A Micro Arc Oxidation Composite Coating Developed on a Biocompatible Magnesium Alloy for Bone Implant Applications

2020 ◽  
Author(s):  
Hamdy Ibrahim
Keyword(s):  
Composite Coating ◽  
Biomedical Applications ◽  
The Body ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Patient Specific ◽  
Coating Process ◽  
Bone Implant ◽  
Corrosion Rates ◽  
Micro Arc Oxidation

Abstract The biocompatibility, mechanical properties and biodegradable nature of Mg alloys have made them attractive for biomedical applications, especially as bone implants. However, one of the main problems that limit the use of Mg alloy for several biomedical applications is their fast corrosion rates inside the body. Coating Mg-based implants is one of the most extensively studied approaches to address the fast corrosion rates of Mg alloys in the physiological environment. Micro arc oxidation (MAO) coating process has shown very promising results towards reducing the corrosion rates of Mg alloys due to the formation of a protective dense, well-adhered and wear-resistant oxide layer on the surface of the Mg alloy. In this study, the feasibility of coating an Mg-Zn-Ca-based alloy with a composite coating made using a micro-arc oxidation coating process and an immersion (dipping process) was investigated. The corrosion properties and surface characteristics of the coated alloy samples are assessed. The created protective composite coating is used to slow the corrosion rates of an Mg-Zn-Ca-based alloy. The developed composite coating resulted in a significant reduction in the corrosion rates. The results of this study show that it is possible to achieve more controlled corrosion rates of Mg-based implants towards patient-specific bone implant applications.

scholarly journals Layer-by-Layer Self-Assembly Composite Coatings for Improved Corrosion and Wear Resistance of Mg Alloy for Biomedical Applications

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 515
Author(s):  
Tongfang Liu ◽  
Song Rui ◽  
Sheng Li
Keyword(s):  
Wear Resistance ◽  
Self Assembly ◽  
Biomedical Applications ◽  
Composite Coatings ◽  
Covalent Bond ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Layer By Layer ◽  
Corrosion Propagation ◽  
Chemical Linkage

Mg alloys are promising biomedical metal due to their natural degradability, good processability, and favorable mechanical properties. However, the poor corrosion resistance limits their further clinical applications. In this study, the combined strategies of surface chemical treatment and layer-by-layer self-assembly were used to prepare composite coatings on Mg alloys to improve the biocorrosion resistance. Specially, alkalized AZ91 Mg alloy generated chemical linkage with silane via Si–O–Mg covalent bond at the interface. Subsequently, Si–OH group from silane formed a crosslinked silane layer by Si–O–Si network. Further chemical assembly with graphene oxide (GO), lengthened the diffusion pathway of corrosive medium. The chemically assembled composite coatings could firmly bond to Mg alloy substrate, which persistently and effectively acted as compact barriers against corrosion propagation. Improved biocorrosion resistance of AZ91 Mg alloy with self-assembly composite coatings of silane/GO was subsequently confirmed by immersion tests. Besides, the Mg alloy exhibited good wear resistance due to outside layer of GO with a lubricant effect. Cell viability of higher than 75% had also been found for the alloy with self-assembly composite coatings, which showed good cytocompatibility.

scholarly journals Designing Advanced Biomedical Biodegradable Mg Alloys: A Review

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 85
Author(s):  
Murtatha M. Jamel ◽  
Mostafa M. Jamel ◽  
Hugo F. Lopez
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Hydrogen Generation ◽  
Mg Alloys ◽  
Living Tissue ◽  
Effective Factors ◽  
Alloying Additions ◽  
Mechanical Integrity ◽  
Corrosion Rates ◽  
Mechanical Properties And Corrosion

The increased demand for alloys that can serve as implantation devices with outstanding bio-properties has led to the development of numerous biomedical Mg-based alloys. These alloys have been extensively investigated for their performance in living tissue with mixed results. Hence, there are still major concerns regarding the use of magnesium alloys for such applications. Among the issues raised are elevated corrosion rates, hydrogen generation, and the maintenance of mechanical integrity for designated healing times. In addition, toxicity can arise from the addition of alloying elements that are intended to improve the mechanical integrity and corrosion resistance of Mg alloys. The current work reviews the recent advances in the development of Mg alloys for applications as bio-absorbable materials in living organic environments. In particular, it attempts to develop a roadmap of effective factors that can be utilized when designing Mg alloys. Among the factors reviewed are the effects of alloying additions and processing methods on the exhibited mechanical properties and corrosion rates in simulated bio-fluids used in biomedical applications.

