Polycrystalline Diamond Coating on Orthopaedic Implants: Realization, and Role of Surface Topology and Chemistry in Adsorption of Proteins and Cell Proliferation

2022 ◽  
Author(s):  
Justas Zalieckas ◽  
Ivan Rios Mondragon ◽  
Paulius Pobedinskas ◽  
Arne Skodvin Kristoffersen ◽  
Samih Mohamed-Ahmed ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Microwave Plasma ◽  
Polycrystalline Diamond ◽  
Surface Topology ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Type I ◽  
Diamond Coatings ◽  
Orthopaedic Implants

Polycrystalline diamond has the potential to improve the osseointegration of orthopaedic implants compared to conventional osteo-implant materials such as titanium. However, despite the excellent biocompatibility and superior mechanical properties, the major challenge of using diamond for implants such as those used for hip arthroplasty is the limitations of microwave plasma chemical vapor deposition (CVD) techniques to synthesize diamond on complex-shaped objects. Here, for the first time we demonstrate diamond growth on titanium acetabular shells using surface wave plasma CVD method. Polycrystalline diamond coatings were synthesized at low temperatures (~400 °C) on three types of acetabular shells with different surface structure and porosity. We achieved diamond growth on highly porous surfaces designed to mimic the structure of the trabecular bone and improve osseointegration. Biocompatibility was investigated on nanocrystalline diamond (NCD) and ultrananocrystalline diamond (UNCD) coatings terminated either with hydrogen or oxygen. To understand the role of diamond surface topology and chemistry in attachment and proliferation of mammalian cells we investigated adsorption of extracellular matrix (ECM) proteins, and monitored metabolic activity of fibroblasts, osteoblasts, and bone marrow-derived mesenchymal stem cells (MSCs). The interaction of bovine serum albumin (BSA) and Type I collagen with diamond surface was investigated by confocal fluorescence lifetime imaging microscopy (FLIM). We found that proliferation of MSCs was better on hydrogen terminated UNCD than on oxygen terminated counterpart. These findings corelate to the behaviour of collagen on diamond substrates observed by FLIM. Hydrogen terminated UNCD provides better adhesion and proliferation for MSCs, compared to titanium, while growth of fibroblasts is poorest on hydrogen terminated NCD and osteoblasts behave similarly on all tested surfaces. These results open new opportunities for application of diamond coatings on orthopaedic implants.

Diamond growth using carbon monoxide as a carbon source

1992 ◽  
Vol 7 (5) ◽  
pp. 1195-1203 ◽  
Author(s):  
F.M. Cerio ◽  
W.A. Weimer ◽  
C.E. Johnson
Keyword(s):  
Carbon Source ◽  
Gas Phase ◽  
Growth Rates ◽  
Microwave Plasma ◽  
Polycrystalline Diamond ◽  
Chemical Mechanism ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Lower Growth ◽  
Temperature Combustion

Polycrystalline diamond films were produced in a microwave plasma assisted CVD reactor using CO as the carbon source gas. Reactor exhaust gas compositions were determined by mass spectrometry using 2–10% CO and 0–1.5% O2 in H2 feed gas mixtures. The chemistry involved in the gas phase is similar to that which occurs when diamond is grown using hydrocarbons as carbon source gases. A chemical mechanism for the oxidation of CH4 in flames appears to be applicable to this system. Addition of O2 to the reactor feed gas results in increased growth rates for low addition levels possibly due to activation of the diamond surface, while lower growth rates result at high addition levels due to oxidation of carbon from the surface and depletion of diamond growth precursors in the gas phase. The chemical reactions that take place in the plasma are similar to those that occur in flames and hot filament reactors, indicating that the plasma acts to induce reactions that are normally associated with high temperature combustion processes.

Large Area Deposition of Polycrystalline Diamond Coatings by Microwave Plasma CVD

2013 ◽  
Vol 72 (4) ◽  
pp. 225-232 ◽  
Author(s):  
Awadesh K. Mallik ◽  
Sandip Bysakh ◽  
Kalyan S. Pal ◽  
Nandadulal Dandapat ◽  
Bichitra K. Guha ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Polycrystalline Diamond ◽  
Diamond Coatings ◽  
Plasma Cvd ◽  
Large Area ◽  
Microwave Plasma Cvd ◽  
Area Deposition

Selective Growth of Polycrystalline Diamond Thin Films

1992 ◽  
Vol 282 ◽  
Author(s):  
R. Ramesham
Keyword(s):  
Plasma Etching ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Selective Growth ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Substrate Type ◽  
Temperature Growth ◽  
Single Crystal Diamond

