8 research outputs found

    Electrochemical behavior of additively manufactured patterned titanium alloys under simulated normal, inflammatory, and severe inflammatory conditions

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    The electrochemical behavior of a biomaterial surface in local conditions is a significant factor affecting the success of the implant placement. This is of a particular importance of metallic biomaterials which can undergo oxidation, corrosion and subsequent degradation. This study reports new data on the electrochemical behavior of additively manufactured (AM) patterned titanium alloys, analyzed after 1 and 12 h immersion in three different media mimicking normal, inflammatory and severe inflammatory conditions. Polarization study showed that corrosion resistance increases with increasing immersion time in all cases. It was found that in inflammatory condition a destructive effect on the passive layer's resistance was triggered by H2O2 whereas in severe inflammatory condition, albumin, lactate, and H2O2 all have a synergistic effect towards decreasing the corrosion resistance of patterned titanium layers. Electrochemical impedance data suggests that in the severe inflammatory condition the charged albumins are attracting to the localized pitting areas, changing diffusion transport of corrosive species at the interface of the metal/passive layer. The electrochemical tests also proven that laser-assisted patterned titanium alloys surfaces have an improved corrosion resistance in simulated solutions compared to untreated titanium of the same composition. It is suggested that new surface topography and wettability are also positive factors contributing to this improved corrosion performance in patterned specimens

    Electrochemical and biological characterization of Ti–Nb–Zr–Si alloy for orthopedic applications

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    | openaire: EC/H2020/860462/EU//PREMUROSA Funding Information: Financial supports of the European Commission under FP6 SME integrated project “Meddelcoat” (contract 026501-2) and from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie ITN “Premurosa” (GA 860462) are gratefully acknowledged. Authors are greatly thankful for the late Dr. A. V. Mazur for help in TNZS alloy preparation, Dr. H. Yu for assistance in thermodynamic database optimization and Dr. D. Sukhomlinov for his help in performing the SEM/EDS. The LEMI assistance in analyzing details for the cells-materials interactions, led by Mrs. Prof. M.-F. Harmand and Mrs. D. Pierron, is also gratefully acknowledged. Publisher Copyright: © 2023, The Author(s).The performance of current biomedical titanium alloys is limited by inflammatory and severe inflammatory conditions after implantation. In this study, a novel Ti–Nb–Zr–Si (TNZS) alloy was developed and compared with commercially pure titanium, and Ti–6Al–4V alloy. Electrochemical parameters of specimens were monitored during 1 h and 12 h immersion in phosphate buffered saline (PBS) as a normal, PBS/hydrogen peroxide (H2O2) as an inflammatory, and PBS/H2O2/albumin/lactate as a severe inflammatory media. The results showed an effect of the H2O2 in inflammatory condition and the synergistic behavior of H2O2, albumin, and lactate in severe inflammatory condition towards decreasing the corrosion resistance of titanium biomaterials. Electrochemical tests revealed a superior corrosion resistance of the TNZS in all conditions due to the presence of silicide phases. The developed TNZS was tested for subsequent cell culture investigation to understand its biocompatibility nature. It exhibited favorable cell-materials interactions in vitro compared with Ti–6Al–4V. The results suggest that TNZS alloy might be a competitive biomaterial for orthopedic applications.Peer reviewe

    Smart Hydrogels for Advanced Drug Delivery Systems

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    | openaire: EC/H2020/860462/EU//PREMUROSA Funding Information: This study has received funding from the European Union?s Horizon 2020 research and innovation Programme under the Marie Sk?odowska-Curie grant agreement no. 860462 for the ?PREMUROSA? project. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Since the last few decades, the development of smart hydrogels, which can respond to stimuli and adapt their responses based on external cues from their environments, has become a thriving research frontier in the biomedical engineering field. Nowadays, drug delivery systems have received great attention and smart hydrogels can be potentially used in these systems due to their high stability, physicochemical properties, and biocompatibility. Smart hydrogels can change their hydrophilicity, swelling ability, physical properties, and molecules permeability, influenced by external stimuli such as pH, temperature, electrical and magnetic fields, light, and the biomolecules’ concentration, thus resulting in the controlled release of the loaded drugs. Herein, this review encompasses the latest investigations in the field of stimuli-responsive drug-loaded hydrogels and our contribution to this matter.Peer reviewe

    Surface functionalization of anodized tantalum with Mn3O4 nanoparticles for effective corrosion protection in simulated inflammatory condition

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    | openaire: EC/H2020/860462/EU//PREMUROSA This study has received funding from the European Union's Horizon 2020 Research and Innovation Program under grant agreement no. 860462 for “PREMUROSA” project (A.B–K., M.G.). The fabrication of the anodic and EPD coatings was performed at Materials and Energy Research Center, Tehran, Iran. The authors are willing to express their gratitude for this support.The study highlights the corrosion behavior of untreated and treated tantalum with addition of trimanganese tetraoxide (Mn3O4) nanoparticles in simulated inflammatory media. The anodic layer was produced on pure tantalum by anodization in electrolytes composed of ammonium fluoride, ethylene glycol, and water. Nanoparticles were deposited uniformly on the surface of the anodized tantalum with the electrophoretic deposition (EPD) method. The results revealed that the anodic/EPD coating possessed more compact microstructure and higher bond strength than the anodic coating. Simulated inflammatory medium was based on phosphate-buffered saline with additions of H2O2 and HCl. Potentiodynamic polarization and electrochemical impedance spectroscopy studies showed that the anodic and Mn3O4 layers protected the tantalum from corroding in an acidic inflammatory condition. Finally, the corrosion protection mechanism of Mn3O4 NPs in inflammatory condition was presented.Peer reviewe

