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Stratton‐Powell AA, Williams S, Tipper JL, Redmond AC, Brockett CL. Mixed material wear particle isolation from periprosthetic tissue surrounding total joint replacements. J Biomed Mater Res B Appl Biomater 2022; 110:2276-2289. [PMID: 35532138 PMCID: PMC9540445 DOI: 10.1002/jbm.b.35076] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 11/05/2021] [Accepted: 04/18/2022] [Indexed: 12/12/2022]
Affiliation(s)
- Ashley A. Stratton‐Powell
- Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds Leeds UK
| | - Sophie Williams
- Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds Leeds UK
| | - Joanne L. Tipper
- Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds Leeds UK
- School of Biomedical Engineering University of Technology Sydney Ultimo New South Wales Australia
| | - Anthony C. Redmond
- NIHR Leeds Biomedical Research Centre Leeds Teaching Hospitals NHS Trust Leeds UK
- Leeds Institute for Rheumatic and Musculoskeletal Medicine, School of Medicine University of Leeds Leeds UK
| | - Claire L. Brockett
- Institute of Medical and Biological Engineering, School of Mechanical Engineering University of Leeds Leeds UK
- NIHR Leeds Biomedical Research Centre Leeds Teaching Hospitals NHS Trust Leeds UK
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2
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Multiple Copies of flhDC in Paraburkholderia unamae Regulate Flagellar Gene Expression, Motility, and Biofilm Formation. J Bacteriol 2021; 203:e0029321. [PMID: 34543106 DOI: 10.1128/jb.00293-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
FlhDC is a heterohexameric complex that acts as a master regulator of flagellar biosynthesis genes in numerous bacteria. Previous studies have identified a single flhDC operon encoding this complex. However, we found that two flhDC loci are present throughout Paraburkholderia, and two additional flhC copies are also present in Paraburkholderia unamae. Systematic deletion analysis in P. unamae of the different flhDC copies showed that one of the operons, flhDC1, plays the predominant role, with deletion of its genes resulting in a severe inhibition of motility and biofilm formation. Expression analysis using promoter-lacZ fusions and real-time quantitative PCR support the primary role of flhDC1 in flagellar gene regulation, with flhDC2 a secondary contributor. Phylogenetic analysis shows the presence of the flhDC1 and flhDC2 operons throughout Paraburkholderia. In contrast, Burkholderia and other bacteria only carry the copy syntenous with flhDC2. The variations in impact each copy of flhDC has on downstream processes indicate that regulation of FlhDC in P. unamae, and likely other Paraburkholderia species, is regulated at least in part by the presence of multiple copies of these genes. IMPORTANCE Motility is important in the colonization of plant roots by beneficial and pathogenic bacteria, with flagella playing essential roles in host cell adhesion, entrance, and biofilm formation. Flagellar biosynthesis is energetically expensive. Its complex regulation by the FlhDC master regulator is well studied in peritrichous flagella expressing enterics. We report the unique presence throughout Paraburkholderia of multiple copies of flhDC. In P. unamae, the flhDC1 copy showed higher expression and a greater effect on swim motility, flagellar development, and regulation of downstream genes, than the flhDC2 copy that is syntenous to flhDC in Escherichia coli and pathogenic Burkholderia spp. The flhDC genes have evolved differently in these plant-growth-promoting bacteria, giving an additional layer of complexity in gene regulation by FlhDC.
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Benya PD, Kavanaugh A, Zakarian M, Söderlind P, Jashashvili T, Zhang N, Waldorff EI, Ryaby JT, Billi F. Pulsed electromagnetic field (PEMF) transiently stimulates the rate of mineralization in a 3-dimensional ring culture model of osteogenesis. PLoS One 2021; 16:e0244223. [PMID: 33539401 PMCID: PMC7861434 DOI: 10.1371/journal.pone.0244223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/04/2020] [Indexed: 11/25/2022] Open
Abstract
Pulsed Electromagnetic Field (PEMF) has shown efficacy in bone repair and yet the optimum characteristics of this modality and its molecular mechanism remain unclear. To determine the effects of timing of PEMF treatment, we present a novel three-dimensional culture model of osteogenesis that demonstrates strong de novo generation of collagen and mineral matrix and exhibits stimulation by PEMF in multiple stages over 62 days of culture. Mouse postnatal day 2 calvarial pre-osteoblasts were cast within and around Teflon rings by polymerization of fibrinogen and cultured suspended without contact with tissue culture plastic. Ring constructs were exposed to PEMF for 4h/day for the entire culture (Daily), or just during Day1-Day10, Day11-Day 27, or Day28-Day63 and cultured without PEMF for the preceding or remaining days, and compared to no-PEMF controls. PEMF was conducted as HF Physio, 40.85 kHz frequency with a 67 ms burst period and an amplitude of 1.19 mT. Osteogenesis was kinetically monitored by repeated fluorescence measurements of continuously present Alizarin Red S (ARS) and periodically confirmed by micro-CT. PEMF treatment induced early-onset and statistically significant transient stimulation (~4-fold) of the mineralization rate when PEMF was applied Daily, or during D1-D10 and D11-D27. Stimulation was apparent but not significant between D28-D63 by ARS but was significant at D63 by micro-CT. PEMF also shifted the micro-CT density profiles to higher densities in each PEMF treatment group. Ring culture generated tissue with a mineral:matrix ratio of 2.0 by thermogravimetric analysis (80% of the calvaria control), and the deposited crystal structure was 50% hydroxyapatite by X-ray diffraction (63% of the calvaria and femur controls), independent of PEMF. These results were consistent with backscatter, secondary electron, and elemental analysis by scanning electron microscopy. Thus, in a defined, strong osteogenic environment, PEMF applied at different times was capable of further stimulation of osteogenesis with the potential to enhance bone repair.
