title: Visualizing light-triggered release of molecules inside living cells.
abstract: The light-triggered release of deoxyribonucleic acid (DNA) from gold nanoparticle-based, plasmon resonant vectors, such as nanoshells, shows great promise for gene delivery in living cells. Here we show that intracellular light-triggered release can be performed on molecules that associate with the DNA in a DNA host-guest complex bound to nanoshells. DAPI (4',6-diamidino-2-phenylindole), a bright blue fluorescent molecule that binds reversibly to double-stranded DNA, was chosen to visualize this intracellular light-induced release process. Illumination of nanoshell-dsDNA-DAPI complexes at their plasmon resonance wavelength dehybridizes the DNA, releasing the DAPI molecules within living cells, where they diffuse to the nucleus and associate with the cell's endogenous DNA. The low laser power and irradiation times required for molecular release do not compromise cell viability. This highly controlled co-release of nonbiological molecules accompanying the oligonucleotides could have broad applications in the study of cellular processes and in the development of intracellular targeted therapies.
authors.affiliation: Department of Chemistry, University, 6100 Main Street, Houston, Texas 77005.|Laboratory for Nanophotonics, and the Rice Quantum Institute, Rice, University, 6100 Main Street, Houston, Texas 77005.
authors.forename: Ryan
authors.initials: R
authors.lastname: Huschka
authors.affiliation: Department of Electrical and Computer Engineering, University, 6100 Main Street, Houston, Texas 77005.|Laboratory for Nanophotonics, and the Rice Quantum Institute, Rice, University, 6100 Main Street, Houston, Texas 77005.
authors.forename: Oara
authors.initials: O
authors.lastname: Neumann
authors.affiliation: Department of Chemistry, University, 6100 Main Street, Houston, Texas 77005.|Laboratory for Nanophotonics, and the Rice Quantum Institute, Rice, University, 6100 Main Street, Houston, Texas 77005.
authors.forename: Aoune
authors.initials: A
authors.lastname: Barhoumi
authors.affiliation: Department of Electrical and Computer Engineering, University, 6100 Main Street, Houston, Texas 77005.|Department of Physics and Astronomy, University, 6100 Main Street, Houston, Texas 77005.|Department of Bioengineering, University, 6100 Main Street, Houston, Texas 77005.|Department of Chemistry, University, 6100 Main Street, Houston, Texas 77005.|Laboratory for Nanophotonics, and the Rice Quantum Institute, Rice, University, 6100 Main Street, Houston, Texas 77005.
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Halas
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival; D004247:DNA / Q000008:administration & dosage* / Q000032:analysis*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000032:analysis; D006801:Humans; D007211:Indoles / Q000032:analysis; D008027:Light; D057145:Nanoshells / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D005456:Fluorescent Dyes; D007211:Indoles; C007293:DAPI; D004247:DNA