Nanostructured Ceramic and Ceramic-Polymer Composites as Dual Functional Interface for Bioresorbable Metallic Implants

2014 ◽  
Vol 1621 ◽  
pp. 39-45 ◽  
Author(s):  
Ian Johnson ◽  
Qiaomu Tian ◽  
Huinan Liu
Keyword(s):  
Degradation Products ◽  
Composite Coatings ◽  
Bone Tissue Regeneration ◽  
Surrounding Tissue ◽  
Dual Functional ◽  
Metallic Implants ◽  
Nanostructured Ceramic ◽  
Absorbable Polymers ◽  
Biological Environment ◽  
Functional Interface

ABSTRACTMillions of medical implants and devices (e.g., screws, plates, and pins) are used each year worldwide in surgery, and traditionally the components have been limited to permanent metals (e.g., stainless steel, titanium alloys) and polyester-based absorbable polymers. Because of clinical problems associated with these traditional materials, a novel class of biodegradable metallic materials, i.e., magnesium-based alloys, attracted great attention and clinical interests. Magnesium (Mg) is particularly attractive for load-bearing orthopedic applications because it has comparable modulus and strength to cortical bone. Controlling the interface of Mg with the biological environment, however, is the key challenge that currently limits this biodegradable metal for broad applications in medical devices and implants. This paper will particularly focus on creating nanostructured interface between the biodegradable metallic implant and surrounding tissue for the dual purposes of (1) mediating the degradation of the metallic implants and (2) simultaneously enhancing bone tissue regeneration and integration. Nanophase hydroxyapatite (nHA) is an excellent candidate as a coating material due to its osteoconductivity that has been widely reported. Applying nHA coatings or nHA containing composite coatings on Mg alloys is therefore promising in serving the needed dual functions. The composite of nHA and poly(lactic-co-glycolic acid) (PLGA) as a dual functional interface provides additional benefits for medical implant applications. Specifically, the polymer phase promotes interfacial adhesion between the nHA and Mg, and the degradation products of PLGA and Mg neutralize each other. Our results indicate that nHA and nHA/PLGA coatings slow down Mg degradation rate and enhance adhesion of bone marrow stromal cells, thus promising as the next-generation multifunctional implant materials. Further optimization of the coatings and their interfacial properties are still needed to bring them into clinical applications.

scholarly journals A Review on the Latest Developments of Conducting Polymer and Composite Coatings for Enhancing Biocompatibility and Corrosion Resistance of Metallic Biomedical Implants

2021 ◽  
Vol 6 (5) ◽  
pp. 146-155
Author(s):  
Mohammed Razzaq Mohammed ◽  
Safaa Hashim Radhi ◽  
Ahmed Namah Hadi
Keyword(s):  
Human Life ◽  
Composite Coatings ◽  
Biological Properties ◽  
Metals And Alloys ◽  
Toxic Substances ◽  
Metallic Implants ◽  
Body Tissues ◽  
Biomedical Field ◽  
Materials Used

The utilisation of metals and alloys in the biomedical field was and is still of immense importance for human life. Typically, the materials used for metallic biomedical applications, particularly those are implanted in vivo, provide appropriate mechanical and biological properties that allow them to accomplish the purpose for which they are used. Nonetheless, there are some inherent limitations impede the optimal use of these materials. One of the most crucial determinants is corrosion, which results in several other problems such as the formation of toxic substances that can not only cause necrosis of the cells attached to the implant, these toxins could also be carried by blood into body tissues and organs. This in turn leads to dire consequences on patient's life. Although a wide variety of approaches may be available to address the corrosion issue, it is alleged that coating these metals and alloys with polymers, especially the conductive ones, is among the best strategies in this regard. This review will highlight the latest developments in using conductive polymers including polypyrrole, polyaniline, polythiophene and their composites in order to enhance biocompatibility, mechanical properties and most importantly corrosion protection performance of metallic implants. The findings obtained from coating 316L stainless steel, titanium and magnesium alloys, which have been widely manipulated in biomedical field as long and short-term implants, will be evaluated.

scholarly journals A brief review on hydroxyapatite production and use in biomedicine

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 282-302 ◽  
Author(s):  
D. S. Gomes ◽  
A. M. C. Santos ◽  
G. A. Neves ◽  
R. R. Menezes
Keyword(s):  
The Body ◽  
Bone Tissue Regeneration ◽  
Synthesis Methods ◽  
Chemical Similarity ◽  
Drug Controlled Release ◽  
Precise Control ◽  
Metallic Implants ◽  
Wide Range ◽  
Biomedical Field ◽  
Size And Morphology

Abstract Hydroxyapatite (HAp) is a bioceramic widely studied due to its chemical similarity with the mineral component of bones. Besides, it is biocompatible, bioactive and thermodynamically stable in the body fluid what poses it as an attractive material for a wide range of applications in the biomedical field. Several efforts have been focused on the synthesis of particles of this material aiming to the precise control of size and morphology, porosity and surface area. HAp is widely used as an implant for bone tissue regeneration, as a coating for metallic implants and in a drug-controlled release. In this sense, the objective of this review is to gather information related to HAp, providing readers with information about synthesis methods, material characteristics and their applications.