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Affiliation(s)
- Paul D. Benya
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Aaron Kavanaugh
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Martin Zakarian
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Philip Söderlind
- Department of Architecture and Urban Design, University of California Los Angeles, Los Angeles, California, United States of America
| | - Tea Jashashvili
- Department of Radiology, Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Nianli Zhang
- Orthofix Medical Inc., Lewisville, Texas, United States of America
| | - Erik I. Waldorff
- Orthofix Medical Inc., Lewisville, Texas, United States of America
| | - James T. Ryaby
- Orthofix Medical Inc., Lewisville, Texas, United States of America
| | - Fabrizio Billi
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail:
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4
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Crainic AM, Callisti M, van Veelen A, Michalik A, Milton JA, Palmer MR, Cook RB. A comparative study on the physicochemical characteristics of nanoparticles released in vivo from CoCrMo tapers and cement-stem interfaces of total hip replacements. J Biomed Mater Res B Appl Biomater 2020; 108:3311-3322. [PMID: 32596955 DOI: 10.1002/jbm.b.34667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 04/24/2020] [Accepted: 05/25/2020] [Indexed: 11/09/2022]
Abstract
The good biocompatibility and corrosion resistance of the bulk CoCrMo alloy has resulted in it being used in the manufacture of implants and load bearing medical devices. These devices, however, can release wear and corrosion products which differ from the composition of the bulk CoCrMo alloy. The physicochemical characteristics of the particles and the associated in vivo reactivity are dictated by the wear mechanisms and electrochemical conditions at the sites of material loss. Debris released from CoCrMo hip bearings, taper junctions, or cement-stem interfaces can, therefore, have different chemical and morphological characteristics, which provide them with different in vivo toxicities. Here, we propose to assess and compare the characteristics of the particles released in vivo from CoCrMo tapers and cement-stem interfaces which have received less attention compared to debris originating from the hip bearings. The study uses state-of-art characterization techniques to provide a detailed understanding of the size, morphology, composition, and chemistry of the particles liberated from the wear and corrosion flakes from revised hip replacements, with an enzymatic treatment. The phase analyses identified Cr2 O3 nanoparticles released from tapers and cement-stem interfaces, whose composition did not vary with origin or particle morphology. The size distributions showed significantly smaller particles were released from the stems, compared to the particles originating from the corresponding tapers. The investigation demonstrates that the tribocorrosive processes occurring at the taper and stem interfaces both result in Cr2 O3 nanoparticle formation.
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Affiliation(s)
- Alina M Crainic
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, UK
| | - Mauro Callisti
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, UK.,Department of Materials Science and Metallurgy, Cambridge University, Cambridge, UK
| | - Arjen van Veelen
- Material Science and Technology Division, Material Science and Technology Division, Los Alamos, NM 87545, UK.,Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025
| | - Agnes Michalik
- National Oceanography Centre Southampton (NOCS), University of Southampton, School of Ocean and Earth Science, Southampton, UK
| | - James A Milton
- National Oceanography Centre Southampton (NOCS), University of Southampton, School of Ocean and Earth Science, Southampton, UK
| | - Martin R Palmer
- National Oceanography Centre Southampton (NOCS), University of Southampton, School of Ocean and Earth Science, Southampton, UK
| | - Richard B Cook
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Southampton, UK
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5
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Wang Q, Eltit F, Garbuz D, Duncan C, Masri B, Greidanus N, Wang R. CoCrMo metal release in metal‐on‐highly crosslinked polyethylene hip implants. J Biomed Mater Res B Appl Biomater 2020; 108:1213-1228. [DOI: 10.1002/jbm.b.34470] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/18/2019] [Accepted: 07/29/2019] [Indexed: 01/26/2023]
Affiliation(s)
- Qiong Wang
- Department of Materials EngineeringUniversity of British Columbia Vancouver British Columbia Canada
- School of Biomedical EngineeringUniversity of British Columbia Vancouver British Columbia Canada
- Centre for Hip Health and Mobility Vancouver British Columbia Canada
| | - Felipe Eltit
- Department of Materials EngineeringUniversity of British Columbia Vancouver British Columbia Canada
- School of Biomedical EngineeringUniversity of British Columbia Vancouver British Columbia Canada
- Centre for Hip Health and Mobility Vancouver British Columbia Canada
| | - Donald Garbuz
- Department of OrthopaedicsUniversity of British Columbia Vancouver British Columbia Canada
| | - Clive Duncan
- Department of OrthopaedicsUniversity of British Columbia Vancouver British Columbia Canada
| | - Bassam Masri
- Department of OrthopaedicsUniversity of British Columbia Vancouver British Columbia Canada
| | - Nelson Greidanus
- Department of OrthopaedicsUniversity of British Columbia Vancouver British Columbia Canada
| | - Rizhi Wang
- Department of Materials EngineeringUniversity of British Columbia Vancouver British Columbia Canada
- School of Biomedical EngineeringUniversity of British Columbia Vancouver British Columbia Canada
- Centre for Hip Health and Mobility Vancouver British Columbia Canada
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6
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Radice S, Holcomb T, Pourzal R, Hallab NJ, Laurent MP, Wimmer MA. Investigation of CoCrMo material loss in a novel bio-tribometer designed to study direct cell reaction to wear and corrosion products. ACTA ACUST UNITED AC 2019; 18. [PMID: 30984811 DOI: 10.1016/j.biotri.2019.100090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Wear and corrosion in total hip replacement negatively impact implant service-life and patient well-being. The aim of this study was to generate a statistical response surface of material loss using an apparatus, capable of testing the effect of wear and corrosion products in situ on cells, such as macrophages. The test chamber of a ball-on-flat tribometer operating inside a CO2 incubator was integrated with an electrochemical setup and adapted for cell culture work. A 20-test series, following a 2-level 3-factor design of experiments, was performed with a ceramic head in reciprocating rotational motion against a CoCrMo-alloy disc, under constant load. The lubricant was cell culture medium (RPMI-1640+10vol% bovine serum). Response surfaces were generated, which statistically showed the influence of motion amplitude, load, and potential on the total mass loss and wear scar volume of the metallic discs. Potential had the highest impact on the total mass loss, while motion amplitude and load significantly influenced the wear scar volume. The concentrations of the alloy elements found in the lubricants reflected the bulk-alloy stoichiometry. The total concentration of Co released into the lubricant (2.3-63 ppm by total mass loss, 1.5 to 62 ppm by ICP-MS) corresponded well with the known range to trigger cell response. Tribocorrosion tests in the presence of cells and tissues, such as macrophages, lymphocytes and/or synovium, will be carried out in the future.
