Enhanced Activity of Carbon Nanotubes-Amphotericin B Conjugates Against Mature Biofilms of Candida albicans

Z. D. Pana1, M. Simitsopoulou1, R. Papi2, C. Antachopoulos1, D. Kyriakidis2, E. Roilides1

Author address: 

13rd Dept Pediatrics, Aristotle Univ., Thessaloniki, Greece, 2Dept of Chemistry, Aristotle Univ.,

Abstract: 

Background: Amphotericin B (AmB) is commonly used against Candida biofilms; however, its application is limited by its toxicity and poor solubility. Candida biofilms are resistant to traditional antifungal treatment therefore the need for alternative and new therapeutic approach is urgent. Multiwall carbon-nanotubes (MWNTs) are novel nanomaterials with unique physical properties that can be used to deliver therapeutic agents to the targeted site of the pathogen. Our aim was to evaluate the antifungal activity of AmB conjugated to MWNTs against Candida albicans mature BF vs. that by AmB alone. Methods: MWNTs were functionalized with polyethylene- glycol (PEG) and then chemically linked to AmB by sonication. The stability behavior of the MWNTs-amphotericin B conjugates was evaluated with the zeta potential. Stocks of two BF-producing C. albicans strains were grown in YNB medium. For mature-BF formation, 106 blastoconidia/mL were added to 96-well plates and incubated at 37oC for 48h. BFs were treated with AmB-PEG-CNTs or AmB at concentrations from 0.007 to 16mg/L for 24 hours. PEGCNTs, non-functionalized CNTs, were used as controls. Percent BF damage (%BD) was assessed by XTT assay. MICs of BF were determined as the minimum antifungal concentration that caused ≥50% BF damage compared to untreated BF. Results: The conjugate efficiency of AmB-MWNTs was 90%, while the zeta potential (a measure of stability behaviour) was - 36.1mV. At concentrations of 16mg/L, PEG-MWNTs and pure MWNTs showed minimal antifungal activity against BF of both Candida strains (10.7% and 11.5% respectively), while AmB (99.1%) and AmB-PEG-MWNTs (100%) displayed high antibiofilm activity. The antibiofilm activity of AmB and AmB-PEG-MWNTs was comparable for the concentrations between 4-16mg/L, whereas in lower concentrations (
2016

abstract No: 

SUNDAY-423

Full conference title: 

ASM Microbe 2016
    • ASM microbe 1st (2016)