayer film

Osteoblast response on co-modified titanium surfaces via anodization and electrospinning

Energy Technology Data Exchange (ETDEWEB)

Bayram, Cem [Nanotechnology and Nanomedicine Division, Hacettepe University, Ankara, Beytepe, 06800 (Turkey); Chemistry Department, Aksaray University, Aksaray, 68100 (Turkey); Demirbilek, Murat; Yalçın, Eda [Nanotechnology and Nanomedicine Division, Hacettepe University, Ankara, Beytepe, 06800 (Turkey); Bozkurt, Murat; Doğan, Metin [Orthopaedics and Traumatology Division, Yıldırım Beyazıt University, School of Medicine, Cankaya, 06550 (Turkey); Denkbaş, Emir Baki, E-mail: denkbas@hacettepe.edu.tr [Chemistry Department, Hacettepe University, Ankara, Beytepe, 06800 (Turkey)

2014-01-01

Topography plays a key role in osseointegration and surface modifications at the subcellular level, increasing initial cell attachment in the early period. In the past decade, nanosized texture on metal like a nanotube layer and also more recently extracellular matrix like surface modifications – such as polymeric nanofibrils – have been proposed for a better osseointegration in the literature. Here, we investigate two types of nanoscaled modifications alone and together for the first time. We characterized different types of surface modifications morphologically and investigated how they affected osteoblast cells in vitro, in terms of cell adhesion, proliferation, alkaline phosphatase activity and calcium content. We anodized titanium samples with a thickness of 0.127 mm to obtain a nanotubular titania layer and the silk fibroin (SF), as a biocompatible polymeric material, was electrospun onto both anodized and unanodized samples to acquire 4 sample groups. We analyzed the resulting samples morphologically by scanning electron microscopy (SEM). Cell adhesion, proliferation, alkaline phosphatase (ALP) activity and calcium content were evaluated at 3, 7 and 14 days. We found that cell proliferation increased by 70% on the groups having two modifications respect to unmodified titanium and after 7 days, ALP activity and calcium content were 110% and 150%, respectively, higher on surfaces having both surface treatments than that of unmodified group. In conclusion, a nanotube layer and SF nanofibers on a titanium surface enhanced cell attachment and proliferation most. Comodification of titanium surfaces by anodization and SF electrospinning may be useful to enhance osseointegration but it requires in vivo confirmation.

Macrophages, Foreign Body Giant Cells and Their Response to Implantable Biomaterials

Directory of Open Access Journals (Sweden)

Zeeshan Sheikh

2015-08-01

Full Text Available All biomaterials, when implanted in vivo, elicit cellular and tissue responses. These responses include the inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the implanted materials. Macrophages are myeloid immune cells that are tactically situated throughout the tissues, where they ingest and degrade dead cells and foreign materials in addition to orchestrating inflammatory processes. Macrophages and their fused morphologic variants, the multinucleated giant cells, which include the foreign body giant cells (FBGCs are the dominant early responders to biomaterial implantation and remain at biomaterial-tissue interfaces for the lifetime of the device. An essential aspect of macrophage function in the body is to mediate degradation of bio-resorbable materials including bone through extracellular degradation and phagocytosis. Biomaterial surface properties play a crucial role in modulating the foreign body reaction in the first couple of weeks following implantation. The foreign body reaction may impact biocompatibility of implantation devices and may considerably impact short- and long-term success in tissue engineering and regenerative medicine, necessitating a clear understanding of the foreign body reaction to different implantation materials. The focus of this review article is on the interactions of macrophages and foreign body giant cells with biomaterial surfaces, and the physical, chemical and morphological characteristics of biomaterial surfaces that play a role in regulating the foreign body response. Events in the foreign body response include protein adsorption, adhesion of monocytes/macrophages, fusion to form FBGCs, and the consequent modification of the biomaterial surface. The effect of physico-chemical cues on macrophages is not well known and there is a complex interplay between biomaterial properties and those that result from interactions with the local environment. By having a

Does surface anodisation of titanium implants change osseointegration and make their extraction from bone any easier?

Science.gov (United States)

Langhoff, J D; Mayer, J; Faber, L; Kaestner, S B; Guibert, G; Zlinszky, K; Auer, J A; von Rechenberg, B

2008-01-01

Titanium implants have a tendency for high bone-implant bonding, and, in comparison to stainless steel implants are more difficult to remove. The current study was carried out to evaluate, i) the release strength of three selected anodized titanium surfaces with increased nanohardness and low roughness, and ii) bone-implant bonding in vivo. These modified surfaces were intended to give improved anchorage while facilitating easier removal of temporary implants. The new surfaces were referenced to a stainless steel implant and a standard titanium implant surface (TiMAX). In a sheep limb model, healing period was 3 months. Bone-implant bonding was evaluated either biomechanically or histologically. The new surface anodized screws demonstrated similar or slightly higher bone-implant-contact (BIC) and torque release forces than the titanium reference. The BIC of the stainless steel implants was significant lower than two of the anodized surfaces (p = 0.04), but differences between stainless steel and all titanium implants in torque release forces were not significant (p = 0.06). The new anodized titanium surfaces showed good bone-implant bonding despite a smooth surface and increased nanohardness. However, they failed to facilitate implant removal at 3 months.

Predicting biomaterial property-dendritic cell phenotype relationships from the multivariate analysis of responses to polymethacrylates

Science.gov (United States)

Kou, Peng Meng; Pallassana, Narayanan; Bowden, Rebeca; Cunningham, Barry; Joy, Abraham; Kohn, Joachim; Babensee, Julia E.

2011-01-01

Dendritic cells (DCs) play a critical role in orchestrating the host responses to a wide variety of foreign antigens and are essential in maintaining immune tolerance. Distinct biomaterials have been shown to differentially affect the phenotype of DCs, which suggested that biomaterials may be used to modulate immune response towards the biologic component in combination products. The elucidation of biomaterial property-DC phenotype relationships is expected to inform rational design of immuno-modulatory biomaterials. In this study, DC response to a set of 12 polymethacrylates (pMAs) was assessed in terms of surface marker expression and cytokine profile. Principal component analysis (PCA) determined that surface carbon correlated with enhanced DC maturation, while surface oxygen was associated with an immature DC phenotype. Partial square linear regression, a multivariate modeling approach, was implemented and successfully predicted biomaterial-induced DC phenotype in terms of surface marker expression from biomaterial properties with R2prediction = 0.76. Furthermore, prediction of DC phenotype was effective based on only theoretical chemical composition of the bulk polymers with R2prediction = 0.80. These results demonstrated that immune cell response can be predicted from biomaterial properties, and computational models will expedite future biomaterial design and selection. PMID:22136715

Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

Data.gov (United States)

U.S. Environmental Protection Agency — A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology has been synthesized and its application as a recyclable...

[Biomaterials in bone repair].

Science.gov (United States)

Puska, Mervi; Aho, Allan J; Vallittu, Pekka K

2013-01-01

In orthopedics, traumatology, and craniofacial surgery, biomaterials should meet the clinical demands of bone that include shape, size and anatomical location of the defect, as well as the physiological load-bearing stresses. Biomaterials are metals, ceramics, plastics or materials of biological origin. In the treatment of large defects, metallic endoprostheses or bone grafts are employed, whereas ceramics in the case of small defects. Plastics are employed on the artificial joint surfaces, in the treatment of vertebral compression fractures, and as biodegradable screws and plates. Porosity, bioactivity, and identical biomechanics to bone are fundamental for achieving a durable, well-bonded, interface between biomaterial and bone. In the case of severe bone treatments, biomaterials should also imply an option to add biologically active substances.

Biocompatibility and Inflammatory Potential of Titanium Alloys Cultivated with Human Osteoblasts, Fibroblasts and Macrophages

Science.gov (United States)

Markhoff, Jana; Krogull, Martin; Schulze, Christian; Rotsch, Christian; Hunger, Sandra; Bader, Rainer

2017-01-01

The biomaterials used to maintain or replace functions in the human body consist mainly of metals, ceramics or polymers. In orthopedic surgery, metallic materials, especially titanium and its alloys, are the most common, due to their excellent mechanical properties, corrosion resistance, and biocompatibility. Aside from the established Ti6Al4V alloy, shape memory materials such as nickel-titanium (NiTi) have risen in importance, but are also discussed because of the adverse effects of nickel ions. These might be reduced by specific surface modifications. In the present in vitro study, the osteoblastic cell line MG-63 as well as primary human osteoblasts, fibroblasts, and macrophages were cultured on titanium alloys (forged Ti6Al4V, additive manufactured Ti6Al4V, NiTi, and Diamond-Like-Carbon (DLC)-coated NiTi) to verify their specific biocompatibility and inflammatory potential. Additive manufactured Ti6Al4V and NiTi revealed the highest levels of metabolic cell activity. DLC-coated NiTi appeared as a suitable surface for cell growth, showing the highest collagen production. None of the implant materials caused a strong inflammatory response. In general, no distinct cell-specific response could be observed for the materials and surface coating used. In summary, all tested titanium alloys seem to be biologically appropriate for application in orthopedic surgery. PMID:28772412

Biocompatibility and Inflammatory Potential of Titanium Alloys Cultivated with Human Osteoblasts, Fibroblasts and Macrophages

Directory of Open Access Journals (Sweden)

Jana Markhoff

2017-01-01

Full Text Available The biomaterials used to maintain or replace functions in the human body consist mainly of metals, ceramics or polymers. In orthopedic surgery, metallic materials, especially titanium and its alloys, are the most common, due to their excellent mechanical properties, corrosion resistance, and biocompatibility. Aside from the established Ti6Al4V alloy, shape memory materials such as nickel-titanium (NiTi have risen in importance, but are also discussed because of the adverse effects of nickel ions. These might be reduced by specific surface modifications. In the present in vitro study, the osteoblastic cell line MG-63 as well as primary human osteoblasts, fibroblasts, and macrophages were cultured on titanium alloys (forged Ti6Al4V, additive manufactured Ti6Al4V, NiTi, and Diamond-Like-Carbon (DLC-coated NiTi to verify their specific biocompatibility and inflammatory potential. Additive manufactured Ti6Al4V and NiTi revealed the highest levels of metabolic cell activity. DLC-coated NiTi appeared as a suitable surface for cell growth, showing the highest collagen production. None of the implant materials caused a strong inflammatory response. In general, no distinct cell-specific response could be observed for the materials and surface coating used. In summary, all tested titanium alloys seem to be biologically appropriate for application in orthopedic surgery.

Biomimetic Deposition of Hydroxyapatite by Mixed Acid Treatment of Titanium Surfaces.

Science.gov (United States)

Zhao, J M; Park, W U; Hwang, K H; Lee, J K; Yoon, S Y

2015-03-01

A simple chemical method was established for inducing bioactivity of Ti metal. In the present study, two kinds of mixed acid solutions were used to treat Ti specimens to induce Ca-P formation. Following a strong mixed acid activation process, Ca-P coatings successfully formed on the Ti surfaces in the simulated body fluid. Strong mixed acid etching was used to increase the roughness of the metal surface, because the porous and rough surfaces allow better adhesion between Ca-P coatings and substrate. Nano-scale modification of titanium surfaces can alter cellular and tissue responses, which may benefit osseointegration and dental implant therapy. Some specimens were treated with a 5 M NaOH aqueous solution, and then heat treated at 600 °C in order to form an amorphous sodium titanate layer on their surface. This treated titanium metal is believed to form a dense and uniform bone-like apatite layer on its surface in a simulated body fluid (SBF). This study proved that mixed acid treatment is not only important for surface passivation but is also another bioactive treatment for titanium surfaces, an alternative to alkali treatment. In addition, mixed acid treatment uses a lower temperature and shorter time period than alkali treatment.

Histological Evaluation of Nano-Micro Titanium Implant Surface Treatment in Beagle Humerus.

Science.gov (United States)

Yun, Kwidug; Kang, Seongsoo; Oh, Gyejeong; Lim, Hyunpil; Lee, Kwangmin; Yang, Hongso; Vang, Mongsook; Park, Sangwon

2016-02-01

The objective of this study was to investigate the effects of nano-micro titanium implant surface using histology in beagle dogs. A total of 48 screw-shaped implants (Megagen, Daegu, Korea) which dimensions were 4 mm in diameter and 8.5 mm in length, were used. The implants were classified into 4 groups (n = 12): machined surface (M group), RBM (Resorbable Blasting Media) surface (R group), nano surface which is nanotube formation on the machined surface (MA group) and nano-micro surface which is nanotube formation on the RBM surface (RA group). Anodic oxidation was performed at a constant voltage of 20 V for 10 min using a DC power supply (Fine Power F-3005; SG EMD, Anyang, Korea). The bone blocks were investigated using histology. There was no inflammation around implants, and new bone formation was shown along with the nano-micro titanium implant surfaces. The amount of bone formation was increased depending on time comparing 4 weeks and 12 weeks. At 12 weeks, lamellar bone was more formed along with the nano-micro titanium implant surfaces than 4 weeks. It indicated that nano-micro surface showed good result in terms of osseointegration.

Improvement of Surface Properties of CP-Titanium by Thermo-Chemical Treatment (TCT) Process

International Nuclear Information System (INIS)

Jeong, Hyeon-Gyeong; Hur, Bo-Young; Lee, Dong-Geun; Lee, Yong-Tai; Yaskiv, O.

2011-01-01

The thermo-chemical treatment (TCT) process was applied to achieve surface hardening of CP titanium. The following three different surface modification conditions were tested so that the best surface hardening process could be selected:(a) PVD, (b) TCT+PVD, and (c) TCT+Aging+PVD. These specimens were tested and analyzed in terms of surface roughness, wear, friction coefficient, and the gradient of hardening from the surface of the matrix. The three test conditions were all beneficial to improve the surface hardness of CP titanium. Moreover, the TCT treated specimens, that is, (b) and (c), showed significantly improved surface hardness and low friction coefficients through the thickness up to 100um. This is due to the functionally gradient hardened surface improvement by the diffused interstitial elements. The hardened surface also showed improvement in bonding between the PVD and TCT surface, and this leads to improvement in wear resistance. However, TCT after aging treatment did not show much improvement in surface properties compared to TCT only. For the best surface hardening on CP titanium, TCT+PVD has advantages in surface durability and economics.

Building blocks of Collagen based biomaterial devices

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Building blocks of Collagen based biomaterial devices. Collagen as a protein. Collagen in tissues and organs. Stabilizing and cross linking agents. Immunogenicity. Hosts (drugs). Controlled release mechanisms of hosts. Biodegradability, workability into devices ...

Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

Science.gov (United States)

A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

Effects of titanium surface topography on morphology and in vitro activity of human gingival fibroblasts.

Science.gov (United States)

Ramaglia, L; Capece, G; Di Spigna, G; Bruno, M P; Buonocore, N; Postiglione, L

2013-01-01

The aim of the present study was to evaluate in vitro the biological behavior of human gingival fibroblasts cultured on two different titanium surfaces. Titanium test disks were prepared with a machined, relatively smooth (S) surface or a rough surface (O) obtained by a double acid etching procedure. Primary cultures of human gingival fibroblasts were plated on the experimental titanium disks and cultured up to 14 days. Titanium disk surfaces were analysed by scanning electron microscopy (SEM). Cell proliferation and a quantitative analysis by ELISA in situ of ECM components as CoI, FN and TN were performed. Results have shown different effects of titanium surface microtopography on cell expression and differentiation. At 96 hours of culture on experimental surfaces human gingival fibroblasts displayed a favourable cell attachment and proliferation on both surfaces although showing some differences. Both the relatively smooth and the etched surfaces interacted actively with in vitro cultures of human gingival fibroblasts, promoting cell proliferation and differentiation. Results suggested that the microtopography of a double acid-etched rough surface may induce a greater Co I and FN production, thus conditioning in vivo the biological behaviour of human gingival fibroblasts during the process of peri-implant soft tissue healing.

On the use of titanium hydride for powder injection moulding of titanium-based alloys

International Nuclear Information System (INIS)

Carrenoo-Morelli, E.; Bidaux, J.-E.

2009-01-01

Full text: Titanium and titanium-based alloys are excellent materials for a number of engineering applications because of their high strength, lightweight, good corrosion resistance, non magnetic characteristic and biocompatibility. The current processing steps are usually costly, and there is a growing demand for net-shape solutions for manufacturing parts of increasing complexity. Powder injection moulding is becoming a competitive alternative, thanks to the advances in production of good quality base-powders, binders and sintering facilities. Titanium hydride powders, have the attractiveness of being less reactive than fine titanium powders, easier to handle, and cheaper. This paper summarizes recent advances on PIM of titanium and titanium alloys from TiH2 powders, including shape-memory NiTi alloys. (author)

In vivo evaluation of defined polished titanium surfaces to prevent soft tissue adhesion.

Science.gov (United States)

Hayes, Jessica S; Welton, Joanne L; Wieling, Ronald; Richards, R Geoff

2012-04-01

Soft tissue-implant adhesion is often required for implant integration into the body; however, in some situations, the tissue is required to glide freely over an implant. In the case of distal radius fracture treatment, current literature describes how titanium and its alloys tend to lead to more intra-tendon inflammatory reactions compared with stainless steel. This leads to tendon-implant adhesion and damage possibly causing limited palmar flexion and even tendon rupture. The goal of this study was to analyze the effect of different surface polishings of titanium and titanium molybdenum implants on soft tissue reactions in vivo, with the aim to prevent direct soft tissue adhesion. Using a nonfracture model, to allow for study of the soft-tissue-implant surface interactions only, six surface variants of the same plate design were implanted onto the tibia of 24 New Zealand white rabbits and left in situ for 12 weeks. Results indicate that paste polished commercially pure titanium and titanium molybdenum alloy had the least soft tissue adhesion, with the concomitant development of a soft tissue capsule. Surface topography did not appear influence the thickness of the connective tissue surrounding the plate. Therefore, suitable surface polishing could be applied to plates for clinical use, where free gliding of tissues is required. Copyright © 2012 Wiley Periodicals, Inc.

Surface Corrosion Resistance in Turning of Titanium Alloy

Directory of Open Access Journals (Sweden)

Rui Zhang

2015-01-01

Full Text Available This work addresses the issues associated with implant surface modification. We propose a method to form the oxide film on implant surfaces by dry turning to generate heat and injecting oxygen-rich gas at the turning-tool flank. The morphology, roughness, composition, and thickness of the oxide films in an oxygen-rich atmosphere were characterized using scanning electron microscopy, optical profiling, and Auger electron spectroscopy. Electrochemical methods were used to study the corrosion resistance of the modified surfaces. The corrosion resistance trends, analyzed relative to the oxide film thickness, indicate that the oxide film thickness is the major factor affecting the corrosion resistance of titanium alloys in a simulated body fluid (SBF. Turning in an oxygen-rich atmosphere can form a thick oxide film on the implant surface. The thickness of surface oxide films processed at an oxygen concentration of 80% was improved to 4.6 times that of films processed at an oxygen concentration of 21%; the free corrosion potential shifted positively by 0.357 V, which significantly improved the corrosion resistance of titanium alloys in the SBF. Therefore, the proposed method may (partially replace the subsequent surface oxidation. This method is significant for biomedical development because it shortens the process flow, improves the efficiency, and lowers the cost.

The Otto Aufranc Award: Enhanced Biocompatibility of Stainless Steel Implants by Titanium Coating and Microarc Oxidation

Science.gov (United States)

Lim, Young Wook; Kwon, Soon Yong; Sun, Doo Hoon

2010-01-01

Background Stainless steel is one of the most widely used biomaterials for internal fixation devices, but is not used in cementless arthroplasty implants because a stable oxide layer essential for biocompatibility cannot be formed on the surface. We applied a Ti electron beam coating, to form oxide layer on the stainless steel surface. To form a thicker oxide layer, we used a microarc oxidation process on the surface of Ti coated stainless steel. Modification of the surface using Ti electron beam coating and microarc oxidation could improve the ability of stainless steel implants to osseointegrate. Questions/purposes The ability of cells to adhere to grit-blasted, titanium-coated, microarc-oxidated stainless steel in vitro was compared with that of two different types of surface modifications, machined and titanium-coated, and microarc-oxidated. Methods We performed energy-dispersive x-ray spectroscopy and scanning electron microscopy investigations to assess the chemical composition and structure of the stainless steel surfaces and cell morphology. The biologic responses of an osteoblastlike cell line (SaOS-2) were examined by measuring proliferation (cell proliferation assay), differentiation (alkaline phosphatase activity), and attraction ability (cell migration assay). Results Cell proliferation, alkaline phosphatase activity, migration, and adhesion were increased in the grit-blasted, titanium-coated, microarc-oxidated group compared to the two other groups. Osteoblastlike cells on the grit-blasted, titanium-coated, microarc-oxidated surface were strongly adhered, and proliferated well compared to those on the other surfaces. Conclusions The surface modifications we used (grit blasting, titanium coating, microarc oxidation) enhanced the biocompatibility (proliferation and migration of osteoblastlike cells) of stainless steel. Clinical Relevance This process is not unique to stainless steel; it can be applied to many metals to improve their biocompatibility

Surface modification of biomaterials based on high-molecular polylactic acid and their effect on inflammatory reactions of primary human monocyte-derived macrophages: perspective for personalized therapy.