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Affiliation(s)
- S Radice
- Department of Orthopedic Surgery, Rush UniversityMedical Center, Chicago, IL, USA
| | - T Holcomb
- Department of Orthopedic Surgery, Rush UniversityMedical Center, Chicago, IL, USA
| | - R Pourzal
- Department of Orthopedic Surgery, Rush UniversityMedical Center, Chicago, IL, USA
| | - N J Hallab
- Department of Orthopedic Surgery, Rush UniversityMedical Center, Chicago, IL, USA
| | - M P Laurent
- Department of Orthopedic Surgery, Rush UniversityMedical Center, Chicago, IL, USA
| | - M A Wimmer
- Department of Orthopedic Surgery, Rush UniversityMedical Center, Chicago, IL, USA
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7
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Kovochich M, Finley BL, Novick R, Monnot AD, Donovan E, Unice KM, Fung ES, Fung D, Paustenbach DJ. Understanding outcomes and toxicological aspects of second generation metal-on-metal hip implants: a state-of-the-art review. Crit Rev Toxicol 2019; 48:853-901. [DOI: 10.1080/10408444.2018.1563048] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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Macrophage Biocompatibility of CoCr Wear Particles Produced under Polarization in Hyaluronic Acid Aqueous Solution. MATERIALS 2018; 11:ma11050756. [PMID: 29738506 PMCID: PMC5978133 DOI: 10.3390/ma11050756] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/26/2018] [Accepted: 05/02/2018] [Indexed: 02/06/2023]
Abstract
Macrophages are the main cells involved in inflammatory processes and in the primary response to debris derived from wear of implanted CoCr alloys. The biocompatibility of wear particles from a high carbon CoCr alloy produced under polarization in hyaluronic acid (HA) aqueous solution was evaluated in J774A.1 mouse macrophages cultures. Polarization was applied to mimic the electrical interactions observed in living tissues. Wear tests were performed in a pin-on-disk tribometer integrating an electrochemical cell in phosphate buffer solution (PBS) and in PBS supplemented with 3 g/L HA, an average concentration that is generally found in synovial fluid, used as lubricant solution. Wear particles produced in 3 g/L HA solution showed a higher biocompatibility in J774A.1 macrophages in comparison to those elicited by particles obtained in PBS. A considerable enhancement in macrophages biocompatibility in the presence of 3 g/L of HA was further observed by the application of polarization at potentials having current densities typical of injured tissues suggesting that polarization produces an effect on the surface of the metallic material that leads to the production of wear particles that seem to be macrophage-biocompatible and less cytotoxic. The results showed the convenience of considering the influence of the electric interactions in the chemical composition of debris detached from metallic surfaces under wear corrosion to get a better understanding of the biological effects caused by the wear products.
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9
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Crainic AM, Callisti M, Palmer MR, Cook RB. Investigation of nano-sized debris released from CoCrMo secondary interfaces in total hip replacements: Digestion of the flakes. J Biomed Mater Res B Appl Biomater 2018; 107:424-434. [PMID: 29663665 DOI: 10.1002/jbm.b.34134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 02/27/2018] [Accepted: 03/23/2018] [Indexed: 11/06/2022]
Abstract
The in vivo release of wear debris and corrosion products from the metallic interfaces of total hip replacements is associated with a wide spectrum of adverse body reactions and systemic manifestations. The origin of debris and the electrochemical conditions at the sites of material loss both play a role in determining the physicochemical characteristics of the particles, and thus influence their in vivo reactivity. Debris retrieved from revised CoCrMo tapers and cement-stem interfaces consists of heterogeneous flakes that comprise mechanically mixed metal particles, corrosion products and organic material. Detailed investigation of the size and composition of the metal debris contained within these composites requires the digestion of the flakes to release the small metal particles. Here, we compare alkaline and enzymatic digestion methods that both aim to fragment the flakes and reveal their smallest building blocks. The characterization of debris cleaned with both methods revealed crystalline Cr oxide nanoparticles and clusters. Comparison between the treatments showed that the alkaline method is more efficient in fragmenting the flakes and provided cleaner and generally smaller nanoparticles than exhibited in debris released with the enzymatic treatment. The provision of cleaner nanoparticles from the alkaline method also allows the physicochemical properties of the particles to be more clearly identified. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 424-434, 2019.
