In by admin

Name Mr. Tyler Maxwell
Organization or Institution UCF
Presentation Type Poster
Topic Biochemistry / Chem Bio.

Heavy Metal Free Quantum Dots - a Robust Delivery Vehicle for Antibiotics for Enhanced Antibacterial Activity


Tyler Maxwell 1,2,, Parthiban Rajasekaran 2, Morgan Schaff 2,  and  Swadeshmukul Santra 1,2,3,4

Author Institution(s)

1Department of Chemistry, 2NanoScience Technology Center, 3Department of Material Science and Engineering, 4Burnett School of Biomedical Sciences, University of Central Florida


Quantum dot (Qdot) luminescent nanocrystals have gathered interest for their use as drug delivery vehicles. However, the use of heavy metals precluded them from usage in actual clinical set up. Herein, we report the design and synthesis of a nontoxic, heavy-metal free ZnS:Mn Qdots for the delivery of antibiotic compounds. The Qdots were synthesized in a one-step, one-pot procedure with EPA approved reagents and coated with N-acetylcystine (a carboxyl containing biomolecule). Drugs were attached to the Qdot both covalently (EDC coupling) and electrostatically using the negative charge of the Qdot coating and positive charge of the drugs (kanamycin and streptomycin). The Qdots were then characterized through spectroscopy (UV-Vis, fluorescence, and infrared) and electron microscopy. Liquid chromatography was used to quantify drug loading of the particles. The therapeutic efficacy of the nanoparticles was evaluated against model pathogenic bacteria (E. coli, and S. aureus) and the toxicity and uptake were tested with eukaryotic cell lines (macrophage, epithelial). The particles were found to be slightly toxic to human cells at high concentrations. Antibiotic Qdots showed comparable efficacy with free drug which is hypothesized to be due to a synergistic effect of the nanoparticle and drug in disrupting bacterial cell membrane and protein synthesis.