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https://www.readbyqxmd.com/read/29104084/orthopaedic-implant-materials-drive-m1-macrophage-polarization-in-a-spleen-tyrosine-kinase-and-mitogen-activated-protein-kinase-dependent-manner
#1
Olwyn R Mahon, Sarah O'Hanlon, Clare C Cunningham, Geraldine M McCarthy, Christopher Hobbs, Valeria Nicolosi, Daniel J Kelly, Aisling Dunne
Total joint replacements (TJR) are costly procedures required to relieve pain and restore function in patients suffering from end-stage arthritis. Despite great progress in the development and durability of TJRs, the generation of prosthesis-associated wear particles over time leads to an inflammatory cascade which culminates in periprosthetic osteolysis. Studies suggest that wear particles drive the polarization/differentiation of immature macrophages towards a pro-inflammatory M1 phenotype rather than an anti-inflammatory M2 phenotype associated with normal bone and wound healing...
November 2, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/29094238/computational-wear-assessment-of-hard-on-hard-hip-implants-subject-to-physically-demanding-tasks
#2
R Nithyaprakash, S Shankar, M S Uddin
Hip implants subject to gait loading due to occupational activities are potentially prone to failures such as osteolysis and aseptic loosening, causing painful revision surgeries. Highly risky gait activities such as carrying a load, stairs up or down and ladder up or down may cause excessive loading at the hip joint, resulting in generation of wear and related debris. Estimation of wear under the above gait activities is thus crucial to design and develop a new and improved implant component. With this motivation, this paper presents an assessment of wear generation of PCD-on-PCD (poly crystalline diamond) hip implants using finite element (FE) analysis...
November 2, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/29058499/direct-fluorescent-labeling-for-efficient-biological-assessment-of-inhalable-particles
#3
Bijay Kumar Poudel, Jae Hong Park, Jiseok Lim, Jeong Hoon Byeon
Labeling of aerosol particles with a radioactive, magnetic, or optical tracer has been employed to confirm particle localization in cell compartments, which has provided useful evidence for correlating toxic effects of inhaled particles. However, labeling requires several physicochemical steps to identify functionalities of the inner or outer surfaces of particles, and moreover, these steps can cause changes in size, surface charge, and bioactivity of the particles, resulting in misinterpretations regarding their toxic effects...
October 23, 2017: Nanotoxicology
https://www.readbyqxmd.com/read/29052372/two-layer-heterogeneous-breast-phantom-for-photoacoustic-imaging
#4
Congxian Jia, William C Vogt, Keith A Wear, T Joshua Pfefer, Brian S Garra
Photoacoustic tomography (PAT) is emerging as a potentially important aid for breast cancer detection. Well-validated tissue-simulating phantoms are needed for objective, quantitative, and physically realistic testing for system development. Prior reported PAT phantoms with homogenous structures do not incorporate the irregular layered structure of breast tissue. To assess the impact of this simplification, we design and construct two-layer breast phantoms incorporating vessel-simulating inclusions and realistic undulations at the fat/fibroglandular tissue interface...
October 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/28992804/surface-modification-of-model-hydrogel-contact-lenses-with-hyaluronic-acid-via-thiol-ene-click-chemistry-for-enhancing-surface-characteristics
#5
Myrto Korogiannaki, Jianfeng Zhang, Heather Sheardown
Discontinuation of contact lens wear as a result of ocular dryness and discomfort is extremely common; as many as 26% of contact lens wearers discontinue use within the first year. While patients are generally satisfied with conventional hydrogel lenses, improving on-eye comfort continues to remain a goal. Surface modification with a biomimetic, ocular friendly hydrophilic layer of a wetting agent is hypothesized to improve the interfacial interactions of the contact lens with the ocular surface. In this work, the synthesis and characterization of poly(2-hydroxyethyl methacrylate) surfaces grafted with a hydrophilic layer of hyaluronic acid are described...
October 2017: Journal of Biomaterials Applications
https://www.readbyqxmd.com/read/28968059/organic-modified-silver-nanoparticles-as-lubricant-additives
#6
Chanaka Kumara, Huimin Luo, Donovan N Leonard, Harry M Meyer, Jun Qu
Advanced lubrication is essential in human life for improving mobility, durability, and efficiency. Here we report the synthesis, characterization, and evaluation of two groups of oil-suspendable silver nanoparticles (NPs) as candidate lubricant additives. Two types of thiolated ligands, 4-(tert-butyl)benzylthiol (TBBT) and dodecanethiol (C12), were used to modify Ag NPs in two size ranges, 1-3 and 3-6 nm. The organic surface layer successfully suspended the Ag NPs in a poly-alpha-olefin (PAO) base oil with concentrations up to 0...
