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The Role Of Surface Chemistry And Wettability Of Microtextured Titanium Surfaces In Osteoblast Differentiation
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Book Synopsis The Role of Surface Chemistry and Wettability of Microtextured Titanium Surfaces in Osteoblast Differentiation by : Jung Hwa Park
Download or read book The Role of Surface Chemistry and Wettability of Microtextured Titanium Surfaces in Osteoblast Differentiation written by Jung Hwa Park and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomaterial surface energy, chemical composition, charge, wettability and roughness all play an important role in determining the degree of the direct bone-to-implant interface, termed osseointegration. Surface chemistry, which is influenced by surface energy, wettability, and composition, is another factor that determines osteoblast phenotype and regulates osteoblast maturation. Increased surface energy is desirable for bone implants due to enhanced interaction between the implant surface and the biological environment. The extent of bone formation in vivo is also increased with increasing water wettability of implants. The physiological role of implant surface chemistry is important in determining the success of implant osseointegration because of molecular rearrangements, surface reactions, contamination, and release of toxic or biologically active ions that are determined by the starting chemistry. However, the role of surface chemistry on osteoblast response is not fully studied. Therefore, the overall goal of this dissertation is to understand how the surface chemistry, including wettability, chemical composition, and charge density, of titanium biomaterials impacts osteoblast maturation (in vitro). This study focuses on the general hypothesis that modifications of surface chemistry of titanium surfaces with sterilization or polyelectrolyte coating on titanium surfaces regulate osteoblast response.
Book Synopsis Issues in Biochemistry and Biomaterials: 2013 Edition by :
Download or read book Issues in Biochemistry and Biomaterials: 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-05-01 with total page 1159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Biochemistry and Biomaterials / 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Molecular Biotechnology. The editors have built Issues in Biochemistry and Biomaterials: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Molecular Biotechnology in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Biochemistry and Biomaterials: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Book Synopsis Handbook of Biomaterials Biocompatibility by : Masoud Mozafari
Download or read book Handbook of Biomaterials Biocompatibility written by Masoud Mozafari and published by Woodhead Publishing. This book was released on 2020-06-17 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Biomaterials Biocompatibility is a systematic reference on host response to different biomaterials, taking into account their physical, mechanical and chemical properties. The book reviews recent progress in the design and study of biomaterials biocompatibility, along with current understanding on how to control immune system response. Sections provide the fundamental theories and challenges of biomaterials biocompatibility, the role of different biomaterials physicochemical surface properties on cell responses, cell responses to different physicochemical properties of polymers, ceramics, metals, carbons and nanomaterials, and biomaterials in different tissues, such as the cardiac, nervous system, cartilage and bone. This resource will be suitable for those working in the fields of materials science, regenerative engineering, medicine, medical devices and nanotechnology. Reviews the fundamental theories and challenges of biomaterials biocompatibility, including an overview of the standards and regulations Provides an overview on the cellular and molecular mechanisms involved in host responses to biomaterials Systematically looks at cellular response and tissue response to a wide range of biomaterials, including polymers, metals, ceramics, alloys and nanomaterials
Book Synopsis Mechanisms Regulating Osteoblast Response to Surface Microtopography and Vitamin D by : Bryan Frederick Bell
Download or read book Mechanisms Regulating Osteoblast Response to Surface Microtopography and Vitamin D written by Bryan Frederick Bell and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive understanding of the interactions between orthopaedic and dental implant surfaces with the surrounding host tissue is essential in the design of advanced biomaterials that better promote bone growth and osseointegration of implants. Dental implants with roughened surfaces and high surface energy are well known to promote osteoblast differentiation in vitro and promote increased bone-to-implant contact in vivo. In addition, increased surface roughness increases osteoblasts response to the vitamin D metabolite 1Î",25(OH)2D3. However, the exact mechanisms mediating cell response to surface properties and 1Î",25(OH)2D3 are still being elucidated. The central aim of the thesis is to investigate whether integrin signaling in response to rough surface microtopography enhances osteoblast differentiation and responsiveness to 1Î",25(OH)2D3. The hypothesis is that the integrin Î"5Î21 plays a role in osteoblast response to surface microtopography and that 1Î",25(OH)2D3 acts through VDR-independent pathways involving caveolae to synergistically enhance osteoblast response