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Affiliation(s)
- Alina M Crainic
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Mauro Callisti
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, University Road, Southampton, SO17 1BJ, UK.,Department of Materials Science and Metallurgy, Cambridge University, Cambridge, CB3 0FS, UK
| | - Martin R Palmer
- School of Ocean and Earth Science, National Oceanography Centre Southampton (NOCS), University of Southampton, European Way, Southampton, SO14 3ZH, UK
| | - Richard B Cook
- National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, University Road, Southampton, SO17 1BJ, UK
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10
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Patel J, Lal S, Nuss K, Wilshaw S, von Rechenberg B, Hall R, Tipper J. Recovery of low volumes of wear debris from rat stifle joint tissues using a novel particle isolation method. Acta Biomater 2018; 71:339-350. [PMID: 29505889 DOI: 10.1016/j.actbio.2018.02.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 02/15/2018] [Accepted: 02/19/2018] [Indexed: 12/17/2022]
Abstract
Less than optimal particle isolation techniques have impeded analysis of orthopaedic wear debris in vivo. The purpose of this research was to develop and test an improved method for particle isolation from tissue. A volume of 0.018 mm3 of clinically relevant CoCrMo, Ti-6Al-4V or Si3N4 particles was injected into rat stifle joints for seven days of in vivo exposure. Following sacrifice, particles were located within tissues using histology. The particles were recovered by enzymatic digestion of periarticular tissue with papain and proteinase K, followed by ultracentrifugation using a sodium polytungstate density gradient. Particles were recovered from all samples, observed using SEM and the particle composition was verified using EDX, which demonstrated that all isolated particles were free from contamination. Particle size, aspect ratio and circularity were measured using image analysis software. There were no significant changes to the measured parameters of CoCrMo or Si3N4 particles before and after the recovery process (KS tests, p > 0.05). Titanium particles were too few before and after isolation to analyse statistically, though size and morphologies were similar. Overall the method demonstrated a significant improvement to current particle isolation methods from tissue in terms of sensitivity and efficacy at removal of protein, and has the potential to be used for the isolation of ultra-low wearing total joint replacement materials from periprosthetic tissues. STATEMENT OF SIGNIFICANCE This research presents a novel method for the isolation of wear particles from tissue. Methodology outlined in this work would be a valuable resource for future researchers wishing to isolate particles from tissues, either as part of preclinical testing, or from explants from patients for diagnostic purposes. It is increasingly recognised that analysis of wear particles is critical to evaluating the safety of an orthopaedic device.
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11
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Markhoff J, Zietz C, Fabry C, Fulda G, Bader R. Influence of analyzed lubricant volumes on the amount and characteristics of generated wear particles from three different types of polyethylene liner materials. J Biomed Mater Res B Appl Biomater 2017. [PMID: 28636252 DOI: 10.1002/jbm.b.33944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The articulating components of artificial joints consist mainly of metals, ceramics, or polymers. Resulting abrasive wear particles can promote osteolysis and aseptic loosening of the endo-prosthetic implants. Ultra-high-molecular-weight-polyethylene is the material used most for bearing couples in total hip replacement. In the present study, three types of polyethylene (PE) liners varying in material composition, i.e., (1) conventional PE (C-PE), (2) sequentially cross-linked PE (SX-PE), (3) cross-linked PE blended with vitamin E (EX-PE) articulating with two types of femoral heads were used. After ultrasound treatment of each simulator lubricant, different concentrations (0.1/0.25/0.5/1.0 mL) were taken and dissolved in hydrochloric acid (37%) in a similar manner. The aim was to analyze the characteristics of wear particles generated in a hip simulator, with respect to different volumes of the lubricant. Within the scope of particle analysis, distinct alterations for particle characteristics were determined in the lubricant volumes and types of PE material used. A significant decrease in particle number for SX-PE liners, compared to the C-PE inserts and even more for EX-PE inserts, was detected at each lubricant volume. Particle morphologies varied depending on PE material. Alterations in particle size and other morphologic parameters between the four tested volumes, could be proven for each PE type. In general, particle sizes and parameters (e.g., length and width) increased with increasing serum volumes. In conclusion, the chosen volume of the simulator lubricant used for particle analysis has a crucial influence on detected particle number, size distribution, and morphologic parameters. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1299-1306, 2018.
