The long-term goal of these studies is to explore the utility of silver carbene complexes as antimicrobial agents in the treatment of pulmonary infections with emphasis on treatment of the chronic infections of the cystic fibrosis (CF) lung. Silver N-heterocyclic carbene complexes have antimicrobial activity against all bacterial species tested to date including the CF lung pathogens Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) organisms. The silver carbene complexes are water soluble, and hence amenable to nebulization for drug delivery. Silver complexes have a long history of safe use for topical applications; however, the use of silver compounds to treat pulmonary infections has not been explored. In addition to in vitro and in vivo toxicity studies aimed at determining the effects of silver complexes on the respiratory epithelium, we will establish the efficacy of these compounds for treatment of the primary CF pathogen P. aeruginosa, as well as the less common Bcc organisms, particularly B. dolosa, the causative agent of a recent epidemic. The B. dolosa strains are the most antibiotic resistant among the Bcc organisms. Virtually nothing is known about the pathogenesis of the lung infections caused by B. dolosa, and no effective therapy currently exists for these patients.
We aim to characterize a novel murine model of B. dolosa infection and use this model, as well as more established models of P. aeruginosa lung infections, to test the in vivo properties of these newly developed silver-based antimicrobial agents. Specifically, we aim to 1) synthesize silver carbene complexes as candidate antimicrobial agents; 2) determine the antimicrobial properties and toxicity profiles of the silver carbene compounds with the most promising physical properties, as well as the mechanisms of epithelial cell-silver toxicity or detoxification; and 3) develop murine models of chronic pulmonary infection with resistant CF pathogens and use these models to determine the in vivo efficacy of the leading silver carbene compounds for treatment of pulmonary infections. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI067856-01
Application #
7024278
Study Section
Special Emphasis Panel (ZRG1-DDR (01))
Program Officer
Taylor, Christopher E,
Project Start
2006-04-01
Project End
2009-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
1
Fiscal Year
2006
Total Cost
$369,121
Indirect Cost
Name
Washington University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Ornelas-Megiatto, Cátia; Shah, Parth N; Wich, Peter R et al. (2012) Aerosolized antimicrobial agents based on degradable dextran nanoparticles loaded with silver carbene complexes. Mol Pharm 9:3012-22
Ibricevic, Aida; Brody, Steven L; Youngs, Wiley J et al. (2010) ATP7B detoxifies silver in ciliated airway epithelial cells. Toxicol Appl Pharmacol 243:315-22
Li, Yali; Hindi, Khadijah; Watts, Kristin M et al. (2010) Shell crosslinked nanoparticles carrying silver antimicrobials as therapeutics. Chem Commun (Camb) 46:121-3
Knapp, Amanda R; Panzner, Matthew J; Medvetz, Doug A et al. (2010) Synthesis and antimicrobial studies of silver N-heterocyclic carbene complexes bearing a methyl benzoate substituent. Inorganica Chim Acta 364:125-131
Hindi, Khadijah M; Panzner, Matthew J; Tessier, Claire A et al. (2009) The medicinal applications of imidazolium carbene-metal complexes. Chem Rev 109:3859-84
Cannon, Carolyn L; Hogue, Lisa A; Vajravelu, Ravy K et al. (2009) In vitro and murine efficacy and toxicity studies of nebulized SCC1, a methylated caffeine-silver(I) complex, for treatment of pulmonary infections. Antimicrob Agents Chemother 53:3285-93
Panzner, Matthew J; Deeraksa, Arpaporn; Smith, Alyssa et al. (2009) Synthesis and in vitro Efficacy Studies of Silver Carbene Complexes on Biosafety Level 3 Bacteria. Eur J Inorg Chem 2009:1739-1745
Panzner, Matthew J; Hindi, Khadijah M; Wright, Brian D et al. (2009) A theobromine derived silver N-heterocyclic carbene: synthesis, characterization, and antimicrobial efficacy studies on cystic fibrosis relevant pathogens. Dalton Trans :7308-13
Hindi, Khadijah M; Ditto, Andrew J; Panzner, Matthew J et al. (2009) The antimicrobial efficacy of sustained release silver-carbene complex-loaded L-tyrosine polyphosphate nanoparticles: characterization, in vitro and in vivo studies. Biomaterials 30:3771-9
Hindi, Khadijah M; Siciliano, Tammy J; Durmus, Semih et al. (2008) Synthesis, stability, and antimicrobial studies of electronically tuned silver acetate N-heterocyclic carbenes. J Med Chem 51:1577-83

Showing the most recent 10 out of 12 publications