Science.gov (United States)

Stankevich, Ksenia S; Gudima, Alexandru; Filimonov, Victor D; Klüter, Harald; Mamontova, Evgeniya M; Tverdokhlebov, Sergei I; Kzhyshkowska, Julia

2015-06-01

Polylactic acid (PLA) based implants can cause inflammatory complications. Macrophages are key innate immune cells that control inflammation. To provide higher biocompatibility of PLA-based implants with local innate immune cells their surface properties have to be improved. In our study surface modification technique for high-molecular PLA (MW=1,646,600g/mol) based biomaterials was originally developed and successfully applied. Optimal modification conditions were determined. Treatment of PLA films with toluene/ethanol=3/7 mixture for 10min with subsequent exposure in 0.001M brilliant green dye (BGD) solution allows to entrap approximately 10(-9)mol/cm(2) model biomolecules. The modified PLA film surface was characterized by optical microscopy, SERS, FT-IR, UV and TG/DTA/DSC analysis. Tensile strain of modified films was determined as well. The effect of PLA films modified with BGD on the inflammatory reactions of primary human monocyte-derived macrophages was investigated. We developed in vitro test-system by differentiating primary monocyte-derived macrophages on a coating material. Type 1 and type 2 inflammatory cytokines (TNFα, CCL18) secretion and histological biomarkers (CD206, stabilin-1) expression were analyzed by ELISA and confocal microscopy respectively. BGD-modified materials have improved thermal stability and good mechanical properties. However, BGD modifications induced additional donor-specific inflammatory reactions and suppressed tolerogenic phenotype of macrophages. Therefore, our test-system successfully demonstrated specific immunomodulatory effects of original and modified PLA-based biomaterials, and can be further applied for the examination of improved coatings for implants and identification of patient-specific reactions to implants. Copyright © 2015. Published by Elsevier B.V.

A Classical Potential to Model the Adsorption of Biological Molecules on Oxidized Titanium Surfaces.

Science.gov (United States)

Schneider, Julian; Ciacchi, Lucio Colombi

2011-02-08

The behavior of titanium implants in physiological environments is governed by the thin oxide layer that forms spontaneously on the metal surface and mediates the interactions with adsorbate molecules. In order to study the adsorption of biomolecules on titanium in a realistic fashion, we first build up a model of an oxidized Ti surface in contact with liquid water by means of extensive first-principles molecular dynamics simulations. Taking the obtained structure as reference, we then develop a classical potential to model the Ti/TiOx/water interface. This is based on the mapping with Coulomb and Lennard-Jones potentials of the adsorption energy landscape of single water and ammonia molecules on the rutile TiO2(110) surface. The interactions with arbitrary organic molecules are obtained via standard combination rules to established biomolecular force fields. The transferability of our potential to the case of organic molecules adsorbing on the oxidized Ti surface is checked by comparing the classical potential energy surfaces of representative systems to quantum mechanical results at the level of density functional theory. Moreover, we calculate the heat of immersion of the TiO2 rutile surface and the detachment force of a single tyrosine residue from steered molecular dynamics simulations, finding good agreement with experimental reference data in both cases. As a first application, we study the adsorption behavior of the Arg-Gly-Asp (RGD) peptide on the oxidized titanium surface, focusing particularly on the calculation of the free energy of desorption.

A titanium surface with nano-ordered spikes and pores enhances human dermal fibroblastic extracellular matrix production and integration of collagen fibers

International Nuclear Information System (INIS)

Yamada, Masahiro; Kato, Eiji; Sakurai, Kaoru; Yamamoto, Akiko

2016-01-01

The acquisition of substantial dermal sealing determines the prognosis of percutaneous titanium-based medical devices or prostheses. A nano-topographic titanium surface with ordered nano-spikes and pores has been shown to induce periodontal-like connective tissue attachment and activate gingival fibroblastic functions. This in vitro study aimed to determine whether an alkali-heat (AH) treatment-created nano-topographic titanium surface could enhance human dermal fibroblastic functions and binding strength to the deposited collagen on the titanium surface. The surface topographies of commercially pure titanium machined discs exposed to two different AH treatments were evaluated. Human dermal fibroblastic cultures grown on the discs were evaluated in terms of cellular morphology, proliferation, extracellular matrix (ECM) and proinflammatory cytokine synthesis, and physicochemical binding strength of surface-deposited collagen. An isotropically-patterned, shaggy nano-topography with a sponge-like inner network and numerous well-organized, anisotropically-patterned fine nano-spikes and pores were observed on each nano-topographic surface type via scanning electron microscopy. In contrast to the typical spindle-shaped cells on the machined surfaces, the isotropically- and anisotropically-patterned nano-topographic titanium surfaces had small circular/angular cells containing contractile ring-like structures and elongated, multi-shaped cells with a developed cytoskeletal network and multiple filopodia and lamellipodia, respectively. These nano-topographic surfaces enhanced dermal-related ECM synthesis at both the protein and gene levels, without proinflammatory cytokine synthesis or reduced proliferative activity. Deposited collagen fibers were included in these surfaces and sufficiently bound to the nano-topographies to resist the physical, enzymatic and chemical detachment treatments, in contrast to machined surfaces. Well-organized, isotropically

Protein-surface interactions on stimuli-responsive polymeric biomaterials.

Science.gov (United States)

Cross, Michael C; Toomey, Ryan G; Gallant, Nathan D

2016-03-04

Responsive surfaces: a review of the dependence of protein adsorption on the reversible volume phase transition in stimuli-responsive polymers. Specifically addressed are a widely studied subset: thermoresponsive polymers. Findings are also generalizable to other materials which undergo a similarly reversible volume phase transition. As of 2015, over 100,000 articles have been published on stimuli-responsive polymers and many more on protein-biomaterial interactions. Significantly, fewer than 100 of these have focused specifically on protein interactions with stimuli-responsive polymers. These report a clear trend of increased protein adsorption in the collapsed state compared to the swollen state. This control over protein interactions makes stimuli-responsive polymers highly useful in biomedical applications such as wound repair scaffolds, on-demand drug delivery, and antifouling surfaces. Outstanding questions are whether the protein adsorption is reversible with the volume phase transition and whether there is a time-dependence. A clear understanding of protein interactions with stimuli-responsive polymers will advance theoretical models, experimental results, and biomedical applications.

Osteogenesis of bone marrow mesenchymal stem cells on strontium-substituted nano-hydroxyapatite coated roughened titanium surfaces

OpenAIRE

Yang, Hua-Wei; Lin, Mao-Han; Xu, Yuan-Zhi; Shang, Guang-Wei; Wang, Rao-Rao; Chen, Kai

2015-01-01

Objective: To investigate osteogenesis of bone marrow mesenchymal stem cells (BMSCs) on strontium-substituted nano-hydroxyapatite (Sr-HA) coated roughened titanium surfaces. Methods: Sr-HA coating and HA coating were fabricated on roughened titanium surfaces by electrochemical deposition technique and characterized by field emission scanning electron microscope (FESM). BMSCs were cultured on Sr-HA coating, HA coating and roughened titanium surfaces respectively. Cell proliferation, alkaline p...

Corrosion behavior of Ti-13Nb-13Zr alloy used as a biomaterial

International Nuclear Information System (INIS)

Niemeyer, T.C.; Grandini, C.R.; Pinto, L.M.C.; Angelo, A.C.D.; Schneider, S.G.

2009-01-01

Titanium alloys were developed as an alternative to stainless steels and have been extensively used as biomaterials ever since. One of these alloys is Ti-13Nb-13Zr (TNZ), a near-beta phase alloy containing elements with excellent biocompatibility. The main advantage of the TNZ alloy, compared to other titanium alloys, such as Ti-6Al-4V and Ti-6Al-7Nb, widely used as biomaterials, is its low elasticity modulus, closer to that of bone, and the absence of aluminum and vanadium, which have been reported to cause long-term adverse effects. In this paper, the corrosion and electrochemical behavior of TNZ alloy (as cast and after oxygen charge) was studied in a PBS solution. The results showed that, with the oxygen load, there is a significant reduction of the anodic current in almost the whole potential spam explored in this work, meaning that the corrosion rate decreases when the doping is performed.

Surface engineering of titanium with potassium hydroxide and its effects on the growth behavior of mesenchymal stem cells.

Science.gov (United States)

Cai, Kaiyong; Lai, Min; Yang, Weihu; Hu, Ran; Xin, Renlong; Liu, Qing; Sung, K L Paul

2010-06-01

To improve the corrosion resistance and biological performance of commercially pure titanium (cp-Ti) substrates, potassium hydroxide was employed to modify the surfaces of titanium substrates, followed by biomimetic deposition of apatite on the substrates in a simulated body fluid. The morphologies of native and treated titanium substrates were characterized by field emission scanning electron microscopy (FE-SEM). Treatment with potassium hydroxide led to the formation of intermediate layers of potassium titanate on the surfaces of titanium substrates, while apatite was subsequently deposited onto the intermediate layer. The formation of potassium titanate and apatite was confirmed by thin-film X-ray diffraction and FE-SEM equipped with energy dispersive spectroscopy, respectively. Electrochemical impedance spectroscopy showed that the formed potassium titanate layer improved the corrosion-resistance properties of titanium substrates. The influence of modified titanium substrates on the biological behavior of mesenchymal stem cells (MSCs), including osteogenic differentiation, was investigated in vitro. Compared with cp-Ti substrates, MSCs cultured onto alkali- and heat-treated titanium substrates and apatite-deposited titanium substrates displayed significantly higher (P<0.05 or P<0.01) proliferation and differentiation levels of alkaline phosphatase and osteocalcin in 7 and 14day cultures, respectively. More importantly, our results suggest that the modified titanium substrates have great potential for inducing MSCs to differentiate into osteoblasts. The approach presented here may be exploited to fabricate titanium-based implants. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Arsenic removal using natural biomaterial-based sorbents.

Science.gov (United States)

Ansone, Linda; Klavins, Maris; Viksna, Arturs

2013-10-01

Arsenic contamination of water is a major problem worldwide. A possible solution can be approached through developing new sorbents based on cost-effective and environmentally friendly natural biomaterials. We have developed new sorbents based on biomaterial impregnation with iron oxyhydroxide. In this study, raw peat material, iron-modified peat, iron-modified biomass (shingles, straw, sands, cane and moss) as well as iron humate were used for the removal of arsenate from contaminated water. The highest sorption capacity was observed in iron-modified peat, and kinetic studies indicated that the amount of arsenic sorbed on this material exceeds 90 % in 5 h. Arsenate sorption on iron-modified peat is characterised by the pseudo-second-order mechanism. The results of arsenic sorption in the presence of competing substances indicated that sulphate, nitrate, chloride and tartrate anions have practically no influence on As(V) sorption onto Fe-modified peat, whereas the presence of phosphate ions and humic acid significantly lowers the arsenic removal efficiency.

Surface modification and endothelialization of biomaterials as potential scaffolds for vascular tissue engineering applications.

Science.gov (United States)

Ren, Xiangkui; Feng, Yakai; Guo, Jintang; Wang, Haixia; Li, Qian; Yang, Jing; Hao, Xuefang; Lv, Juan; Ma, Nan; Li, Wenzhong

2015-08-07

Surface modification and endothelialization of vascular biomaterials are common approaches that are used to both resist the nonspecific adhesion of proteins and improve the hemocompatibility and long-term patency of artificial vascular grafts. Surface modification of vascular grafts using hydrophilic poly(ethylene glycol), zwitterionic polymers, heparin or other bioactive molecules can efficiently enhance hemocompatibility, and consequently prevent thrombosis on artificial vascular grafts. However, these modified surfaces may be excessively hydrophilic, which limits initial vascular endothelial cell adhesion and formation of a confluent endothelial lining. Therefore, the improvement of endothelialization on these grafts by chemical modification with specific peptides and genes is now arousing more and more interest. Several active peptides, such as RGD, CAG, REDV and YIGSR, can be specifically recognized by endothelial cells. Consequently, graft surfaces that are modified by these peptides can exhibit targeting selectivity for the adhesion of endothelial cells, and genes can be delivered by targeting carriers to specific tissues to enhance the promotion and regeneration of blood vessels. These methods could effectively accelerate selective endothelial cell recruitment and functional endothelialization. In this review, recent developments in the surface modification and endothelialization of biomaterials in vascular tissue engineering are summarized. Both gene engineering and targeting ligand immobilization are promising methods to improve the clinical outcome of artificial vascular grafts.

Texturing in titanium grade 2 surface irradiate with ultrashort pulse laser

International Nuclear Information System (INIS)

Nogueira, Alessandro Francelino

2015-01-01

The texturing laser micromachining is an important alternative to improve the bonding adhesion between composites and titanium, which are applied to structural components in the aerospace industry. The texturing running on titanium plates is due to the fact that the preferred joining technique for many composite materials is the adhesive bonding. In this work, titanium plates were texturized using laser ultrashort pulses temporal widths of femtoseconds. This process resulted in minimal heat transfer to the material, avoiding deformation of the titanium plate surface as well as the formation of resolidified material in the ablated region. These drawbacks have occurred with the use of nanoseconds pulses. Were performed three types of texturing using laser with femtosecond pulses, with variations in the distances between the machined lines. The analysis of the obtained surfaces found that the wettability increases when there is the increased distance between the texturing lines. Advancing in the analysis by optical profilometry of textured surfaces was observed that there is substantial increase in the volume available for penetration of structural adhesive when the distances between the textured lines are diminished. In tensile tests conducted it was observed that there is an increase in shear strength of the adhesive joint by reducing the distance between the textured lines. (author)

Attachment and growth behaviour of human gingival fibroblasts on titanium and zirconia ceramic surfaces

International Nuclear Information System (INIS)

Pae, Ahran; Kim, Hyeong-Seob; Woo, Yi-Hyung; Lee, Heesu; Kwon, Yong-Dae

2009-01-01

The attachment, growth behaviour and the genetic effect of human gingival fibroblasts (HGF) cultured on titanium and different zirconia surfaces were investigated. HGF cells were cultured on (1) titanium discs with a machined surface, (2) yttrium-stabilized tetragonal zirconia polycrystals (Y-TZP) with a smooth surface and (3) Y-TZP with 100 μm grooves. The cell proliferation activity was evaluated through a MTT assay at 24 h and 48 h, and the cell morphology was examined by SEM. The mRNA expression of integrin-β1, type I and III collagen, laminin and fibronectin in HGF were evaluated by RT-PCR after 24 h. From the MTT assay, the mean optical density values for the titanium and grooved zirconia surfaces after 48 h of HGF adhesion were greater than the values obtained for the smooth zirconia surfaces. SEM images showed that more cells were attached to the grooves, and the cells appeared to follow the direction of the grooves. The results of RT-PCR suggest that all groups showed comparable fibroblast-specific gene expression. A zirconia ceramic surface with grooves showed biological responses that were comparable to those obtained with HGF on a titanium surface.

The Sustainable Improvement of Manufacturing for Nano-Titanium

Directory of Open Access Journals (Sweden)

Chia-Nan Wang

2016-04-01

Full Text Available Scientists have found that nanomaterials possess many outstanding features in their tiny grain structure compared to other common materials. Titanium at the nano-grain scale shows many novel characteristics which demonstrate suitability for use in surgical implants. In general, equal channel angular pressing (ECAP is the most popular and simple process to produce nano-titanium. However, ECAP is time-consuming, power-wasting, and insufficiently produces the ultrafine grain structure. Therefore, the objective of this research is to propose a new method to improve the ECAP’s performances to reach the ultrafine grain structure, and also to save production costs, based on the innovation theory of Teoriya Resheniya Izobreatatelskih Zadatch (TRIZ. Research results show that the process time is reduced by 80%, and 94% of the energy is saved. Moreover, the grain size of the diameter for nano-titanium can be reduced from 160 nanometers (nm to 80 nm. The results are a 50% reduction of diameter and a 75% improvement of volume. At the same time, the method creates a refined grain size and good mechanical properties in the nano-titanium. The proposed method can be applied to produce any nanomaterial as well as biomaterials.

Bacterial biofilm formation versus mammalian cell growth on titanium-based mono- and bi-functional coating

Directory of Open Access Journals (Sweden)

G Subbiahdoss

2010-05-01

Full Text Available Biomaterials-associated-infections (BAI are serious complications in modern medicine. Although non-adhesive coatings, like polymer-brush coatings, have been shown to prevent bacterial adhesion, they do not support cell growth. Bi-functional coatings are supposed to prevent biofilm formation while supporting tissue integration. Here, bacterial and cellular responses to poly(ethylene glycol (PEG brush-coatings on titanium oxide presenting the integrin-active peptide RGD (arginine-glycine-aspartic acid (bioactive “PEG-RGD” were compared to mono-functional PEG brush-coatings (biopassive “PEG” and bare titanium oxide (TiO2 surfaces under flow. Staphylococcus epidermidis ATCC 35983 was deposited on the surfaces under a shear rate of 11 s-1 for 2 h followed by seeding of U2OS osteoblasts. Subsequently, both S. epidermidis and U2OS cells were grown simultaneously on the surfaces for 48 h under low shear (0.14 s-1. After 2 h, staphylococcal adhesion was reduced to 3.6±1.8 × 103 and 6.0±3.9 × 103 cm-2 on PEG and PEG-RGD coatings respectively, compared to 1.3±0.4 × 105 cm-2 for the TiO2 surface. When allowed to grow for 48 h, biofilms formed on all surfaces. However, biofilms detached from the PEG and PEG-RGD coatings when exposed to an elevated shear (5.6 s-1 U2OS cells neither adhered nor spread on PEG brush-coatings, regardless of the presence of biofilm. In contrast, in the presence of biofilm, U2OS cells adhered and spread on PEG-RGD coatings with a significantly higher surface coverage than on bare TiO2. The detachment of biofilm and the high cell surface coverage revealed the potential significance of PEG-RGD coatings in the context of the “race for the surface” between bacteria and mammalian cells.