October 11, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28945331/unexpected-tribological-synergy-in-polymer-blend-coatings-leveraging-phase-separation-to-isolate-domain-size-effects-and-reduce-friction
#7
Jillian A Emerson, Nikolay T Garabedian, Axel C Moore, David L Burris, Eric M Furst, Thomas H Epps
We employed a systematic processing approach to control phase separation in polymer blend thin films and significantly reduce dynamic friction coefficients (μ)s. We leveraged this modulation of phase separation to generate composite surfaces with dynamic friction coefficients that were substantially lower than expected on the basis of simple mixing rules, and in several cases, these friction coefficients were lower than those of both pure components. Using a model polyisoprene [PI]/polystyrene [PS] composite system, a minimum μ was found in films with PS mass fractions between 0...
October 4, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28884180/facile-synthesis-of-photoluminescent-inorganic-organic-hybrid-carbon-dots-codoped-with-b-and-n-towards-an-efficient-lubrication-additive
#8
Yunxiao Zhang, Tao Cai, Wangji Shang, Dan Liu, Qiang Guo, Shenggao Liu
A novel environmentally friendly bis-functional dicationic ionic liquid containing chelated orthoborate was synthesized and polycondensed with glutamic acid in order to synthesize inorganic-organic carbon dots (CD/IL) consisting of an ionic liquid moiety inserted in the carbon skeleton. The obtained CD/IL was found to be a new kind of nitrogen/boron-codoped nanomaterial, one with a mean particle diameter of 2.66 nm. CD/IL was verified to be a high-performance lubricant additive: in particular, the anti-wear and friction-reducing properties of poly(ethylene glycol) (PEG) were improved by 89...
September 28, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28879770/in-situ-synthesis-of-monomer-casting-nylon-6-graphene-polysiloxane-nanocomposites-intercalation-structure-synergistic-reinforcing-and-friction-reducing-effect
#9
Chengjie Li, Meng Xiang, Xiaowen Zhao, Lin Ye
On the basis of the industrialized graphene nanosheets (GNs) product, we synthesized monomer casting nylon-6 (MC PA6)/GN-3-aminopropyl-terminated poly(dimethylsiloxane) (APDMS) nanocomposite in situ through the anchoring effect of APDMS onto the GN surface. APDMS/PA6 molecules were confirmed to intercalate into the GN layers by the formation of strong interfacial interactions. The intercalation ratio and the average layer thickness of the grafted GN sample decreased in the presence of APDMS. Moreover, for MC PA6/GN-APDMS nanocomposite, GN-APDMS was uniformly distributed in the matrix and no phase separation was observed...
September 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28670899/poly-alkyl-methacrylate-brush-grafted-silica-nanoparticles-as-oil-lubricant-additives-effects-of-alkyl-pendant-groups-on-oil-dispersibility-stability-and-lubrication-property
#10
Bryan T Seymour, Roger A E Wright, Alexander C Parrott, Hongyu Gao, Ashlie Martini, Jun Qu, Sheng Dai, Bin Zhao
This article reports on the synthesis of a series of poly(alkyl methacrylate) brush-grafted, 23 nm silica nanoparticles (hairy NPs) and the study of the effect of alkyl pendant length on their use as oil lubricant additives for friction and wear reduction. The hairy NPs were prepared by surface-initiated reversible addition-fragmentation chain transfer polymerization from trithiocarbonate chain transfer agent (CTA)-functionalized silica NPs in the presence of a free CTA. We found that hairy NPs with sufficiently long alkyl pendant groups (containing >8 carbon atoms, such as 12, 13, 16, and 18 in this study) could be readily dispersed in poly(alphaolefin) (PAO), forming clear, homogeneous dispersions, and exhibited excellent stability at low and high temperatures as revealed by visual inspection and dynamic light scattering studies...