    Octacalcium Phosphate-Laden Hydrogels on 3D-Printed Titanium Biomaterials Improve Corrosion Resistance in Simulated Biological Media

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    | openaire: EC/H2020/860462/EU//PREMUROSA Funding Information: Financial support from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie ITN “Premurosa” (GA 860462) is gratefully acknowledged. The authors also acknowledge the access to the infrastructure and expertise of the BBCE—the Baltic Biomaterials Centre of Excellence (European Union’s Horizon 2020 research and innovation program under the grant agreement No. 857287). Publisher Copyright: © 2023 by the authors.The inflammatory-associated corrosion of metallic dental and orthopedic implants causes significant complications, which may result in the implant’s failure. The corrosion resistance can be improved with coatings and surface treatments, but at the same time, it might affect the ability of metallic implants to undergo proper osteointegration. In this work, alginate hydrogels with and without octacalcium phosphate (OCP) were made on 3D-printed (patterned) titanium alloys (Ti Group 2 and Ti-Al-V Group 23) to enhance their anticorrosion properties in simulated normal, inflammatory, and severe inflammatory conditions in vitro. Alginate (Alg) and OCP-laden alginate (Alg/OCP) hydrogels were manufactured on the surface of 3D-printed Ti substrates and were characterized with wettability analysis, XRD, and FTIR. The electrochemical characterization of the samples was carried out with open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). It was observed that the hydrophilicity of Alg/OCP coatings was higher than that of pure Alg and that OCP phase crystallinity was increased when samples were subjected to simulated biological media. The corrosion resistance of uncoated and coated samples was lower in inflammatory and severe inflammatory environments vs. normal media, but the hydrogel coatings on 3D-printed Ti layers moved the corrosion potential towards more nobler values, reducing the corrosion current density in all simulated solutions. These measurements revealed that OCP particles in the Alg hydrogel matrix noticeably increased the electrical charge transfer resistance at the substrate and coating interface more than with Alg hydrogel alone.Peer reviewe

    Effects of co-incorporated ternary elements on biocorrosion stability, antibacterial efficacy, and cytotoxicity of plasma electrolytic oxidized titanium for implant dentistry

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    Funding Information: This research work has been supported with research grant (No.: 247383 ) by Materials and Energy Research Center (MERC), Karaj, Iran . Publisher Copyright: © 2021 Elsevier B.V.In this study, calcium, phosphorus, and copper co-incorporated titanium oxide (TiO2) layers were prepared on titanium substrates using the plasma electrolytic oxidation process. Thereafter, their features were studied to be used in dental implants. Surface characterization revealed that the addition of calcium and copper ions to the phosphate-based electrolyte led to the development of the ternary elements incorporated TiO2 layer with greater surface homogeneity, roughness, hydrophobicity, and growth rate. As well, electrochemical impedance spectroscopy proved that the placement of the ternary elements caused more compaction of the TiO2 layer by reducing inherent defects. Thus, the corrosion behavior of the TiO2 layer in artificial saliva solution has promoted, which consequently enhanced the corrosion potential by 187 mV and diminished the corrosion current density by one order of magnitude. Antibacterial assessment against Escherichia coli showed that incorporation of copper along with calcium and phosphorus significantly restored the bactericidal activity of the TiO2 layer. Furthermore, the integration, proliferation, and viability of MG-63 osteoblastic cells have considerably improved in the biological response to the calcium, phosphorus, and copper-containing layer.Peer reviewe

    Additive Manufacturing: An Opportunity for the Fabrication of Near-Net-Shape NiTi Implants

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    Nickel–titanium (NiTi) is a shape-memory alloy, a type of material whose name is derived from its ability to recover its original shape upon heating to a certain temperature. NiTi falls under the umbrella of metallic materials, offering high superelasticity, acceptable corrosion resistance, a relatively low elastic modulus, and desirable biocompatibility. There are several challenges regarding the processing and machinability of NiTi, originating from its high ductility and reactivity. Additive manufacturing (AM), commonly known as 3D printing, is a promising candidate for solving problems in the fabrication of near-net-shape NiTi biomaterials with controlled porosity. Powder-bed fusion and directed energy deposition are AM approaches employed to produce synthetic NiTi implants. A short summary of the principles and the pros and cons of these approaches is provided. The influence of the operating parameters, which can change the microstructural features, including the porosity content and orientation of the crystals, on the mechanical properties is addressed. Surface-modification techniques are recommended for suppressing the Ni ion leaching from the surface of AM-fabricated NiTi, which is a technical challenge faced by the long-term in vivo application of NiTi

    Surface modified NiTi smart biomaterials: surface engineering and biological compatibility

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    NiTi metallic biomaterials have a broad spectrum of clinical applications from heart stents to orthopedic implants. Recently, the use of NiTi smart biomaterials has received growing attention due to their striking features, including a low elastic modulus, shape memory behavior and acceptable biocompatibility. However, leaching of Ni ions from the surface of NiTi, the need for decreased elastic modulus and the desire for improved biological properties, including better material-cell interactions, biomineralization, and antibacterial activity, have provided the driving force for a wide variety of surface-modification techniques to address these problems before using NiTi in vivo. Depending on the target application, both dry and wet coating techniques have been employed to deposit biocompatible and bioactive layers over NiTi smart biomaterials. The influence of such coatings on the biological characteristics of the NiTi is illustrated. R&D activities have proved fruitful but much work needs to be done before clinical use of coated-NiTi
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