Chimeric Peptides as Implant Functionalization Agents for Titanium Alloy Implants with Antimicrobial Properties

Science.gov (United States)

Yucesoy, Deniz T.; Hnilova, Marketa; Boone, Kyle; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2015-04-01

Implant-associated infections can have severe effects on the longevity of implant devices and they also represent a major cause of implant failures. Treating these infections associated with implants by antibiotics is not always an effective strategy due to poor penetration rates of antibiotics into biofilms. Additionally, emerging antibiotic resistance poses serious concerns. There is an urge to develop effective antibacterial surfaces that prevent bacterial adhesion and proliferation. A novel class of bacterial therapeutic agents, known as antimicrobial peptides (AMPs), are receiving increasing attention as an unconventional option to treat septic infection, partly due to their capacity to stimulate innate immune responses and for the difficulty of microorganisms to develop resistance towards them. While host and bacterial cells compete in determining the ultimate fate of the implant, functionalization of implant surfaces with AMPs can shift the balance and prevent implant infections. In the present study, we developed a novel chimeric peptide to functionalize the implant material surface. The chimeric peptide simultaneously presents two functionalities, with one domain binding to a titanium alloy implant surface through a titanium-binding domain while the other domain displays an antimicrobial property. This approach gains strength through control over the bio-material interfaces, a property built upon molecular recognition and self-assembly through a titanium alloy binding domain in the chimeric peptide. The efficiency of chimeric peptide both in-solution and absorbed onto titanium alloy surface was evaluated in vitro against three common human host infectious bacteria, Streptococcus mutans, Staphylococcus epidermidis, and Escherichia coli. In biological interactions such as occur on implants, it is the surface and the interface that dictate the ultimate outcome. Controlling the implant surface by creating an interface composed chimeric peptides may therefore

Effect of plasma surface functionalization on preosteoblast cells spreading and adhesion on a biomimetic hydroxyapatite layer formed on a titanium surface

International Nuclear Information System (INIS)

Myung, Sung Woon; Ko, Yeong Mu; Kim, Byung Hoon

2013-01-01

This study examined the plasma surface modification of biomimetic hydroxyapatite (HAp) formed on a titanium (Ti) surface as well as its influence on the behavior of preosteoblast cells. Ti substrates pre-treated with a plasma-polymerized thin film rich in carboxyl groups were subjected to a biomimetic process in a simulated body fluid solution to synthesize the HAp. The HAp layer grown on Ti substrate was then coated with two types of plasma polymerized acrylic acid and allyl amine thin film. The different types of Ti substrates were characterized by attenuated total reflection Fourier transform infrared spectroscopy, energy dispersive spectroscopy and X-ray diffraction. HAp with a Ca/P ratio from 1.25 to 1.38 was obtained on the Ti substrate and hydrophilic carboxyl (-COOH) and amine (-NH 2 ) functional groups were introduced to its surface. Scanning electron microscopy was used to observe the surface of the HAp coatings and the morphology of MC3T3-E1 cells. These results showed that the -COOH-modified HAp surfaces promoted the cell spreading synergistically by changing the surface morphology and chemical state.-NH 2 modified HAp had the lowest cell spreading and proliferation compared to HAp and -COOH-modified HAp. These results correspond to fluorescein analysis, which showed many more cell spreading of COOH/HAp/Ti surface compared to HAp and NH 2 modified HAp. A MTT assay was used to evaluate cell proliferation. The results showed that the proliferation of MC3T3-E1 cells increased in the order of COOH/HAp/Ti > HAp/Ti > NH 2 /Ti > Ti, corresponding to the effect of cell spreading for 6 days. The change in morphology and the chemical surface properties of the biomaterial via plasma polymerization can affect the behavior of MC3T3-E1 cells.

Effect of plasma surface functionalization on preosteoblast cells spreading and adhesion on a biomimetic hydroxyapatite layer formed on a titanium surface

Energy Technology Data Exchange (ETDEWEB)

Myung, Sung Woon; Ko, Yeong Mu; Kim, Byung Hoon, E-mail: kim5055@chosun.ac.kr

2013-12-15

This study examined the plasma surface modification of biomimetic hydroxyapatite (HAp) formed on a titanium (Ti) surface as well as its influence on the behavior of preosteoblast cells. Ti substrates pre-treated with a plasma-polymerized thin film rich in carboxyl groups were subjected to a biomimetic process in a simulated body fluid solution to synthesize the HAp. The HAp layer grown on Ti substrate was then coated with two types of plasma polymerized acrylic acid and allyl amine thin film. The different types of Ti substrates were characterized by attenuated total reflection Fourier transform infrared spectroscopy, energy dispersive spectroscopy and X-ray diffraction. HAp with a Ca/P ratio from 1.25 to 1.38 was obtained on the Ti substrate and hydrophilic carboxyl (-COOH) and amine (-NH{sub 2}) functional groups were introduced to its surface. Scanning electron microscopy was used to observe the surface of the HAp coatings and the morphology of MC3T3-E1 cells. These results showed that the -COOH-modified HAp surfaces promoted the cell spreading synergistically by changing the surface morphology and chemical state.-NH{sub 2} modified HAp had the lowest cell spreading and proliferation compared to HAp and -COOH-modified HAp. These results correspond to fluorescein analysis, which showed many more cell spreading of COOH/HAp/Ti surface compared to HAp and NH{sub 2} modified HAp. A MTT assay was used to evaluate cell proliferation. The results showed that the proliferation of MC3T3-E1 cells increased in the order of COOH/HAp/Ti > HAp/Ti > NH{sub 2}/Ti > Ti, corresponding to the effect of cell spreading for 6 days. The change in morphology and the chemical surface properties of the biomaterial via plasma polymerization can affect the behavior of MC3T3-E1 cells.

Surface defects in PMD-EDM of titanium alloy, Ti-6246

International Nuclear Information System (INIS)

Sharif, S.; Rival; Noordin, M.Y.

2007-01-01

Titanium alloys which are categorized as lightweight materials, poses greater strength and toughness are usually known to create major challenges during machining. Electrical discharge machining (EDM) which is very prominent amongst the non-conventional machining methods is expected to be used quite extensively in machining titanium alloys. EDM process is known to cause surface damaged layers which consists of three types of surfaces; spattered, recast and heat affected zone. This project was undertaken to study the machining performance of EDM and powder mixed dielectric-electrical discharge machining (PMD E DM) in machining Ti-6246 with respect to the surface integrity of machined surface by using copper tungsten (CuW) electrode. The machining parameters considered are voltage (V), current (I), pulse on time(T on ), interval time (T off ) and concentration of the SiC powder (C) in dielectric fluid. The respected responses investigated include surface alteration and overcut. It was found that PMD-EDM process produced less damaging effect on the surface layer of the machined surface and widened the overcut. (author)

Effect of amorphous fluorinated coatings on photocatalytic properties of anodized titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Persico, Federico [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131, Milano (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9, 50121 Firenze (Italy); Sansotera, Maurizio, E-mail: maurizio.sansotera@polimi.it [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131, Milano (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9, 50121 Firenze (Italy); Diamanti, Maria Vittoria [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131, Milano (Italy); Magagnin, Luca; Venturini, Francesco; Navarrini, Walter [Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Politecnico di Milano, via Mancinelli 7, 20131, Milano (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via G. Giusti, 9, 50121 Firenze (Italy)

2013-10-31

The photocatalytic activity promoted by anodized titanium surfaces coated with different amorphous perfluoropolymers was evaluated. A copolymer between tetrafluoroethylene and perfluoro-4-trifluoromethoxy-1,3-dioxole and two perfluoropolyethers containing ammonium phosphate and triethoxysilane functionalities, respectively, were tested as coating materials. These coatings revealed good adhesion to the anodized titanium substrate and conferred to it both hydrophobicity and oleophobicity. The photocatalytic activity of the coating on anodized titanium was evaluated by monitoring the degradation of stearic acid via Infrared spectroscopy. The degradation rate of stearic acid was reduced but not set to zero by the presence of the fluorinated coatings, leading to the development of advanced functional coatings. The morphological variations of the coatings as a result of photocatalysis were also determined by atomic force microscopy. - Highlights: • Coated anodized titanium surfaces show a decreased wettability. • Evaluation of the stability of perfluorinated coatings towards photocatalysis. • Amorphous perfluorinated coatings do not hinder photocatalytic activity.

Bone integration capability of nanopolymorphic crystalline hydroxyapatite coated on titanium implants

Directory of Open Access Journals (Sweden)

Suzuki T

2012-02-01

Full Text Available Masahiro Yamada*, Takeshi Ueno*, Naoki Tsukimura, Takayuki Ikeda, Kaori Nakagawa, Norio Hori, Takeo Suzuki, Takahiro OgawaLaboratory of Bone and Implant Sciences, The Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry, UCLA School of Dentistry, Los Angeles, CA, USA *These authors contributed equally to this workAbstract: The mechanism by which hydroxyapatite (HA-coated titanium promotes bone–implant integration is largely unknown. Furthermore, refining the fabrication of nanostructured HA to the level applicable to the mass production process for titanium implants is challenging. This study reports successful creation of nanopolymorphic crystalline HA on microroughened titanium surfaces using a combination of flame spray and low-temperature calcination and tests its biological capability to enhance bone–implant integration. Sandblasted microroughened titanium implants and sandblasted + HA-coated titanium implants were subjected to biomechanical and histomorphometric analyses in a rat model. The HA was 55% crystallized and consisted of nanoscale needle-like architectures developed in various diameters, lengths, and orientations, which resulted in a 70% increase in surface area compared to noncoated microroughened surfaces. The HA was free from impurity contaminants, with a calcium/phosphorus ratio of 1.66 being equivalent to that of stoichiometric HA. As compared to microroughened implants, HA-coated implants increased the strength of bone–implant integration consistently at both early and late stages of healing. HA-coated implants showed an increased percentage of bone–implant contact and bone volume within 50 µm proximity of the implant surface, as well as a remarkably reduced percentage of soft tissue intervention between bone and the implant surface. In contrast, bone volume outside the 50 µm border was lower around HA-coated implants. Thus, this study

Mg-containing hydroxyapatite coatings produced by plasma electrolytic oxidation of titanium

Energy Technology Data Exchange (ETDEWEB)

Antonio, Cesar Augusto; Rangel, Elidiane Cipriano; Durrant, Steven Frederick; Cruz, Nilson Cristino da, E-mail: cesar.augustoa@hotmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil). Lab. de Plasmas Tecnologicos; Delgado-Silva, Adriana de Oliveira [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil); Tabacniks, Manfredo H. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

2017-07-15

Plasma Electrolytic Oxidation (PEO) is promising for the processing of biomaterials because it enables the production of surfaces with adjustable composition and structure. In this work, aimed at the improvement of the bioactivity of titanium, PEO has been used to grow calcium phosphide coatings on titanium substrates. The effects of the addition of magnesium acetate to the electrolytes on the composition of the coatings produced during 120 s on Ti disks using bipolar voltage pulses and solutions of calcium and magnesium acetates and sodium glycerophosphate as electrolytes have been studied. Scanning electron microscopy, X-ray energy dispersive spectroscopy, Rutherford backscattering spectroscopy, X-ray diffractometry with Rietveld refinement and profilometry were used to characterize the modified samples. Coatings composed of nearly 50 % of Mg-doped hydroxyapatite have been produced. In certain conditions up to 4% Mg can be incorporated into the coating without any observable significant structural modifications of the hydroxyapatite. (author)

Optical detections from worn and unworn titanium compound surfaces

DEFF Research Database (Denmark)

Rasmussen, Inge Lise; Guibert, M.; Martin, J.-M.

2010-01-01

of a titanium nitride (TiN) layer we obtain an increase in the reflected light as a result of wear. The relative change of reflectance of light from the tribological TiAlN coated surface to the underlying layer of TiN is similar for non-worn surfaces and for surfaces exposed to an abrasive wear process...... of a residual thickness of realistic tribological coatings prior to complete wear....

Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces

International Nuclear Information System (INIS)

Wang Chengyue; Zhao Baohong; Ai Hongjun; Wang Yiwei

2008-01-01

This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants

Pectin nanocoating of titanium implant surfaces - an experimental study in rabbits

DEFF Research Database (Denmark)

Gurzawska, Katarzyna Aleksandra; Dirscherl, Kai; Jørgensen, Bodil

2017-01-01

that may increase adhesion of bone proteins, and bone cells at the implant surface. Nanocoating with pectins, plant cell wall-derived polysaccharides, is frequently done using rhamnogalacturonan-I (RG-I). AIM: The aim of the study was to evaluate the effect of nanocoating titanium implants with plant cell...... wall-derived rhamnogalacturonan-I, on bone healing and osseointegration. MATERIAL AND METHODS: Machined titanium implants were coated with three modifications of rhamnogalacturonan-I (RG-I). Chemical and physical surface properties were examined before insertion of nanocoated implants (n = 96....... The bone response to the nanocoated implants was analyzed qualitatively and quantitatively after 2, 4, 6, and 8 weeks of healing using light microscopy and histomorphometric methods. RESULTS: The RG-I coating influenced the surface chemical composition; wettability and roughness, making the surface more...

Biomaterials in Cardiovascular Research: Applications and Clinical Implications

Directory of Open Access Journals (Sweden)

Saravana Kumar Jaganathan

2014-01-01

Full Text Available Cardiovascular biomaterials (CB dominate the category of biomaterials based on the demand and investments in this field. This review article classifies the CB into three major classes, namely, metals, polymers, and biological materials and collates the information about the CB. Blood compatibility is one of the major criteria which limit the use of biomaterials for cardiovascular application. Several key players are associated with blood compatibility and they are discussed in this paper. To enhance the compatibility of the CB, several surface modification strategies were in use currently. Some recent applications of surface modification technology on the materials for cardiovascular devices were also discussed for better understanding. Finally, the current trend of the CB, endothelization of the cardiac implants and utilization of induced human pluripotent stem cells (ihPSCs, is also presented in this review. The field of CB is growing constantly and many new investigators and researchers are developing interest in this domain. This review will serve as a one stop arrangement to quickly grasp the basic research in the field of CB.

Surface hardening of titanium alloys with melting depth controlled by heat sink

Science.gov (United States)

Oden, Laurance L.; Turner, Paul C.

1995-01-01

A process for forming a hard surface coating on titanium alloys includes providing a piece of material containing titanium having at least a portion of one surface to be hardened. The piece having a portion of a surface to be hardened is contacted on the backside by a suitable heat sink such that the melting depth of said surface to be hardened may be controlled. A hardening material is then deposited as a slurry. Alternate methods of deposition include flame, arc, or plasma spraying, electrodeposition, vapor deposition, or any other deposition method known by those skilled in the art. The surface to be hardened is then selectively melted to the desired depth, dependent on the desired coating thickness, such that a molten pool is formed of the piece surface and the deposited hardening material. Upon cooling a hardened surface is formed.

Effect of Q-switched Laser Surface Texturing of Titanium on Osteoblast Cell Response

Science.gov (United States)

Voisey, K. T.; Scotchford, C. A.; Martin, L.; Gill, H. S.

Titanium and its alloys are important biomedical materials. It is known that the surface texture of implanted medical devices affects cell response. Control of cell response has the potential to enhance fixation of implants into bone and, in other applications, to prevent undesired cell adhesion. The potential use of a 100W Q-switched YAG laser miller (DMG Lasertec 60 HSC) for texturing titanium is investigated. A series of regular features with dimensions of the order of tens of micrometers are generated in the surface of titanium samples and the cell response to these features is determined. Characterisation of the laser milled features reveals features with a lengthscale of a few microns superposed on the larger scale structures, this is attributed to resolidification of molten droplets generated and propelled over the surface by individual laser pulses. The laser textured samples are exposed to osteoblast cells and it is seen that cells do respond to the features in the laser textured surfaces.

Sol–gel synthesis of tantalum oxide and phosphonic acid-modified carbon nanotubes composite coatings on titanium surfaces

International Nuclear Information System (INIS)

Maho, Anthony; Detriche, Simon; Delhalle, Joseph; Mekhalif, Zineb

2013-01-01

Carbon nanotubes used as fillers in composite materials are more and more appreciated for the outstanding range of accessible properties and functionalities they generate in numerous domains of nanotechnologies. In the framework of biological and medical sciences, and particularly for orthopedic applications and devices (prostheses, implants, surgical instruments, …), titanium substrates covered by tantalum oxide/carbon nanotube composite coatings have proved to constitute interesting and successful platforms for the conception of solid and biocompatible biomaterials inducing the osseous regeneration processes (hydroxyapatite growth, osteoblasts attachment). This paper describes an original strategy for the conception of resistant and homogeneous tantalum oxide/carbon nanotubes layers on titanium through the introduction of carbon nanotubes functionalized by phosphonic acid moieties (-P(=O)(OH) 2 ). Strong covalent C-P bonds are specifically inserted on their external sidewalls with a ratio of two phosphonic groups per anchoring point. Experimental results highlight the stronger “tantalum capture agent” effect of phosphonic-modified nanotubes during the sol–gel formation process of the deposits compared to nanotubes bearing oxidized functions (-OH, -C=O, -C(=O)OH). Particular attention is also paid to the relative impact of the rate of functionalization and the dispersion degree of the carbon nanotubes in the coatings, as well as their wrapping level by the tantalum oxide matrix material. The resulting effect on the in vitro growth of hydroxyapatite is also evaluated to confirm the primary osseous bioactivity of those materials. Chemical, structural and morphological features of the different composite deposits described herein are assessed by X-ray photoelectron spectroscopy (XPS), scanning (SEM) and transmission (TEM) electronic microscopies, energy dispersive X-rays analysis (EDX) and peeling tests. Highlights: ► Formation of tantalum/carbon nanotube

Sol–gel synthesis of tantalum oxide and phosphonic acid-modified carbon nanotubes composite coatings on titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Maho, Anthony [Laboratory of Chemistry and Electrochemistry of Surfaces, University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Fonds pour la Formation à la Recherche dans l' Industrie et dans l' Agriculture (FRIA), Rue d' Egmont 5, B-1000 Bruxelles (Belgium); Detriche, Simon; Delhalle, Joseph [Laboratory of Chemistry and Electrochemistry of Surfaces, University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium); Mekhalif, Zineb, E-mail: zineb.mekhalif@fundp.ac.be [Laboratory of Chemistry and Electrochemistry of Surfaces, University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur (Belgium)

2013-07-01

Carbon nanotubes used as fillers in composite materials are more and more appreciated for the outstanding range of accessible properties and functionalities they generate in numerous domains of nanotechnologies. In the framework of biological and medical sciences, and particularly for orthopedic applications and devices (prostheses, implants, surgical instruments, …), titanium substrates covered by tantalum oxide/carbon nanotube composite coatings have proved to constitute interesting and successful platforms for the conception of solid and biocompatible biomaterials inducing the osseous regeneration processes (hydroxyapatite growth, osteoblasts attachment). This paper describes an original strategy for the conception of resistant and homogeneous tantalum oxide/carbon nanotubes layers on titanium through the introduction of carbon nanotubes functionalized by phosphonic acid moieties (-P(=O)(OH){sub 2}). Strong covalent C-P bonds are specifically inserted on their external sidewalls with a ratio of two phosphonic groups per anchoring point. Experimental results highlight the stronger “tantalum capture agent” effect of phosphonic-modified nanotubes during the sol–gel formation process of the deposits compared to nanotubes bearing oxidized functions (-OH, -C=O, -C(=O)OH). Particular attention is also paid to the relative impact of the rate of functionalization and the dispersion degree of the carbon nanotubes in the coatings, as well as their wrapping level by the tantalum oxide matrix material. The resulting effect on the in vitro growth of hydroxyapatite is also evaluated to confirm the primary osseous bioactivity of those materials. Chemical, structural and morphological features of the different composite deposits described herein are assessed by X-ray photoelectron spectroscopy (XPS), scanning (SEM) and transmission (TEM) electronic microscopies, energy dispersive X-rays analysis (EDX) and peeling tests. Highlights: ► Formation of tantalum

Adherence of extracellular matrix components to modified surfaces of titanium alloys

International Nuclear Information System (INIS)

Stelzer, C; Uhlmann, E; Meinke, M; Lademann, J; Hansen, U

2009-01-01

The adherence of biological materials on metal surfaces is of special importance in biology and medicine. The underlying interactions between surface and biological materials (e.g. extracellular matrix components or cells) are responsible for the application as a medical device. Numerous products are made of pure titanium and titanium alloys. This paper shows the influence of a laser production technology on machined surfaces of TiAl 6 V 4 and the resulting adherence of biological material on the basis of the surface characterisation. In this study, different machined TiAl 6 V 4 surfaces were used for coatings with extracellular matrix components. For this process, different coating with collagen I monomers and a complex mixture of extracellular matrix proteins derived from the dermal-epidermal basement membrane zone were analysed. The efficiency of the coating was analysed by different methods and the results are presented in this paper

Plasma Electrolytic Oxidation of Titanium Implant Surfaces: Microgroove-Structures Improve Cellular Adhesion and Viability.

Science.gov (United States)

Hartjen, Philip; Hoffmann, Alexia; Henningsen, Anders; Barbeck, Mike; Kopp, Alexander; Kluwe, Lan; Precht, Clarissa; Quatela, Olivia; Gaudin, Robert; Heiland, Max; Friedrich, Reinhard E; Knipfer, Christian; Grubeanu, Daniel; Smeets, Ralf; Jung, Ole

2018-01-01

Plasma electrolytic oxidation (PEO) is an established electrochemical treatment technique that can be used for surface modifications of metal implants. In this study we to treated titanium implants with PEO, to examine the resulting microstructure and to characterize adhesion and viability of cells on the treated surfaces. Our aim was to identify an optimal surface-modification for titanium implants in order to improve soft-tissue integration. Three surface-variants were generated on titanium alloy Ti6Al4V by PEO-treatment. The elemental composition and the microstructures of the surfaces were characterized using energy dispersive X-ray spectroscopy, scanning electron microscopy and profilometry. In vitro cytocompatibility of the surfaces was assessed by seeding L929 fibroblasts onto them and measuring the adhesion, viability and cytotoxicity of cells by means of live/dead staining, XTT assay and LDH assay. Electron microscopy and profilometry revealed that the PEO-surface variants differed largely in microstructure/topography, porosity and roughness from the untreated control material as well as from one another. Roughness was generally increased after PEO-treatment. In vitro, PEO-treatment led to improved cellular adhesion and viability of cells accompanied by decreased cytotoxicity. PEO-treatment provides a promising strategy to improve the integration of titanium implants with surrounding tissues. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

The Role of Titanium Surface Microtopography on Adhesion, Proliferation, Transformation, and Matrix Deposition of Corneal Cells.