July 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28657292/plasma-functionalized-polytetrafluoroethylene-nanoparticles-for-improved-wear-in-lubricated-contact
#11
Vinay Sharma, Richard Timmons, Ali Erdemir, Pranesh B Aswath
Plasma-functionalized polytetrafluoroethylene (PTFE) nanoparticles were employed to evaluate their utility in improving the lubrication property of a group III mineral oil with a significantly low amount of zinc dialkyl dithiophosphate (ZDDP). The particles were coated with two consecutive films; the initial coating contained silica to enhance amorphous glassy tribofilm formation, followed by a methacrylate film to protect the silica coating and enhance dispersibility in the oil. The functionalized nanoparticles were evaluated for their tribological performance using a high-frequency reciprocating rig, in a cylinder-on-flat configuration...
July 20, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28576053/antibacterial-sno2-nanorods-as-efficient-fillers-of-poly-propylene-fumarate-co-ethylene-glycol-biomaterials
#12
Ana M Díez-Pascual, Angel L Díez-Vicente
Antibacterial and biocompatible SnO2 nanorods have been easily synthesized through a hydrothermal process with the aid of a cationic surfactant, and incorporated as nanoreinforcements in poly(propylene fumarate-co-ethylene glycol) (P(PF-co-EG)) copolymer crosslinked with N-vinyl-pyrrolidone (NVP) by sonication and thermal curing. The nanorods were randomly and individually dispersed inside the P(PF-co-EG) network, and noticeably increased the thermal stability, hydrophilicity, degree of crystallinity, protein absorption capability as well as stiffness and strength of the matrix, whilst decreased its level of porosity and biodegradation rate...
September 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28575980/laser-textured-co-cr-mo-alloy-stored-chitosan-poly-ethylene-glycol-composite-applied-on-artificial-joints-lubrication
#13
Hailin Lu, Shanshan Ren, Junde Guo, Yue Li, Jianhui Li, Guangneng Dong
Arthroplasty brings the wear problems because of body fluid has poor performance as lubricant. Lubricant which is used in artificial joints will rapidly degrade and be absorbed by human body after injecting. To prolong the lubricant's effectiveness, this study prepared chitosan/poly(ethylene glycol) (CS/PEG) and textures to play a role in joint lubrication and wear protection. Chitosan (CS) and poly(ethylene glycol) which have biocompatibility and biodegradability properties can be used in human body. The tribological results shown that CS/PEG sol has excellent performance when this sol was composed by 2wt% CS and 30wt% PEG, the average friction coefficient below 0...
September 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28485068/wear-resistance-of-poly-2-methacryloyloxyethyl-phosphorylcholine-grafted-carbon-fiber-reinforced-poly-ether-ether-ketone-liners-against-metal-and-ceramic-femoral-heads
#14
Shihori Yamane, Masayuki Kyomoto, Toru Moro, Masami Hashimoto, Yoshio Takatori, Sakae Tanaka, Kazuhiko Ishihara
Younger, active patients who undergo total hip arthroplasty (THA) have increasing needs for wider range of motion and improved stability of the joint. Therefore, bearing materials having not only higher wear resistance but also mechanical strength are required. Carbon fiber-reinforced poly(ether ether ketone) (CFR-PEEK) is known as a super engineering plastic that has great mechanical strength. In this study, we focused on poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted CFR-PEEK and investigated the effects of PMPC grafting and the femoral heads materials on the wear properties of CFR-PEEK liners...
May 9, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28412447/improved-release-of-triamcinolone-acetonide-from-medicated-soft-contact-lenses-loaded-with-drug-nanosuspensions
#15
Eva García-Millán, Mónica Quintáns-Carballo, Francisco Javier Otero-Espinar
Drug nanosuspensions (NSs) show a significant potential to improve loading and release properties of the poorly water soluble drug triamcinolone acetonide (TA) from poly(hydroxyethyl methacrylate) (pHEMA) soft contact lenses. In this work, TA NSs were developed by a controlled precipitation method using a fractional factorial Plackett-Burmann design. Poloxamer 407 (PL) and polyvinyl alcohol (PVA) as stabilizing agents were selected. NSs were characterized in terms of their drug content, particle size and morphology...