Graphene oxide as dual functional interface modifier for improving wettability and retarding recombination in hybrid perovskite solar cells

2014 ◽  
Vol 2 (47) ◽  
pp. 20105-20111 ◽  
Author(s):  
Wenzhe Li ◽  
Haopeng Dong ◽  
Xudong Guo ◽  
Nan Li ◽  
Jiangwei Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Solar Cells ◽  
Photovoltaic Performance ◽  
Perovskite Solar Cells ◽  
Dual Functional ◽  
Hybrid Perovskite ◽  
Functional Interface ◽  
Sensitized Solar Cells

GO as an amphiphilic modifier enhances the selective contact between perovskite and the HTL to improve the photovoltaic performance of perovskite-sensitized solar cells.

scholarly journals Evaluation of Aloe Vera Coated Polylactic Acid Scaffolds for Bone Tissue Engineering

2020 ◽  
Vol 10 (7) ◽  
pp. 2576
Author(s):  
Ricardo Donate ◽  
María Elena Alemán-Domínguez ◽  
Mario Monzón ◽  
Jianshu Yu ◽  
Francisco Rodríguez-Esparragón ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Polylactic Acid ◽  
Photoelectron Spectroscopy ◽  
Aloe Vera ◽  
Extracellular Proteins ◽  
Bone Tissue Regeneration ◽  
Surrounding Tissue ◽  
Water Contact

3D-printed polylactic acid (PLA) scaffolds have been demonstrated as being a promising tool for the development of tissue-engineered replacements of bone. However, this material lacks a suitable surface chemistry to efficiently interact with extracellular proteins and, consequently, to integrate into the surrounding tissue when implanted in vivo. In this study, aloe vera coatings have been proposed as a strategy to improve the bioaffinity of this type of structures. Aloe vera coatings were applied at three different values of pH (3, 4 and 5), after treating the surface of the PLA scaffolds with oxygen plasma. The surface modification of the material has been assessed through X-ray photoelectron spectroscopy (XPS) analysis and water contact angle measurements. In addition, the evaluation of the enzymatic degradation of the structures showed that the pH of the aloe vera extracts used as coating influences the degradation rate of the PLA-based scaffolds. Finally, the cell metabolic activity of an in vitro culture of human fetal osteoblastic cells on the samples revealed an improvement of this parameter on aloe vera coated samples, especially for those treated at pH 3. Hence, these structures showed potential for being applied for bone tissue regeneration.

scholarly journals The Role of Zwitterionic Materials in the Fight against Proteins and Bacteria

Medicines ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 125 ◽  
Author(s):  
Montserrat Colilla ◽  
Isabel Izquierdo-Barba ◽  
María Vallet-Regí
Keyword(s):  
Tissue Regeneration ◽  
Bone Tissue Regeneration ◽  
Local Drug Delivery ◽  
Clinical Use ◽  
Metallic Implants ◽  
Specific Proteins ◽  
Biomedical Field ◽  
Advanced Biomaterials ◽  
Major Progress

Zwitterionization of biomaterials has been heightened to a potent tool to develop biocompatible materials that are able to inhibit bacterial and non-specific proteins adhesion. This constitutes a major progress in the biomedical field. This manuscript overviews the main functionalization strategies that have been reported up to date to design and develop these advanced biomaterials. On this regard, the recent research efforts that were dedicated to provide their surface of zwitterionic nature are summarized by classifying biomaterials in two main groups. First, we centre on biomaterials in clinical use, concretely bioceramics, and metallic implants. Finally, we revise emerging nanostructured biomaterials, which are receiving growing attention due to their multifunctionality and versatility mainly in the local drug delivery and bone tissue regeneration scenarios.

scholarly journals Evaluation of Magnesium-based Medical Devices in Preclinical Studies: Challenges and Points to Consider

2019 ◽  
Vol 47 (3) ◽  
pp. 390-400 ◽  
Author(s):  
Madeleine Chagnon ◽  
Louis-Georges Guy ◽  
Nicolette Jackson
Keyword(s):  
Animal Studies ◽  
Degradation Products ◽  
Degradation Process ◽  
Gas Production ◽  
Mg Alloys ◽  
Bioabsorbable Polymer ◽  
Cardiovascular Stents ◽  
Metallic Implants ◽  
Pathology Data