Science.gov (United States)

Zhou, Chengxin; Lei, Fengyang; Chodosh, James; Paschalis, Eleftherios I

2016-04-01

Titanium (Ti) is an excellent implantable biomaterial that can be further enhanced by surface topography optimization. Despite numerous data from orthopedics and dentistry, the effect of Ti surface topography on ocular cells is still poorly understood. In light of the recent adaptation of Ti in the Boston Keratoprosthesis artificial cornea, we attempted to perform an extended evaluation of the effect of Ti surface topography on corneal cell adhesion, proliferation, cytotoxicity, transformation, and matrix deposition. Different surface topographies were generated on medical grade Ti-6Al-4V-ELI (extra-low interstitial), with linearly increased roughness (polished to grit blasted). Biological response was evaluated in vitro using human corneal limbal epithelial (HCLE) cells, stromal fibroblasts (HCF), and endothelial cells (HCEnC). None of the Ti surface topographies caused cytotoxicity to any of the three corneal cell types. However, rough Ti surface inhibited HCLE and HCF cell adhesion and proliferation, while HCEnC proliferation was unaffected. Long-term experiments with HCF revealed that rough Ti surface with R(a) (the arithmetic average of the profile height from the mean line) ≥ 1.15 μm suppressed HCF focal adhesion kinase phosphorylation, changed fibroblast morphology, and caused less aligned and reduced deposition of collagen matrix as compared to smooth Ti (R(a) ≤ 0.08 μm). In the presence of transforming growth factor β1 (TGFβ1) stimulation, rough Ti inhibited alpha-smooth muscle actin (α-SMA) expression and collagen deposition, leading to decreased myofibroblast transformation and disorganization of the collagen fibrils as compared to smooth Ti. This study suggests that Ti surface topography regulates corneal cell behavior in a tissue-dependent manner that varies across the corneal strata. Contrary to the accepted paradigm, smooth surface topography can enhance cell adhesion and proliferation and increase matrix deposition by corneal cells.

Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Cao, Huiliang; Qin, Hui; Zhao, Yaochao; Jin, Guodong; Lu, Tao; Meng, Fanhao; Zhang, Xianlong; Liu, Xuanyong

2016-02-22

Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.

Nano-thick calcium oxide armed titanium: boosts bone cells against methicillin-resistant Staphylococcus aureus

Science.gov (United States)

Cao, Huiliang; Qin, Hui; Zhao, Yaochao; Jin, Guodong; Lu, Tao; Meng, Fanhao; Zhang, Xianlong; Liu, Xuanyong

2016-02-01

Since the use of systemic antibiotics for preventing acute biomaterial-associated infections (BAIs) may build up bacterial resistance and result in huge medical costs and unpredictable mortality, new precaution strategies are required. Here, it demonstrated that titanium armed with a nano-thick calcium oxide layer was effective on averting methicillin-resistant Staphylococcus aureus (MRSA) infections in rabbits. The calcium oxide layer was constructed by, firstly, injecting of metallic calcium into titanium via a plasma immersion ion implantation process, and then transforming the outer most surface into oxide by exposing to the atmosphere. Although the calcium oxide armed titanium had a relative low reduction rate (~74%) in growth of MRSA in vitro, it could markedly promote the osteogenic differentiation of bone marrow stem cells (BMSCs), restore local bone integration against the challenge of MRSA, and decrease the incidence of MRSA infection with a rate of 100% (compared to the titanium control). This study demonstrated for the first time that calcium, as one of the major elements in a human body, could be engineered to avert MRSA infections, which is promising as a safe precaution of disinfection for implantable biomedical devices.

Effects of intraoral aging on surface properties of coated nickel-titanium archwires.

Science.gov (United States)

Rongo, Roberto; Ametrano, Gianluca; Gloria, Antonio; Spagnuolo, Gianrico; Galeotti, Angela; Paduano, Sergio; Valletta, Rosa; D'Antò, Vincenzo

2014-07-01

To evaluate the effects of intraoral aging on surface properties of esthetic and conventional nickel-titanium (NiTi) archwires. Five NiTi wires were considered for this study (Sentalloy, Sentalloy High Aesthetic, Superelastic Titanium Memory Wire, Esthetic Superelastic Titanium Memory Wire, and EverWhite). For each type of wire, four samples were analyzed as received and after 1 month of clinical use by an atomic force microscope (AFM) and a scanning electronic microscope (SEM). To evaluate sliding resistance, two stainless steel plates with three metallic or three monocrystalline brackets, bonded in passive configuration, were manufactured; four as-received and retrieved samples for every wire were pulled five times at 5 mm/min for 1 minute by means of an Instron 5566, recording the greatest friction value (N). Data were analyzed by one-way analysis of variance and by Student's t-test. After clinical use, surface roughness increased considerably. The SEM images showed homogeneity for the as-received control wires; however, after clinical use esthetic wires exhibited a heterogeneous surface with craters and bumps. The lowest levels of friction were observed with the as-received Superelastic Titanium Memory Wire on metallic brackets. When tested on ceramic brackets, all the wires exhibited an increase in friction (t-test; P Sentalloy, showed a statistically significant increase in friction between the as-received and retrieved groups (t-test; P < .05). Clinical use of the orthodontic wires increases their surface roughness and the level of friction.

Mechanical properties of open-cell metallic biomaterials manufactured using additive manufacturing

International Nuclear Information System (INIS)

Campoli, G.; Borleffs, M.S.; Amin Yavari, S.; Wauthle, R.; Weinans, H.; Zadpoor, A.A.

2013-01-01

Highlights: ► Finite element (FE) models were used to predict the mechanical properties of porous biomaterials. ► Porous materials were produced using additive manufacturing techniques. ► Manufacturing irregularities need to be implemented in FE models. ► FE models are more accurate than analytical models in predicting mechanical properties. - Abstract: An important practical problem in application of open-cell porous biomaterials is the prediction of the mechanical properties of the material given its micro-architecture and the properties of its matrix material. Although analytical methods can be used for this purpose, these models are often based on several simplifying assumptions with respect to the complex architecture and cannot provide accurate prediction results. The aim of the current study is to present finite element (FE) models that can predict the mechanical properties of porous titanium produced using selective laser melting or selective electron beam melting. The irregularities caused by the manufacturing process including structural variations of the architecture are implemented in the FE models using statistical models. The predictions of FE models are compared with those of analytical models and are tested against experimental data. It is shown that, as opposed to analytical models, the predictions of FE models are in agreement with experimental observations. It is concluded that manufacturing irregularities significantly affect the mechanical properties of porous biomaterials

Effective atomic numbers (Z_e_f_f) of based calcium phosphate biomaterials: a comparative study

International Nuclear Information System (INIS)

Fernandes Zenobio, Madelon Aparecida; Gonçalves Zenobio, Elton; Silva, Teógenes Augusto da; Socorro Nogueira, Maria do

2016-01-01

This study determined the interaction of radiation parameters of four biomaterials as attenuators to measure the transmitted X-rays spectra, the mass attenuation coefficient and the effective atomic number by spectrometric system comprising the CdTe detector. The biomaterial BioOss"® presented smaller mean energy than the other biomaterials. The μ/ρ and Z_e_f_f of the biomaterials showed their dependence on photon energy. The data obtained from analytical methods of x-ray spectra, µ/ρ and Z_e_f_f_, using biomaterials as attenuators, demonstrated that these materials could be used as substitutes for dentin, enamel and bone. Further, they are determinants for the characterization of the radiation in tissues or equivalent materials. - Highlights: • Measure of the transmitted x-rays spectra using based calcium phosphate biomaterials as attenuators. • Determination effective atomic number using four dental biomaterials. • Determination of the mass attenuation coefficient (µ/ρ) of the biomaterials samples calculated by the WinXCOM software. • Determination of the chemical composition of calcium phosphate biomaterials.

Solid-state (49/47)Ti NMR of titanium-based MCM-41 hybrid materials.

Science.gov (United States)

Ballesteros, Ruth; Fajardo, Mariano; Sierra, Isabel; Force, Carmen; del Hierro, Isabel

2009-11-03

Titanium solid-state NMR spectroscopy data for a series of organic-inorganic titanium MCM-41 based materials have been collected. These materials have been synthesized by first modifying the mesoporous silica MCM-41 in one step with a mixture of silanes: a triazine propyl triethoxysilane acting as functional linker and methyltrimethoxysilane or hexamethyldisilizane as capped agents to mask the remaining silanol groups. Second, the appropiate titanium precursor Ti(OPr(i))(4), [{Ti(OPr(i))(3)(OMent)}(2)] (OMent = 1R,2S,5R-(-)-menthoxo), Ti(OPr(i))(4), or [Ti(eta(5)-C(5)HMe(4))Cl(3)], has been immobilized by reaction with the modified MCM-41. Finally, after Ti(OPr(i))(4) immobilization onto the organomodified support the reaction with the chiral (+)-diethyl-l-tartrate was accomplished. The materials without functional linker have been also prepared by reaction in one step of the capped agent and the titanium precursor with the mesoporous silica. Relevant correlations of titanium NMR resonance chemical shifts and line widths can be inferred depending on different factors. The immobilization procedure used to prepare titanium-based MCM-41 hybrid materials and the choice of the silylating reagents employed to mask the silanol groups present on the silica surfaces produce significant differences in the Ti NMR spectra. Furthermore, depending on the electronic and sterical influence of the substituents directly attached to the titanium center, chemical shifts and line widths are modified providing novel information about titanium structure.

Study of the microstructural and mechanical properties of titanium-niobium-zirconium based alloys processed with hydrogen and powder metallurgy for use in dental implants

International Nuclear Information System (INIS)

Duvaizem, Jose Helio

2009-01-01

Hydrogen has been used as pulverization agent in alloys based on rare earth and transition metals due to its extremely high diffusion rate even on low temperatures. Such materials are used on hydrogen storage dispositives, generation of electricity or magnetic fields, and are produced by a process which the first step is the transformation of the alloy in fine powder by miling. Besides those, hydrogenium is also being used to obtain alloys based on titanium - niobium - zirconium in the pulverization. Powder metallurgy is utilized on the production of these alloys, making it possible to obtain structures with porous surface as result, requirement for its application as biomaterials. Other advantages of powder metallurgy usage include better surface finish and better microstructural homogeneity. In this work samples were prepared in the Ti-13Nb-13Zr composition. The hydrogenation was performed at 700 degree C, 600 degree C, and 500 degree C for titanium, niobium and zirconium respectively. After hydrogenation, the milling stage was carried out on high energy planetary ball milling with 200rpm during 90 minutes, and also in conventional ball milling for 30 hours. Samples were pressed in uniaxial press, followed by isostatic cold press, and then sintered at 1150 degree C for 7-13 hours. Microstructural properties of the samples were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction. Mechanical and structural properties determined were density, microhardness and moduli of elasticity. The sample sintered at 1150 degree C for 7h, hydrogenated using 10.000 mbar and produced by milling on high energy planetary ball milling presented the best mechanical properties and microstructural homogeneity. (author)

Corrosion behaviour of electropolished AISI 316L austenitic biomaterial in physiological solution

Science.gov (United States)

Zatkalíková, V.; Markovičová, L.; Škorvanová, M.

2017-11-01

Due to suitable mechanical properties, satisfactory corrosion resistance and relatively low cost, austenitic stainless steels are important biomaterials for manufacture of implants and various medical instruments and devices. Their corrosion properties and biocompatibility are significantly affected by protective passive surface film quality, which depends on used mechanical and chemical surface treatment. This article deals with corrosion resistance of AISI 316L stainless steel, which is the most widely used Cr-Ni-Mo austenitic biomaterial. Corrosion behaviour of five various surfaces (original, electropolished, three surfaces with combined treatment finished by electropolishing) is evaluated on the bases of cyclic potentiodynamic polarization tests performed in physiological solution at the temperature of 37± 0.5 °C.

An XPS study on the attachment of triethoxsilylbutyraldehyde to two titanium surfaces as a way to bond chitosan

Energy Technology Data Exchange (ETDEWEB)

Martin, Holly J. [Dave C. Swalm School of Chemical Engineering, James Worth Bagley College of Engineering, Mississippi State University, Box 9595, Mississippi State, MS 39762 (United States)], E-mail: hjp2@msstate.edu; Schulz, Kirk H. [Dave C. Swalm School of Chemical Engineering, James Worth Bagley College of Engineering, Mississippi State University, Box 9595, Mississippi State, MS 39762 (United States); Bumgardner, Joel D. [Department of Biomedical Engineering, Herff College of Engineering, University of Memphis, 330 Engineering Technology Building, Memphis, TN 38152 (United States); Walters, Keisha B. [Dave C. Swalm School of Chemical Engineering, James Worth Bagley College of Engineering, Mississippi State University, Box 9595, Mississippi State, MS 39762 (United States)

2008-05-30

A bioactive coating has the ability to create a strong interface between bone tissue and implant. Chitosan, a biopolymer derived from the exoskeletons of shellfish, exhibits many bioactive properties that make it an ideal material for use as a coating such as antibacterial, biodegradable, non-toxic, and the ability to attract and promote bone cell growth and organized bone formation. A previous study reported on the bonding of chitosan to a titanium surface using a three-step process. In the current study, 86.4% de-acetylated chitosan coatings were bound to implant quality titanium in a two-step process that involved the deposition of triethoxsilylbutyraldehyde (TESBA) in toluene, followed by a reaction between the aldehyde of TESBA with chitosan. The chitosan coatings were examined on two different metal treatments to determine if any major differences in the ability of titanium to bind chitosan could be detected. The surface of the titanium metal and the individual reaction steps were examined using X-ray photoelectron spectroscopy (XPS). Following the deposition of TESBA, significant changes were seen in the amounts of oxygen, silicon, carbon, and titanium present on the titanium surface, which were consistent with the anticipated reaction steps. It was demonstrated that more TESBA was bound to the piranha-treated titanium surface as compared to the passivated titanium surface. The two different silane molecules, aminopropyltriethoxysilane (APTES) and TESBA, did not affect the chemistry of the resultant chitosan films. XPS showed that both the formation of unwanted polysiloxanes and the removal of the reactive terminal groups were prevented by using toluene as the carrier solvent to bond TESBA to the titanium surfaces, instead of an aqueous solvent. Qualitatively, the chitosan films demonstrated improved adhesion after using toluene, as the films remained attached to the titanium surface even when placed under the ultra-high vacuum necessary for XPS, unlike the

An XPS study on the attachment of triethoxsilylbutyraldehyde to two titanium surfaces as a way to bond chitosan

International Nuclear Information System (INIS)

Martin, Holly J.; Schulz, Kirk H.; Bumgardner, Joel D.; Walters, Keisha B.

2008-01-01

A bioactive coating has the ability to create a strong interface between bone tissue and implant. Chitosan, a biopolymer derived from the exoskeletons of shellfish, exhibits many bioactive properties that make it an ideal material for use as a coating such as antibacterial, biodegradable, non-toxic, and the ability to attract and promote bone cell growth and organized bone formation. A previous study reported on the bonding of chitosan to a titanium surface using a three-step process. In the current study, 86.4% de-acetylated chitosan coatings were bound to implant quality titanium in a two-step process that involved the deposition of triethoxsilylbutyraldehyde (TESBA) in toluene, followed by a reaction between the aldehyde of TESBA with chitosan. The chitosan coatings were examined on two different metal treatments to determine if any major differences in the ability of titanium to bind chitosan could be detected. The surface of the titanium metal and the individual reaction steps were examined using X-ray photoelectron spectroscopy (XPS). Following the deposition of TESBA, significant changes were seen in the amounts of oxygen, silicon, carbon, and titanium present on the titanium surface, which were consistent with the anticipated reaction steps. It was demonstrated that more TESBA was bound to the piranha-treated titanium surface as compared to the passivated titanium surface. The two different silane molecules, aminopropyltriethoxysilane (APTES) and TESBA, did not affect the chemistry of the resultant chitosan films. XPS showed that both the formation of unwanted polysiloxanes and the removal of the reactive terminal groups were prevented by using toluene as the carrier solvent to bond TESBA to the titanium surfaces, instead of an aqueous solvent. Qualitatively, the chitosan films demonstrated improved adhesion after using toluene, as the films remained attached to the titanium surface even when placed under the ultra-high vacuum necessary for XPS, unlike the

Structure, composition and morphology of bioactive titanate layer on porous titanium surfaces

Science.gov (United States)

Li, Jinshan; Wang, Xiaohua; Hu, Rui; Kou, Hongchao

2014-07-01

A bioactive coating was produced on pore surfaces of porous titanium samples by an amendatory alkali-heat treatment method. Porous titanium was prepared by powder metallurgy and its porosity and average size were 45% and 135 μm, respectively. Coating morphology, coating structure and phase constituents were examined by SEM, XPS and XRD. It was found that a micro-network structure with sizes of cells, and redundant Ca ion was detected in the titanate layer. The concentration distribution of Ti, O, Ca and Na in the coating showed a compositional gradient from the intermediate layer toward the outer surface. These compositional gradients indicate that the coating bonded to Ti substrate without a distinct interface. After immersion into the SBF solution for 3 days, a bone-like carbonate-hydroxylapatite showing a good biocompatibility was detected on the coating surface. And the redundant Ca advanced the bioactivity of the coating. Thus, the present modification is expected to allow the use of the bioactive porous titanium as artificial bones even under load-bearing conditions.

Synthesis of a nanocomposite biomaterial for implant tissue engineering

OpenAIRE

Santos Montes, Angélica

2015-01-01

In order to improve health and quality of life, the challenge to develop new biomaterials has become extremely relevant. In this project, our main objective is to obtain a nanocomposite biopolymer that serves as a temporal synthetic extracellular matrix for cell growth and tissue regeneration. This matrix consists of a hydrogel lm of chitosan or agarose doped with di erent ceramic nanoparticles: titanium dioxide (TiO2) and aluminum oxide (Al2O3). Once developed, this composite will be tested...

Improved thrombogenicity on oxygen etched Ti6Al4V surfaces

International Nuclear Information System (INIS)

Riedel, Nicholas A.; Smith, Barbara S.; Williams, John D.; Popat, Ketul C.

2012-01-01

Thrombus formation on blood contacting biomaterials continues to be a key factor in initiating a critical mode of failure in implantable devices, requiring immediate attention. In the interest of evaluating a solution for one of the most widely used biomaterials, titanium and its alloys, this study focuses on the use of a novel surface oxidation treatment to improve the blood compatibility. This study examines the possibility of using oblique angle ion etching to produce a high quality oxide layer that enhances blood compatibility on medical grade titanium alloy Ti6Al4V. An X-ray photoelectron spectroscopy (XPS) analysis of these oxygen-rich surfaces confirmed the presence of TiO 2 peaks and also indicated increased surface oxidation as well as a reduction in surface defects. After 2 h of contact with whole human plasma, the oxygen etched substrates demonstrated a reduction in both platelet adhesion and activation as compared to bare titanium substrates. The whole blood clotting behavior was evaluated for up to 45 min, showing a significant decrease in clot formation on oxygen etched substrates. Finally, a bicinchoninic acid (BCA) total protein assay and XPS were used to evaluate the degree of key blood serum protein (fibrinogen, albumin, immunoglobulin G) adsorption on the substrates. The results showed similar protein levels for both the oxygen etched and control substrates. These results indicate that oblique angle oxygen etching may be a promising method to increase the thrombogenicity of Ti6Al4V. - Highlights: ►Oblique angle oxygen ion etching creates a high quality, uniform oxide surface. ►Oxygen etched substrates showed fewer adhered platelets. ►Platelet activation was reduced by the improved oxide surface. ►Oxygen etched substrates exhibited increased whole blood clotting times. ►Although clotting reductions were seen, protein adsorption remained similar.