to surface roughness and 1Î",25(OH)2D3. To test this hypothesis the objectives of the studies performed in this thesis were: 1) to determine if Î"5Î21 signaling is required for osteoblast response to surface microstructure; 2) to determine if increased responsiveness to 1Î",25(OH)2D3 requires the vitamin D receptor, 3) to determine if rough titanium surfaces functionalized with the peptides targeting integrins (RGD) and transmembrane proteoglycans (KRSR) will enhance both osteoblast proliferation and differentiation, and 4) to determine whether caveolae, which are associated with integrin and 1Î",25(OH)2D3 signaling, are required for enhance osteogenic response to surface microstructure and 1Î",25(OH)2D3. The results demonstrate that integrins, VDR, and caveolae play important roles in mediating osteoblast response to surface properties and 1Î",25(OH)2D3. Silencing of the Î21 integrin in osteoblast-like MG63 cells significantly reduced osteogenic response to surface topography and 1Î",25(OH)2D3. Silencing of the Î"5 subunit did not alter the response of MG63 cells to changing surface roughness or chemistry, although future work must confirm these results given similar cell surface Î"5 integrin expression observed in control and Î"5-silenced cells. Multifunctional RGD, KRSR, and KSSR coated surfaces show that RGD increased osteoblast proliferation and reduced differentiation, KRSR had no affect on osteoblast phenotype, and KSSR increased osteoblast differentiation. These results suggest that titanium surfaces can be modified to manipulate proliferation and differentiation and that RGD/KSSR functionalized surfaces could be further investigated for use as osteointegrative surfaces. The results using VDR deficient osteoblasts demonstrate that 1Î",25(OH)2D3 acts via VDR-dependent mechanisms in cells cultured on titanium surfaces that support terminal differentiation. In caveolae deficient osteoblasts, 1Î",25(OH)2D3 affected cell number, alkaline phosphatase activity, and TGF-Î21 levels, although levels of osteocalcin and PGE2 were not affected. These results are consistent with the hypothesis that VDR is required for the actions of 1Î",25(OH)2D3, but that caveolae-dependent membrane 1Î",25(OH)2D3 signaling modulates traditional VDR signaling. The exact mechanisms for this interaction remain to be shown. Overall, these results are important in better understanding the role of Î21 integrin partners in mediating osteoblast response to implant surfaces and in understanding how integrin signaling can alter osteoblast differentiation and responsiveness to 1Î",25(OH)2D3 via genomic and non-genomic pathways.
Book Synopsis Hyper-hydrophilic Titanium Surfaces Improve Osteoblast Attachment by Enhancing Fibronectin Adsorption at the Interface by : Parisi Ludovica
Download or read book Hyper-hydrophilic Titanium Surfaces Improve Osteoblast Attachment by Enhancing Fibronectin Adsorption at the Interface written by Parisi Ludovica and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Implants osseointegration is affected by cell responses at the bone-implant interface, which depends on the chemical composition,micro topography and wettability of the surface, which, in turn, influence protein adsorption.Aim: To investigate whether hyperhydrophilicity alters surface selectivity for fibronectin, a protein which plays a pivotal role in cell adhesionand proliferation.Materials and Methods: Acid-etched sandblasted surfaces were treated through a proprietary process in order to obtain hyper-hydrophilic surfaces. Surfacefeatures were characterized by X-Ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and themeasurement of the contact angle. Protein adsorption was assessed by SDS-PAGE analysis, and the influence of surface infibronectin adsorption was assayed through Western Blot. Cell attachment to the surfaces was then studied. Murine osteoblastsMC3T3-E1 cells were cultured for 24 hours in complete medium. Their morphology and adhesion were studied through theimmuno-staining for cytoskeleton and for focal adhesions and through the use of SEM microscopy coupled to Focused Ion Beam(FIB). FIB analysis allowed to cut cells during SEM observation and to investigate their interactions with the surface. Furthermore, celladhesion was assessed by quantitating the amount of attached cells to the surface at different experimental points through achemiluminescence assay.Results: Our results showed that the experimental treatment induced a gain of titanium hydrophilicity, without inducing any modification inchemical composition or topography. SDS-PAGE revealed a great amount of proteins adsorbed on treated surfaces, while WesternBlot indicated that hydrophilicity increased the amount of fibronectin adsorbed on the surface.Moreover, hyper-hydrophilic surfaces allowed a closer adhesion of cells. Immuno-staining revealed healthy cells on both surfaces,however cells growing on hydrophilic surfaces expressed a higher amount of focal adhesions. Similarly, the adhesion curve showed afaster cell adhesion to hydrophilic titanium already after 30 minutes of culture. SEM-FIB analysis demonstrated that cells on untreatedsurfaces adhered preferentially to the micro texture peaks, while hyper-hydrophilicity promotes the adhesion of cell body to the peaksthroughout the sample. Cells appeared thinner and spread on the entire surface.Conclusions: Taken together, our data show that hyper-hydrophilicity affects protein adsorption. In particular, we observed a more selectiveadsorption of fibronectin, which may be responsible for improved cell adhesion to micro-patterned titanium.
