DESIGN AND OPTIMIZATION OF PARAMETERS AFFECTING THE PERFORMANCE OF AN ANTIBACTERIAL SYSTEM USING ELECTRICALLY ACTIVATED METALS

Open Access
Author:
Charumani, Charumani
Graduate Program:
Industrial Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
  • Richard Allen Wysk, Thesis Advisor
Keywords:
  • ELECTRICALLY ACTIVATED METALS
  • ANTIBACTERIAL
  • DESIGN PARAMETERS
Abstract:
ABSTRACT Infections associated with residual hardware devices (RHD) are becoming a challenging problem for the medical industry. Treatment of the residual hardware device infections usually involves lengthy and painful procedures. Antibiotic resistance developed by the pathogens over time is another concern. It has become essential to search for alternative antibacterial treatments to mitigate the effect of these infections. Some of the transition metals of group 11 to 14 of the Periodic Table have been investigated for their antibacterial efficacy and the bacterial resistance, and in particular silver ions have been identified as the most effective antibacterial agent. However there is no established delivery system reported which can ensure the delivery of silver ions to the site of infections associated with implanted devices. This study examines an engineered system using silver ions to create an antibiotic environment that can significantly reduce RHD associated infections. The key is to continually generate silver ions in local concentrations allowed inside the human body so that long-term microbial control can be achieved. A brief review of residual hardware device infections, the use of antibiotic silver ions, and the concept behind such a system is followed by a summary of the in-vitro tests, exploring the design constraints and working of the proposed system. The performance metric of the system and the variables affecting it have been identified for the prophylactic action of silver ions system. An experimental design is also presented to evaluate the parameter space of the variables affecting the performance of the system. The Kirby-Bauer agar gel diffusion techniques were used to evaluate the bactericidal efficacy of the silver ions system against S. aureus bacteria. In addition, the issues of current and ionic concentrations were studied including device amperage, surface area of cathode and anode, as well as the separation distance between anode and cathode. Anodic devices performed better and the current in the system and the surface are of the anode were identified as most important variables affecting the device performance. This new system allowed ionized silver to travel through media containing microbes, thus attacking the bacteria directly. The system tested demonstrated an unparalleled inhibition of the growth of microbes.