Electrochemical and surface characterization of a nickel-titanium alloy

NARCIS (Netherlands)

Wever, Dirk; Veldhuizen, AG; de Vries, J; Busscher, HJ; Uges, DRA; van Horn, James

1998-01-01

For clinical implantation purposes of shape memory metals the nearly equiatomic nickel-titanium (NiTi) alloy is generally used. In this study, the corrosion properties and surface characteristics of this alloy were investigated and compared with two reference controls, AISI 316 LVM stainless steel

Teeth and bones: applications of surface science to dental materials and related biomaterials

Science.gov (United States)

Jones, F. H.

2001-05-01

Recent years have seen a considerable upsurge in publications concerning the surface structure and chemistry of materials with biological or biomedical applications. Within the body, gas-solid interactions become relatively less significant and solid-liquid or solid-solid interfaces dominate, providing new challenges for the surface scientist. The current paper aims to provide a timely review of the use of surface analysis and modification techniques within the biomaterials field. A broad overview of applications in a number of related areas is given with particular attention focusing on those materials commonly encountered in dentistry and oral or maxillofacial implantology. Several specific issues of current interest are discussed. The interaction between synthetic and natural solids, both in the oral environment and elsewhere in the body is important in terms of adhesion, related stresses and strains and ultimately the longevity of a dental restoration, biomedical implant, or indeed the surrounding tissue. Exposure to body fluids, of course, can also affect stability, leading to the degradation or corrosion of materials within the body. Whilst this could potentially be harmful, e.g., if cytotoxic elements are released, it may alternatively provide a route to the preferential release of beneficial substances. Furthermore, in some cases, the controlled disintegration of a biomaterial is desirable, allowing the removal of an implant, e.g., without the need for further surgery. The presence of cells in the immediate bioenvironment additionally complicates the situation. A considerable amount of current research activity is targeted at the development of coatings or surface treatments to encourage tissue growth. If this is to be achieved by stimulating enhanced cell productivity, determination of the relationship between cell function and surface composition is essential.

Human Vitronectin-Derived Peptide Covalently Grafted onto Titanium Surface Improves Osteogenic Activity: A Pilot In Vivo Study on Rabbits.

Science.gov (United States)

Cacchioli, Antonio; Ravanetti, Francesca; Bagno, Andrea; Dettin, Monica; Gabbi, Carlo

2009-10-01

Peptide and protein exploitation for the biochemical functionalization of biomaterial surfaces allowed fabricating biomimetic devices able to evoke and promote specific and advantageous cell functions in vitro and in vivo. In particular, cell adhesion improvement to support the osseointegration of implantable devices has been thoroughly investigated. This study was aimed at checking the biological activity of the (351-359) human vitronectin precursor (HVP) sequence, mapped on the human vitronectin protein; the peptide was covalently linked to the surface of titanium cylinders, surgically inserted in the femurs of New Zealand white rabbits and analyzed at short experimental time points (4, 9, and 16 days after surgery). To assess the osteogenic activity of the peptide, three vital fluorochromic bone markers were used (calcein green, xylenol orange, and calcein blue) to stain the areas of newly grown bone. Static and dynamic histomorphometric parameters were measured at the bone-implant interface and at different distances from the surface. The biological role of the (351-359)HVP sequence was checked by comparing peptide-grafted samples and controls, analyzing how and how much its effects change with time across the bone regions surrounding the implant surface. The results obtained reveal a major activity of the investigated peptide 4 days after surgery, within the bone region closest to the implant surface, and larger bone to implant contact 9 and 16 days after surgery. Thus, improved primary fixation of endosseous devices can be foreseen, resulting in an increased osteointegration.

Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

Energy Technology Data Exchange (ETDEWEB)

Hsiao, Chaio-Ru [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China); Lin, Cheng-Wei [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); Chou, Chia-Man, E-mail: cmchou@vghtc.gov.tw [Department of Surgery, Taichung Veterans General Hospital, No. 1650, Sec. 4, Taiwan Boulevard, Seatwen District, Taichung City 40705, Taiwan (China); Department of Medicine, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Beitou District, Taipei City 11221, Taiwan (China); Chung, Chi-Jen, E-mail: cjchung@seed.net.tw [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); He, Ju-Liang [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China)

2015-08-15

Highlights: • Biomaterials modified by nanoparticle-containing plasma polymerized films. • A superhydrophoic film was obtained, and the properties of the coating were examined. • In vitro blood compatibility tests revealed neither platelet adhesion nor fibrinogen adsorption. • Surface modification technology of medical devices: non-cytotoxic and no blood clot formation. - Abstract: This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF{sub 4}) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF{sub 4} (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF{sub 4} (f{sub H}) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiO{sub x} nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The −CF functional group, −CF{sub 2} bonding, and SiO{sub x} were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply

Porous titania surfaces on titanium with hierarchical macro- and mesoporosities for enhancing cell adhesion, proliferation and mineralization

International Nuclear Information System (INIS)

Han, Guang; Müller, Werner E.G.; Wang, Xiaohong; Lilja, Louise; Shen, Zhijian

2015-01-01

Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5 μm. An additional mesoporous titania top layer following the contour of the macropores, of 100–200 nm thickness and with a pore diameter of 10 nm, was formed by using the evaporation-induced self-assembly (EISA) method with titanium (IV) tetraethoxide as the precursor. A coherent laminar titania surface layer was thus obtained, creating a hierarchical macro- and mesoporous surface that was characterized by high-resolution electron microscopy. The interfacial bonding between the surface layers and the titanium matrix was characterized by the scratch test that confirmed a stable and strong bonding of titania surface layers on titanium. The wettability to water and the effects on the osteosarcoma cell line (SaOS-2) proliferation and mineralization of the formed titania surface layers were studied systematically by cell culture and scanning electron microscopy. The results proved that the porous titania surface with hierarchical macro- and mesoporosities was hydrophilic that significantly promoted cell attachment and spreading. A synergistic role of the hierarchical macro- and mesoporosities was revealed in terms of enhancing cell adhesion, proliferation and mineralization, compared with the titania surface with solo scale topography. - Highlights: • We developed a hierarchical macro- and mesoporous surface layer on titanium. • New surface layer was strong enough to sustain on implant surface. • New surface owned better surface wettability. • New surface can promote SaOS-2 cell adhesion, proliferation and mineralization. • Synergistic effects on cell responses occur when two porous structures coexist

Porous titania surfaces on titanium with hierarchical macro- and mesoporosities for enhancing cell adhesion, proliferation and mineralization

Energy Technology Data Exchange (ETDEWEB)

Han, Guang [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm (Sweden); Müller, Werner E.G.; Wang, Xiaohong [ERC Advanced Grant Research Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz (Germany); Lilja, Louise [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm (Sweden); Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping (Sweden); Shen, Zhijian, E-mail: shen@mmk.su.se [Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm (Sweden)

2015-02-01

Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5 μm. An additional mesoporous titania top layer following the contour of the macropores, of 100–200 nm thickness and with a pore diameter of 10 nm, was formed by using the evaporation-induced self-assembly (EISA) method with titanium (IV) tetraethoxide as the precursor. A coherent laminar titania surface layer was thus obtained, creating a hierarchical macro- and mesoporous surface that was characterized by high-resolution electron microscopy. The interfacial bonding between the surface layers and the titanium matrix was characterized by the scratch test that confirmed a stable and strong bonding of titania surface layers on titanium. The wettability to water and the effects on the osteosarcoma cell line (SaOS-2) proliferation and mineralization of the formed titania surface layers were studied systematically by cell culture and scanning electron microscopy. The results proved that the porous titania surface with hierarchical macro- and mesoporosities was hydrophilic that significantly promoted cell attachment and spreading. A synergistic role of the hierarchical macro- and mesoporosities was revealed in terms of enhancing cell adhesion, proliferation and mineralization, compared with the titania surface with solo scale topography. - Highlights: • We developed a hierarchical macro- and mesoporous surface layer on titanium. • New surface layer was strong enough to sustain on implant surface. • New surface owned better surface wettability. • New surface can promote SaOS-2 cell adhesion, proliferation and mineralization. • Synergistic effects on cell responses occur when two porous structures coexist.

Fibroblast adhesion and activation onto micro-machined titanium surfaces.

Science.gov (United States)

Guillem-Marti, J; Delgado, L; Godoy-Gallardo, M; Pegueroles, M; Herrero, M; Gil, F J

2013-07-01

Surface modifications performed at the neck of dental implants, in the manner of micro-grooved surfaces, can reduce fibrous tissue encapsulation and prevent bacterial colonization, thereby improving fibrointegration and the formation of a biological seal. However, the applied procedures are technically complex and/or time consuming methods. The aim of this study was to analyse the fibroblast behaviour on modified titanium surfaces obtained, applying a simple and low-cost method. An array of titanium surfaces was obtained using a commercial computerized numerical control lathe, modifying the feed rate and the cutting depth. To elucidate the potential ability of the generated surfaces to activate connective tissue cells, a thorough gene (by real time - qPCR) and protein (by western blot or zymography) expression and cellular response characterization (cell morphology, cell adhesion and cell activation by secreting extracellular matrix (ECM) components and their enzyme regulators) was performed. Micro-grooved surfaces have statistically significant differences in the groove's width (approximately 10, 50 and 100 μm) depending on the applied advancing fixed speed. Field emission scanning electron microscopy images showed that fibroblasts oriented along the generated grooves, but they were only entirely accommodated on the wider grooves (≥50 μm). Micro-grooved surfaces exhibited an earlier cell attachment and activation, as seen by collagen Iα1 and fibronectin deposition and activation of ECM remodelling enzymes, compared with the other surfaces. However, fibroblasts could remain in an activated state on narrower surfaces (fibrotic response. © 2012 John Wiley & Sons A/S.

[Bioactivity of ultraviolet ray-treated titanium surface in nitrogen storing environment].

Science.gov (United States)

Wang, Heng; Shang, Ren; Guan, Yun; Wang, Yan; Teng, Wei

2013-05-01

To evaluate the adhesion, proliferation and differentiation of osteoblast-like cells on the ultraviolet (UV)-treated titanium in different storing environment, and to find a way to enhance the bioactivity of titanium and to prevent its age-related degradation. Acid-etched titanium disks stored under ambient conditions for 4 weeks and treated with UV light for 48 h.Then disks were divided into three groups and placed in a sealed container for 0 h (no-stored,NO group) , 4 weeks (air-stored, AS group) or in a sealed container filled with nitrogen for 4 weeks (nitrogen-stored,NS group) respectively. A group of UV-untreated titanium served as negative control (NC group).The surface morphology was evaluated using scanning electron microscopy (SEM), and hydrophilicity of disks were measured using contact angle measuring device. Cell counting kit-8 was used to measure the cell adhesion and proliferation. Cell differentiation was evaluated by testing alkaline phosphatase (ALP) activity using ALP reagent kit. There was no difference in surface topography among groups.Contact angels in NS group [(67.70 ± 3.59)°] and NO group [(0.70 ± 0.28)°] were smaller than the others (P 0.05). Osteoblast-like cells had an abundant spread on NS and NO group during 2 h incubation, but did not exactly spread on AS and NC group after incubation for 4 h. No difference were found in ALP among groups. UV treatment can enhance bioactivity of titanium, and nitrogen storage can slow down its biological aging.

The combined action of UV irradiation and chemical treatment on the titanium surface of dental implants

Energy Technology Data Exchange (ETDEWEB)

Spriano, Silvia [Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi, 24-10129 Torino (Italy); Ferraris, Sara, E-mail: sara.ferraris@polito.it [Politecnico di Torino, Department of Applied Science and Technology, Corso Duca degli Abruzzi, 24-10129 Torino (Italy); Bollati, Daniele; Morra, Marco; Cassinelli, Clara [Nobil Bio Ricerche, Portacomaro (Italy); Lorenzon, Giorgio [Centro Chirurgico, Via Mallonetto, 47, 10032, Brandizzo Torino (Italy)

2015-09-15

Highlights: • A combined UV irradiation and H{sub 2}O{sub 2} treatment was applied to titanium surfaces. • A thin, homogeneous, not porous, crack-free and bioactive oxide layer was obtained. • The process significantly improves the biological response of titanium surfaces. • A clinical case demonstrates the effectiveness of the proposed treatment. - Abstract: The purpose of this paper is to describe an innovative treatment for titanium dental implants, aimed at faster and more effective osteointegration. The treatment has been performed with the use of hydrogen peroxide, whose action was enhanced by concomitant exposure to a source of ultraviolet light. The developed surface oxide layer was characterized from the physical and chemical points of view. Moreover osteoblast-like SaOS2 cells were cultured on treated and control titanium surfaces and cell behavior investigated by scanning electron microscope observation and gene expression measurements. The described process produces, in only 6 min, a thin, homogeneous, not porous, free of cracks and bioactive (in vitro apatite precipitation) oxide layer. High cell density, peculiar morphology and overexpression of several genes involved with osteogenesis have been observed on modified surfaces. The proposed process significantly improves the biological response of titanium surfaces, and is an interesting solution for the improvement of bone integration of dental implants. A clinical application of the described surfaces, with a 5 years follow-up, is reported in the paper, as an example of the effectiveness of the proposed treatment.

Modeling and optimization of kerf taper and surface roughness in laser cutting of titanium alloy sheet

Energy Technology Data Exchange (ETDEWEB)

Pandey, Arun Kumar; Dubey, Avanish Kumar [Motilal Nehru National Institute of Technology Allahabad, Uttar Pradesh (India)

2013-07-15

Laser cutting of titanium and its alloys is difficult due to it's poor thermal conductivity and chemical reactivity at elevated temperatures. But demand of these materials in different advanced industries such as aircraft, automobile and space research, require accurate geometry with high surface quality. The present research investigates the laser cutting process behavior of titanium alloy sheet (Ti-6Al-4V) with the aim to improve geometrical accuracy and surface quality by minimizing the kerf taper and surface roughness. The data obtained from L{sub 27} orthogonal array experiments have been used for developing neural network (NN) based models of kerf taper and surface roughness. A hybrid approach of neural network and genetic algorithm has been proposed and applied for the optimization of different quality characteristics. The optimization results show considerable improvements in both the quality characteristics. The results predicted by NN models are well in agreement with the experimental data.

Osseointegration improvement by plasma electrolytic oxidation of modified titanium alloys surfaces.

Science.gov (United States)

Echeverry-Rendón, Mónica; Galvis, Oscar; Quintero Giraldo, David; Pavón, Juan; López-Lacomba, José Luis; Jiménez-Piqué, Emilio; Anglada, Marc; Robledo, Sara M; Castaño, Juan G; Echeverría, Félix

2015-02-01

Titanium (Ti) is a material frequently used in orthopedic applications, due to its good mechanical properties and high corrosion resistance. However, formation of a non-adherent fibrous tissue between material and bone drastically could affect the osseointegration process and, therefore, the mechanical stability of the implant. Modifications of topography and configuration of the tissue/material interface is one of the mechanisms to improve that process by manipulating parameters such as morphology and roughness. There are different techniques that can be used to modify the titanium surface; plasma electrolytic oxidation (PEO) is one of those alternatives, which consists of obtaining porous anodic coatings by controlling parameters such as voltage, current, anodizing solution and time of the reaction. From all of the above factors, and based on previous studies that demonstrated that bone cells sense substrates features to grow new tissue, in this work commercially pure Ti (c.p Ti) and Ti6Al4V alloy samples were modified at their surface by PEO in different anodizing solutions composed of H2SO4 and H3PO4 mixtures. Treated surfaces were characterized and used as platforms to grow osteoblasts; subsequently, cell behavior parameters like adhesion, proliferation and differentiation were also studied. Although the results showed no significant differences in proliferation, differentiation and cell biological activity, overall results showed an important influence of topography of the modified surfaces compared with polished untreated surfaces. Finally, this study offers an alternative protocol to modify surfaces of Ti and their alloys in a controlled and reproducible way in which biocompatibility of the material is not compromised and osseointegration would be improved.

Fatigue behavior of porous biomaterials manufactured using selective laser melting.

Science.gov (United States)

Yavari, S Amin; Wauthle, R; van der Stok, J; Riemslag, A C; Janssen, M; Mulier, M; Kruth, J P; Schrooten, J; Weinans, H; Zadpoor, A A

2013-12-01

Porous titanium alloys are considered promising bone-mimicking biomaterials. Additive manufacturing techniques such as selective laser melting allow for manufacturing of porous titanium structures with a precise design of micro-architecture. The mechanical properties of selective laser melted porous titanium alloys with different designs of micro-architecture have been already studied and are shown to be in the range of mechanical properties of bone. However, the fatigue behavior of this biomaterial is not yet well understood. We studied the fatigue behavior of porous structures made of Ti6Al4V ELI powder using selective laser melting. Four different porous structures were manufactured with porosities between 68 and 84% and the fatigue S-N curves of these four porous structures were determined. The three-stage mechanism of fatigue failure of these porous structures is described and studied in detail. It was found that the absolute S-N curves of these four porous structures are very different. In general, given the same absolute stress level, the fatigue life is much shorter for more porous structures. However, the normalized fatigue S-N curves of these four structures were found to be very similar. A power law was fitted to all data points of the normalized S-N curves. It is shown that the measured data points conform to the fitted power law very well, R(2)=0.94. This power law may therefore help in estimating the fatigue life of porous structures for which no fatigue test data is available. It is also observed that the normalized endurance limit of all tested porous structures (<0.2) is lower than that of corresponding solid material (c.a. 0.4). © 2013.

Handheld skin printer: in situ formation of planar biomaterials and tissues.

Science.gov (United States)

Hakimi, Navid; Cheng, Richard; Leng, Lian; Sotoudehfar, Mohammad; Ba, Phoenix Qing; Bakhtyar, Nazihah; Amini-Nik, Saeid; Jeschke, Marc G; Günther, Axel

2018-05-15

We present a handheld skin printer that enables the in situ formation of biomaterial and skin tissue sheets of different homogeneous and architected compositions. When manually positioned above a target surface, the compact instrument (weight <0.8 kg) conformally deposits a biomaterial or tissue sheet from a microfluidic cartridge. Consistent sheet formation is achieved by coordinating the flow rates at which bioink and cross-linker solution are delivered, with the speed at which a pair of rollers actively translate the cartridge along the surface. We demonstrate compatibility with dermal and epidermal cells embedded in ionically cross-linkable biomaterials (e.g., alginate), and enzymatically cross-linkable proteins (e.g., fibrin), as well as their mixtures with collagen type I and hyaluronic acid. Upon rapid crosslinking, biomaterial and skin cell-laden sheets of consistent thickness, width and composition were obtained. Sheets deposited onto horizontal, agarose-coated surfaces were used for physical and in vitro characterization. Proof-of-principle demonstrations for the in situ formation of biomaterial sheets in murine and porcine excisional wound models illustrate the capacity of depositing onto inclined and compliant wound surfaces that are subject to respiratory motion. We expect the presented work will enable the in situ delivery of a wide range of different cells, biomaterials, and tissue adhesives, as well as the in situ fabrication of spatially organized biomaterials, tissues, and biohybrid structures.

Fabrication of biomimetic resorption lacunae-like structure on titanium surface and its osteoblast responses

Science.gov (United States)

Huo, Fangjun; Guo, Weihua; Wu, Hao; Wang, Yueting; He, Gang; Xie, Li; Tian, Weidong

2018-04-01

Biomimetic specific surface structure could improve biological behaviors of specific cells and eventual tissue integration. Featuring titanium surface with structures resembling bone resorption lacunae (RL) can be a promising approach to improve the osteoblast responses and osseointegration of implants. As a most common used dental implant surface, sandblasting and acid etching (SLA) surface has micro-sized structures with dimensions similar to RL, but great differences exist when it comes to shape and contour. In this work, by anodizing titanium substrate in a novel HCOONa/CH3COONa electrolyte, RL-like crater structures were fabricated with highly similar size, shape and contour. Compared with SLA, it was much more similar to RL structure in shape and contour. Furthermore, through subsequent alkali-heat treatment, nano-sized structures that overlaid the whole surface were obtained, which further mimic undercuts features inside the RL. The as-prepared surface was consisted of crystalline titania and exhibited super-hydrophilicity with good stability. In vitro evaluation results showed that the surface could significantly improve adhesion, proliferation and differentiation of MG63 cells in comparison with SLA. This new method may be a promising candidate for biomimetic modification of titanium implant to promote osseointegration.

Biomaterials

NARCIS (Netherlands)

Van Mourik, P.; Van Dam, J.; Picken, S.J.; Ursem, B.