Book Synopsis Effect of Surface Wettability, Morphology and Chemistry on the Biocompatibility of Laser Textured Titanium Surfaces by : Xun Zhao
Download or read book Effect of Surface Wettability, Morphology and Chemistry on the Biocompatibility of Laser Textured Titanium Surfaces written by Xun Zhao and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Investigation on the Surface Modification of Titanium Based Alloys for Improved Bioactivity by : Mohammad Mohsin Hossain
Download or read book Investigation on the Surface Modification of Titanium Based Alloys for Improved Bioactivity written by Mohammad Mohsin Hossain and published by . This book was released on 2012 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium-based engineering materials are currently considered to be the best artificial implant materials because of their good mechanical strength, resistance to corrosion, and their nontoxic compatibility with the stable oxide, TiO2. Ti6Al4V alloy is biologically inert, showing limited interaction with human tissue to their native oxide surface, which generally results in mechanical fixation. If the material is able to interact directly with tissue through chemical bonding, thus leading to a bioactive fixation, this will make a better and stronger implant for the promotion of cell attachment and migration and bone growth. Surface modification can improve the properties of surface oxide, leading to the formation of a stable oxide layer on the alloy's surface, and thus resulting in greater bioactivity. Surface modification is performed through surface chemical treatments, coatings deposition and chemical and thermal oxidation at a variety of process temperatures. The acid-alkaline-treated surface shows rougher, higher wettability and the presence of oxide of TiO2, as per the averaged results. In a comparison of roughness, wettability, and surface chemistry, no differences are observed between the original and solvent-treated surfaces. The crystalline structure of the surface treated samples reveals alpha and beta phases of Ti6Al4V alloy. However, the alpha 110 peak has only appeared on acid-alkaline substrate. This appearance is probably caused by a change of orientation of the crystallographic plane. Bioactivity results show no differences in Ca-P deposition between the surfaces, leading to CaHPO4, Ca/P~1.0. Some clusters deposit only on the original and solvent-treated surfaces which contain higher Ca-P than the surfaces in the non-cluster region, as observed by SEMEDS. Chemical oxidation treatments are conducted on the original surfaces by the H2O2, 37°C and H2O2, 80°C. Crystalline phases are generally associated with titanium alpha-beta, and a few with anatase and rutile. All the oxidised surfaces are defected by the presence of pores. Ti peaks are seen on the surfaces oxidised by H2O2, 37°C but no longer seen on the surfaces oxidised by H2O2, 80°C, except on the oxidised original surface. TiO2 concentrations are found quantitatively in the Ti 2p and O 1s spectra. A hydroxyl-rich oxides concentration is found at similar levels on all the oxidised surfaces. The oxidised acid-alkaline surface appears to be rougher than the other oxidised surfaces but the effects on the surface hydrophilicity are similar. Bioactivity results show a higher concentration of Ca-P deposits, leading to hydroxyapatite, Ca/P~1.6±0.1. The Ca-P deposition in SBF is increased from 3 to 14 days, as observed by XPS. Thick cluster layers are observed on the oxidised surfaces of the samples incubated for 14 days; these are composed of O, Ca and P; Ca/P~1.5, as observed by SEMEDS. Coating depositions of Ti and TiO2 are performed on the solvent-treated surface. XPS results show no Ti peaks present on the TiO2-deposited surface. The TiO2-deposited surface appears to be rougher and less hydrophilic than other surfaces. No significantly different Ca-P depositions are found on the deposited surfaces as results of CaHPO4 and Ca/P~1.0, which do not exhibit a good bioactive response. The chemically oxidised surfaces show a similarly roughened effect on all the oxidised surfaces. The oxidised Ti- and TiO2-deposited surfaces appear to be more hydrophilic than the oxidised solvent-treated alloys. The chemically oxidised surfaces reveal that Ca-P depositions increase, leading to hydroxyapatite, Ca/P~1.6±0.1 and that there are no differences in the oxidised deposited surfaces of