ABSTRACTMicrowave plasma assisted CVD is employed to grow diamond films using a gas mixture of H2 and CH4on various substrates. Diamond has a tendency not to nucleate growth on mirror-smooth finished substrates irrespective of the substrate type (except single crystal diamond). We have developed various processes to enhance the nucleation density of the diamond substantially by damaging or seeding the surface of the substrates. Several process techniques such as 1. silicon nitride and silicon dioxide process, 2. ultrasonic agitation process, 3. selective seeding of diamond by electroplating of Cu, 4. patterning of diamond films by air-microwave plasma etching, etc., were developed to achieve the patterns of diamond on various substrates. Selective growth of doped diamond and low temperature growth of diamond for microelectronic applications have also been achieved by using the above processes (1 and 2). Details on selective diamond growth processes and the morphology of as-deposited selective diamond by SEM are presented.

Simulations of CVD Diamond Film Growth: 2D Models for the identities and concentrations of gas-phase species adsorbing on the surface

2011 ◽  
Vol 1282 ◽  
Author(s):  
Paul W. May ◽  
Yuri A. Mankelevich
Keyword(s):  
Gas Phase ◽  
Film Growth ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Process Conditions ◽  
Ultrananocrystalline Diamond ◽  
Single Crystal Diamond

ABSTRACTA prerequisite for modelling the growth of diamond by CVD is knowledge of the identities and concentrations of the gas-phase species which impact upon the growing diamond surface. Two methods have been devised for the estimation of this information, and have been used to determine adsorption rates for CxHy hydrocarbons for process conditions that experimentally produce single-crystal diamond, microcrystalline diamond films, nanocrystalline diamond films and ultrananocrystalline diamond films. Both methods rely on adapting a previously developed model for the gas-phase chemistry occurring in a hot filament or microwave plasma reactor. Using these methods, the concentrations of most of the CxHy radical species, with the exception of CH3, at the surface have been found to be several orders of magnitude smaller than previously believed. In most cases these low concentrations suggest that reactions such as direct insertion of C1Hy (y = 0-2) and/or C2 into surface C–H or C–C bonds can be neglected and that such species do not contribute significantly to the diamond growth process in the reactors under study.

scholarly journals Isotope Effect in Thermal Conductivity of Polycrystalline CVD-Diamond: Experiment and Theory

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 322
Author(s):  
Alexander V. Inyushkin ◽  
Alexander N. Taldenkov ◽  
Victor G. Ralchenko ◽  
Andrey P. Bolshakov ◽  
Alexander V. Khomich
Keyword(s):  
Thermal Conductivity ◽  
Chemical Vapor Deposition ◽  
Isotopic Composition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Plasma Chemical Vapor Deposition

We measured the thermal conductivity κ(T) of polycrystalline diamond with natural (natC) and isotopically enriched (12C content up to 99.96 at.%) compositions over a broad temperature T range, from 5 to 410 K. The high quality polycrystalline diamond wafers were produced by microwave plasma chemical vapor deposition in CH4-H2 mixtures. The thermal conductivity of 12C diamond along the wafer, as precisely determined using a steady-state longitudinal heat flow method, exceeds much that of the natC sample at T>60 K. The enriched sample demonstrates the value of κ(298K)=25.1±0.5 W cm−1 K−1 that is higher than the ever reported conductivity of natural and synthetic single crystalline diamonds with natural isotopic composition. A phenomenological theoretical model based on the full version of Callaway theory of thermal conductivity is developed which provides a good approximation of the experimental data. The role of different resistive scattering processes, including due to minor isotope 13C atoms, defects, and grain boundaries, is estimated from the data analysis. The model predicts about a 37% increase of thermal conductivity for impurity and dislocation free polycrystalline chemical vapor deposition (CVD)-diamond with the 12C-enriched isotopic composition at room temperature.

Diamond Growth on (a) Large Mo Cylinders at 30 Torr and (b) Flat Mo at One Atmospheric Pressure of H2 and CH4

1996 ◽  
Vol 441 ◽  
Author(s):  
R. Ramesham ◽  
M. F. Rose
Keyword(s):  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Diamond Growth ◽  
Single Filament ◽  
Active Length ◽  
Microwave Plasma Cvd ◽  
Hot Filament ◽  
First Time

Abstract(a) Polycrystalline diamond films have been grown on cylindrical Mo substrates by hot filament and microwave plasma CVD techniques using a gas mixture of hydrogen and methane. A single hot tungsten filament has been used to demonstrate the growth of adherent diamond films on large cylinders. To our knowledge this is the first report on such large cylindrical substrate (area: 41 cm2 ) using a single filament of active length of 3.75 cm. (b) Polycrystalline diamond films have been deposited by hot-filament technique for the first time using methane and hydrogen at an atmospheric pressure of hydrogen on flat substrates. The diamond growth has been performed at various pressures ranging from 34.5 to 750 Torr. The as-deposited films were analyzed by SEM and Raman to determine morphology and chemical nature, respectively.A. Growth of Diamond Film on Molybdenum Cylinders