2013-01-01

The metabolic pathways of living organisms produce biomaterials. Hence, in principle biomaterials are fully sustainable. This does not mean that their processing and application have no impact on the environment, e.g. the recycling of natural rubber remains a problem. Biomaterials are applied in a

Immobilisation of linear and cyclic RGD-peptides on titanium surfaces and their impact on endothelial cell adhesion and proliferation

Directory of Open Access Journals (Sweden)

PW Kämmerer

2011-04-01

Full Text Available Functional coatings on titanium vascular stents and endosseous dental implants could probably enhance endothelial cell (EC adhesion and activity with a shortening of the wound healing time and an increase of peri-implant angiogenesis during early bone formation. Therefore, the role of the structure of linear and cyclic cell adhesive peptides Arg-Gly-Asp (l-RGD and c-RGD on differently pre-treated titanium (Ti surfaces (untreated, silanised vs. functionalised with l- and c-RGD peptides on EC cell coverage and proliferation was evaluated. After 24 h and after 3 d, surface coverage of adherent cells was quantified and an alamarBlue® proliferation assay was conducted. After 24 h, l-RGD modified surfaces showed a significantly better coverage of adhered cells than untreated titanium (p=0.01. Differences between l-RGD surfaces and silanised Ti (p=0.066 as well as between l-RGD and c-RGD surfaces (p=0.191 were not significant. After 3 d, c-RGD surfaces showed a significantly higher cell coverage than untreated Ti, silanised and l-RGD titanium surfaces (all p<0.0001. After 24 h, c-RGD modified surfaces showed significant higher cell proliferation compared to untreated Ti (p=0.003. However, there were no differences in proliferation between c-RGD and l-RGD (p=0.126 or c-RGD and silanised titanium (p=0.196. After 3 d, proliferation on c-RGD surfaces outranged significantly untreated titanium (p=0.004, silanised (p=0.001 and l-RGD surfaces (p=0.023, whereas no significant difference could be found between untreated Ti and l-RGD surfaces (p=0.54. According to these results, the biomimetic coating of c-RGD peptides on conventional titanium surfaces showed a positive effect on EC cell coverage and proliferation. We were able to show that modifications of titanium surfaces with c-RGD are a promising approach in promoting endothelial cell growth.

Physicochemical state of the nanotopographic surface of commercially pure titanium following anodization-hydrothermal treatment reveals significantly improved hydrophilicity and surface energy profiles.

Science.gov (United States)

Takebe, Jun; Ito, Shigeki; Miura, Shingo; Miyata, Kyohei; Ishibashi, Kanji

2012-01-01

A method of coating commercially pure titanium (cpTi) implants with a highly crystalline, thin hydroxyapatite (HA) layer using discharge anodic oxidation followed by hydrothermal treatment (Spark discharged Anodic oxidation treatment ; SA-treated cpTi) has been reported for use in clinical dentistry. We hypothesized that a thin HA layer with high crystallinity and nanostructured anodic titanium oxide film on such SA-treated cpTi implant surfaces might be a crucial function of their surface-specific potential energy. To test this, we analyzed anodic oxide (AO) cpTi and SA-treated cpTi disks by SEM and AFM. Contact angles and surface free energy of each disk surface was measured using FAMAS software. High-magnification SEM and AFM revealed the nanotopographic structure of the anodic titanium oxide film on SA-treated cpTi; however, this was not observed on the AO cpTi surface. The contact angle and surface free energy measurements were also significantly different between AO cpTi and SA-treated cpTi surfaces (Tukey's, P<0.05). These data indicated that the change of physicochemical properties of an anodic titanium oxide film with HA crystals on an SA-treated cpTi surface may play a key role in the phenomenon of osteoconduction during the process of osseointegration. Copyright © 2011 Elsevier B.V. All rights reserved.

Biomaterials based strategies for skeletal muscle tissue engineering: existing technologies and future trends.

Science.gov (United States)

Qazi, Taimoor H; Mooney, David J; Pumberger, Matthias; Geissler, Sven; Duda, Georg N

2015-01-01

Skeletal muscles have a robust capacity to regenerate, but under compromised conditions, such as severe trauma, the loss of muscle functionality is inevitable. Research carried out in the field of skeletal muscle tissue engineering has elucidated multiple intrinsic mechanisms of skeletal muscle repair, and has thus sought to identify various types of cells and bioactive factors which play an important role during regeneration. In order to maximize the potential therapeutic effects of cells and growth factors, several biomaterial based strategies have been developed and successfully implemented in animal muscle injury models. A suitable biomaterial can be utilized as a template to guide tissue reorganization, as a matrix that provides optimum micro-environmental conditions to cells, as a delivery vehicle to carry bioactive factors which can be released in a controlled manner, and as local niches to orchestrate in situ tissue regeneration. A myriad of biomaterials, varying in geometrical structure, physical form, chemical properties, and biofunctionality have been investigated for skeletal muscle tissue engineering applications. In the current review, we present a detailed summary of studies where the use of biomaterials favorably influenced muscle repair. Biomaterials in the form of porous three-dimensional scaffolds, hydrogels, fibrous meshes, and patterned substrates with defined topographies, have each displayed unique benefits, and are discussed herein. Additionally, several biomaterial based approaches aimed specifically at stimulating vascularization, innervation, and inducing contractility in regenerating muscle tissues are also discussed. Finally, we outline promising future trends in the field of muscle regeneration involving a deeper understanding of the endogenous healing cascades and utilization of this knowledge for the development of multifunctional, hybrid, biomaterials which support and enable muscle regeneration under compromised conditions

Time-resolved imaging and immobilization study of biomaterials on hydrophobic and superhydrophobic surfaces by means of laser-induced forward transfer

International Nuclear Information System (INIS)

Boutopoulos, Christos; Chatzipetrou, Marianneza; Zergioti, Ioanna; Papathanasiou, Athanasios G

2014-01-01

In this work, we present the generation of high velocity liquid jets of a photosynthetic biomaterial in buffer solution (i.e. thylakoid membranes) and a test solution, using the laser-induced forward transfer (LIFT) technique. The high impact pressure of the collision of the jets on solid substrates, ranging from 0.045 MPa–35 MPa, resulted in strong physical immobilization of the photosynthetic biomaterial on superhydrophobic (SH) poly(methyl methacrylate) (PMMA) surfaces and hydrophobic gold surfaces. The immobilization efficiency was evaluated by fluorescence microscopy, while time-resolved imaging of the LIFT process was carried out to study the corresponding LIFT dynamics. The results show that this simple, direct and chemical-linkers-free immobilization technique is valuable for several biosensors and microfluidic applications since it can be applied to a variety of hydrophobic and SH substrates, leading to the selective immobilization of the biomaterials, due to the high spatial printing resolution of the LIFT technique. (letter)

Surface modification of TC4 titanium alloy by high current pulsed electron beam (HCPEB) with different pulsed energy densities

International Nuclear Information System (INIS)

Gao, Yu-kui

2013-01-01

Highlights: •The hardness changes were determined by nanoindention method. •The surface integrity changes were investigated by different techniques. •The mechanism was analyzed based on AFM and TEM investigations. -- Abstract: Surface changes including surface topography and nanohardness distribution along surface layer were investigated for TC4 titanium alloy by different energy densities of high current pulsed electron beam (HCPEB). The surface topography was characterized by SEM and AFM, and cross-sectional TEM observation was performed to reveal the surface modification mechanism of TC4 titanium alloy by HCPEB. The surface roughness was modified by HCPEB and the polishing mechanism was analyzed by studying the cross section microstructure of electron beam treated specimens by SEM. The fine grain structure inherited from the rapid solidification of the melted layer as well as the strain hardening of the sub-surface are two of the factors responsible the increase in nanohardness

Some Biomaterials based on Collagen in Human Health care

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Some Biomaterials based on Collagen in Human Health care. Ophthalmology. Wound healing. Burn Dressing. Tumor Treatment. Tissue Engineered devices. for cardio-vascular functions; For managing chronic illnesses including diabetic ulcers and foot. Smart shoe.

Surface coating for blood-contacting devices

Science.gov (United States)

Nair, Ajit Kumar Balakrishnan

The major problems always encountered with the blood-contacting surfaces are their compatibility, contact blood damage, and thrombogenicity. Titanium nitride (TiN) is a hard, inert, ceramic material that is widely used in the engineering industry. TiN has been proven to be a good biomaterial in its crystalline form, in orthopedic, and in tissue implant applications. This dissertation describes a method to coat amorphous TiN on the blood-contacting surfaces of certain medical devices using the room-temperature sputtering process and to characterize, to test, and to evaluate the coating for a reliable, durable, and compatible blood-contacting surface The blood-compatibility aspects were evaluated with standard, established protocols and procedures to prove the feasibility. An amorphous TiN coating is developed, characterized, tested, and blood compatibility evaluated by applying to the blood-contacting surfaces of stainless steel, catheters, and blood filters. The flexibility characteristics were proven by applying it to the diaphragms of the pulsatile pneumatic ventricular assist device. The results show that amorphous titanium nitride is flexible and adherent to polymeric substrates like polyurethane and polyester. Blood compatibility evaluation showed comparable results with catheters and superior behavior with stainless steel and polyester filters. It is concluded that amorphous titanium nitride can be considered to be applied to the surfaces of some of the medical devices in order to improve blood compatibility.

Study of surface phenomena in biomaterials: The influence of physical factors

Energy Technology Data Exchange (ETDEWEB)

Sachelarie, Liliana, E-mail: lisachero@yahoo.com; Vasiliu, Mihaela Papusa; Ciobanu, Catalina

2015-10-15

This study's purpose is pointing out the phenomenon that occurs at time of interaction between the tissue with implant. The materials used are Ti and its alloys. The oral tissue must be compatible with the materials used in surgical implant to human body. The bio-materials surface behavior is influenced by physical characteristics. The methods we use show a number of bio-compatibility aspects. The success of an implant in a hard tissue depends not only on the initial attachment and the osteogenic cells consecutive proliferation, but also on their capacity to create a new bone.

An unscaled parameter to measure the order of surfaces: a new surface elaboration to increase cells adhesion.

Science.gov (United States)

Bigerelle, M; Anselme, K; Dufresne, E; Hardouin, P; Iost, A

2002-08-01

We present a new parameter to quantify the order of a surface. This parameter is scale-independent and can be used to compare the organization of a surface at different scales of range and amplitude. To test the accuracy of this roughness parameter versus a hundred existing ones, we created an original statistical bootstrap method. In order to assess the physical relevance of this new parameter, we elaborated a great number of surfaces with various roughness amplitudes on titanium and titanium-based alloys using different physical processes. Then we studied the influence of the roughness amplitude on in vitro adhesion and proliferation of human osteoblasts. It was then shown that our new parameter best discriminates among the cell adhesion phenomena than others' parameters (Average roughness (Ra em leader )): cells adhere better on isotropic surfaces with a low order, provided this order is quantified on a scale that is more important than that of the cells. Additionally, on these low ordered metallic surfaces, the shape of the cells presents the same morphological aspect as that we can see on the human bone trabeculae. The method used to prepare these isotropic surfaces (electroerosion) could be undoubtedly and easily applied to prepare most biomaterials with complex geometries and to improve bone implant integration. Moreover, the new order parameter we developed may be particularly useful for the fundamental understanding of the mechanism of bone cell installation on a relief and of the formation of bone cell-material interface.

Formation of mixed and patterned self-assembled films of alkylphosphonates on commercially pure titanium surfaces

Energy Technology Data Exchange (ETDEWEB)

Rudzka, Katarzyna; Sanchez Treviño, Alda Y.; Rodríguez-Valverde, Miguel A., E-mail: marodri@ugr.es; Cabrerizo-Vílchez, Miguel A.

2016-12-15

Highlights: • Chemically-tailored titanium surfaces were prepared by self-assembly of alkylphosphonates. • Mixed self-assembled films were prepared with aqueous mixtures of two alkylphosphonates. • Single self-assembled films were altered by laser abrasion. • Mixed and patterned self-assembled films on titanium may guide the bone-like formation. - Abstract: Titanium is extensively employed in biomedical devices, in particular as implant. The self-assembly of alkylphosphonates on titanium surfaces enable the specific adsorption of biomolecules to adapt the implant response against external stimuli. In this work, chemically-tailored cpTi surfaces were prepared by self-assembly of alkylphosphonate molecules. By bringing together attributes of two grafting molecules, aqueous mixtures of two alkylphosphonates were used to obtain mixed self-assembled films. Single self-assembled films were also altered by laser abrasion to produce chemically patterned cpTi surfaces. Both mixed and patterned self-assembled films were confirmed by AFM, ESEM and X-ray photoelectron spectroscopy. Water contact angle measurements also revealed the composition of the self-assembly films. Chemical functionalization with two grafting phosphonate molecules and laser surface engineering may be combined to guide the bone-like formation on cpTi, and the future biological response in the host.

Surface characterisation and electrochemical behaviour of porous titanium dioxide coated 316L stainless steel for orthopaedic applications

International Nuclear Information System (INIS)

Nagarajan, S.; Rajendran, N.

2009-01-01

Porous titanium dioxide was coated on surgical grade 316L stainless steel (SS) and its role on the corrosion protection and enhanced biocompatibility of the materials was studied. X-ray diffraction analysis (XRD), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) were carried out to characterise the surface morphology and also to understand the structure of the as synthesised coating on the substrates. The corrosion behaviour of titanium dioxide coated samples in simulated body fluid was evaluated using polarisation and impedance spectroscopy studies. The results reveal that the titanium dioxide coated 316L SS exhibit a higher corrosion resistance than the uncoated 316L SS. The titanium dioxide coated surface is porous, uniform and also it acts as a barrier layer to metallic substrate and the porous titanium dioxide coating induces the formation of hydroxyapatite layer on the metal surface.

Optimized in vitro procedure for assessing the cytocompatibility of magnesium-based biomaterials.

Science.gov (United States)

Jung, Ole; Smeets, Ralf; Porchetta, Dario; Kopp, Alexander; Ptock, Christoph; Müller, Ute; Heiland, Max; Schwade, Max; Behr, Björn; Kröger, Nadja; Kluwe, Lan; Hanken, Henning; Hartjen, Philip

2015-09-01

Magnesium (Mg) is a promising biomaterial for degradable implant applications that has been extensively studied in vitro and in vivo in recent years. In this study, we developed a procedure that allows an optimized and uniform in vitro assessment of the cytocompatibility of Mg-based materials while respecting the standard protocol DIN EN ISO 10993-5:2009. The mouse fibroblast line L-929 was chosen as the preferred assay cell line and MEM supplemented with 10% FCS, penicillin/streptomycin and 4mM l-glutamine as the favored assay medium. The procedure consists of (1) an indirect assessment of effects of soluble Mg corrosion products in material extracts and (2) a direct assessment of the surface compatibility in terms of cell attachment and cytotoxicity originating from active corrosion processes. The indirect assessment allows the quantification of cell-proliferation (BrdU-assay), viability (XTT-assay) as well as cytotoxicity (LDH-assay) of the mouse fibroblasts incubated with material extracts. Direct assessment visualizes cells attached to the test materials by means of live-dead staining. The colorimetric assays and the visual evaluation complement each other and the combination of both provides an optimized and simple procedure for assessing the cytocompatibility of Mg-based biomaterials in vitro. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Influence of the peroxide group on the surface of titanium dioxide synthesized by the OPM route

International Nuclear Information System (INIS)

Santos, Estela Melare Ribeiro dos; Kubo, Andressa Mayumi; Gorup, Luiz Fernando; Francatto, Patricia; Souza Neto, Francisco Nunes de; Leite, Edson Roberto; Longo, Elson; Camargo, Emerson Rodrigues

2016-01-01

Full text: In the context of nanotechnology, there is a growing demand for environmentally sustainable solutions and technological innovations that are linked to reducing energy consumption and minimizing waste generation during the synthesis process. The Oxidant Peroxide Method for titanium dioxide synthesis (TiO 2 -OPM) is based on the oxidation of titanium ions to obtain nanometric powders that are highly reactive particles with controlled morphology. This method is easy and advantageous because it uses reagents of low toxicity, without the necessity to operate in inert atmosphere and at high temperatures. In this work, we obtained nanometric powders of TiO 2 -OPM from metallic titanium (TiO 2 -Met), and titanium isopropoxide (TiO 2 -Iso). Separately, the precursors reacts with hydrogen peroxide in ammoniacal medium in order to compare their reactivity by quantifying the peroxo groups on the surface. Scanning electronic microscopy (SEM) images showed nanoparticles of 10nm of both materials. X-ray diffraction (XRD) patterns showed typical structures of crystalline materials with mixture of anatase and rutile phase of titanium dioxide. Raman spectroscopy also cooperated with the XRD patterns showing vibrational modes of the mixture of phases (anatase and rutile) in both materials. Thermogravimetric analysis (TGA) showed that the two materials lost mass, in which in the first stage (80 - 125 deg C) occurred 24% of loss and in the second stage (235-265 deg C) is between 10% - 13%, and is related to the elimination of peroxo groups at the surface due to thermal treatment. Differential scanning calorimetry (DSC) revealed peaks related to exothermic decomposition of the peroxo groups (200 - 250 deg C) that coincided with peak rates of mass loss in the TGA. And the redox titration showed that the surface of the TiO 2 -Met had peroxo groups in 8.6 % w/w and 10.1 % w/w for TiO 2 -Iso, resulting in an increase of peroxo groups on the surface, making the TiO 2 -Iso route

Influence of the peroxide group on the surface of titanium dioxide synthesized by the OPM route

Energy Technology Data Exchange (ETDEWEB)

Santos, Estela Melare Ribeiro dos; Kubo, Andressa Mayumi; Gorup, Luiz Fernando; Francatto, Patricia; Souza Neto, Francisco Nunes de; Leite, Edson Roberto; Longo, Elson; Camargo, Emerson Rodrigues, E-mail: estelamelare@yahoo.com.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil)

2016-07-01

Full text: In the context of nanotechnology, there is a growing demand for environmentally sustainable solutions and technological innovations that are linked to reducing energy consumption and minimizing waste generation during the synthesis process. The Oxidant Peroxide Method for titanium dioxide synthesis (TiO{sub 2}-OPM) is based on the oxidation of titanium ions to obtain nanometric powders that are highly reactive particles with controlled morphology. This method is easy and advantageous because it uses reagents of low toxicity, without the necessity to operate in inert atmosphere and at high temperatures. In this work, we obtained nanometric powders of TiO{sub 2}-OPM from metallic titanium (TiO{sub 2}-Met), and titanium isopropoxide (TiO{sub 2}-Iso). Separately, the precursors reacts with hydrogen peroxide in ammoniacal medium in order to compare their reactivity by quantifying the peroxo groups on the surface. Scanning electronic microscopy (SEM) images showed nanoparticles of 10nm of both materials. X-ray diffraction (XRD) patterns showed typical structures of crystalline materials with mixture of anatase and rutile phase of titanium dioxide. Raman spectroscopy also cooperated with the XRD patterns showing vibrational modes of the mixture of phases (anatase and rutile) in both materials. Thermogravimetric analysis (TGA) showed that the two materials lost mass, in which in the first stage (80 - 125 deg C) occurred 24% of loss and in the second stage (235-265 deg C) is between 10% - 13%, and is related to the elimination of peroxo groups at the surface due to thermal treatment. Differential scanning calorimetry (DSC) revealed peaks related to exothermic decomposition of the peroxo groups (200 - 250 deg C) that coincided with peak rates of mass loss in the TGA. And the redox titration showed that the surface of the TiO{sub 2}-Met had peroxo groups in 8.6 % w/w and 10.1 % w/w for TiO{sub 2}-Iso, resulting in an increase of peroxo groups on the surface, making

Surface Modification Reaction of Photocatalytic Titanium Dioxide with Triethoxysilane for Improving Dispersibility

International Nuclear Information System (INIS)

Lee, Myung Jin; Kim, Ji Ho; Park, Young Tae

2010-01-01

We have carried out the surface modification of photocatalytic TiO 2 with triethoxysilane through dehydrogenation reaction and characterized the modified photocatalyst by spectroscopic methods, such as FT-IR, solid-state 29 Si MAS NMR, XPS, and XRF, etc. We also examined photocatalytic activity of the immobilized photocatalytic titanium dioxide with triethoxysilane by decolorization reaction of dyes such as cong red and methylene blue under visible light. Dispersion test showed that the photocatalytic titanium dioxide immobilized with triethoxysilane group has kept higher dispersibility than titanium dioxide itself. No appreciable precipitation takes place even after standing for 24 h in the 4:6 mixture ratio of ethanol and water

Innate Immunity and Biomaterials at the Nexus: Friends or Foes.