any of the samples incubated from between 3 to 14 days. The Ca-P depositions on the oxidised deposited surfaces are found to have almost half the value of those on the oxidised solventtreated surfaces. The effects of thermal and chemical oxidation on the Ti-deposited samples are investigated. The crystalline structure is transformed from anatase to rutile in an increasing thermal temperature treatment of up to 800°C. At higher magnification, a thin layer with a porous structure is observed on the chemically oxidised surfaces. Shiny oxide layers are seen on the thermally oxidised surfaces. The concentration of atomic oxygen increases as the thermal temperature is increased from 100°C to 800°C, as observed by EDS. The surface chemistry results show that the content of chemically and thermally oxidised surfaces comprises hydroxyl-rich oxides and hydroxyl-poor oxides, respectively. Bioactivity results show that the chemically oxidised surface is able to deposit more Ca-P, leading to the formation of hydroxyapatite, Ca/P~1.7±0.1. However, the thermally oxidised surfaces deposit Ca(H2PO4)2 and, CaCO3 and P2O5 at temperatures of 100°C, 400°C and 800°C, respectively, at Ca/P~0.5. It has been conclusively proved that Ca-P depositions are dependent on the presence of hydroxyl-rich oxides. Apatite nucleation can be formally initiated at the stage of the completion of Ca-P depositions and can actively promote bone-growth after the material has been implanted.
Book Synopsis Possible Role of Microcrystallinity on Surface Properties of Titanium Surfaces for Biomedical Application by : Federico Mussano
Download or read book Possible Role of Microcrystallinity on Surface Properties of Titanium Surfaces for Biomedical Application written by Federico Mussano and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dental implantology has grown tremendously, since the introduction of titanium. To enhance osseointegration, roughening techniques such as grit blasting, chemical etch, electrochemical anodization have been used with good results. An oxide layer mainly composed of TiO2 covers the surface of dental implants ensuring excellent corrosion resistance and chemical stability. Despite its biological role in achieving bone interlock, surprisingly, little is known about the structure of TiO2, which may be either amorphous or crystalline. Furthermore, at least two crystalline polymorph phases can be found at the bone-implant interface: anatase (tetragonal) and rutile (tetragonal). Therefore, besides the recognized importance of surface topography, energy, and charge, a more refined knowledge of surface chemistry is advisable when studying the bone-implant interface. Recently, sophisticated analysis techniques have been applied to dental implants such as Raman spectroscopy and X-ray diffraction to obtain structural-crystallographic characterization.
Book Synopsis Surface Modification of Titanium Substrates with Polymer Brushes to Control Cell Adhesion for Bioapplications by : Jenny E. Raynor
Download or read book Surface Modification of Titanium Substrates with Polymer Brushes to Control Cell Adhesion for Bioapplications written by Jenny E. Raynor and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modification of the surface chemistry of materials used as implants in biomedical applications affords the ability to control cell adhesion, prevent inflammation and enhance integration with the host. Titanium and its alloys are strong and lightweight thereby making them desirable for applications such as hip and knee replacements, dental implants, and cardiac pacemaker implants. However, the lifetime of these implants is often limited by poor incorporation into the surrounding bone which results in loosening and wear. In order to overcome these limitations we have studied the modification of titanium substrates with a self-assembled monolayer that can be used to perform surface-initiated atom transfer radical polymerization (SI-ATRP) of a monomer to afford polymer brushes that effectively prevent the adhesion of cells. In addition, the polymer brushes afford the ability to tether a peptide sequence. Specific peptides containing adhesion sequences have been tethered to the polymer brushes. The resulting surfaces promote cell adhesion and osteoblast differentiation, thereby increasing bone tissue formation around the implant resulting in better incorporation of the implant.
