Chemical Mechanical Surface Nano-Structuring (CMNS) Implementation on Titanium Based Implants to Enhance Corrosion Resistance and Control Biocompatibility

MRS Advances ◽  
2020 ◽  
Vol 5 (43) ◽  
pp. 2209-2219
Author(s):  
Kimberly Beers ◽  
Debashish Sur ◽  
G. Bahar Basim
Keyword(s):  
Cell Attachment ◽  
Density Ratio ◽  
Three Dimensional ◽  
High Strength ◽  
Surface Characteristics ◽  
Tissue Growth ◽  
Protective Oxide ◽  
Cardiac Pacemakers ◽  
Mechanical Surface

AbstractTitanium is the metal of choice for many implantable devices including dental prostheses, orthopaedic devices and cardiac pacemakers. Titanium and its alloys are favoured for hard tissue replacement because of their high strength to density ratio providing excellent mechanical properties and biocompatible surface characteristics promoting in-vivo passivation due to spontaneous formation of a native protective oxide layer in the presence of an oxidizer. This study focuses on the development of a three-dimensional chemical, mechanical, surface nano-structuring (CMNS) process to induce smoothness or controlled nano-roughness on the bio-implant surfaces, particularly for applications in dental implants. CMNS is an extension of the chemical mechanical polishing (CMP) process. CMP is utilized in microelectronics manufacturing for planarizing the wafer surfaces to enable photolithography and multilayer metallization. In biomaterials applications, the same approach can be utilized to induce controlled surface nanostructure on three-dimensional implantable objects to promote or demote cell attachment. As a synergistic method of nano-structuring on the implant surfaces, CMNS also makes the titanium surface more adaptable for the bio-compatible coatings as well as the cell and tissue growth as demonstrated by the electrochemical and surface wettability evaluations on implants prepared by DI-water machining versus oil based machining.

scholarly journals Compressive behaviours of octet-truss lattices

2020 ◽  
Vol 234 (16) ◽  
pp. 3257-3269 ◽  
Author(s):  
Yifan Li ◽  
Huaiyuan Gu ◽  
Martyn Pavier ◽  
Harry Coules
Keyword(s):  
Failure Modes ◽  
Density Ratio ◽  
Three Dimensional ◽  
Compressive Load ◽  
High Strength ◽  
Detailed Comparison ◽  
Compressive Response ◽  
Beam Elements ◽  
Structural Applications ◽  
Octet Truss

Octet-truss lattice structures can be used for lightweight structural applications due to their high strength-to-density ratio. In this research, octet-truss lattice specimens were fabricated by stereolithography additive manufacturing with a photopolymer resin. The mechanical properties of this structure have been examined in three orthogonal orientations under the compressive load. Detailed comparison and description were carried out on deformation mechanisms and failure modes in different lattice orientations. Finite element models using both beam elements and three-dimensional solid elements were used to simulate the compressive response of this structure. Both the load reaction and collapse modes obtained in simulations were compared with test results. Our results indicate that three-dimensional continuum element models are required to accurately capture the behaviour of real trusses, taking into account the effects of finite-sized beams and joints.

scholarly journals Titanium oral implants: surface characteristics, interface biology and clinical outcome

2010 ◽  
Vol 7 (suppl_5) ◽  
Author(s):  
Anders Palmquist ◽  
Omar M. Omar ◽  
Marco Esposito ◽  
Jukka Lausmaa ◽  
Peter Thomsen
Keyword(s):  
Surface Properties ◽  
Cellular Response ◽  
Randomized Clinical Trials ◽  
Three Dimensional ◽  
Cell Communication ◽  
Surface Characteristics ◽  
Titanium Implants ◽  
Material Surface ◽  
Oral Implants

Bone-anchored titanium implants have revolutionized oral healthcare. Surface properties of oral titanium implants play decisive roles for molecular interactions, cellular response and bone regeneration. Nevertheless, the role of specific surface properties, such as chemical and phase composition and nanoscale features, for the biological in vivo performance remains to be established. Partly, this is due to limited transfer of state-of-the-art preparation techniques to complex three-dimensional geometries, analytical tools and access to minute, intact interfacial layers. As judged by the available results of a few randomized clinical trials, there is no evidence that any particular type of oral implant has superior long-term success. Important insights into the recruitment of mesenchymal stem cells, cell–cell communication at the interface and high-resolution imaging of the interface between the surface oxide and the biological host are prerequisites for the understanding of the mechanisms of osseointegration. Strategies for development of the next generation of material surface modifications for compromised tissue are likely to include time and functionally programmed properties, pharmacological modulation and incorporation of cellular components.