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Affiliation(s)
- Jana Markhoff
- Department of Orthopaedics, University Medicine Rostock, Biomechanics and Implant Technology Laboratory, Rostock, 18057, Germany
| | - Carmen Zietz
- Department of Orthopaedics, University Medicine Rostock, Biomechanics and Implant Technology Laboratory, Rostock, 18057, Germany
| | - Christian Fabry
- Department of Orthopaedics, University Medicine Rostock, Biomechanics and Implant Technology Laboratory, Rostock, 18057, Germany
| | - Gerhard Fulda
- Centre for Electron Microscopy, University Medicine Rostock, 18057, Rostock, Germany
| | - Rainer Bader
- Department of Orthopaedics, University Medicine Rostock, Biomechanics and Implant Technology Laboratory, Rostock, 18057, Germany
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12
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In-situ Generated Tribomaterial in Metal/Metal Contacts: current understanding and future implications for implants. ACTA ACUST UNITED AC 2017; 10:42-50. [PMID: 28808674 DOI: 10.1016/j.biotri.2017.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Artificial hip joints operate in aqueous biofluids that are highly reactive towards metallic surfaces. The reactivity at the metal interface is enhanced by mechanical interaction due to friction, which can change the near-surface structure of the metal and surface chemistry. There are now several reports in the literature about the in-situ generation of reaction films and tribo-metallurgical transformations on metal-on-metal hip joints. This paper summarizes current knowledge and provides a mechanistic interpretation of the surface chemical and metallurgical phenomena. Basic concepts of corrosion and wear are illustrated and used to interpret available literature on in-vitro and in-vivo studies of metal-on-metal hip joints. Based on this review, three forms of tribomaterial, characterized by different combinations of oxide films and organic layers, can be determined. It is shown that the generation of these tribofilms can be related to specific electrochemical and mechanical phenomena in the metal interface. It is suggested that the generation of this surface reaction layer constitutes a way to minimize (mechanical) wear of MoM hip implants.
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13
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Kovochich M, Fung ES, Donovan E, Unice KM, Paustenbach DJ, Finley BL. Characterization of wear debris from metal-on-metal hip implants during normal wear versus edge-loading conditions. J Biomed Mater Res B Appl Biomater 2017; 106:986-996. [PMID: 28480531 DOI: 10.1002/jbm.b.33902] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 03/14/2017] [Accepted: 04/03/2017] [Indexed: 12/12/2022]
Abstract
Advantages of second-generation metal-on-metal (MoM) hip implants include low volumetric wear rates and the release of nanosized wear particles that are chemically inert and readily cleared from local tissue. In some patients, edge loading conditions occur, which result in higher volumetric wear. The objective of this study was to characterize the size, morphology, and chemistry of wear particles released from MoM hip implants during normal (40° angle) and edge-loading (65° angle with microseparation) conditions. The mean primary particle size by volume under normal wear was 35 nm (range: 9-152 nm) compared with 95 nm (range: 6-573 nm) under edge-loading conditions. Hydrodynamic diameter analysis by volume showed that particles from normal wear were in the nano- (<100 nm) to submicron (<1000 nm) size range, whereas edge-loading conditions generated particles that ranged from <100 nm up to 3000-6000 nm in size. Particles isolated from normal wear were primarily chromium (98.5%) and round to oval in shape. Edge-loading conditions generated more elongated particles (4.5%) (aspect ratio ≥ 2.5) and more CoCr alloy particles (9.3%) compared with normal wear conditions (1.3% CoCr particles). By total mass, edge-loading particles contained approximately 640-fold more cobalt than normal wear particles. Our findings suggest that high wear conditions are a potential risk factor for adverse local tissue effects in MoM patients who experience edge loading. This study is the first to characterize both the physical and chemical characteristics of MoM wear particles collected under normal and edge-loading conditions. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 986-996, 2018.
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15
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A preliminary evaluation of immune stimulation following exposure to metal particles and ions using the mouse popliteal lymph node assay. Toxicol Appl Pharmacol 2016; 308:77-90. [DOI: 10.1016/j.taap.2016.07.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/17/2016] [Accepted: 07/26/2016] [Indexed: 01/22/2023]
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16
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Lal S, Hall RM, Tipper JL. A novel method for isolation and recovery of ceramic nanoparticles and metal wear debris from serum lubricants at ultra-low wear rates. Acta Biomater 2016; 42:420-428. [PMID: 27395827 DOI: 10.1016/j.actbio.2016.07.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/16/2016] [Accepted: 07/05/2016] [Indexed: 12/12/2022]
Abstract
UNLABELLED Ceramics have been used to deliver significant improvements in the wear properties of orthopaedic bearing materials, which has made it challenging to isolate wear debris from simulator lubricants. Ceramics such as silicon nitride, as well as ceramic-like surface coatings on metal substrates have been explored as potential alternatives to conventional implant materials. Current isolation methods were designed for isolating conventional metal, UHMWPE and ceramic wear debris. In this paper, we describe a methodology for isolation and recovery of ceramic or ceramic-like coating particles and metal wear particles from serum lubricants under ultra-low and low wear performance. Enzymatic digestion was used to digest the serum proteins and sodium polytungstate was used as a novel density gradient medium to isolate particles from proteins and other contaminants by ultracentrifugation. This method demonstrated over 80% recovery of particles and did not alter the size or morphology of ceramic and metal particles during the isolation process. STATEMENT OF SIGNIFICANCE Improvements in resistance to wear and mechanical damage of the articulating surfaces have a large influence on longevity and reliability of joint replacement devices. Modern ceramics have demonstrated ultra-low wear rates for hard-on-hard total hip replacements. Generation of very low concentrations of wear debris in simulator lubricants has made it challenging to isolate the particles for characterisation and further analysis. We have introduced a novel method to isolate ceramic and metal particles from serum-based lubricants using enzymatic digestion and novel sodium polytungstate gradients. This is the first study to demonstrate the recovery of ceramic and metal particles from serum lubricants at lowest detectable in vitro wear rates reported in literature.
