Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials ...in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.
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TiO2 nanostructures represent a key platform for biomedical applications, due to the combination of biocompatibility and high surface area. Especially TiO2 nanotube layers have been ...widely investigated due to controllable nanotopographic effects as well as for electrodes in electrostimulation experiments. In the present work we produce Ar/H2-reduced ‘black’ TiO2 nanotube arrays with a strongly enhanced electrical conductivity and explore their interaction with mesenchymal stem cells when used as electrodes to apply electric fields (EF) across the cells. While we observe no significant change in cell adhesion and their focal contact formation on these high conductivity nanotubes, we do observe a rapid stem cell response when EF is engaged using the ‘black’ TiO2 nanotube arrays as electrodes. Compared to as-formed nanotube arrays, a faster stem cell growth was observed and a lower EF intensity caused an intracellular calcium level elevation. Our results indicate that the increased conductivity in TiO2 nanotubes significantly enhances the early stem cell response to minimal electric field stimuli.
The use of TiO2 nanostructures in biomedical applications is widely investigated, especially considering the nanostructured surface influence on the biomaterial-cell interactions. We have previously shown that an applied electric field (EF) on stem cells grown on TiO2 nanotubes leads to synergistic osteogenic stimulation in the absence of biochemical bone-inducing supplements. Here we report that black (i.e. highly conductive nanotubes obtained by reduction treatments) TiO2 nanotubes enable short-time EF effects on stem cells: we observe a faster stem cell growth and a significantly enhanced early stem cell response to minimal EF stimuli. The application of such nanostructures under electric field is promising for therapeutic interventions for bone regeneration and tissue engineering approaches.
Presently, industrial processes are increasingly based on the equipment that communicates with each other. IoT is present in all branches of the manufacturing process, from the flows of the equipment ...that work together to achieve the finished product, to the equipment for checking the quality of the process, to the existing logistics infrastructure inside the factory, to the coordination and administration side. One of the problems raised by using IoT is that related to data security and integrity. We are talking about data protection for unauthorized access: maintaining confidentiality at the level of the different departments in the production flow, protecting the data provided by equipment and preventing the injection of unauthorized data flows and we are talking about ensuring data integrity: the data from the equipment must be resistant to any disturbances that occur in the industrial environment on the communication channels (wireless or wired), be assured the correctness of the transmission of the commands from the operator to the equipment. The paper proposes a specialized IoT interface that ensures the protection and integrity of the data transmitted between endpoints. The protection is provided by a light encryption algorithm based on two keys stored at the source and the recipient and on a very simple but efficient coding / decoding scheme. Data integrity is ensured by an 8-bit code word algorithm that allows for the detection of 2 wrong bits and the correction of a wrong bit for a 4-bit packet. All these features are provided by a computer system integrated in the IoT equipment. The efficiency of the solution is illustrated by a case study where in the manufacturing process of pistons it was desired to introduce specific elements Industry 4.0: communication between equipment in order to detect problems in the flow of manufacture (a Poka Yoke system). On the one hand, the system is presented without the protection solution in which there are several communication errors due to the disturbances induced on the communication channels on the other side to the system, the interface proposed in this article is added (at minimum cost) and the performances will be presented in the communication introduced by it.
Controlled-diameter TiO2 nanotubes were obtained by electrochemical anodizing of two different substrates (Ti and Ti6Al7Nb) in an aqueous electrolyte. As-formed TiO2 nanotubes are amorphous and by ...subjecting to thermal treatments, the structure becomes crystalline. An optimal thermal treatment with a specific anatase/rutile ratio was chosen, determined from X-ray diffraction (XRD). The electrochemical behaviour of annealed and as-formed samples was followed with Tafel plots and Electrochemical impedance spectroscopy (EIS), while surface analysis involved scanning electron microscopy (SEM) and contact angle measurements (CA). Annealed samples have a more hydrophilic character than as-formed as well as a better stability in bioliquids. Such behaviour of annealed samples is connected with a better biocompatibility expressed in terms of cell morphology and gene expression of bone specific markers obtained from Reverse Transcription Polymerase Chain Reaction (RT-PCR).
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► TiO2 nanotubes are obtained on Ti and on Ti6Al7Nb, furthermore optimal thermal treatments are chosen. ► Annealed TiO2 nanotubes are more stable regarding corrosion. ► RT-PCR data present a two fold increase of osteocalcin expression in MG-63 cells grown on annealed TiO2 nanotubes. ► All these data suggest that annealed TiO2 nanotubes may represent a promising material for orthopaedic cellular therapy.
