DYNAMIC SURFACES FOR URINARY CATHETERS: THE EFFECT OF POLY (GLYCEROL SEBACATE CITRATE) COMPOSITION ON DEGRADATION, ENCRUSTATION RESISTANCE AND BACTERIAL RESPONSE
type: CreativeWork
description: Encrustation and blockage of urinary catheters, caused by the formation of crystalline biofilms, has been a problem since their invention more than 90 years ago. This thesis addresses the issue via a biomaterials approach, specifically, utilising poly glycerol sebacate citrate (PGSC) produced in-house. The effects of citric acid concentration on the degradation characteristics, mechanical behaviour, hydrophilicity and encrustation resistance of bulk samples were investigated and the feasibility of coating a silicone catheter material with PGSC using oxygen plasma treatment was assessed. The effect of citric acid concentration on encrustation resistance properties and against E. coli and P. mirabilis infections was then analysed. To optimise the production of the PGSC, the effect of N2 atmosphere on the PGS prepolymers was evaluated with Fourier-transform infrared spectroscopy (FTIR). A static N2 atmosphere was found to cause the oxidation of glycerol to glyceraldehyde and hence, preparation in a flowing N2 atmosphere was adopted. PGSC with different citric acid concentrations (0.25, 0.5, 0.6, 0.7 and 0.75 molar ratio with respect to glycerol) were synthesised by dissolving PGS prepolymer and citric acid in ethanol, followed by curing. A possible mechanism for esterification was proposed where increasing citric acid concentration led to the activation of secondary alcohols on glycerol molecules. Degradation experiments in artificial urine (AU) and deionised water (DW) were undertaken and the degradation pH, percentage mass loss and absorption of media were measured as a function of citrate concentration. Encrustation resistance was measured in an environment simulating P. mirabilis infection by adding urease solution to AU and was found to increase with increasing citric acid concentration. PGSC with a citric acid molar ratio of 0.6 was found to be optimal in terms of balancing encrustation resistance and degradation rate. Tensile testing was conducted on PGSC sample…
abstract: Encrustation and blockage of urinary catheters, caused by the formation of crystalline biofilms, has been a problem since their invention more than 90 years ago. This thesis addresses the issue via a biomaterials approach, specifically, utilising poly glycerol sebacate citrate (PGSC) produced in-house. The effects of citric acid concentration on the degradation characteristics, mechanical behaviour, hydrophilicity and encrustation resistance of bulk samples were investigated and the feasibility of coating a silicone catheter material with PGSC using oxygen plasma treatment was assessed. The effect of citric acid concentration on encrustation resistance properties and against E. coli and P. mirabilis infections was then analysed. To optimise the production of the PGSC, the effect of N2 atmosphere on the PGS prepolymers was evaluated with Fourier-transform infrared spectroscopy (FTIR). A static N2 atmosphere was found to cause the oxidation of glycerol to glyceraldehyde and hence, preparation in a flowing N2 atmosphere was adopted. PGSC with different citric acid concentrations (0.25, 0.5, 0.6, 0.7 and 0.75 molar ratio with respect to glycerol) were synthesised by dissolving PGS prepolymer and citric acid in ethanol, followed by curing. A possible mechanism for esterification was proposed where increasing citric acid concentration led to the activation of secondary alcohols on glycerol molecules. Degradation experiments in artificial urine (AU) and deionised water (DW) were undertaken and the degradation pH, percentage mass loss and absorption of media were measured as a function of citrate concentration. Encrustation resistance was measured in an environment simulating P. mirabilis infection by adding urease solution to AU and was found to increase with increasing citric acid concentration. PGSC with a citric acid molar ratio of 0.6 was found to be optimal in terms of balancing encrustation resistance and degradation rate. Tensile testing was conducted on PGSC sample…
author: Zhang, Lu
language: eng
keywords: biodegradable polymer, poly glycerol sebacate citrate, urinary catheter, anti-encrustation, Catheter-associated urinary tract infection, encrustation resistance, biofilm, polymer synthesis, degradation characteristics, mechanical behaviour, hydrophilicity, oxygen plasma treatment, degradation chemistry, artificial urine, degradation mechanism, degradation behaviour, anti-bacterial, E. coli, P. mirabilis
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/1f1b016e-fcaf-4559-a1e0-6f89f47cb3b9/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2024-01-30
date modified: 2026-07-22T22:24:08Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.112041