Improvement of corrosion resistance of magnesium alloys for biomedical applications

2015 ◽  
Vol 33 (3-4) ◽  
pp. 101-117 ◽  
Author(s):  
Kai Chen ◽  
Jianwei Dai ◽  
Xiaobo Zhang
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Biomedical Applications ◽  
Mg Alloys ◽  
Localized Corrosion ◽  
Biodegradable Implants ◽  
Ordered Structure ◽  
Corrosion Rates ◽  
Long Period ◽  
Treatment Techniques

AbstractIn recent years, magnesium (Mg) alloys have attracted great attention due to superior biocompatibility, biodegradability, and other characteristics important for use in biodegradable implants. However, the development of Mg alloys for clinical application continues to be hindered by high corrosion rates and localized corrosion modes, both of which are detrimental to the mechanical integrity of a load-bearing temporary implant. To overcome these challenges, technologies have been developed to improve the corrosion resistance of Mg alloys, among which surface treatment is the most common way to enhance not only the corrosion resistance, but also the bioactivity of biodegradable Mg alloys. Nevertheless, surface treatments are unable to fundamentally solve the problems of fast corrosion rate and localized corrosion. Therefore, it is of great importance to alter and improve the intrinsic corrosion behavior of Mg alloys for biomedical applications. To show the significance of the intrinsic corrosion resistance of biodegradable Mg alloys and attract much attention on this issue, this article presents a review of the improvements made to enhance intrinsic corrosion resistance of Mg alloys in recent years through the design and preparation of the Mg alloys, including purifying, alloying, grain refinement, and heat treatment techniques. The influence of long-period stacking-ordered structure on corrosion behavior of the biodegradable Mg alloys is also discussed.

scholarly journals Biodegradable Magnesium Bone Implants Coated with a Novel Bioceramic Nanocomposite

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1315 ◽  
Author(s):  
Mehdi Razavi ◽  
Mohammadhossein Fathi ◽  
Omid Savabi ◽  
Lobat Tayebi ◽  
Daryoosh Vashaee
Keyword(s):  
Corrosion Rate ◽  
Protective Layer ◽  
Nanocomposite Coating ◽  
The Body ◽  
Mg Alloys ◽  
Surrounding Tissue ◽  
Zinc Alloy ◽  
Micro Arc Oxidation ◽  
Significant Release

Magnesium (Mg) alloys are being investigated as a biodegradable metallic biomaterial because of their mechanical property profile, which is similar to the human bone. However, implants based on Mg alloys are corroded quickly in the body before the bone fracture is fully healed. Therefore, we aimed to reduce the corrosion rate of Mg using a double protective layer. We used a magnesium-aluminum-zinc alloy (AZ91) and treated its surface with micro-arc oxidation (MAO) technique to first form an intermediate layer. Next, a bioceramic nanocomposite composed of diopside, bredigite, and fluoridated hydroxyapatite (FHA) was coated on the surface of MAO treated AZ91 using the electrophoretic deposition (EPD) technique. Our in vivo results showed a significant enhancement in the bioactivity of the nanocomposite coated AZ91 implant compared to the uncoated control implant. Implantation of the uncoated AZ91 caused a significant release of hydrogen bubbles around the implant, which was reduced when the nanocomposite coated implants were used. Using histology, this reduction in the corrosion rate of the coated implants resulted in an improved new bone formation and reduced inflammation in the interface of the implants and the surrounding tissue. Hence, our strategy using a MAO/EPD of a bioceramic nanocomposite coating (i.e., diopside-bredigite-FHA) can significantly reduce the corrosion rate and improve the bioactivity of the biodegradable AZ91 Mg implant.

scholarly journals Surface Treatment of Zn-Mn-Mg Alloys by Micro-Arc Oxidation in Silicate-Based Solutions with Different NaF Concentrations

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4289
Author(s):  
Shineng Sun ◽  
Guo Ye ◽  
Ziting Lu ◽  
Yuming Weng ◽  
Guofeng Ma ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Corrosion Behavior ◽  
Biomedical Applications ◽  
Electrochemical Impedance ◽  
Mg Alloys ◽  
X Ray Diffraction ◽  
Submicron Scale ◽  
Micro Arc Oxidation ◽  
Hank’S Solution ◽  
Zn Alloys