The present paper investigates two different titanium alloys: Ti6Al7Nb – a well‐established implant biomaterial and Ti6Al4Zr – a relatively new titanium alloy. Roughness is evaluated with atomic ...force microscopy (AFM) and the hydrophilic/hydrophobic balance by contact angle measurements. Furthermore, an extensive characterization was done in order to evaluate and compare the electrochemical behaviour for both titanium alloys in artificial Fusayama and Afnor saliva, at different immersion times, and consisted of Tafel plots, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Also, metals ions release was measured using inductively coupled plasma mass spectrometry (ICP‐MS). In both studied artificial saliva, Ti6Al4Zr alloy presents a better electrochemical behaviour according to corrosion rates from both electrochemical techniques and ICP‐MS.
Poka Yoke is a method of quality management which is related to prevent faults from arising during production processes. It deals with "fail-sating" or "mistake-proofing". The Poka-yoke concept was ...generated and developed by Shigeo Shingo for the Toyota Production System. Poka Yoke is used in many fields, especially in monitoring production processes. In many cases, identifying faults in a production process involves a higher cost than necessary cost of disposal. Usually, poke yoke solutions are based on multiple sensors that identify some nonconformities. This means the presence of different equipment (mechanical, electronic) on production line. As a consequence, coupled with the fact that the method itself is an invasive, affecting the production process, would increase its price diagnostics. The bulky machines are the means by which a Poka Yoke system can be implemented become more sophisticated. In this paper we propose a solution for the Poka Yoke system based on image analysis and identification of faults. The solution consists of a module for image acquisition, mid-level processing and an object recognition module using associative memory (Hopfield network type). All are integrated into an embedded system with AD (Analog to Digital) converter and Zync 7000 (22 nm technology).
This paper presents a method for locating the operators, equipment and parts using radio communications systems. Specifically there will be radio transceiver arranged in a network of active and ...passive radio receivers placed on personnel, equipment or parts. Based on a radio triangulation method, it is determined the location of the all resources and parts involved in manufacturing process. The transceivers communicate with each other via "routers" - also components of the network. Such a structure may extend over large distances even in indoor spaces where there are obstacles (walls between rooms). The location is done by determining the power of transmission signal for at least three end points. The receiver position is then transmitted over the network through routers, to a central server where all positions of the resources are centralized. Our solution is a non-invasive and low cost method for determining resource position in the factory. The system can be used for both resource planning production for current process more efficient and for further analysis of the movement of resources during previous processes with possible adjustments to the workspace and re-planning of resources for future processes.
The electric vehicle is a new consumer of electricity that is becoming more and more widespread. Under these circumstances, new strategies for optimizing power consumption and increasing vehicle ...autonomy must be designed. These must include route planning along with consumption, fuelling points and points of interest. The hardware and software solution proposed by us allows: non-invasive monitoring of power consumption, energy autonomy - it does not add any extra consumption, data transmission to a server and data fusion with the route, the points of interest of the route and the power supply points. As a result: an optimal route planning service will be provided to the driver, considering the route, the requirements of the electric vehicle and the consumer profile. The solution can be easily installed on any type of electric car - it does not involve any intervention on the equipment.
Biomaterial implantation in a living tissue triggers the activation of macrophages in inflammatory events, promoting the transcription of pro-inflammatory mediator genes. The initiation of macrophage ...inflammatory processes is mainly regulated by signaling proteins of mitogen-activated protein kinase (MAPK) and by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways. We have previously shown that titania nanotubes modified Ti surfaces (Ti/TiO2) mitigate the immune response, compared with flat Ti surfaces; however, little is known regarding the underlying mechanism. Therefore, the aim of this study is to investigate the mechanism(s) by which this nanotopography attenuates the inflammatory activity of macrophages. Thus, we analyzed the effects of TiO2 nanotubes on the activation of MAPK and NF-κB signaling pathways in standard and lipopolysaccharide-evoked conditions. Results showed that the Ti/TiO2 significantly reduce the expression levels of the phosphorylated forms of p38, ERK1/2, c-Jun NH2-terminal kinase (JNK), IKKβ, and IkB-α. Furthermore, a significant reduction in the p65 nuclear accumulation on the nanotubular surface was remarked. Following, by using specific MAPK inhibitors, we observed that lipopolysaccharide-induced production of monocyte chemotactic protein-1 and nitric oxide was significantly inhibited on the Ti/TiO2 surface via p38 and ERK1/2, but not via JNK. However, the selective inhibitor for JNK signaling pathway (SP600125) was effective in reducing tumor necrosis factor alpha release as well as monocyte chemotactic protein-1 and nitric oxide production. Altogether, these data suggest that titania nanotubes can attenuate the macrophage inflammatory response via suppression of MAPK and NF-κB pathways providing a potential mechanism for their anti-inflammatory activity.
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