Author :Mohamed Moustafa Mohamed Ali Said Publisher :Open Dissertation Press ISBN 13 :9781361308806 Total Pages : pages Book Rating :4.3/5 (88 download)
Book Synopsis Characterization of Titanium Surfaces with Different Treatment and Aging Processes by : Mohamed Moustafa Mohamed Ali Said
Download or read book Characterization of Titanium Surfaces with Different Treatment and Aging Processes written by Mohamed Moustafa Mohamed Ali Said and published by Open Dissertation Press. This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Characterization of Titanium Surfaces With Different Treatment and Aging Processes" by Mohamed Moustafa Mohamed Ali, Said, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The aims of this study were to, 1) investigate the surface characteristics of polished titanium plates/discs treated with acid-etching and ultraviolet irradiation (UV); and 2) investigate the change in surface characteristics of polished titanium plates/discs treated with acid-etching and UV irradiation after aging in air, saline and citric acid for six weeks. A total of one hundred and ninety-eight commercially pure grade two titanium plates and 50 titanium discs were prepared. Titanium samples were divided into four groups: 1) polished group, 2) polished and UV group, 3) acid-etched group and 4) acid-etched and UV group. Polishing was performed by abrasive silicon carbide paper grinding. UV treatment was performed by 15W germicidal UVC, 254 nm, for 48 h. Acid-etching was performed with 67% H2SO4 at 120 C for 75 s. The four groups were then subjected to an aging process for six weeks in sealed containers with three different media: air, physiologic saline and citric acid. They were analyzed immediately after treatment and after aging for surface characterization: topography, roughness, wettability, crystallinity, and chemistry. The polished surface showed relatively smooth surface with typical grooves from the grinding process. Acid-etching produced micro-roughened surface with sharp pits and ridges. The average surface roughness of polished, polished-UV was lower than that of the acid-etched and acid-etched-UV surfaces (p Immediately after preparation and treatment, the polished and acid-etched titanium surfaces appeared to be hydrophilic with similar contact angle values (p > 0.05). After UV treatment, there was a significant reduction in contact angles (superhydrophilic) in both surfaces (p Titanium hydride crystals were present in the acid-etched and acid-etched-UV surfaces but not in the polished and polished-UV surfaces. Titanium tetrachloride crystals were present in saline-stored surfaces. The polished surface acquired significantly higher titanium and oxygen concentrations and lower carbon contaminants compared to acid-etched surface. UV treatment substantially decreased carbon contamination and increased the titanium and oxygen concentrations in the acid-etched groups (p UV treatment may be an effective way to produce clean titanium surfaces with less carbon especially after roughening the titanium surface by acid-etching. Storage of the freshly prepared titanium surface in media such as saline or citric acid could preserve the hydrophilic property of these surfaces, however, it may also negatively influence the surface chemistry due to increased carbon contaminants. DOI: 10.5
Book Synopsis The Role of Nanostructural and Electrical Surface Properties on the Osteogenic Potential of Titanium Implants by : Rolando Arturo Gittens Ibacache
Download or read book The Role of Nanostructural and Electrical Surface Properties on the Osteogenic Potential of Titanium Implants written by Rolando Arturo Gittens Ibacache and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dental and orthopaedic implants are currently the solutions of choice for teeth and joint replacements with success rates continually improving, but they still have undesirable failure rates in patients who are compromised by disease or age, and who in many cases are the ones most in need. The success of titanium (Ti) implants depends on their ability to osseointegrate with the surrounding bone and this, in turn, is greatly dependent on the surface characteristics of the device. Advancements in surface analysis and surface modification techniques have improved the biological performance of metallic implants by mimicking the hierarchical structure of bone associated with regular bone remodeling. In this process, damaged bone is resorbed by osteoclasts, which produce resorption lacunae containing high microroughness generated after mineral dissolution under the ruffled border, as well as superimposed nanoscale features created by the collagen fibers left at the surface. Indeed, increasing Ti surface roughness at the micro and sub-microscale level has been shown to increase osteoblast differentiation in vitro, increase bone-to-implant contact in vivo, and accelerate healing times clinically. Recently, the clinical application of surface nanomodification of implants has been evaluated. Still, most clinically-available devices remain smooth at the nanoscale and fundamental questions remain to be elucidated about the effect of nanoroughness on the initial response of osteoblast lineage cells. \r : Another property that could be used to control osteoblast development and the process of osseointegration is the electrical surface charge of implants. The presence of endogenous electrical signals in bone has been implicated in the processes of bone remodeling and repair. The existence of these native signals has prompted the use of external electrical stimulation to enhance bone growth in cases of fractures with delayed union or nonunion, with several in vitro and in vivo reports confirming its beneficial effects on bone formation. However, the use of electrical stimulation on Ti implants to enhance osseointegration is less understood, in part because of the lack of in vitro models that truly represent the in vivo environment. In addition, an aspect that has not been thoroughly examined is the electrical implication of implant corrosion and its effect on the surrounding tissue. Implants are exposed to extreme conditions in the body such as high pH during inflammation, and cyclic loads. These circumstances may lead to corrosion events that generate large electrochemical currents and potentials, and may cause abnormal cell and tissue responses that could be partly responsible for complications such as aseptic loosening of implants. \r : Consequently, Ti implants with tailored surface characteristics such as nanotopography and electrical polarization, could promote bone healing and osseointegration to ensure successful outcomes for patients by mimicking the biological environment of bone without the use of systemic drugs. The objective of this thesis is to understand how surface nanostructural and electrical characteristics of Ti and Ti alloy surfaces may affect osteoblast lineage cell response in vitro for normal tissue regeneration and repair. Our central hypothesis is that combined micro/nanostructured surfaces, as well as direct stimulation of Ti surfaces with fixed direct current (DC) potentials, can enhance osteoblast differentiation.