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Affiliation(s)
- S Lal
- School of Biomedical Sciences, University of Leeds, UK; School of Mechanical Engineering, University of Leeds, UK.
| | - R M Hall
- School of Mechanical Engineering, University of Leeds, UK
| | - J L Tipper
- School of Biomedical Sciences, University of Leeds, UK; School of Mechanical Engineering, University of Leeds, UK
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Vasconcelos DM, Santos SG, Lamghari M, Barbosa MA. The two faces of metal ions: From implants rejection to tissue repair/regeneration. Biomaterials 2016; 84:262-275. [DOI: 10.1016/j.biomaterials.2016.01.046] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/20/2016] [Accepted: 01/21/2016] [Indexed: 12/20/2022]
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de Villiers D, Shelton JC. Measurement outcomes from hip simulators. Proc Inst Mech Eng H 2016; 230:398-405. [DOI: 10.1177/0954411916628559] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/15/2015] [Indexed: 11/15/2022]
Abstract
Simulation of wear in total hip replacements has been recognised as an important factor in determining the likelihood of clinical success. However, accurate measurement of wear can be problematic with factors such as number and morphology of wear particles produced as well as ion release proving more important in the biological response to hip replacements than wear volume or wear rate alone. In this study, hard-on-hard (CoCr alloy, AgCrN coating) and hard-on-soft (CoCr alloy and CrN coating on vitamin E blended highly cross-linked polyethylene) bearing combinations were tested in an orbital hip simulator under standard and some adverse conditions. Gravimetric wear rates were determined for all bearings, with cobalt and where applicable, silver release determined throughout testing. Isolation of wear particles from the lubricating fluid was used to determine the influence of different bearing combinations and wear conditions on particle morphology. It was found that cobalt and silver could be measured in the lubricating fluid even when volumetric wear was not detectable. In hard-on-hard bearings, Pearson’s correlation of 0.98 was established between metal release into the lubricating fluid and wear volume. In hard-on-soft bearings, coating the head did not influence the polyethylene wear rates measured under standard conditions but did influence the cobalt release; the diameter influenced both polyethylene wear and cobalt release, and the introduction of adverse testing generated smaller polyethylene particles. While hip simulators can be useful to assess the wear performance of a new material or design, measurement of other outcomes may yield greater insight into the clinical behaviour of the bearings in vivo.
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Affiliation(s)
- Danielle de Villiers
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Julia C Shelton
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
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Bitounis D, Pourchez J, Forest V, Boudard D, Cottier M, Klein JP. Detection and analysis of nanoparticles in patients: A critical review of the status quo of clinical nanotoxicology. Biomaterials 2015; 76:302-12. [PMID: 26561929 DOI: 10.1016/j.biomaterials.2015.10.061] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/16/2015] [Accepted: 10/26/2015] [Indexed: 11/16/2022]
Abstract
On the cusp of massive commercialization of nanotechnology-enhanced products and services, the physical and chemical analysis of nanoparticles in human specimens merits immediate attention from the research community as a prerequisite for a confident clinical interpretation of their occurrence in the human organism. In this review, we describe the caveats in current practices of extracting and isolating nanoparticles from clinical samples and show that they do not help truly define the clinical significance of detected exogenous nano-sized objects. Finally, we suggest a systematic way of tackling these demanding scientific tasks. More specifically, a precise and true qualitative evaluation of nanoparticles in human biological samples is still hindered by various technical reasons. Such a procedure is more refined when the nature of the pollutants is known, like in the case of nano-sized wear debris originating from biomedical prostheses. Nevertheless, nearly all available analytical methods provide unknown quantitative accuracy and qualitative precision due to the challenging physical and chemical nature of nanoparticles. Without trustworthy information to describe the nanoparticulate load of clinical samples, it is impossible to accurately assess its pathological impact on isolated cases or allow for relevant epidemiological surveys on large populations. Therefore, we suggest that the many and various specimens stored in hospitals be used for the refinement of methods of exhaustive quantitative and qualitative characterization of prominent nanoparticles in complex human milieu.
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Affiliation(s)
- Dimitrios Bitounis
- Université de Lyon, Université Jean Monnet, EA 4624 LINA, 10 rue de la Marandière, 42270, Saint Priest en Jarez, France.
| | - Jérémie Pourchez
- Ecole Nationale Supérieure des Mines, CIS-EMSE, F42023, 158 Cours Fauriel, CS62362, Saint-Etienne, France
| | - Valérie Forest
- Ecole Nationale Supérieure des Mines, CIS-EMSE, F42023, 158 Cours Fauriel, CS62362, Saint-Etienne, France
| | - Delphine Boudard
- Université de Lyon, Université Jean Monnet, EA 4624 LINA, 10 rue de la Marandière, 42270, Saint Priest en Jarez, France
| | - Michèle Cottier
- Université de Lyon, Université Jean Monnet, EA 4624 LINA, 10 rue de la Marandière, 42270, Saint Priest en Jarez, France
| | - Jean-Philippe Klein
- Université de Lyon, Université Jean Monnet, EA 4624 LINA, 10 rue de la Marandière, 42270, Saint Priest en Jarez, France
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Toxicology of wear particles of cobalt-chromium alloy metal-on-metal hip implants Part I: Physicochemical properties in patient and simulator studies. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 11:1201-15. [DOI: 10.1016/j.nano.2014.12.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/19/2014] [Accepted: 12/03/2014] [Indexed: 12/27/2022]
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De Pasquale D, Stea S, Squarzoni S, Bordini B, Amabile M, Catalani S, Apostoli P, Toni A. Metal-on-metal hip prostheses: correlation between debris in the synovial fluid and levels of cobalt and chromium ions in the bloodstream. INTERNATIONAL ORTHOPAEDICS 2015; 38:469-75. [PMID: 24122048 DOI: 10.1007/s00264-013-2137-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 09/19/2013] [Indexed: 12/12/2022]
Abstract
PURPOSE Hip prostheses with metal-on-metal (MoM) coupling can release cobalt-chromium particles and ions. The aim of this work is to verify the correlation between particles in the synovial fluid and circulating ions. METHODS Forty patients were enrolled; particles from synovial fluid were analysed by SEM–EDX (Scanning Electron Microscopy-Energy Dispersion X-rays analysis) and levels of circulating Co and Cr were assayed by ICP-MS (inductively-coupled plasma mass spectrometry). RESULTS In 16 cases we did not find any particles in the synovial fluid and the Co level in whole blood was 0.05–4.42 ppb; in seven with few particles the blood level was 2.2–15.6 ppb; in six cases with several particles the level was 5.0–54.3 ppb; finally, in 11 cases we isolated not only Co-Cr particles, but also Cr particles with low or absent Co and in these patients the circulating level of Co was 23.8–109.6 ppb. Co in serumand Cr level both whole blood and serum have shown a similar trend to Co; the correlation between all these values and the corresponding particles is statistically significant in all cases. CONCLUSION Co and Cr both in serum and whole blood represents a systemic representation of the particle release at local level and can therefore be used to confirm a diagnosis and monitor the wear process of MoM articular prostheses.