Newly developed Zn-Mn-Mg alloys can be invoked as biomedical materials because of their excellent mechanical properties. However, the corrosion behavior of Zn-Mn-Mg alloys was still lacking in research. It had grown to be a hot research topic to improve the corrosion behavior of Zn alloys by surface treatment to meet the application of degradable Zn alloys in biomedical applications. Micro arc oxidation (MAO) is a simple and effective method to improve the corrosion behavior of the alloy. MAO coatings were successfully prepared on the surface of Zn-Mn-Mg alloys by MAO in silicate-based solutions with different NaF concentrations. The microstructure and phase composition of MAO coatings prepared on Zn-Mn-Mg alloys with different NaF concentrations in the electrolyte was examined by a scanning electron microscope and X-ray diffraction. The results showed that the MAO coatings are porous and mainly composed of ZnO. With the increasing NaF concentration in the electrolyte, the average thickness increases. The distribution of the micro/nanopores was uniform, and the pore size ranged from the submicron scale to several micrometers after MAO treatment in the electrolyte containing different concentrations of NaF. Potential dynamic polarization curves and electrochemical impedance spectroscopy were employed to assess the corrosion behavior of MAO coatings in Hank’s solution. The highest corrosion rate can be achieved after MAO treatment, with an electrolyte concentration of 1.5 g/L NaF in Hank’s solution. These results indicated that MAO coating can accelerate the corrosion resistance of a Zn-Mn-Mg alloy.

STUDY OF CHITOSAN COATINGS ON NANOPARTICLES FOR BIOMEDICAL APPLICATIONS

2004 ◽  
Vol 03 (04n05) ◽  
pp. 685-689 ◽  
Author(s):  
W. B. TAN ◽  
Y. ZHANG
Keyword(s):  
Biomedical Applications ◽  
Au Nanoparticles ◽  
Biomedical Application ◽  
The Body ◽  
Nanometer Scale ◽  
Hydroxyl Groups ◽  
Coating Process ◽  
Naturally Occurring ◽  
The Relationship

Of late, much work and interest had been generated in the fields involving nanoparticles. Due to their nanometer scale, these particles have been proven to be promising in diverse applications such as electronics and medicine, amongst others. In addition, an emerging and attractive use of nanoparticles as biotherapeutic delivery agents within the body was introduced. However, in order to use these nanoparticles in any biomedical application, they must be rendered biocompatible. In this paper, we attempt to coat chitosan, a naturally-occurring polymer which is biocompatible, biodegradable and nontoxic, onto the surfaces of nanoparticles. 5 nm gold ( Au ) nanoparticles were chosen for our study as they are commercially available. The presence of a chitosan shell not only renders these nanoparticles biocompatible, the amino and hydroxyl groups of chitosan also allow the immobilization of many biotherapeutic agents. The relationship between the concentration of the chitosan used in the coating process and the thickness of the chitosan shell formed is investigated. It is hoped that the results of this study can also be applied to other nanoparticles, in addition to Au , that are intended to be used in bioapplications.

scholarly journals Degradation Resistance and In Vitro Cytocompatibility of Iron-Containing Coatings Developed on WE43 Magnesium Alloy by Micro-Arc Oxidation

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1138
Author(s):  
Rongfa Zhang ◽  
Zeyu Zhang ◽  
Yuanyuan Zhu ◽  
Rongfang Zhao ◽  
Shufang Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Ceramic Coatings ◽  
The Body ◽  
Mg Alloy ◽  
Vital Functions ◽  
Fe Content ◽  
Ferric Sodium ◽  
Micro Arc Oxidation ◽  
Important Trace Element

Iron (Fe) is an important trace element for life and plays vital functions in maintaining human health. In order to simultaneously endow magnesium alloy with good degradation resistance, improved cytocompatibility, and the proper Fe amount for the body accompanied with degradation of Mg alloy, Fe-containing ceramic coatings were fabricated on WE43 Mg alloy by micro-arc oxidation (MAO) in a nearly neutral pH solution with added 0, 6, 12, and 18 g/L ferric sodium ethylenediaminetetraacetate (NaFeY). The results show that compared with the bare Mg alloy, the MAO samples with developed Fe-containing ceramic coatings significantly improve the degradation resistance and in vitro cytocompatibility. Fe in anodic coatings is mainly present as Fe2O3. The increased NaFeY concentration favorably contributes to the enhancement of Fe content but is harmful to the degradation resistance of MAO coatings. Our study reveals that the developed Fe-containing MAO coating on Mg alloy exhibits potential in clinical applications.