scholarly journals Improved Bioactivity of 3D Printed Porous Titanium Alloy Scaffold with Chitosan/Magnesium-Calcium Silicate Composite for Orthopaedic Applications

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 203 ◽  
Author(s):  
Chun-Hao Tsai ◽  
Chih-Hung Hung ◽  
Che-Nan Kuo ◽  
Cheng-Yu Chen ◽  
Yu-Ning Peng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Silicate ◽  
Cell Attachment ◽  
Three Dimensional ◽  
Bone Defects ◽  
Metal Alloys ◽  
Potential Candidate ◽  
Natural Bone

Recently, cases of bone defects have been increasing incrementally. Thus, repair or replacement of bone defects is gradually becoming a huge problem for orthopaedic surgeons. Three-dimensional (3D) scaffolds have since emerged as a potential candidate for bone replacement, of which titanium (Ti) alloys are one of the most promising candidates among the metal alloys due to their low cytotoxicity and mechanical properties. However, bioactivity remains a problem for metal alloys, which can be enhanced using simple immersion techniques to coat bioactive compounds onto the surface of Ti–6Al–4V scaffolds. In our study, we fabricated magnesium-calcium silicate (Mg–CS) and chitosan (CH) compounds onto Ti–6Al–4V scaffolds. Characterization of these surface-modified scaffolds involved an assessment of physicochemical properties as well as mechanical testing. Adhesion, proliferation, and growth of human Wharton’s Jelly mesenchymal stem cells (WJMSCs) were assessed in vitro. In addition, the cell attachment morphology was examined using scanning electron microscopy to assess adhesion qualities. Osteogenic and mineralization assays were conducted to assess osteogenic expression. In conclusion, the Mg–CS/CH coated Ti–6Al–4V scaffolds were able to exhibit and retain pore sizes and their original morphologies and architectures, which significantly affected subsequent hard tissue regeneration. In addition, the surface was shown to be hydrophilic after modification and showed mechanical strength comparable to natural bone. Not only were our modified scaffolds able to match the mechanical properties of natural bone, it was also found that such modifications enhanced cellular behavior such as adhesion, proliferation, and differentiation, which led to enhanced osteogenesis and mineralization downstream. In vivo results indicated that Mg–CS/CH coated Ti–6Al–4V enhances the bone regeneration and ingrowth at the critical size bone defects of rabbits. These results indicated that the proposed Mg–CS/CH coated Ti–6Al–4V scaffolds exhibited a favorable, inducive micro-environment that could serve as a promising modification for future bone tissue engineering scaffolds.

Requirements for the Manufacturing of Scaffold Biomaterial With Features at Multiple Scales

2005 ◽  
Author(s):  
I. M. Sebastine ◽  
D. J. Williams
Keyword(s):  
Tissue Engineering ◽  
Multiple Scales ◽  
Cell Attachment ◽  
Structural Parameters ◽  
Complex Function ◽  
Three Dimensional ◽  
Cell Orientation ◽  
Length Scales

Tissue engineering aims to restore the complex function of diseased tissue using cells and scaffold materials. Tissue engineering scaffolds are three-dimensional (3D) structures that assist in the tissue engineering process by providing a site for cells to attach, proliferate, differentiate and secrete an extra-cellular matrix, eventually leading cells to form a neo-tissue of predetermined, three-dimensional shape and size. For a scaffold to function effectively, it must possess the optimum structural parameters conducive to the cellular activities that lead to tissue formation; these include cell penetration and migration into the scaffold, cell attachment onto the scaffold substrate, cell spreading and proliferation and cell orientation. In vivo, cells are organized in functional tissue units that repeat on the order of 100 μm. Fine scaffold features have been shown to provide control over attachment, migration and differentiation of cells. In order to design such 3D featured constructs effectively understanding the biological response of cells across length scales from nanometer to millimeter range is crucial. Scaffold biomaterials may need to be tailored at three different length scales: nanostructure (<1μm), microstructure (<20–100μm), and macrostructure (>100μm) to produce biocompatible and biofunctional scaffolds that closely resemble the extracellular matrix (ECM) of the natural tissue environment and promote cell adhesion, attachment, spreading, orientation, rate of movement, and activation. Identification of suitable fabrication techniques for manufacturing scaffolds with the required features at multiple scales is a significant challenge. This review highlights the effect and importance of the features of scaffolds that can influence the behaviour of cells/tissue at different length scales in vitro to increase our understanding of the requirements for the manufacture of functional 3D tissue constructs.