Book Synopsis Investigation of Materials Surface Chemistry on Osteoblast Proliferation, Migration and Differentiation by : Xia Lu (M.S.)
Download or read book Investigation of Materials Surface Chemistry on Osteoblast Proliferation, Migration and Differentiation written by Xia Lu (M.S.) and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Role of Phospholipase D in Osteoblasts in Response to Titanium Surfaces by : Mimi Fang
Download or read book The Role of Phospholipase D in Osteoblasts in Response to Titanium Surfaces written by Mimi Fang and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomaterial surface properties such as microtopography and energy can change cellular responses at the cell-implant interface. Phospholipase D (PLD) is required for differentiation of osteoblast-like MG63 cells on machined and grit-blasted titanium surfaces. Here, we determined if PLD is also required on microstructured/high-energy substrates and the mechanism involved.
Book Synopsis Regenerative Medicine by : Gustav Steinhoff
Download or read book Regenerative Medicine written by Gustav Steinhoff and published by Springer Science & Business Media. This book was released on 2013-03-20 with total page 1211 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of regenerative medicine has developed rapidly over the past 20 years with the advent of molecular and cellular techniques. This textbook, Regenerative Medicine: From Protocol to Patient, aims to explain the scientific knowledge and emerging technology as well as the clinical application in different organ systems and diseases. International leading experts from four continents describe the latest scientific and clinical knowledge of the field of regenerative medicine. The process of translating science of laboratory protocols into therapies is explained in sections on regulatory, ethical and industrial issues. This textbook is organized into five parts: (I) Biology of Tissue Regeneration, (II) Stem Cell Science and Technology, (III) Tissue Engineering, Biomaterials and Nanotechnology, (IV) Regenerative Therapies and (V) Regulation and Ethics. The textbook aims to give the student, the researcher, the health care professional, the physician and the patient a complete survey on the current scientific basis, therapeutical protocols, clinical translation and practiced therapies in regenerative medicine.
Book Synopsis The Effect of Grain Refinement of Titanium on Its Mechanical Performance and Cell Response by : Alexander Medvedev
Download or read book The Effect of Grain Refinement of Titanium on Its Mechanical Performance and Cell Response written by Alexander Medvedev and published by . This book was released on 2015 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium and its alloys have long been in the focus of biomedical research as some of the most suitable materials for implant production. This fact is attributed to an excellent combination of mechanical, biological and physico-chemical properties, such as low density and high mechanical strength, resulting in the highest specific strength among most common implant materials, reduced elastic modulus (compared to stainless steel or CoCrMo alloys), excellent corrosion resistance, and enhanced biocompatibility.Recently, titanium alloy Ti6Al4V, the most common titanium implant material so far, was in the focus of several studies that claimed it has a potential to be toxic to humans due to the release of aluminium and vanadium ions in the surrounding tissues when placed within the host. This problem can be overcome by using titanium with lower alloying content, for example, commercially pure (CP) titanium, such as Grade 2 or Grade 4. Unfortunately, CP titanium shows significant decrease in mechanical properties compared to Ti6Al4V. There are ways, however, to enhance the strength of materials without altering their chemical composition. Particularly, severe plastic deformation (SPD) has been shown to dramatically enhance the strength of various materials while retaining good ductility.It is well known that the surface of medical implants plays a crucial role in the success and outcome of the surgery and determines the longevity of implants. Therefore, it is common to modify the surface of these devices in order to increase the surface area, alter its chemistry or wettability. There are numerous techniques available nowadays that allow modification of implant surface, however, only a handful of them were implemented in industry. One of such processes - SLA (Shot-blasted with Large grit and Acid etching) - is considered