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Topolovec M, Cör A, Milošev I. Metal-on-metal vs. metal-on-polyethylene total hip arthroplasty tribological evaluation of retrieved components and periprosthetic tissue. J Mech Behav Biomed Mater 2014; 34:243-52. [DOI: 10.1016/j.jmbbm.2014.02.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 02/12/2014] [Accepted: 02/15/2014] [Indexed: 11/27/2022]
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Schröder C, Reinders J, Zietz C, Utzschneider S, Bader R, Kretzer JP. Characterization of polyethylene wear particle: The impact of methodology. Acta Biomater 2013; 9:9485-91. [PMID: 23933100 DOI: 10.1016/j.actbio.2013.07.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/25/2013] [Accepted: 07/31/2013] [Indexed: 10/26/2022]
Abstract
Due to the prevalence of problems caused by wear particles, the reduced durability of total joint replacements is well documented. The characterization of wear debris enables the size and morphology of these wear particles to be measured and provides an assessment of the biological response in vivo. However, the impact of different methodologies of particle analysis is not yet clear. Hence, the aim of this investigation was to analyze the influence of different particle characterization methods performed by three research centers within the scope of a "round robin test". To obtain knowledge about possible pitfalls, single steps of the particle characterization process (storage, pore size of the filter, coating durations by gold sputtering and scanning electron microscopy (SEM) magnification) were analyzed. The round robin test showed significant differences between the research groups, especially for the morphology of the particles. The SEM magnification was identified as having the greatest influence on the size and shape of the particles, followed by the storage conditions of the wear particle containing lubricant. Gold sputter coating and filter pore size also exhibit significant effects. However, even though they are statistically significant, it should be emphasized that the differences are small. In conclusion, particle characterization is a complex analytical method with a multiplicity of influencing factors. It becomes apparent that a comparison of wear particle results between different research groups is challenging.
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Paustenbach DJ, Galbraith DA, Finley BL. Interpreting cobalt blood concentrations in hip implant patients. Clin Toxicol (Phila) 2013; 52:98-112. [DOI: 10.3109/15563650.2013.857024] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Pedowitz RA, Billi F, Kavanaugh A, Colbert A, Liu S, Savoie FH, You Z. Arthroscopic surgical tools: a source of metal particles and possible joint damage. Arthroscopy 2013; 29:1559-65. [PMID: 23910000 PMCID: PMC3759605 DOI: 10.1016/j.arthro.2013.05.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 05/29/2013] [Accepted: 05/30/2013] [Indexed: 02/02/2023]
Abstract
PURPOSE Our goals were (1) to characterize metal microparticles created by standard arthroscopic instruments and (2) to examine the in vitro cellular responses induced by those particles, including possible synergistic effects with local anesthetic. METHODS We applied standard surgical tools to 16 foam bone blocks immersed in saline solution (plus 3 non-instrumented controls). Eight specimens underwent 4 minutes of exposure to a 4.0-mm full-radius shaver rotating forward at 6,000 rpm. In the other blocks, 4 holes were created with a 3.0-mm drill through a sleeve. Particles were isolated onto silicon wafers by density gradient ultra-centrifugation, and scanning electron microscopy was used to analyze a minimum of 1,000 particles per wafer. Metal particles were then isolated and purified. Aliquots of sterilized micro-particles were applied to cultured bovine chondrocytes (with or without local anesthetic) and to cultured human or bovine synoviocytes. Chondrocyte viability was assessed with live/dead cell assay by flow cytometry. Synoviocyte responses were assessed with quantitative polymerase chain reaction. RESULTS Stainless steel or aluminum particles were found in each sample (the same composition as surgical instruments). The mean particle size was 1 to 2 μm (range, 50 nm to 20 μm). Chondrocyte exposure (1 hour) to metal debris induced a small but statistically significant increase in cell death, without any synergistic effect of local anesthetic. Proinflammatory chemokines were consistently upregulated in both human and bovine synoviocytes exposed to metallic microparticles for 3, 24, and 48 hours. CONCLUSIONS This study shows that metallic microdebris is liberated by common arthroscopic instruments, at scales much smaller than previously recognized. These particles are bioactive, as shown by the in vitro synoviocyte responses initiated by metallic microparticles. CLINICAL RELEVANCE Our findings suggest that metallic microparticles could induce intra-articular damage through a synoviocyte-mediated cytokine response if their concentrations reach clinically significant levels.
