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Antibacterial effects of sputter deposited silver-doped hydroxyapatite thin films

dc.contributor.authorTrujillo, Nathan Anthony, author
dc.contributor.authorPopat, Ketul, advisor
dc.contributor.authorWilliams, John, advisor
dc.contributor.authorReynolds, Melissa, committee member
dc.contributor.authorCrans, Debbie, committee member
dc.date.accessioned2007-01-03T05:16:30Z
dc.date.available2007-01-03T05:16:30Z
dc.date.issued2011
dc.description.abstractOver recent years, researchers have studied innovative ways to increase the lifespan of orthopedic implants in order to meet the soaring demand of hip and knee replacements. Since many of these implants fail as a result of loosening, wear, and inflammation caused by repeated loading on the joints, coatings such as hydroxyapatite (HAp) on titanium with a unique topography have been shown to improve the interface between the implant and the natural tissue. Other serious problems with long-term or ideally permanent implants are bacterial colonization. It is important to prevent initial bacterial colonization as existing colonies have potential to become encased in an extracellular matrix polymer (biofilm) which is resistant to antibacterial agents. The following work considers the potential of etching using plasma based ion implantation and ion beam sputter deposition to produce hydroxyapatite thin films on etched titanium doped with silver as an antibacterial component. Plasma-based ion implantation was used to examine the effects of pre-etching on plain titanium. Topographical changes to the titanium samples were examined and compared via scanning electron microscopy. It was determined that plasma-based ion implantation at -700eV could etch titanium to produce similar topography as ion beam etching in a shorter processing time. Hydroxyapatite and silver-doped hydroxyapatite thin films were then sputter deposited on titanium substrates etched at -700eV. For silver-doped films, two concentrations of silver (~0.5wt% and ~1.5wt%) were used. Silver concentrations in the film were determined using energy dispersive x-ray spectroscopy. Film thicknesses were determined by measuring the surface profile using contact profilometry. Staphylococcus epidermidis (SE) and Pseudomonas aeruginosa (PA) adhesion studies were performed on plain titanium, titanium coated with hydroxyapatite, titanium coated with ~0.5 wt% silver-doped hydroxyapatite, and titanium coated with ~1.5wt% silver-doped hydroxyapatite. It was discovered during the study that the films were delaminating from the samples thus killing bacteria in suspension. Release studies performed in addition to adhesion confirmed that the silver-doped films prevented SE and PA bacterial growth in suspension. To prevent delamination, the films were annealed by heat treatment in air at a temperature of 600°C. X-ray diffraction confirmed the presence of a crystalline hydroxyapatite phase on each sample type. Films were immersed in PBS at 37°C and remained in incubation for four weeks to determine there was no delamination or silver leaching.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierTrujillo_colostate_0053N_10412.pdf
dc.identifier.urihttp://hdl.handle.net/10217/47415
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectantibacterial
dc.subjecthydroxyapatite
dc.subjectplasma
dc.subjectsilver
dc.subjecttitanium
dc.titleAntibacterial effects of sputter deposited silver-doped hydroxyapatite thin films
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineBioengineering
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

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