Vascularized Cardiac Spheroids as Novel 3D in vitro Models to Study Cardiac Fibrosis

2017 ◽  
Vol 204 (3-4) ◽  
pp. 191-198 ◽  
Author(s):  
Gemma A. Figtree ◽  
Kristen J. Bubb ◽  
Owen Tang ◽  
Eddy Kizana ◽  
Carmine Gentile
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Three Dimensional ◽  
In Vitro Models ◽  
Tissue Growth ◽  
Cardiovascular Research

Spheroid cultures are among the most explored cellular biomaterials used in cardiovascular research, due to their improved integration of biochemical and physiological features of the heart in a defined architectural three-dimensional microenvironment when compared to monolayer cultures. To further explore the potential use of spheroid cultures for research, we engineered a novel in vitro model of the heart with vascularized cardiac spheroids (VCSs), by coculturing cardiac myocytes, endothelial cells, and fibroblasts isolated from dissociated rat neonatal hearts (aged 1-3 days) in hanging drop cultures. To evaluate the validity of VCSs in recapitulating pathophysiological processes typical of the in vivo heart, such as cardiac fibrosis, we then treated VCSs with transforming growth factor beta 1 (TGFβ1), a known profibrotic agent. Our mRNA analysis demonstrated that TGFβ1-treated VCSs present elevated levels of expression of connective tissue growth factor, fibronectin, and TGFβ1 when compared to control cultures. We demonstrated a dramatic increase in collagen deposition following TGFβ1 treatment in VCSs in the PicroSirius Red-stained sections. Doxorubicin, a renowned cardiotoxic and profibrotic agent, triggered apoptosis and disrupted vascular networks in VCSs. Taken together, our findings demonstrate that VCSs are a valid model for the study of the mechanisms involved in cardiac fibrosis, with the potential to be used to investigate novel mechanisms and therapeutics for treating and preventing cardiac fibrosis in vitro.

scholarly journals Investigating the Effect of Carbon Nanomaterials Reinforcing Poly(Ε-Caprolactone) Scaffolds for Bone Repair Applications

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Yanhao Hou ◽  
Weiguang Wang ◽  
Paulo Jorge Da Silva Bartolo
Keyword(s):  
Mechanical Properties ◽  
Bone Repair ◽  
Carbon Nanomaterials ◽  
Cell Attachment ◽  
Three Dimensional ◽  
Surface Characteristics ◽  
Mechanical Support ◽  
Tissue Formation ◽  
Different Types ◽  
3D Printed

Scaffolds, three-dimensional (3D) substrates providing appropriate mechanical support and biological environments for new tissue formation, are the most common approaches in tissue engineering. To improve scaffold properties such as mechanical properties, surface characteristics, biocompatibility and biodegradability, different types of fillers have been used reinforcing biocompatible and biodegradable polymers. This paper investigates and compares the mechanical and biological behaviors of 3D printed poly(ε-caprolactone) scaffolds reinforced with graphene (G) and graphene oxide (GO) at different concentrations. Results show that contrary to G which improves mechanical properties and enhances cell attachment and proliferation, GO seems to show some cytotoxicity, particular at high contents.

scholarly journals Fabrication and Multiscale Structural Properties of Interconnected Porous Biomaterial for Tissue Engineering by Freeze Isostatic Pressure (FIP)

2018 ◽  
Vol 9 (3) ◽  
pp. 51 ◽  
Author(s):  
Mythili Prakasam ◽  
Ali Chirazi ◽  
Grzegorz Pyka ◽  
Anna Prokhodtseva ◽  
Daniel Lichau ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Mechanical Strength ◽  
Cell Attachment ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
High Strength ◽  
Processing Parameters ◽  
Fabrication Technology ◽  
Porous Network ◽  
Pore Connectivity

Biomaterial for tissue engineering is a topic of huge progress with a recent surge in fabrication and characterization advances. Biomaterials for tissue engineering applications or as scaffolds depend on various parameters such as fabrication technology, porosity, pore size, mechanical strength, and surface available for cell attachment. To serve the function of the scaffold, the porous biomaterial should have enough mechanical strength to aid in tissue engineering. With a new manufacturing technology, we have obtained high strength materials by optimizing a few processing parameters such as pressure, temperature, and dwell time, yielding the monolith with porosity in the range of 80%–93%. The three-dimensional interconnectivity of the porous media through scales for the newly manufactured biomaterial has been investigated using newly developed 3D correlative and multi-modal imaging techniques. Multiscale X-ray tomography, FIB-SEM Slice & View stacking, and high-resolution STEM-EDS electronic tomography observations have been combined allowing quantification of morphological and geometrical spatial distributions of the multiscale porous network through length scales spanning from tens of microns to less than a nanometer. The spatial distribution of the wall thickness has also been investigated and its possible relationship with pore connectivity and size distribution has been studied.

