1. Multifunctional stratified composite coatings by electrophoretic deposition and RF co-sputtering for orthopaedic implants
- Author
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Steffen Fastner, Muhammad Atiq Ur Rehman, Sara Ferraris, Monica Ferraris, G. Gautier di Confiengo, Aldo R. Boccaccini, Emre Yavuz, Sergio Perero, and Qaisar Nawaz
- Subjects
Materials science ,Simulated body fluid ,Nanoparticle ,02 engineering and technology ,Energy dispersive spectroscopy ,010402 general chemistry ,01 natural sciences ,law.invention ,Nanoclusters ,Electrophoretic deposition ,law ,Sputtering ,Peek ,General Materials Science ,Bioactive glass ,Electrophoretic coatings ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Body fluids ,Chemical engineering ,Mechanics of Materials ,ddc:620 ,0210 nano-technology ,Layer (electronics) - Abstract
In this study, multifunctional stratified antibacterial and bioactive coatings were deposited and characterised. Initially, PEEK/bioactive glass (BG)/ mesoporous bioactive glass nanoparticle (MBGN) layers with a thickness of 110–120 μm were deposited on stainless steel substrates using electrophoretic deposition (EPD). Thin silver nanocluster-silica composite layers with a thickness of 70–155 nm were then deposited by radio frequency (RF) co-sputtering on the previously deposited EPD coatings. The deposition was carried for two different sputtering times (20 min and 40 min), which led to different layer thicknesses. PEEK/BG/MBGNs coatings were also deposited via single-step EPD. A comparison between the physicomechanical and biological characteristics of single layer PEEK/BG/MBGNs composite coating and bilayer Ag-PEEK/BG/MBGNs is presented. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) indicated that silver nanoclusters were homogeneously distributed in the multilayered EPD/RF coatings. An apatite-like structure was formed on the surface of the coatings upon immersion in simulated body fluid (SBF) after 1 day. Silver nanoclusters embedded in the silica matrix as a top layer provided controlled release of silver ions which led to a potent antibacterial effect against E. coli and S. carnosus. Single layer coatings exhibited a burst release of Ag ions, which led to antibacterial effects but were toxic to osteoblast cells. Finally, the results of WST-8 assays confirmed that the multi-structured coatings allow osteoblast-like cells to proliferate and attach strongly on the surface of the coatings.
- Published
- 2021
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