Fluorescent Dye Encapsulated ZnO Particles with Cell-Specific Toxicity for Potential Use in Biomedical Applications

Hua Wang, Boise State University
Denise Wingett, Boise State University
Mark H. Engelhard, Pacific Northwest National Laboratory
Kevin Feris, Boise State University
K. M. Reddy, Boise State University
Paul Turner, Boise State University
Janet Layne, Boise State University
Cory Hanley, Boise State University
Jason Bell, Boise State University
Dmitri Tenne, Boise State University
Chongmin Wang, Pacific Northwest National Laboratory
Alex Punnoose, Boise State University

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Journal of Materials Science-Materials in Medicine, Volume 20, Issue 1, 11-22. DOI: 10.1007/s10856-008-3541-z

Abstract

Fluorescein isothiocyanate (FITC)-encapsulated SiO₂ core-shell particles with a nanoscale ZnO finishing layer have been synthesized for the first time as multifunctional "smart" nanostructures. Detailed characterization studies confirmed the formation of an outer ZnO layer on the SiO₂–FITC core. These ~200 nm sized particles showed promise toward cell imaging and cellular uptake studies using the bacterium Escherichia coli and Jurkat cancer cells, respectively. The FITC encapsulated ZnO particles demonstrated excellent selectivity in preferentially killing Jurkat cancer cells with minimal toxicity to normal primary immune cells (18% and 75% viability remaining, respectively, after exposure to 60 μg/ml) and inhibited the growth of both gram-positive and gram-negative bacteria at concentrations ≥250–500 μg/ml (for Staphylococcus aureus and Escherichia coli, respectively). These results indicate that the novel FITC encapsulated multifunctional particles with nanoscale ZnO surface layer can be used as smart nanostructures for particle tracking, cell imaging, antibacterial treatments and cancer therapy.