one of the most promising since it has been adopted by several different companies around the world. The main aim of the present work was to use SPD to increase the strength of CP titanium of two purity grades - Grade 2 and Grade 4 - in order to develop a material that, as a result of a combination of high strength and good biocompatibility, could be used to replace Ti6Al4V as a major titanium-based material on the market. Moreover, we performed all experiments on samples with two distinctly different types of surfaces - polished and SLA-treated - to highlight the effect of grain refinement on the outcome of subsequent surface modification. To the best of our knowledge, no work examining a combined effect of grain refinement and surface modification on mechanical and biological properties has been previously described in the literature. The results discussed in this thesis suggest that, as a result of a significant refinement of microstructure by SPD processing, mechanical properties of CP titanium can match (fatigue) or even exceed (tensile) those of Ti6Al4V. It was observed that SLA treatment results in the formation of a surface layer with refined structure which aided in enhancing fatigue properties of as-received titanium after surface modification. Although such layer was not found in case of SPD-processed samples, which led to a slight decrease of fatigue life compared to samples with polished surface, fatigue properties of SPD-processed titanium were still superior to those of Ti6Al4V. Fatigue testing in simulated body fluid, designed to test how titanium with refined structure reacts to aggressive environment, indicated no deterioration of fatigue life of titanium, regardless of microstructure.It has been demonstrated that surface properties of titanium were notably influenced by the grain size and the subsequent SLA treatment. Roughness of polished samples was shown to be a function of the grain size of material. At the same time, mechanical properties are believed to be responsible for differences in roughness of SLA-modified surface, as surface roughening primarily occurs by means of grit-blasting with its effect highly dependent on the strength/ductility of the surface. Wettability of titanium has been observed to be determined by the surface texture, being a product of variations in the processing route. This effect retained after severe surface roughening as well, although, overall, surface of SLA-treated titanium samples were found to be much more hydrophobic. Simultaneously, variations in wettability between samples of different conditions became less pronounced. Chemical analysis of CP Ti with varying microstructure and surface quality revealed no effect of microstructure on the chemical state of the polished surface. At the same time, it was noted that SLA treatment of ultrafine-grained titanium may favour the formation of a thicker, more chemically uniform oxide layer. Finally, an assessment of biological properties of CP Ti has been made. The results indicate a positive effect of ultrafine-grained structure and associated surface properties on the attachment, proliferation and differentiation of two types of tissue cells - human osteosarcoma SaOS-2 cells and adipose-derived mesenchymal stem cells (adMSC) on both types of surfaces. At the same time, bacterial adhesion was also significantly enhanced on the surface of SLA-treated titanium. This fact suggests that an utilisation of surface modification techniques in industrial processes of implant production should be most carefully controlled in order to reduce possibility of serious complication that may be caused by bacterial colonisation.Overall, experimental results presented in this thesis indicate that SPD, especially in combination with surface modification techniques, such as SLA treatment, has a great potential to improve both mechanical and biological properties of commercially pure titanium to make it a highly favourable and competitive candidate for the replacement of Ti6Al4V alloy. Our research suggests that there may be only one potential drawback of a combination of SPD and SLA, namely, enhanced adhesion of bacterial cells on the surface of such materials. However, this negative effect is not attributed to SPD processing, but rather to the increased surface roughness inherent to the SLA treatment. We suggest that this issue can be addressed by developing proper handling, storage and pre-implantation preparation protocols, a process that was not covered in current work but could be included as a part of the basis for the future work.