April 12, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28397530/comparison-of-fixation-techniques-of-3d-woven-poly-%C3%AF%C2%B5-caprolactone-scaffolds-for-cartilage-repair-in-a-weightbearing-porcine-large-animal-model
#16
James M Friedman, Mackenzie L Sennett, Marcelo B Bonadio, Kerry O Orji, Alexander L Neuwirth, Niobra Keah, James L Carey, Franklin T Moutos, Bradley T Estes, Farshid Guilak, Henning Madry, Robert L Mauck, George R Dodge
Objective To test different fixation methods of a 3-dimensionally woven poly(ϵ-caprolactone) (PCL) scaffold within chondral defects of a weightbearing large animal model. Methods Full thickness chondral defects were made in the femoral condyles of 15 adult male Yucatan mini-pigs. Two surgical approaches were compared including total arthrotomy (traditional) and a retinaculum-sparing, minimally invasive surgery (MIS) approach. Following microfracture (MFX), scaffolds were placed without fixation or were fixed with fibrin glue, suture, or subchondral anchor...
April 1, 2017: Cartilage
https://www.readbyqxmd.com/read/28263442/the-effects-of-presence-of-a-backside-screw-hole-on-biotribological-behavior-of-phospholipid-polymer-grafted-crosslinked-polyethylene
#17
Kenichi Watanabe, Toru Moro, Masayuki Kyomoto, Kenichi Saiga, Shuji Taketomi, Yuho Kadono, Yoshio Takatori, Sakae Tanaka, Kazuhiko Ishihara
One of the important factors in determining the success of joint replacement is the wear performance of polyethylene. Although highly crosslinked polyethylene (CLPE) is presently used, it is still not adequate. We have developed a surface modification technology using poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) in an attempt to improve wear performance. In this study, we evaluated the wear and creep deformation resistances of 3-mm and 6-mm thick PMPC-grafted CLPE disks, set on a metal back-plate, with and without a sham screw hole...
March 6, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28254324/modification-of-ti6al4v-implant-surfaces-by-biocompatible-tio2-pcl-hybrid-layers-prepared-via-sol-gel-dip-coating-structural-characterization-mechanical-and-corrosion-behavior
#18
Michelina Catauro, Flavia Bollino, Roberto Giovanardi, Paolo Veronesi
Surface modification of metallic implants is a promising strategy to improve tissue tolerance, osseointegration and corrosion resistance of them. In the present work, bioactive and biocompatible organic-inorganic hybrid coatings were prepared using a sol-gel dip coating route. They consist of an inorganic TiO2 matrix in which different percentages of poly(ε-caprolactone) (PCL), a biodegradable and biocompatible polymer, were incorporated. The coatings were used to modify the surface of Ti6Al4V substrates in order to improve their wear and corrosion resistance...
May 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28183604/wear-behaviour-of-uhmwpe-reinforced-by-carbon-nanofiller-and-paraffin-oil-for-joint-replacement
#19
Samy Yousef, Annamaria Visco, Giovanna Galtieri, Davide Nocita, Claudia Espro
The majority of artificial joints incorporate biomedical grade Ultra High Molecular Weight Poly Ethylene (UHMWPE), whose wear is considered most important in controlling service time of the whole joint. The aim of this work was to improve wear resistance of UHMWPE through the addition of 0.5-2.0wt% of Carbon Nano Filler (CNF) and 2% wt of Paraffin Oil (PO) using ball milling (BM) and extrusion techniques (EX). The wear tests on these nanocomposites were conducted by a pin on disc in dry (air) and wet media (simulated synovial fluid or artificial lubricant, and bovine synovial fluid or natural lubricant)...
April 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28183011/semi-degradable-porous-poly-vinyl-alcohol-hydrogel-scaffold-for-cartilage-repair-evaluation-of-the-initial-and-cell-cultured-tribological-properties
#20
Yi Cao, Dangsheng Xiong, Kun Wang, Yuxiang Niu
Tissue engineering for articular cartilage repair has shown success in ensuring the integration of neocartilage with surrounding tissue, but the rapid restoration of biomechanical and biotribological functions remains a significant challenge. Poly (vinyl alcohol) (PVA) hydrogel is regarded as a potential articular cartilage replacement for its fair mechanical strength and low surface friction, while its lack of bioactivity limits its utility. Combining the advantages of tissue engineering materials and PVA hydrogel, we developed a semi-degradable porous PVA hydrogel through addition of ploy (lactic-co-glycolic acid) (PLGA) microspheres and salt-leaching technique...
February 2, 2017: Journal of the Mechanical Behavior of Biomedical Materials
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