AVS 54th International Symposium | |
Biomaterial Interfaces | Thursday Sessions |
Session BI+AS+NS-ThA |
Session: | Surface Analysis and Related Methods for Biological Materials |
Presenter: | B.J. Tyler, University of Utah |
Authors: | B.J. Tyler, University of Utah S. Rangarajan, University of Utah J. Moeller, University of Muenster, Germany H.F. Arlinghaus, University of Muenster, Germany |
Correspondent: | Click to Email |
The high tolerance of microbial biofilms to important antimicrobial agents creates an import problem for treatment of infections associated with implanted medical devices. Several important hypotheses for this drug resistance involve mass transport limitation within the biofilms. We have been using 2_D and 3_D ToF-SIMS analysis to investigate transport of drugs and nutrients through C. albicans biofilms. Analysis has been performed using a novel ToF-SIMS system which incorporates a cryo-sectioning chamber and precise temperature control during analysis. This instrument has allowed us to map the distribution of key nutrients and drugs with in the biofilm as well as to identify viable vs. nonviable cells. Through these studies, we have determined that the multiple cellular layers and extracellular polymers are not the most important mass transport barrier. Common drugs are able to permeate to the bottom of the biofilm within 5 minutes but are still unable to penetrate the cell wall of persister cells found at the base of the biofilm. Current work is focusing on cell wall and membrane changes within a subpopulation of the biofilm cells which apparently limits transport of antimicrobials into the cells. Multivariate statistical techniques have been crucial for the analysis of these samples and discussion of the relevant statistical methods employed will be presented.