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Affiliation(s)
- Robert A. Pedowitz
- Department of Orthopedic Surgery, David Geffen School of Medicine, UCLA, Los Angeles, CA
| | - Fabrizio Billi
- Department of Orthopedic Surgery, David Geffen School of Medicine, UCLA, Los Angeles, CA
| | - Aaron Kavanaugh
- Department of Orthopedic Surgery, David Geffen School of Medicine, UCLA, Los Angeles, CA
| | - Andrew Colbert
- Department of Orthopedic Surgery, David Geffen School of Medicine, UCLA, Los Angeles, CA
| | - Sen Liu
- Department of Orthopaedic Surgery and Tulane Institute of Sports Medicine, Tulane University School of Medicine, New Orleans, LA,Department of Structural & Cellular Biology, Tulane Cancer Center, Louisiana Cancer Research Consortium, Tulane Center for Aging, Tulane Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, LA
| | - Felix H. Savoie
- Department of Orthopaedic Surgery and Tulane Institute of Sports Medicine, Tulane University School of Medicine, New Orleans, LA
| | - Zongbing You
- Department of Orthopaedic Surgery and Tulane Institute of Sports Medicine, Tulane University School of Medicine, New Orleans, LA,Department of Structural & Cellular Biology, Tulane Cancer Center, Louisiana Cancer Research Consortium, Tulane Center for Aging, Tulane Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, LA
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Esposito C, Maclean F, Campbell P, Walter WL, Walter WK, Bonar SF. Periprosthetic tissues from third generation alumina-on-alumina total hip arthroplasties. J Arthroplasty 2013; 28:860-6. [PMID: 23489720 DOI: 10.1016/j.arth.2012.10.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/22/2012] [Accepted: 10/23/2012] [Indexed: 02/01/2023] Open
Abstract
The histological features of periprosthetic tissues are related to the bioreactivity of particles generated by the prosthesis. This study analyzed synovial-like pseudocapsules collected from 21 patients with alumina ceramic-on-ceramic hip arthroplasties and correlated histological features with wear of the ceramic bearings, duration of implantation and clinical factors such as neck-to-rim impingement. A histopathological classification system was developed for this purpose. The pseudocapsules were viable, with few foreign body type giant cells and occasional lymphocytes. This differs from tissues in polyethylene containing hip arthroplasties which often have extensive foreign body type inflammatory changes or from metal-on-metal hip arthroplasties in which extensive necrosis is common. Soft-tissue inflammation was not associated with failure of the hip arthroplasties, and may be clinically insignificant in alumina-on-alumina total hip arthroplasties.
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A new method for shape and texture classification of orthopedic wear nanoparticles. J Appl Biomater Funct Mater 2012; 10:141-8. [PMID: 23015373 DOI: 10.5301/jabfm.2012.9680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/25/2012] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Detailed morphologic analysis of particles produced during wear of orthopedic implants is important in determining a correlation among material, wear, and biological effects. However, the use of simple shape descriptors is insufficient to categorize the data and to compare the nature of wear particles generated by different implants. An approach based on Discrete Fourier Transform (DFT) is presented for describing particle shape and surface texture. METHOD Four metal-on-metal bearing couples were tested in an orbital wear simulator under standard and adverse (steep-angled cups) wear simulator conditions. Digitized Scanning Electron Microscope (SEM) images of the wear particles were imported into MATLAB to carry out Fourier descriptor calculations via a specifically developed algorithm. The descriptors were then used for studying particle characteristics (shape and texture) as well as for cluster classification. RESULTS AND CONCLUSIONS Analysis of the particles demonstrated the validity of the proposed model by showing that steep-angle Co-Cr wear particles were more asymmetric, compressed, extended, triangular, square, and roughened at 3 Mc than after 0.25 Mc. In contrast, particles from standard angle samples were only more compressed and extended after 3 Mc compared to 0.25 Mc. Cluster analysis revealed that the 0.25 Mc steep-angle particle distribution was a subset of the 3 Mc distribution.
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Lu F, Royle M, Lali FV, Hart AJ, Collins S, Housden J, Shelton JC. Simple isolation method for the bulk isolation of wear particles from metal on metal bearing surfaces generated in a hip simulator test. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2012; 23:891-901. [PMID: 22391991 DOI: 10.1007/s10856-012-4573-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 01/27/2012] [Indexed: 05/31/2023]
Abstract
Isolation and characterization of metal-on-metal (MoM) wear particles from simulator lubricants is essential to understand wear behaviour, ion release and associated corrosive activity related to the wear particles. Substantial challenges remain to establish a simple, precise and repeatable protocol for the isolation and analysis of wear particles due to their extremely small size, their tendency to agglomerate and degrade. In this paper, we describe a simple and efficient method for the bulk isolation and characterisation of wear particles from MoM bearings. Freeze drying was used to remove the large volume of water from the serum lubricant, enzymes used to digest the proteins and ultracentrifugation to finally isolate and purify the particles. The present study involved a total of eight steps for the isolation process and a wear particle extraction efficiency of 45% was achieved.
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Affiliation(s)
- Fang Lu
- School of Engineering and Material Science, Queen Mary University of London, London, UK
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