Absorbable metallic implants have been under investigation for more than a century. Animal and human studies have shown that magnesium (Mg) alloys can be safely used in bioresorbable scaffolds. Several cardiovascular and orthopedic biodegradable metallic devices have recently been approved for use in humans. Bioresorbable Mg implants present many advantages when compared to bioabsorbable polymer or nonabsorbable metallic implants, including similar strength and mechanical properties as existing implant-grade metals without the drawbacks of permanence or need for implant removal. Imaging visibility is also improved compared to polymeric devices. Additionally, with Mg-based cardiovascular stents, the risk of late stent thrombosis and need for long-term anti-platelet therapy may be reduced as the host tissue absorbs the Mg degradation products and the morphology of the vessel returns to a near-normal state. Absorbable Mg implants present challenges in the conduct of preclinical animal studies and interpretation of pathology data due to their particular degradation process associated with gas production and release of by-products. This article will review the different uses of Mg implants, the Mg alloys, the distinctive degradation features of Mg, and the challenges confronting pathologists at tissue collection, fixation, imaging, slide preparation, evaluation, and interpretation of Mg implants.

scholarly journals Advances in Antibacterial Functionalized Coatings on Mg and Its Alloys for Medical Use—A Review

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 828
Author(s):  
Dan Zhang ◽  
Ying Liu ◽  
Zhaogang Liu ◽  
Qiang Wang
Keyword(s):  
Corrosion Resistance ◽  
Degradation Rate ◽  
Composite Coatings ◽  
Alkaline Ph ◽  
Antibacterial Ability ◽  
Infected Wounds ◽  
Patients With Diabetes ◽  
Biological Environment ◽  
Functionalized Coatings

As a revolutionary implant material, magnesium and its alloys have many exciting performances, such as biodegradability, mechanical compatibility, and excellent biosecurity. However, the rapid and uncontrollable degradation rate of magnesium greatly hampers its clinical use. Many efforts have been taken to enhance the corrosion resistance of magnesium. However, it must be noted that improving the corrosion resistance of magnesium will lead to the compromise of its antibacterial abilities, which are attribute and proportional to the alkaline pH during its degradation. Providing antibacterial functionalized coating is one of the best methods for balancing the degradation rate and the antibacterial ability of magnesium. Antibacterial functionalized magnesium is especially well-suited for patients with diabetes and infected wounds. Considering the extremely complex biological environment in the human body and the demands of enhancing corrosion resistance, biocompatibility, osteogenesis, and antibacterial ability, composite coatings with combined properties of different materials may be promising. The aim of this review isto collect and compare recent studies on antibacterial functionalized coatings on magnesium and its alloys. The clinical applications of antibacterial functionalized coatings and their material characteristics, antibacterial abilities, in vitro cytocompatibility, and corrosion resistance are also discussed in detail.

Haemostatic abnormalities and thrombotic disorders in malignant lymphoma

2005 ◽  
Vol 93 (01) ◽  
pp. 153-159 ◽  
Author(s):  
Tomohiro Sase ◽  
Motoko Yamaguchi ◽  
Shoko Ogawa ◽  
Yuko Kamikura ◽  
Masakatsu Nishikawa ◽  
...  
Keyword(s):  
Malignant Lymphoma ◽  
Plasma Levels ◽  
Nk Cell ◽  
Cell Lymphoma ◽  
Vascular Endothelial Cells ◽  
Degradation Products ◽  
Clinical Stage ◽  
Stage Iv ◽  
Surrounding Tissue ◽  
D Dimer

SummaryWe examined haemostatic abnormalities and thrombotic disorders in 217 patients with malignant lymphoma. Plasma levels of fibrinogen and D-dimer were significantly higher in patients with malignant lymphoma than in healthy subjects.The incidence of severe complications, such as disseminated intravascular coagulation (DIC) and interstitial pneumonia (IP), differed with each clinical stage or histological type, but they occurred frequently in stage IV or natural killer (NK) cell lymphoma. Plasma levels of fibrinogen degradation products (FDP) and D-dimer, leukocyte tissue factor (TF) mRNA and plasma TF antigen were significantly higher in stage IV than in stage I, II or III. Plasma levels of FDP, D-dimer, and leukocyte TF mRNA in NK cell lymp homa were markedly higher than in other types of lymphoma. Immunohistochemical staining of NK cell lymphoma revealed that granulocyte macrophage colony-stimulating factor was positive in tumour cells, whereas von Willebrand factor and TF were positive in vascular endothelial cells of surrounding tissue. Our results suggested that patients with stage IV disease and NK cell lymphoma were in abnormal thrombotic and haemostatic state, and may frequently develop DIC and IP. One of the mechanisms of DIC and IP may involve elevated cytokine production by lymphoma cells, which can stimulate the expression of TF in blood cells or surrounding tissue.

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