scholarly journals Application of ZnO-Based Nanocomposites for Vaccines and Cancer Immunotherapy

Pharmaceutics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 493 ◽  
Author(s):  
Prashant Sharma ◽  
Na-Yoon Jang ◽  
Jae-Won Lee ◽  
Bum Chul Park ◽  
Young Keun Kim ◽  
...  
Keyword(s):  
Immune System ◽  
Biomedical Application ◽  
Three Dimensional ◽  
Surface Characteristics ◽  
Cost Effective ◽  
Vaccine Platform ◽  
Therapeutic Vaccines ◽  
Recent Advances ◽  
Effective Design

Engineering and application of nanomaterials have recently helped advance various biomedical fields. Zinc oxide (ZnO)-based nanocomposites have become one of the most promising candidates for biomedical applications due to their biocompatibility, unique physicochemical properties, and cost-effective mass production. In addition, recent advances in nano-engineering technologies enable the generation of ZnO nanocomposites with unique three-dimensional structures and surface characteristics that are optimally designed for in vivo applications. Here, we review recent advances in the application of diverse ZnO nanocomposites, with an especial focus on their development as vaccine adjuvant and cancer immunotherapeutics, as well as their intrinsic properties interacting with the immune system and potential toxic effect in vivo. Finally, we summarize promising proof-of-concept applications as prophylactic and therapeutic vaccines against infections and cancers. Understanding the nano-bio interfaces between ZnO-based nanocomposites and the immune system, together with bio-effective design of the nanomaterial using nano-architectonic technology, may open new avenues in expanding the biomedical application of ZnO nanocomposites as a novel vaccine platform.

Comparison between conventional shot peening and ultrasonic shot peening

2018 ◽  
Vol 19 (6) ◽  
pp. 603
Author(s):  
Sondes Manchoul ◽  
Rabi Ben Sghaier ◽  
Rawdha Seddik ◽  
Raouf Fathallah
Keyword(s):  
Residual Stresses ◽  
Shot Peening ◽  
Treatment Process ◽  
Three Dimensional ◽  
Surface Characteristics ◽  
Aisi 316L ◽  
Plastic Deformations ◽  
Ultrasonic Shot Peening ◽  
Three Dimensional Models ◽  
Mechanical Surface

Shot peening process is a mechanical surface treatment process widely used in the industry. Ultrasonic shot peening and conventional shot peening are two important mechanisms of this process. This work aims at studying and comparing the influence of conventional shot peening and ultrasonic shot peening on the surface characteristics (residual stresses, equivalent plastic deformations, and roughness). Three-dimensional models are established to simulate the two mechanisms by using the finite elements software ABAQUS/PYTHON. The residual stresses distributions, as well as the roughness and the equivalent plastic deformations of the AISI 2205 and the AISI 316L induced by both models, are predicted and compared.

Patterned Adhesion of Cells

2007 ◽  
Vol 1020 ◽  
Author(s):  
Robert Lee Zimmerman ◽  
Ismet Gurhan ◽  
Daryush ILA
Keyword(s):  
Cell Growth ◽  
Cell Attachment ◽  
Ion Beam ◽  
Silver Ions ◽  
Inhibitory Effect ◽  
Tissue Growth ◽  
Biocompatible Materials ◽  
Silver Deposition

AbstractIt is well known that silver deposition avoids bacterial growth and inhibits the natural process of attachment of connective tissue to biocompatible materials in vivo. We have completed a five year investigation of the precise spatial control of cell growth on glassy polymeric carbon implanted with silver using ion beam techniques, and the persistence of the inhibitory effect on cell growth. Long term inhibition of cell growth on GPC is a desirable improvement on current cardiac implants and other biocompatible materials placed in the blood stream. We have used implanted silver ions near the surface of GPC to completely inhibit cell attachment and adhesion. Cells attach and strongly adhere to areas close to the silver implanted surfaces. Patterned ion implantation permits precise control of tissue growth on GPC and other biocompatible substrates. Cell growth limited to micrometric patterns on a substrate may be useful for in vitro studies of associated biological processes in an otherwise identical environment. The patterned inhibition of cell attachment persists for periods of time significant relative to typical implant lifetimes.

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