Science.gov (United States)

Christo, Susan N; Diener, Kerrilyn R; Bachhuka, Akash; Vasilev, Krasimir; Hayball, John D

2015-01-01

Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical "antigen." In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a "combined" immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

Innate Immunity and Biomaterials at the Nexus: Friends or Foes

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Susan N. Christo

2015-01-01

Full Text Available Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

Porous titanium bases for osteochondral tissue engineering

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Nover, Adam B.; Lee, Stephanie L.; Georgescu, Maria S.; Howard, Daniel R.; Saunders, Reuben A.; Yu, William T.; Klein, Robert W.; Napolitano, Anthony P.; Ateshian, Gerard A.

2015-01-01

Tissue engineering of osteochondral grafts may offer a cell-based alternative to native allografts, which are in short supply. Previous studies promote the fabrication of grafts consisting of a viable cell-seeded hydrogel integrated atop a porous, bone-like metal. Advantages of the manufacturing process have led to the evaluation of porous titanium as the bone-like base material. Here, porous titanium was shown to support the growth of cartilage to produce native levels of Young’s modulus, using a clinically relevant cell source. Mechanical and biochemical properties were similar or higher for the osteochondral constructs compared to chondral-only controls. Further investigation into the mechanical influence of the base on the composite material suggests that underlying pores may decrease interstitial fluid pressurization and applied strains, which may be overcome by alterations to the base structure. Future studies aim to optimize titanium-based tissue engineered osteochondral constructs to best match the structural architecture and strength of native grafts. Statement of Significance The studies described in this manuscript follow up on previous studies from our lab pertaining to the fabrication of osteochondral grafts that consist of a bone-like porous metal and a chondrocyte-seeded hydrogel. Here, tissue engineered osteochondral grafts were cultured to native stiffness using adult chondrocytes, a clinically relevant cell source, and a porous titanium base, a material currently used in clinical implants. This porous titanium is manufactured via selective laser melting, offering the advantages of precise control over shape, pore size, and orientation. Additionally, this manuscript describes the mechanical influence of the porous base, which may have applicability to porous bases derived from other materials. PMID:26320541

Improving the antimicrobial properties of titanium condenser material by surface modification using nanotechnology

International Nuclear Information System (INIS)

George, Rani P.; Dash, S.; Krishnan, R.; Kamruddin, M.; Kalavathi, S.; Tyagi, A.K.; Manoharan, N.; Dayal, R.K.; Vishwakarma, Vinita; Theresa, Josephine

2008-01-01

Biofouling is one of the major problems faced by condenser materials of power plants using seawater for cooling. Fouling control strategies in condensers include a combination of mechanical and chemical treatments like sponge ball cleaning, back washing and chlorination. In general, numerous studies have shown that no routine treatment regime can successfully keep the condenser tube clean over a period extending to years. Surface properties of the substratum influence initial adhesion and growth of bacterial cells on materials, modification of the surface for mitigating microbial attachment is the need of the hour. Metal nanoparticles are known to exhibit enhanced physical and chemical properties when compared to their bulk counter parts because of their high surface to volume ratios. Metals like copper are very toxic to microorganisms and effectively kill most of the microbes by blocking the respiratory enzyme. Copper alloys with their excellent resistance to biofouling are used extensively for marine applications. However, they are prone to localized corrosion initiation and consequently are getting replaced by extremely corrosion resistant titanium. Still, the inertness and biocompatibility of titanium makes it very susceptible to biofouling. Hence, this study attempts to use nano technology methods of surface modification of titanium using thin film of copper and also multilayers and bilayers of copper and nickel. This is aimed at improving the antimicrobial properties of this condenser pipe material. These nano structured thin films have been grown on titanium substrate using pulsed DC magnetron-sputtering and pulsed laser deposition. The thin films were characterized using Atomic Force Microscopy (AFM), Glancing Incidence X-ray Diffraction (GIXRD) and scanning electron microscopy (SEM with EDAX analysis). Antimicrobial properties were evaluated by exposure studies in seawater and bacterial cultures and by post exposure analysis using culture and

Evaluation of the safety and efficiency of novel metallic ultrasonic scaler tip on titanium surfaces.

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Baek, Seung-Ho; Shon, Won-Jun; Bae, Kwang-Shik; Kum, Kee-Yeon; Lee, Woo-Cheol; Park, Young-Seok

2012-11-01

To evaluate the safety and efficiency of novel ultrasonic scaler tips, conventional stainless-steel tips, and plastic tips on titanium surfaces. Mechanical instrumentation was carried out using conventional ultrasonic scalers (EMS, Nyon, Switzerland) with novel metallic implant tip (BS), a plastic-headed tip (ES), a plastic tip (PS) and a conventional stainless-steel tip (CS) on 10 polished commercially pure titanium disks (Grade II) per group. Arithmetic mean roughness (R(a) ) and maximum height roughness (R(y) ) of titanium samples were measured and dissipated power of the scaler tip in the tip-surface junction was estimated to investigate the scaling efficiency. The instrumented surface morphology of samples was viewed with a scanning electron microscope (SEM) and surface profile of the each sample was investigated using contact mode with a commercial atomic force microscope (AFM). There were no significant differences in surface roughness (R(a) and R(y) ) among BS, ES, and PS group. However, CS group showed significant higher surface roughness (R(a) and R(y) ). The efficiency of CS tip is twice as much higher than that of BS tip, the efficiency of BS tip is 20 times higher than that of PS tip, and the efficiency of BS tip is 90 times higher than that of ES tip. Novel metallic copper alloy ultrasonic scaler tips may minimally influence the titanium surface, similar to plastic tip. Therefore, they can be a suitable instrument for implant maintenance therapy. © 2011 John Wiley & Sons A/S.

Metallic Biomaterials: Current Challenges and Opportunities

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Karthika Prasad

2017-07-01

Full Text Available Metallic biomaterials are engineered systems designed to provide internal support to biological tissues and they are being used largely in joint replacements, dental implants, orthopaedic fixations and stents. Higher biomaterial usage is associated with an increased incidence of implant-related complications due to poor implant integration, inflammation, mechanical instability, necrosis and infections, and associated prolonged patient care, pain and loss of function. In this review, we will briefly explore major representatives of metallic biomaterials along with the key existing and emerging strategies for surface and bulk modification used to improve biointegration, mechanical strength and flexibility of biometals, and discuss their compatibility with the concept of 3D printing.

Behavior of Human Bone Marrow-Derived Mesenchymal Stem Cells on Various Titanium-Based Coatings

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Chengjuan Qu

2016-10-01

Full Text Available The chemical composition and texture of titanium coatings can influence the growth characteristics of the adhered cells. An enhanced proliferation of the human mesenchymal stem cells (hMSCs would be beneficial. The present study was aimed to investigate whether titanium deposited at different atmospheres would affect the cell growth properties, cellular morphology, and expression of surface markers of hMSCs. Titanium-based coatings were deposited on silicon wafers under oxygen, nitrogen, or argon atmospheres by ultra-short pulsed laser deposition using two different gas pressures followed by heating at 400 °C for 2 h. The characteristics of the coated surfaces were determined via contact angle, zeta potential, and scanning electron microscopy (SEM techniques. Human MSCs were cultivated on differently coated silicon wafers for 48 h. Subsequently, the cell proliferation rates were analyzed with an MTT assay. The phenotype of hMSCs was checked via immunocytochemical stainings of MSC-associated markers CD73, CD90, and CD105, and the adhesion, spreading, and morphology of hMSCs on coated materials via SEM. The cell proliferation rates of the hMSCs were similar on all coated silicon wafers. The hMSCs retained the MSC phenotype by expressing MSC-associated markers and fibroblast-like morphology with cellular projections. Furthermore, no significant differences could be found in the size of the cells when cultured on all various coated surfaces. In conclusion, despite certain differences in the contact angles and the zeta potentials of various titanium-based coatings, no single coating markedly improved the growth characteristics of hMSCs.

MicroCT Analysis of Micro-Nano Titanium Implant Surface on the Osseointegration.

Science.gov (United States)

Ban, Jaesam; Kang, Seongsoo; Kim, Jihyun; Lee, Kwangmin; Hyunpil, Lim; Vang, Mongsook; Yang, Hongso; Oh, Gyejeong; Kim, Hyunseung; Hwang, Gabwoon; Jung, Yongho; Lee, Kyungku; Park, Sangwon; Yunl, Kwidug

2015-01-01

This study was to investigate the effects of micro-nano titanium implant surface on the osseointegration. A total of 36 screw-shaped implants were used. The implant surfaces were classified into 3 groups (n = 12): machined surface (M group), nanosurface which is nanotube formation on the machined surface (MA group) and nano-micro surface which is nanotube formation on the RBM surface (RA group). Anodic oxidation was performed at a 20 V for 10 min with 1 M H3PO4 and 1.5 wt% HF solutions. The implants were installed on the humerus on 6 beagles. After 4 and 12 weeks, the morphometric analysis with micro CT (skyscan 1172, SKYSCAN, Antwerpen, Belgium) was done. The data were statistically analyzed with two-way ANOVA. Bone mineral density and bone volume were significantly increased depending on time. RA group showed the highest bone mineral density and bone volume at 4 weeks and 12 weeks significantly. It indicated that nano-micro titanium implant surface showed faster and more mature osseointegration.

Prevention of pin tract infection with titanium-copper alloys.

Science.gov (United States)

Shirai, Toshiharu; Tsuchiya, Hiroyuki; Shimizu, Tohru; Ohtani, Kaori; Zen, Yo; Tomita, Katsuro

2009-10-01

The most frequent complication in external fixation is pin tract infection. To reduce the incidence of implant-associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium-Copper (Ti-Cu) alloy on implant infection, and to determine the potential use of the Ti-Cu alloy as a biomaterial. Two forms of Ti-Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli. The reaction of pathogens to the Ti-Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti-Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti-1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti-Cu alloys were evaluated in a rabbit model. The tissue-implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid-formation. Ti-1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid-formation. Copper blood levels were measured before surgery and at 14 days postoperatively. Preoperative and postoperative blood copper values were not statistically different. Overall, it was concluded that Ti-Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti-1% Cu alloy shows particular promise as a biomaterial. (c) 2009 Wiley Periodicals, Inc.

The electrochemical behavior and surface structure of titanium electrodes modified by ion beams

International Nuclear Information System (INIS)

Huang, G.F.; Xie, Z.; Huang, W.Q.; Yang, S.B.; Zhao, L.H.

2004-01-01

Industrial grade titanium modified by ion implantation and sputtering was used as electrodes. The effect of ion beam modification on the electrochemical behavior and surface structure of electrodes was investigated. Also discussed is the hydrogen evolution process of the electrode in acidic solution. Several ions such as Fe + , C + , W + , Ni + and others, were implanted into the electrode. The electrochemical tests were carried out in 1N H 2 SO 4 solution at 30±1 deg. C. The electrode potential was measured versus a saturate calomel electrode as a function of immersion time. The cathodic polarization curves were measured by the stable potential static method. The surface layer composition and the chemical state of the electrodes were also investigated by Auger electron spectrometer (AES) and X-ray photoelectron spectroscopy (XPS) technique. The results show that: (1) the stability of modified electrodes depends on the active elements introduced by ion implantation and sputtering deposition. (2) The hydrogen evolution activity of industrial grade titanium may be improved greatly by ion beam modification. (3) Ion beam modification changed the composition and the surface state of electrodes over a certain depth range and forms an activity layer having catalytic hydrogen evolution, which inhibited the absorption of hydrogen and formation of titanium hydride. Thus promoted hydrogen evolution and improved the hydrogen evolution catalytic activity in industrial grade titanium

Biological Activity of Mesoporous Dendrimer-Coated Titanium Dioxide: Insight on the Role of the Surface-Interface Composition and the Framework Crystallinity.

Science.gov (United States)

Milowska, Katarzyna; Rybczyńska, Aneta; Mosiolek, Joanna; Durdyn, Joanna; Szewczyk, Eligia M; Katir, Nadia; Brahmi, Younes; Majoral, Jean-Pierre; Bousmina, Mosto; Bryszewska, Maria; El Kadib, Abdelkrim

2015-09-16

Hitherto, the field of nanomedicine has been overwhelmingly dominated by the use of mesoporous organosilicas compared to their metal oxide congeners. Despite their remarkable reactivity, titanium oxide-based materials have been seldom evaluated and little knowledge has been gained with respect to their "structure-biological activity" relationship. Herein, a fruitful association of phosphorus dendrimers (both "ammonium-terminated" and "phosphonate-terminated") and titanium dioxide has been performed by means of the sol-gel process, resulting in mesoporous dendrimer-coated nanosized crystalline titanium dioxide. A similar organo-coating has been reproduced using single branch-mimicking dendrimers that allow isolation of an amorphous titanium dioxide. The impact of these materials on red blood cells was evaluated by studying cell hemolysis. Next, their cytotoxicity toward B14 Chinese fibroblasts and their antimicrobial activity were also investigated. Based on their variants (cationic versus anionic terminal groups and amorphous versus crystalline titanium dioxide phase), better understanding of the role of the surface-interface composition and the nature of the framework has been gained. No noticeable discrimination was observed for amorphous and crystalline material. In contrast, hemolysis and cytotoxicity were found to be sensitive to the nature of the interface composition, with the ammonium-terminated dendrimer-coated titanium dioxide being the most hemolytic and cytotoxic material. This surface-functionalization opens the door for creating a new synergistic machineries mechanism at the cellular level and seems promising for tailoring the biological activity of nanosized organic-inorganic hybrid materials.

Osteogenic potential of laser modified and conditioned titanium zirconium surfaces

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P David Charles

2016-01-01

Full Text Available Statement of Problem: The osseointegration of dental implant is related to their composition and surface treatment. Titanium zirconium (TiZr has been introduced as an alternative to the commercially pure titanium and its alloys as dental implant material, which is attributed to its superior mechanical and biological properties. Surface treatments of TiZr have been introduced to enhance their osseointegration ability; however, reliable, easy to use surface modification technique has not been established. Purpose: The purpose of this study was to evaluate and compare the effect of neodymium-doped yttrium aluminum garnet (Nd-YAG laser surface treatment of TiZr implant alloy on their osteogenic potential. Materials and Methods: Twenty disc-shaped samples of 5 mm diameter and 2 mm height were milled from the TiZr alloy ingot. The polished discs were ultrasonically cleaned in distilled water. Ten samples each were randomly selected as Group A control samples and Group B consisted of Nd-YAG laser surface etched and conditioned test samples. These were evaluated for cellular response. Cellular adhesion and proliferation were quantified, and the results were statistically analyzed using nonparametric analysis. Cellular morphology was observed using electron and epiflurosence microscopy. Results: Nd-YAG laser surface modified and conditioned TiZr samples increased the osteogenic potential. Conclusion: Nd-YAG laser surface modification of TiZr, improves the cellular activity, surface roughness, and wettability, thereby increasing the osteogenic potential.

Surface modification of the titanium implant using TEA CO2 laser pulses in controllable gas atmospheres - Comparative study

International Nuclear Information System (INIS)

Ciganovic, J.; Stasic, J.; Gakovic, B.; Momcilovic, M.; Milovanovic, D.; Bokorov, M.; Trtica, M.

2012-01-01

Interaction of a TEA CO 2 laser, operating at 10.6 μm wavelength and pulse duration of 100 ns (FWHM), with a titanium implant in various gas atmospheres was studied. The Ti implant surface modification was typically studied at the moderate laser beam energy density/fluence of 28 J/cm 2 in the surrounding of air, N 2 , O 2 or He. The energy absorbed from the TEA CO 2 laser beam is partially converted to thermal energy, which generates a series of effects, such as melting, vaporization of the molten material, shock waves, etc. The following titanium implant surface changes and phenomena were observed, depending on the gas used: (i) creation of cone-like surface structures in the atmospheres of air, N 2 and O 2 , and dominant micro-holes/pores in He ambient; (ii) hydrodynamic features, most prominent in air; (iii) formation of titanium nitride and titanium oxide layers, and (iv) occurrence of plasma in front of the implant. It can be concluded from this study that the reported laser fluence and gas ambiences can effectively be applied for enhancing the titanium implant roughness and creation of titanium oxides and nitrides on the strictly localized surface area. The appearance of plasma in front of the implants indicates relatively high temperatures created above the surface. This offers a sterilizing effect, facilitating contaminant-free conditions.

Preparation of Bioactive Titanium Surfaces via Fluoride and Fibronectin Retention

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Carlos Nelson Elias

2012-01-01

Full Text Available Statement of Problem. The chemical or topographic modification of the dental implant surface can affect bone healing, promote accelerated osteogenesis, and increase bone-implant contact and bonding strength. Objective. In this work, the effects of dental implant surface treatment and fibronectin adsorption on the adhesion of osteoblasts were analyzed. Materials and Methods. Two titanium dental implants (Porous-acid etching and PorousNano-acid etching followed by fluoride ion modification were characterized by high-resolution scanning electron microscopy, atomic force microscopy, and X-ray diffraction before and after the incorporation of human plasma fibronectin (FN. The objective was to investigate the biofunctionalization of these surfaces and examine their effects on the interaction with osteoblastic cells. Results. The evaluation techniques used showed that the Porous and PorousNano implants have similar microstructural characteristics. Spectrophotometry demonstrated similar levels of fibronectin adsorption on both surfaces (80%. The association indexes of osteoblastic cells in FN-treated samples were significantly higher than those in samples without FN. The radioactivity values associated with the same samples, expressed as counts per minute (cpm, suggested that FN incorporation is an important determinant of the in vitro cytocompatibility of the surfaces. Conclusion. The preparation of bioactive titanium surfaces via fluoride and FN retention proved to be a useful treatment to optimize and to accelerate the osseointegration process for dental implants.

The effect of heat- or ultra violet ozone-treatment of titanium on complement deposition from human blood plasma.

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Linderbäck, Paula; Harmankaya, Necati; Askendal, Agneta; Areva, Sami; Lausmaa, Jukka; Tengvall, Pentti

2010-06-01

Titanium (Ti) is a well known metallic biomaterial extensively used in dental, orthopaedic-, and occasionally also in blood contacting applications. It integrates well to bone and soft tissues, and is shown upon blood plasma contact to activate the intrinsic pathway of coagulation and bind complement factor 3b. The material properties depend largely on those of the nm-thick dense layer of TiO(2) that becomes rapidly formed upon contact with air and water. The spontaneously formed amorphous Ti-oxide has a pzc approximately 5-6 and its water solubility is at the order of 1-2 micromolar. It is often subjected to chemical- and heat treatments in order to increase the anatase- and rutile crystallinity, to modify the surface topography and to decrease the water solubility. In this work, we prepared sol-gel derived titanium and smooth PVD titanium surfaces, and analysed their oxide and protein deposition properties in human blood plasma before and after annealing at 100-500 degrees C or upon UVO-treatment for up to 96 hours. The blood plasma results show that complement deposition vanished irreversibly after heat treatment at 250-300 degrees C for 30 minutes or after UVO exposure for 24 hours or longer. XPS and infrared spectroscopy indicated change of surface water/hydroxyl binding upon the heat- and UVO treatments, and increased Ti oxidation. XRD analysis confirmed an increased crystallinity and both control (untreated) and annealed smooth titanium displayed low XRD-signals indicating some nanocrystallinity, with predominantly anatase phase. The current results show that the behaviour of titanium dioxide in blood contact can be controlled through relatively simple means, such as mild heating and illumination in UV-light, which both likely irreversibly change the stoichiometry and structure of the outmost layers of titanium dioxide and its OH/H(2)O binding characteristics. (c) 2010 Elsevier Ltd. All rights reserved.

The influence of cooling techniques on cutting forces and surface roughness during cryogenic machining of titanium alloys

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Wstawska Iwona

2016-12-01

Full Text Available Titanium alloys are one of the materials extensively used in the aerospace industry due to its excellent properties of high specific strength and corrosion resistance. On the other hand, they also present problems wherein titanium alloys are extremely difficult materials to machine. In addition, the cost associated with titanium machining is also high due to lower cutting velocities and shorter tool life. The main objective of this work is a comparison of different cooling techniques during cryogenic machining of titanium alloys. The analysis revealed that applied cooling technique has a significant influence on cutting force and surface roughness (Ra parameter values. Furthermore, in all cases observed a positive influence of cryogenic machining on selected aspects after turning and milling of titanium alloys. This work can be also the starting point to the further research, related to the analysis of cutting forces and surface roughness during cryogenic machining of titanium alloys.

