Year: 2011
Type: article
Abstract: Iron oxide nanoparticles are among the most commercially important nanoparticles being used in this burgeoning industry.Research has shown iron nanoparticles to have an inhibitory effect against several different genera of bacteria: Staphylococcus, Bacillus and Pseudmonas spp.In this study we looked at the effect of three different sets of Fe 3 O 4 nanoparticles (FeNPs) on the development of Pseudomonas aeruginosa PAO1 biofilms.Two of these NPs are also referred to as SPIONs (superparamagnetic iron oxide nanoparticles).Exposure of cells to these FeNPs at concentrations up to 200µg/ml resulted in an increase in biofilm biomass by 16h under static conditions and a corresponding increase in cell density in the bulk liquid.In contrast, these biofilms had decreased levels of extracellular DNA (eDNA).Fe(II) levels in the supernatants of biofilms formed in the presence of FeNPs exceeded 100µM compared with 20µM in control media without cells.Spent cell supernatants had little effect on Fe(II) levels.Cells also had an effect on the aggregation behavior of these nanoparticles.FeNPs incubated with cells exhibited a decrease in the number and size of FeNP aggregates visible using light microscopy.Additionally, FeNPs incubated with cells were altered in their response upon exposure to a iv supermagnet.When exposed to a supermagnet FeNPs in fresh media or spent culture supernatants formed large aggregates visible in the light microscope, and could be pelleted in microtitre plate wells.In contrast, FeNPs incubated with cells were unaffected by exposure to the supermagnet and could not be pelleted.The results of this study indicate a need to reconsider the effects of FeNPs on bacterial growth and biofilm formation and the effect the bacterial cells may have on the use and recovery of SPION v ACKNOWLEDGEMENTS I want to first and foremost thank my beautiful wife, Shawn, who sacrificed the most during the long hours of studying and research so that I may succeed; who reveled in my successes; and most importantly for putting up with me day in and day out.I love you.I would also like to thank the rest of my family for all their support throughout my program.I am indebted to my mother, Evelyn Waller, for her selflessness and for instilling the love of learning and hard work.I can't think my sister, Mary, and her husband, Bob, enough for their encouragement and understanding and not giving up on me.Thanks to my sister-in-law, Brooke, her husband, Harvey, and for my nieces and nephews (Jillian, Max, and Marco) for understanding my absences from family events.Secondly, I want to think the professors at UD who taught and supported me during my time here.I especially want to think my
Author: Carl Edwin Haney
Institution: University of Dayton
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2620871885