Long-Term Inhibition of Biofilm Formation on Silicone Urinary Catheters Utilizing Thin Film Coatings
Thursday, December 12, 2019
10:30 AM-12:30 PM
BIOMED PhD Thesis Defense
Title:
Long-Term Inhibition of Biofilm Formation on Silicone Urinary Catheters Utilizing Thin Film Coatings
Speaker:
Camilla A. Nix, PhD Candidate
School of Biomedical Engineering, Science and Health Systems
Drexel University
Advisor:
Yinghui Zhong, PhD
Associate Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University
Details:
An indwelling urinary catheter is an implanted medical device used for urine collection from patients with limited mobility and/or urinary incontinence. A patient will receive a short-term catheter (less than 14 days) or a “chronic” catheter (greater than 30 days), depending on their medical need. Approximately 23% of hospitalized patients may require short or long-term use of a catheter during their hospital stay; however, the use of a catheter greatly increases patient morbidity because it increases the risk for the development of a urinary tract infection. Catheter-associated urinary tract infection (CAUTI) was reported to occur in 50% of patients when the catheter is in operation for more than 5 days. For patients who require the use of a chronic catheter, up to 71% will develop a urinary tract infection, with the highest risk factor being the number of days the catheter is in place.
Biofilm formation is the main cause of CAUTI. Inhibition of biofilm formation can be achieved via surface modification of the urinary catheters with anti-fouling or drug eluting coatings. Antifouling coatings include anti-adhesive coatings, which are made from polymer brushes and hydrophilic polymers to prevent adhesion, and positive-charged bactericidal polymers that kill bacteria upon contact. Drug-releasing coatings allow for elution of antibiotics, antimicrobials, or bactericidal compounds to kill non-adherent bacteria.
Anti-fouling coatings are usually not as effective as drug-releasing coatings in inhibiting CAUTI, especially for long-term usage. However, for preventive purposes, drug administration should be minimized, unless necessary. Therefore, the overall goal of this dissertation was to design, develop, and characterize an effective anti-adhesive coating and an effective drug-releasing coating for short-term and long-term catheters, respectively. We found that the anti-adhesive coating could inhibit up to 85% of cell adhesion and 60% of cell viability over a 30-day period, and the drug-releasing coating could inhibit up to 99% of cell viability over a 30-day period Additionally, we studied whether a combined anti-adhesive and drug-releasing coating was more effective than either one alone. We found that the combined coating was equally as effective as the drug-releasing coating, with significantly less total drug release compared to the drug-releasing coating, representing a safer coating design.
Contact Information
Ken Barbee
215-895-1335
barbee@drexel.edu