Phenotypic Screening Identifies Synergistically Acting Natural Product Enhancing the Performance of Biomaterial Based Wound Healing

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Srinivasan Sivasubramanian

2017-07-01

Full Text Available The potential of multifunctional wound heal biomaterial relies on the optimal content of therapeutic constituents as well as the desirable physical, chemical, and biological properties to accelerate the healing process. Formulating biomaterials such as amnion or collagen based scaffolds with natural products offer an affordable strategy to develop dressing material with high efficiency in healing wounds. Using image based phenotyping and quantification, we screened natural product derived bioactive compounds for modulators of types I and III collagen production from human foreskin derived fibroblast cells. The identified hit was then formulated with amnion to develop a biomaterial, and its biophysical properties, in vitro and in vivo effects were characterized. In addition, we performed functional profiling analyses by PCR array to understand the effect of individual components of these materials on various genes such as inflammatory mediators including chemokines and cytokines, growth factors, fibroblast stimulating markers for collagen secretion, matrix metalloproteinases, etc., associated with wound healing. FACS based cell cycle analyses were carried out to evaluate the potential of biomaterials for induction of proliferation of fibroblasts. Western blot analyses was done to examine the effect of biomaterial on collagen synthesis by cells and compared to cells grown in the presence of growth factors. This work demonstrated an uncomplicated way of identifying components that synergistically promote healing. Besides, we demonstrated that modulating local wound environment using biomaterials with bioactive compounds could enhance healing. This study finds that the developed biomaterials offer immense scope for healing wounds by means of their skin regenerative features such as anti-inflammatory, fibroblast stimulation for collagen secretion as well as inhibition of enzymes and markers impeding the healing, hydrodynamic properties complemented

Molecular Characterization of Macrophage-Biomaterial Interactions

OpenAIRE

Moore, Laura Beth; Kyriakides, Themis R.

2015-01-01

Implantation of biomaterials in vascularized tissues elicits the sequential engagement of molecular and cellular elements that constitute the foreign body response. Initial events include the non-specific adsorption of proteins to the biomaterial surface that render it adhesive for cells such as neutrophils and macrophages. The latter undergo unique activation and in some cases undergo cell-cell fusion to form foreign body giant cells that contribute to implant damage and fibrotic encapsulati...

Characterisation of DLC films deposited using titanium isopropoxide (TIPOT) at different flow rates.

Science.gov (United States)

Said, R; Ali, N; Ghumman, C A A; Teodoro, O M N D; Ahmed, W

2009-07-01

In recent years, there has been growing interest in the search for advanced biomaterials for biomedical applications, such as human implants and surgical cutting tools. It is known that both carbon and titanium exhibit good biocompatibility and have been used as implants in the human body. It is highly desirable to deposit biocompatible thin films onto a range of components in order to impart biocompatibility and to minimise wear in implants. Diamond like carbon (DLC) is a good candidate material for achieving biocompatibility and low wear rates. In this study, thin films of diamond-like-carbon DLC were deposited onto stainless steel (316) substrates using C2H2, argon and titanium isopropoxide (TIPOT) precursors. Argon was used to generate the plasma in the plasma enhanced vapour deposition (PECVD) system. A critical coating feature governing the performance of the component during service is film thickness. The as-grown films were in the thickness range 90-100 nm and were found to be dependent on TIPOT flow rate. Atomic force microscopy (AFM) was used to characterise the surface roughness of the samples. As the flow rate of TIPOT increased the average roughness was found to increase in conjunction with the film thickness. Raman spectroscopy was used to investigate the chemical structure of amorphous carbon matrix. Surface tension values were calculated using contact angle measurements. In general, the trend of the surface tension results exhibited an opposite trend to that of the contact angle. The elemental composition of the samples was characterised using a VG ToF SIMS (IX23LS) instrument and X-ray photoelectron spectroscopy (XPS). Surprisingly, SIMS and XPS results showed that the DLC samples did not show evidence of titanium since no peaks representing to titanium appeared on the SIMS/XPS spectra.

UV-killed Staphylococcus aureus enhances adhesion and differentiation of osteoblasts on bone-associated biomaterials.

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Somayaji, Shankari N; Huet, Yvette M; Gruber, Helen E; Hudson, Michael C

2010-11-01

Titanium alloys (Ti) are the preferred material for orthopedic applications. However, very often, these metallic implants loosen over a long period and mandate revision surgery. For implant success, osteoblasts must adhere to the implant surface and deposit a mineralized extracellular matrix (ECM). Here, we utilized UV-killed Staphylococcus aureus as a novel osteoconductive coating for Ti surfaces. S. aureus expresses surface adhesins capable of binding to bone and biomaterials directly. Furthermore, interaction of S. aureus with osteoblasts activates growth factor-related pathways that potentiate osteogenesis. Although UV-killed S. aureus cells retain their bone-adhesive ability, they do not stimulate significant immune modulator expression. All of the abovementioned properties were utilized for a novel implant coating so as to promote osteoblast recruitment and subsequent cell functions on the bone-implant interface. In this study, osteoblast adhesion, proliferation, and mineralized ECM synthesis were measured on Ti surfaces coated with fibronectin with and without UV-killed bacteria. Osteoblast adhesion was enhanced on Ti alloy surfaces coated with bacteria compared to uncoated surfaces, while cell proliferation was sustained comparably on both surfaces. Osteoblast markers such as collagen, osteocalcin, alkaline phosphatase activity, and mineralized nodule formation were increased on Ti alloy coated with bacteria compared to uncoated surfaces.

Biomaterials based strategies for rotator cuff repair.

Science.gov (United States)

Zhao, Song; Su, Wei; Shah, Vishva; Hobson, Divia; Yildirimer, Lara; Yeung, Kelvin W K; Zhao, Jinzhong; Cui, Wenguo; Zhao, Xin

2017-09-01

Tearing of the rotator cuff commonly occurs as among one of the most frequently experienced tendon disorders. While treatment typically involves surgical repair, failure rates to achieve or sustain healing range from 20 to 90%. The insufficient capacity to recover damaged tendon to heal to the bone, especially at the enthesis, is primarily responsible for the failure rates reported. Various types of biomaterials with special structures have been developed to improve tendon-bone healing and tendon regeneration, and have received considerable attention for replacement, reconstruction, or reinforcement of tendon defects. In this review, we first give a brief introduction of the anatomy of the rotator cuff and then discuss various design strategies to augment rotator cuff repair. Furthermore, we highlight current biomaterials used for repair and their clinical applications as well as the limitations in the literature. We conclude this article with challenges and future directions in designing more advanced biomaterials for augmentation of rotator cuff repair. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanically-competent and cytocompatible polycaprolactone-borophosphosilicate hybrid biomaterials.

Science.gov (United States)

Mondal, Dibakar; Dixon, S Jeffrey; Mequanint, Kibret; Rizkalla, Amin S

2017-11-01

Organic-inorganic class II hybrid materials have domain sizes at the molecular level and chemical bonding between the organic and inorganic phases. We have previously reported the synthesis of class II hybrid biomaterials from alkoxysilane-functionalized polycaprolactone (PCL) and borophosphosilicate (B 2 O 3 -P 2 O 5 -SiO 2 ) glass (BPSG) through a non-aqueous sol-gel process. In the present study, the mechanical properties and degradability of these PCL/BPSG hybrid biomaterials were studied and compared to those of their conventional composite counterparts. The compressive strength, modulus and toughness of the hybrid biomaterials were significantly greater compared to the conventional composites, likely due to the covalent bonding between the organic and inorganic phases. A hybrid biomaterial (50wt% PCL and 50wt% BPSG) exhibited compressive strength, modulus and toughness values of 32.2 ± 3.5MPa, 573 ± 85MPa and 1.54 ± 0.03MPa, respectively; whereas the values for composite of similar composition were 18.8 ± 1.6MPa, 275 ± 28MPa and 0.76 ± 0.03MPa, respectively. Degradation in phosphate-buffered saline was slower for hybrid biomaterials compared to their composite counterparts. Thus, these hybrid materials possess superior mechanical properties and more controlled degradation characteristics compared to their corresponding conventional composites. To assess in vitro cytocompatibility, MC3T3-E1 pre-osteoblastic cells were seeded onto the surfaces of hybrid biomaterials and polycaprolactone (control). Compared to polycaprolactone, cells on the hybrid material displayed enhanced spreading, focal adhesion formation, and cell number, consistent with excellent cytocompatibility. Thus, based on their mechanical properties, degradability and cytocompatibility, these novel biomaterials have potential for use as scaffolds in bone tissue engineering and related applications. Copyright © 2017. Published by Elsevier Ltd.

Laser surface treatment for enhanced titanium to carbon fiber-reinforced polymer adhesion

NARCIS (Netherlands)

Palavra, Armin; Coelho, Bruno N.; de Hosson, Jeff Th. M.; Lima, Milton S. F.; Carvalho, Sheila M.; Costa, Adilson R.

The adhesion between carbon fiber-reinforced polymer (CFRP) and titanium parts can be improved by laser surface texturing before gluing them together. Here, a pulsed Nd:YAG laser was employed before bonding of the textured surfaces using an epoxy paste adhesive. To investigate the influence of the

Effect of Amelogenin Coating of a Nano-Modified Titanium Surface on Bioactivity

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Chisato Terada

2018-04-01

Full Text Available The interactions between implants and host tissues depend on several factors. In particular, a growing body of evidence has demonstrated that the surface texture of an implant influences the response of the surrounding cells. The purpose of this study is to develop new implant materials aiming at the regeneration of periodontal tissues as well as hard tissues by coating nano-modified titanium with amelogenin, which is one of the main proteins contained in Emdogain®. We confirmed by quartz crystal microbalance evaluation that amelogenin is easy to adsorb onto the nano-modified titanium surface as a coating. Scanning electron microscopy, scanning probe microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy analyses confirmed that amelogenin coated the nano-modified titanium surface following alkali-treatment. In vitro evaluation using rat bone marrow and periodontal ligament cells revealed that the initial adhesion of both cell types and the induction of hard tissue differentiation such as cementum were improved by amelogenin coating. Additionally, the formation of new bone in implanted surrounding tissues was observed in in vivo evaluation using rat femurs. Together, these results suggest that this material may serve as a new implant material with the potential to play a major role in the advancement of clinical dentistry.

Cytotoxic effect of galvanically coupled magnesium-titanium particles.

Science.gov (United States)

Kim, Jua; Gilbert, Jeremy L

2016-01-01

Recent work has shown that reduction reactions at metallic biomaterial surfaces can induce significant killing of cells in proximity to the surface. To exploit this phenomenon for therapeutic purposes, for example, for cancer tumor killing or antibacterial effects (amongst other applications), magnesium metal particles, galvanically coupled to titanium by sputtering, have been evaluated for their cell-killing capability (i.e. cytotoxicity). Magnesium (Mg) particles large enough to prevent particle phagocytosis were investigated, so that only electrochemical reactions, and not particle toxicity per se, caused cytotoxic effects. Titanium (Ti) coated magnesium particles, as well as magnesium-only particles were introduced into MC3T3-E1 mouse pre-osteoblast cell cultures over a range of particle concentrations, and cells were observed to die in a dosage-dependent manner. Ti-coated magnesium particles killed more cells at lower particle concentration than magnesium alone (Pmagnesium and magnesium-titanium had no significant difference at similar particle concentrations. Complete cell killing occurred at 750μg/ml and 1500μg/ml for Mg-Ti and Mg, respectively. Thus, this work demonstrates that galvanically coupled Mg-Ti particles have a significant cell killing capability greater than Mg alone. In addition, when the pH associated with complete killing with particles was created using NaOH only (no particles), then the percentage of cells killed was significantly less (Pmagnesium-titanium microparticles kill cells more effectively than magnesium particles alone. The killing effect was shown to not be due to pH shifts since no differences were seen for different particle types and pH adjusted medium without particles did not exhibit the same level of killing. The significance of this work is the recognition of this killing effect with Mg particles and the potential therapeutic applications in infection control and cancer treatment that this process may provide. Copyright �

Biocompatibility of titanium based implants treated with plasma immersion ion implantation

International Nuclear Information System (INIS)

Maendl, S.; Sader, R.; Thorwarth, G.; Krause, D.; Zeilhofer, H.-F.; Horch, H.H.; Rauschenbach, B.

2003-01-01

In this work, the biocompatibility of titanium before and after oxygen PIII is investigated using a rat animal model. Pure titanium (grade 2) and pre-anodized titanium were implanted with oxygen at elevated temperatures between 200 and 550 deg. C and subsequently analyzed for oxygen content and phase composition. No deterioration of the tensile strength and the yield strength was detected after the implantation. The mechanical stability of the osseointegration was determined with a pull-out test, where an increased shear strength was measured after PIII treatment. Only a slight improvement of the bone contact area, from an already excellent starting value, was observed for pure titanium. In contrast, a significant improvement was found for anodized titanium after PIII treatment. This astonishing difference can be explained with the surface topography and the phase composition of the anodized titanium samples

Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

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Ievgen Volodymyrovych PYLYPCHUK

2014-09-01

Full Text Available Hydroxyapatite (HA has long been used as a coating material in the implant industry for orthopedic implant applications. HA is the natural inorganic constituent of bone and teeth. By coating titanium (base material of implant engineering because of its lightness and durability with hydroxyapatite, we can provide higher biocompatibility of titanium implants, according to HA ability to form a direct biochemical bond with living tissues. This article reports a biomimetic approach for coating hydroxyapatite with titanium A method of modifying the surface of titanium by organic modifiers (for creating functional groups on the surface, followed by formation "self-assembled" layer of biomimetic hydroxyapatite in simulated body fluid (SBF. FTIR and XPS confirmed the formation of hydroxyapatite coatings on titanium surface. Comparative study of the formation of HA on the surface of titanium plates modified by different functional groups: Ti(≡OH, Ti/(≡Si-OH and Ti/(≡COOH is conducted. It was found that the closest to natural stoichiometric hydroxyapatite Ca/P ratio was obtained on Ti/(≡COOH samples. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4974

Relationship between unit cell type and porosity and the fatigue behavior of selective laser melted meta-biomaterials.

Science.gov (United States)

Amin Yavari, S; Ahmadi, S M; Wauthle, R; Pouran, B; Schrooten, J; Weinans, H; Zadpoor, A A

2015-03-01

Meta-materials are structures when their small-scale properties are considered, but behave as materials when their homogenized macroscopic properties are studied. There is an intimate relationship between the design of the small-scale structure and the homogenized properties of such materials. In this article, we studied that relationship for meta-biomaterials that are aimed for biomedical applications, otherwise known as meta-biomaterials. Selective laser melted porous titanium (Ti6Al4V ELI) structures were manufactured based on three different types of repeating unit cells, namely cube, diamond, and truncated cuboctahedron, and with different porosities. The morphological features, static mechanical properties, and fatigue behavior of the porous biomaterials were studied with a focus on their fatigue behavior. It was observed that, in addition to static mechanical properties, the fatigue properties of the porous biomaterials are highly dependent on the type of unit cell as well as on porosity. None of the porous structures based on the cube unit cell failed after 10(6) loading cycles even when the applied stress reached 80% of their yield strengths. For both other unit cells, higher porosities resulted in shorter fatigue lives for the same level of applied stress. When normalized with respect to their yield stresses, the S-N data points of structures with different porosities very well (R(2)>0.8) conformed to one single power law specific to the type of the unit cell. For the same level of normalized applied stress, the truncated cuboctahedron unit cell resulted in a longer fatigue life as compared to the diamond unit cell. In a similar comparison, the fatigue lives of the porous structures based on both truncated cuboctahedron and diamond unit cells were longer than that of the porous structures based on the rhombic dodecahedron unit cell (determined in a previous study). The data presented in this study could serve as a basis for design of porous biomaterials

Engineering of biomaterials

CERN Document Server

dos Santos, Venina; Savaris, Michele

2017-01-01

This book focuses on biomaterials of different forms used for medical implants. The authors introduce the characteristics and properties of biomaterials and then dedicate special chapters to metallic, ceramic, polymeric and composite biomaterials. Case studies on sterilization methods by biomaterials are also presented. Finally, the authors describe the degradation and effects of biomaterials in living tissue.

Laser-induced oxidation of titanium substrate: Analysis of the physicochemical structure of the surface and sub-surface layers

Energy Technology Data Exchange (ETDEWEB)

Antończak, Arkadiusz J., E-mail: arkadiusz.antonczak@pwr.edu.pl [Laser and Fiber Electronics Group, Faculty of Electrical Engineering, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Skowroński, Łukasz; Trzcinski, Marek [Institute of Mathematics and Physics, University of Technology and Life Sciences, Kaliskiego 7, 85-789 Bydgoszcz (Poland); Kinzhybalo, Vasyl V. [Wroclaw Research Centre EIT+, Stabłowicka 147, 54-066 Wrocław (Poland); Institute of Low Temperature and Structure Research, Okólna 2, 50-422 Wrocław (Poland); Łazarek, Łukasz K.; Abramski, Krzysztof M. [Laser and Fiber Electronics Group, Faculty of Electrical Engineering, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)

2015-01-15

Highlights: • Chemical structure of the films induced by laser on titanium surface was analyzed. • It was shown that outer layer of this films consist of oxides doped with nitrogen. • The optical properties of the laser-induced oxynitride films were characterized. • We found that the films demonstrated significant absorption in the band of 300–580 nm. • The morphology of the layers as a function of the laser fluence was investigated. - Abstract: This paper presents the results of the analysis of the complex chemical structure of the layers made on titanium in the process of the heating of its surfaces in an atmospheric environment, by irradiating samples with a nanosecond-pulsed laser. The study was carried out for electroplated, high purity, polycrystalline titanium substrates using a Yb:glass fiber laser. All measurements were made for samples irradiated in a broad range of accumulated fluence, below the ablation threshold. It has been determined how the complex index of refraction of both the oxynitride layers and the substrate vary as a function of accumulated laser fluence. It was also shown that the top layer of the film produced on titanium, which is transparent, is not a pure TiO{sub 2} as had been supposed before. The XPS and XRD analyses confirmed the presence of nitrogen compounds and the existence of nonstoichiometric compounds. By sputtering of the sample's surface using an Ar{sup +} ion gun, the changes in the concentration of individual elements as a function of the layer's cross-section were determined. Lastly, an analysis of the surface morphology has also been carried out, explaining why the layers crack and exfoliate from their substrate.

Nanopatterned bulk metallic glass-based biomaterials modulate macrophage polarization.

Science.gov (United States)

Shayan, Mahdis; Padmanabhan, Jagannath; Morris, Aaron H; Cheung, Bettina; Smith, Ryan; Schroers, Jan; Kyriakides, Themis R

2018-06-01

Polarization of macrophages by chemical, topographical and mechanical cues presents a robust strategy for designing immunomodulatory biomaterials. Here, we studied the ability of nanopatterned bulk metallic glasses (BMGs), a new class of metallic biomaterials, to modulate murine macrophage polarization. Cytokine/chemokine analysis of IL-4 or IFNγ/LPS-stimulated macrophages showed that the secretion of TNF-α, IL-1α, IL-12, CCL-2 and CXCL1 was significantly reduced after 24-hour culture on BMGs with 55 nm nanorod arrays (BMG-55). Additionally, under these conditions, macrophages increased phagocytic potential and exhibited decreased cell area with multiple actin protrusions. These in vitro findings suggest that nanopatterning can modulate biochemical cues such as IFNγ/LPS. In vivo evaluation of the subcutaneous host response at 2 weeks demonstrated that the ratio of Arg-1 to iNOS increased in macrophages adjacent to BMG-55 implants, suggesting modulation of polarization. In addition, macrophage fusion and fibrous capsule thickness decreased and the number and size of blood vessels increased, which is consistent with changes in macrophage responses. Our study demonstrates that nanopatterning of BMG implants is a promising technique to selectively polarize macrophages to modulate the immune response, and also presents an effective tool to study mechanisms of macrophage polarization and function. Implanted biomaterials elicit a complex series of tissue and cellular responses, termed the foreign body response (FBR), that can be influenced by the polarization state of macrophages. Surface topography can influence polarization, which is broadly characterized as either inflammatory or repair-like. The latter has been linked to improved outcomes of the FBR. However, the impact of topography on macrophage polarization is not fully understood, in part, due to a lack of high moduli biomaterials that can be reproducibly processed at the nanoscale. Here, we studied

Novel immobilizations of an adhesion peptide on the TiO2 surface: An XPS investigation

International Nuclear Information System (INIS)