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Title Quantifying nisin adsorption behavior at pendant polyethylene oxide brush layers
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Publication Date
Date Available
Date Accessioned
Degree MS
Discipline/Department Chemical Engineering
Degree Level masters
University/Publisher Oregon State University
Abstract A more quantitative understanding of peptide loading and release from polyethylene oxide (PEO) brush layers will provide direction for development of new strategies for drug storage and delivery. The antimicrobial peptide nisin shows potent activity against Gram-positive bacteria including the most prevalent implant-associated pathogens, its mechanism of action minimizes the opportunity for the rise of resistant bacteria and it does not appear to be toxic to humans, suggesting good potential for its use in antibacterial coatings for selected medical devices. In this work, optical waveguide lightmode spectroscopy was used to record changes in adsorbed mass during cyclic adsorption-elution experiments with nisin, at uncoated and PEO-coated surfaces. PEO layers were prepared by radiolytic grafting of Pluronic® surfactant F108 or F68 to silanized silica surfaces, producing long- or short-chain PEO layers, respectively. Kinetic patterns were interpreted with reference to a model accounting for history-dependent adsorption, in order to evaluate rate constants for nisin adsorption and desorption, as well as the effect of pendant PEO on the lateral clustering behavior of nisin. Lateral rearrangement and clustering of adsorbed nisin was apparent on uncoated and F68-coated surfaces, but not on F108-coated surfaces. In addition, nisin showed greater resistance to elution by peptide-free buffer from uncoated and F68-coated surfaces. These results are consistent with shorter PEO chains allowing for peptide adsorption to the base substrate in the case of F68-coated surfaces, while adsorption to the F108-coated surfaces is apparently governed by the presence of a hydrophobic core within the brush layer itself. Further, these results suggest that while peptide location within the hydrophobic core provides stability against lateral rearrangement, the pendant PEO chains themselves provide no steric barrier to nisin rearrangement within the brush layer.
Subjects/Keywords Protein; Nisin  – Absorption and adsorption
Contributors McGuire, Joseph (advisor); Schilke, Karl F. (committee member)
Language en
Country of Publication us
Record ID handle:1957/30210
Repository oregonstate
Date Retrieved
Date Indexed 2017-03-17
Grantor Oregon State University
Issued Date 2012-06-01 00:00:00
Note [] Graduation date: 2012; [peerreview] no;

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…21 NISIN ADSORPTION ............................................................................................................ 21 RESULTS AND DISCUSSION…

…22 TRIBLOCK ADSORPTION ...................................................................................................... 22 PEO LAYER STABILITY AND PROTEIN REPULSION ..................................................................... 24 NISIN

…Fibrinogen Repulsion Data ............................................................................... 25 Figure 11. Nisin Adsorption onto Uncoated, F108 coated, and F68 coated Surfaces ...... 26 Figure 12. Schematic for Nisin Integration into F108 Layers…

…28 Figure 13. Schematic for Nisin Integration into F68 Layers .............................................. 29 Figure 14. Nisin Adsorption on an Uncoated Surface with H.D. Overlay.......................... 30 Figure 15. Nisin Adsorption on an F108…

…coated Surface with H.D. Overlay ..................... 32 Figure 16. Nisin Adsorption on an F68 coated Surface with H.D. Overlay ....................... 33 Figure 17. Adsorption Rate vs. Adsorbed Concentration Data…

…45 Quantifying Nisin Adsorption Behavior at Pendant Polyethylene Oxide Brush Layers Introduction Infections associated with implantable devices are a major health concern. For example, over 450,000 people in the US require chronic hemodialysis in…

…integration into 3 brush layers. Exposing uncoated and PEO coated surfaces to nisin rich solutions will provide a precise measure of adsorbed mass over time. This data can then be further analyzed to obtain kinetic rate constants for adsorption and…

…the injection loop. Approximately six mL of solution was passed through the loop to purge any remaining rinse buffer. Adsorption was performed for 30 minutes, immediately followed by a 30 minute rinse with protein free buffer. Nisin Adsorption A 0.5 mg…

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