Modelling biofilms on infected chronic wounds

  • Yanyan Cheng

Student thesis: Doctoral ThesisDoctor of Science (DSc)

Abstract

Chronic wounds, such as venous, pressure, arterial, and diabetic ulcers, are a public health concern worldwide. Chronic wounds are those that take more than four weeks to heal as compared to common wounds. Interestingly, the number of patients with long-lasting or permanent wounds has increased over the last two decades, and so has the cost of care. There is growing evidence that bacteria infiltrate chronic wounds and form a biofilm, which influences wound healing and treatment effectiveness. The aim of this project is to develop a dynamic ex vivo flow system to simulate Staphylococcus aureus biofilm on the infected chronic wounds using artificial wound fluid, 3D printing technology, and porcine skin. The basic application of this flow system is mimicking both systemic and topical treatment of infected chronic wounds. Furthermore, this dynamic model is also to be used to compare the killing effects on mature S. aureus MRSA 252 biofilm of commercial antibiotic discs, antibiotics-loaded paper discs and antibiotic-loaded electrospun nanofibrous matrices. The materials used in electrospinning are poly-ε-caprolactone (PCL), silk fibroin (SF), whereas the antibiotics chosen to be loaded into electrospun nanofibrous matrices are commonly used agents for topical use, being gentamicin, tetracycline, and fusidic acid. Our newly developed dynamic model was demonstrated to be effective in simulating single-strain S. aureus MRSA 252 biofilm on infected chronic wounds. As compared to a conventional colony biofilm assay (CBA), our flow system generated an air-liquid-solid interface, which is closer to real-world conditions. Both CBA and flow systems were used to monitor drug delivery from electrospun matrices. The findings added to the solid evidence that our newly designed ex vivo model is beneficial in mimicking the growth of biofilms on chronic wounds and is useful to test different treatments of biofilm-associated infected wounds.
Date of Award13 Dec 2021
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorAlbert Bolhuis (Supervisor) & Paul De Bank (Supervisor)

Keywords

  • Biofilm
  • Flow system
  • Ex vivo model
  • Artificial wound fluid
  • Antibiotic treatment

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