Design and development of a chlorhexidine releasing antibacterial catheter material

Gambrill, Benjamin 2025. Design and development of a chlorhexidine releasing antibacterial catheter material. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Urinary catheters are among the most commonly used medical devices in clinical practice. The use of such devices carries risk of patients developing catheter-associated urinary tract infections (CAUTI). To tackle this, several attempts at catheter innovation have resulted in antimicrobial catheter devices, namely, silver-alloy and nitrofurantoin catheters. These commercial catheters are able to release antimicrobials from the catheter material, preventing onset of bacterial infection, at least for some time. Catheter innovation is made more difficult by antibiotic resistance, which makes selection of a suitable antimicrobial difficult. An ideal innovation would utilise an antimicrobial with minimal existing bacterial resistance, thereby maximising long-term clinical use. The aim of the research presented in this thesis was the design and development of a novel antimicrobial catheter device. Here a layer-by-layer approach was used to prepare a material consisting of polyelectrolytes, including antimicrobial chlorhexidine and hydrolysable polymer poly β-amino ester, synthesised using piperazine and 1,4-butanediol diacrylate. It was proposed that hydrolysable polymer would enable release of chlorhexidine over time, therefore producing a drug delivery system. The prepared material was tested for drug release over time and the drug release data used to determine the antimicrobial potential of the catheter under ordinary usage procedures as well as under storage and sterilisation conditions. Finally, a bladder model was used in an attempt to contextualise the prepared material. The findings suggest that urine and urethra pH would influence how drug releases, and therefore how long bacterial growth could be prevented for. The prepared material was found to be suitable for expected catheter storage conditions, and resilient against 3 some sterilisation conditions. The antimicrobial layers present on both sides of the material would prevent biofilm formation inside the catheter tube and bacterial infection within the epithelial lining for a duration similar to short term catheterisation. Finally, it was found that the catheter material could be useable in a bladder model with considerations for bacterial inclusion, and the potential for using other poly β-amino esters, synthesised using different amines and diacrylates, which could aid in the antibacterial potential of the material. The catheter material prepared as part of this research was found to be suitable as a material for short term catheterisation, given 3 days of bacterial growth being prevented, with drug release for at least 14 days.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Schools > Pharmacy
Subjects:	Q Science > Q Science (General)
Date of First Compliant Deposit:	2 April 2026
Last Modified:	02 Apr 2026 15:10
URI:	https://orca.cardiff.ac.uk/id/eprint/186151

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