In the clinical setting, polyvinyl chloride (PVC) accounts for 25% of all polymers used in medical device applications. However, medical devices fabricated with PVC, such as endotracheal tubes, extracorporeal circuits (ECCs), or intravenous catheters suffer from thrombosis and infection. Mortality associated with hospital associated infections (HAIs) exceed 100,000 deaths each year. One method to overcome these challenges is to develop bioactive polymers with nitric oxide (NO) release. Nitric oxide exhibits many physiological roles including, antibacterial, antithrombic, anti-inflammatory activity. In this study, Tygon® PVC tubing was impregnated with a NO donor molecule, S-nitroso-N-acetylpenicillamine (SNAP), via a simple solvent-swelling-impregnation method, where polymer samples were submerged in a SNAP impregnation-solvent (methanol, acetone, plasticizer). An additional topcoat of a biocompatible CarboSil 2080A (CB) was applied to reduce SNAP leaching. The SNAP-PVC-CB were characterized for NO release using chemiluminescence, leaching with UV-Vis spectroscopy, surface characterization with scanning electron microscopy, tensile strength analysis, stability during storage and sterilization, and antimicrobial properties in vitro. The SNAP-PVC-CB exhibited NO flux of 4.29 ± 0.80 x 10-10 mol cm-2 min-1 over the initial 24 h under physiological conditions and continued to release physiological levels of NO for up 14 d (incubated in PBS at 37 °C). The addition of CB-topcoat reduced the total SNAP leaching by 86% during incubation. Mechanical properties and surface topography remained similar to original PVC after SNAP-impregnation and application of CB-topcoat. After ethylene oxide sterilization and 1-month storage, SNAP-PVC-CB demonstrated excellent SNAP stability (ca. 90% SNAP remaining). In a 24 h antibacterial assay, SNAP-PVC reduce viable bacteria colonization (ca. 1 log reduction) of S. aureus and E. coli compared to PVC controls. This novel method for SNAP-impregnation of medical grade plasticized PVC holds great potential for improving the biocompatibility of post-fabricated PVC medical devices.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd-7796 |
| Date | 01 January 2019 |
| Creators | Feit, Corbin |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations |
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