Book Synopsis Laser Textured Calcium Phosphate Bio-ceramic Coatings on Ti-6A1-4V for Improved Wettability and Bone Cell Compatibility by : Sameer Ranjan Paital
Download or read book Laser Textured Calcium Phosphate Bio-ceramic Coatings on Ti-6A1-4V for Improved Wettability and Bone Cell Compatibility written by Sameer Ranjan Paital and published by . This book was released on 2010 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction at the surfaces of load bearing implant biomaterials with tissues and physiological fluids is an area of crucial importance to all kinds of medical technologies. To achieve the best clinical outcome and restore the function of the diseased tissue, several surface engineering strategies have been discussed by scientific community throughout the world. In the current work, we are focusing on one such technique based on laser surface engineering to achieve the appropriate surface morphology and surface chemistry. Here by using a pulsed and continuous wave laser direct melting techniques we synthesize three dimensional textured surfaces of calcium phosphate (Ca-P) based surface chemistry on Ti-6Al-4V. The influence of each processing type on the micro texture and phase evolution and thereby its associated effect on wettability, in vitro bioactivity, and in vitro biocompatibility are systematically discussed. For samples processed using the pulsed laser, it was realized that with increasing laser scan speed and laser pulse frequency there was a transition from surface textures with sharp circular grooves to surface textures with radial grooves and thereby improved hydrophilicity. For CW laser processing the results demonstrated improved hydrophilicity for the samples processed at 100 [MU]m line spacing as compared to the samples processed at 200 [MU]m line spacing. Owing to the importance of Si for cartilage and hard tissue repair, a preliminary effort for synthesizing Ca-P-SiO2 composite coating on Ti-6Al-4V surface were also conducted. As a future potential technique we also explored the Laser Interference Patterning (LIP) technique to achieve the textured surfaces and developed understanding on their wetting behavior. In the current work, by adjusting the laser processing parameters we were able to synthesize textured coatings with biocompatible phases. The in vitro bioactivity and in vitro biocompatibility of the coatings were proved by the precipitation of an apatite like phase following immersion in simulated body fluid (SBF), and increased proliferation and spreading of the MC3T3-E1 like cells. The results and understanding of the current research is encouraging in terms of looking at other bio-ceramic precursor compositions and laser process parameter window for synthesizing better textured biocompatible coatings.
Book Synopsis Sr-loaded Titanium Surface Enhance MC3T3-E1 Osteoblastic Activity- a Preliminary in Vitro Study by :
Download or read book Sr-loaded Titanium Surface Enhance MC3T3-E1 Osteoblastic Activity- a Preliminary in Vitro Study written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: BackgroundMultifunctional titanium surfaces with high osteogenic activity and antibacterial properties is substantially desired in implant dentistry. Recently, the benefits of strontium (Sr) loaded titanium surfaces on promoting both osteoblast activity and bone formation were reported in vitro and in vivo, respectively. On the other hand, little is known about the influence of physico-chemical properties of Sr-loaded titanium surfaces on bacterial adhesion. Aim/HypothesisThis study aimed to evaluate the physico-chemical properties of Sr-loaded titanium specimens, and its influence on Staphylococcus aureus (S. aureus; ATCC #33591) adhesion and osteoblast (MC3T3-E1) cell activity. Material and MethodsCommercially pure titanium discs were polished with SiC sandpapers (up to grit #2500) and equally divided into three groups: 1) machined surface (MS), 2) alkaline etched surface (AES), and 3) Sr-loaded to AES (Sr-AES). The AES group was obtained by fully immersing part of the MS discs into 5 M NaOH at 60 u00b0C, for 24 hours. Part of the AES discs was submitted to alkali-hydrothermal treatment with 60 mM Sr(OH)2 u2219 8H2O solution, in steel autoclave, to generate Sr-AES group. The surface physico-chemical properties were determined by means of field-emission gun scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDX), contact angle with deionized water and diiodomethane (surface free energy), and surface roughness (Ra and Rz value). The response of MC3T3-E1 cells activity was assessed by AlamarBlue assay, whereas S. aureus cells adhesion was measured by couting colony forming units per milliliter (c.f.u./mL). Cells morphologies were determined by FE-SEM analysis. ResultsFE-SEM analysis showed a polished-like surface in MS group, whereas AES specimens presented a fine network nanostructured surface. The Sr-AES group exhibited the same nanostructured pattern surface as AES group, with embbeded particles of Sr. The EDX spectra confirmed amounts of Sr in the Sr-AES group. A well-structured cubic-shape of calcium was detected on AES and Sr-AES specimens. From contact angle measurements, the treatments performed on AES and Sr-AES groups increased both wettability with water and the surface free energy, compared to MS group. In addition, Sr-AES group presented an amphiphilic characteristic. No diferences were observed from surface roughness analysis. The AlamarBlue assay showed that Sr-AES group increased MC3T3-E1 activity at day 14. No diferences were observed on S. aureus adhesion to the different substrates. FE-SEM images showed that osteoblastic cell monolayers and S. aureus aggregate were present on all especimens. Conclusions and Clinical ImplicationsOur preliminary results indicate that Sr incorporation to a fine network nanostructured titanium surface has potential to enhance osteoblast cell activity at day 14. The nanostructured roughness observed on AES and Sr-AES groups had not effect on S. aureus cell adhesion. Sr-AES is a low-cost treatment and may be a promising option to improve implants osseointegration.