scholarly journals Fabrication of hydroxyapatite coatings on AZ31 Mg alloy by micro-arc oxidation coupled with sol–gel treatment

RSC Advances ◽  
2018 ◽  
Vol 8 (22) ◽  
pp. 12368-12375 ◽  
Author(s):  
Hui Tang ◽  
Wei Tao ◽  
Chao Wang ◽  
Huilong Yu
Keyword(s):  
Mechanical Properties ◽  
Sol Gel ◽  
Orthopedic Implants ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Hydroxyapatite Coatings ◽  
Az31 Mg Alloy ◽  
Gel Treatment ◽  
Micro Arc Oxidation

Magnesium (Mg) alloys, can potentially be used as biodegradable orthopedic implants because of their biodegradability and good mechanical properties.

Scaffolds for Drug Delivery in Tissue Engineering

2008 ◽  
Vol 1 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Vikas V. Gaikwad ◽  
Abasaheb B. Patil ◽  
Madhuri V. Gaikwad
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Heart Diseases ◽  
Cartilage Regeneration ◽  
Tissue Growth ◽  
The Body ◽  
Patient Specific ◽  
In Situ Gel ◽  
Heart Muscle Cells

Scaffolds are used for drug delivery in tissue engineering as this system is a highly porous structure to allow tissue growth.  Although several tissues in the body can regenerate, other tissue such as heart muscles and nerves lack regeneration in adults. However, these can be regenerated by supplying the cells generated using tissue engineering from outside. For instance, in many heart diseases, there is need for heart valve transplantation and unfortunately, within 10 years of initial valve replacement, 50–60% of patients will experience prosthesis associated problems requiring reoperation. This could be avoided by transplantation of heart muscle cells that can regenerate. Delivery of these cells to the respective tissues is not an easy task and this could be done with the help of scaffolds. In situ gel forming scaffolds can also be used for the bone and cartilage regeneration. They can be injected anywhere and can take the shape of a tissue defect, avoiding the need for patient specific scaffold prefabrication and they also have other advantages. Scaffolds are prepared by biodegradable material that result in minimal immune and inflammatory response. Some of the very important issues regarding scaffolds as drug delivery systems is reviewed in this article.

Biocompatible Polymers and their Potential Biomedical Applications: A Review

2019 ◽  
Vol 25 (34) ◽  
pp. 3608-3619 ◽  
Author(s):  
Uzma Arif ◽  
Sajjad Haider ◽  
Adnan Haider ◽  
Naeem Khan ◽  
Abdulaziz A. Alghyamah ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Side Effects ◽  
Biomedical Applications ◽  
Living System ◽  
Health Condition ◽  
The Body ◽  
Biocompatible Polymers ◽  
Nano Technology ◽  
Artificial Grafts ◽  
Immunological Reactions

Background: Biocompatible polymers are gaining great interest in the field of biomedical applications. The term biocompatibility refers to the suitability of a polymer to body and body fluids exposure. Biocompatible polymers are both synthetic (man-made) and natural and aid in the close vicinity of a living system or work in intimacy with living cells. These are used to gauge, treat, boost, or substitute any tissue, organ or function of the body. A biocompatible polymer improves body functions without altering its normal functioning and triggering allergies or other side effects. It encompasses advances in tissue culture, tissue scaffolds, implantation, artificial grafts, wound fabrication, controlled drug delivery, bone filler material, etc. Objectives: This review provides an insight into the remarkable contribution made by some well-known biopolymers such as polylactic-co-glycolic acid, poly(ε-caprolactone) (PCL), polyLactic Acid, poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), Chitosan and Cellulose in the therapeutic measure for many biomedical applications. Methods: : Various techniques and methods have made biopolymers more significant in the biomedical fields such as augmentation (replaced petroleum based polymers), film processing, injection modeling, blow molding techniques, controlled / implantable drug delivery devices, biological grafting, nano technology, tissue engineering etc. Results: The fore mentioned techniques and other advanced techniques have resulted in improved biocompatibility, nontoxicity, renewability, mild processing conditions, health condition, reduced immunological reactions and minimized side effects that would occur if synthetic polymers are used in a host cell. Conclusion: Biopolymers have brought effective and attainable targets in pharmaceutics and therapeutics. There are huge numbers of biopolymers reported in the literature that has been used effectively and extensively.

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