Fracture strength measurement of filament assisted CVD polycrystalline diamond films

1992 ◽  
Vol 7 (6) ◽  
pp. 1432-1437 ◽  
Author(s):  
G.F. Cardinale ◽  
C.J. Robinson
Keyword(s):  
Fracture Strength ◽  
Microwave Plasma ◽  
Natural Diamond ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
High Strength ◽  
Coarse Grained ◽  
Diamond Growth ◽  
Growth Surface

The fracture strength of polycrystalline diamond films deposited by filament assisted chemical vapor deposition in the thickness range of 3.5 to 160 μm is investigated. Using a burst pressure technique, the fracture strengths of circular diamond film specimens are calculated. An average fracture strength of 730 MPa for nine samples was computed. This value is in good agreement with published strengths of microwave plasma deposited diamond films, comparable to other high strength materials, and within an order of magnitude of the fracture strength of bulk natural diamond. The average fracture strength of the fine-grained substrate interface appears consistently higher than that of the coarse-grained diamond growth surface.

scholarly journals Characterizations of microwave plasma CVD grown polycrystalline diamond coatings for advanced technological applications

2014 ◽  
Vol 8 (2) ◽  
pp. 69-80 ◽  
Author(s):  
Awadesh Mallik ◽  
Nandadulal Dandapat ◽  
Shirshendu Chakraborty ◽  
Ashok Mandal ◽  
Jiten Ghosh ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Polycrystalline Diamond ◽  
Potential Candidate ◽  
Diamond Coatings ◽  
Etching Technique ◽  
X Ray ◽  
Microwave Plasma Cvd ◽  
Scanning Electronmicroscopy

Polycrystalline diamond (PCD) coatings ranging from few microns to several hundred microns thickness have been grown by 915MHz microwave plasma reactor with 9000W power. The coatings were deposited on 100mm diameter silicon (Si) substrate from few hours to several days of continuous runs. PCD coatings were made freestanding by wet chemical etching technique. The deposited PCDs were evaluated by X-ray diffraction (XRD), scanning electronmicroscopy (SEM), Raman spectroscopy,X-ray photoelectron spectroscopy (XPS) for physical characterization and compared with authors? earlier work. Refractive index of 2.41 was obtained at 633 nm wavelength and a maximum of 6.6 W?cm-1K-1 value for thermal conductivity could be achieved with the grown coatings. The values are well above the existing non-diamond heat spreading substrates, which makes the grown PCDs as candidates for heat spreaders in different technological applications. High refractive in- dex along with translucent nature of the white freestanding PCDs, make them potential candidate for optical windows.

scholarly journals PRMT1-mediated methylation of the microprocessor-associated proteins regulates microRNA biogenesis

2019 ◽  
Vol 48 (1) ◽  
pp. 96-115 ◽  
Author(s):  
Valeria Spadotto ◽  
Roberto Giambruno ◽  
Enrico Massignani ◽  
Marija Mihailovich ◽  
Marianna Maniaci ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
High Resolution Mass Spectrometry ◽  
Mirna Biogenesis ◽  
Type I ◽  
Protein Arginine Methyltransferases ◽  
Step Process ◽  
Methylation State ◽  
Processing Step ◽  
Associated Proteins

Abstract MicroRNA (miRNA) biogenesis is a tightly controlled multi-step process operated in the nucleus by the activity of the Microprocessor and its associated proteins. Through high resolution mass spectrometry (MS)- proteomics we discovered that this complex is extensively methylated, with 84 methylated sites associated to 19 out of its 24 subunits. The majority of the modifications occurs on arginine (R) residues (61), leading to 81 methylation events, while 30 lysine (K)-methylation events occurs on 23 sites of the complex. Interestingly, both depletion and pharmacological inhibition of the Type-I Protein Arginine Methyltransferases (PRMTs) lead to a widespread change in the methylation state of the complex and induce global decrease of miRNA expression, as a consequence of the impairment of the pri-to-pre-miRNA processing step. In particular, we show that the reduced methylation of the Microprocessor subunit ILF3 is linked to its diminished binding to the pri-miRNAs miR-15a/16, miR-17–92, miR-301a and miR-331. Our study uncovers a previously uncharacterized role of R-methylation in the regulation of miRNA biogenesis in mammalian cells.

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