Multimodal near-infrared-emitting PluS Silica nanoparticles with fluorescent, photoacoustic, and photothermal capabilities.
PURPOSE
The aim of the present study was to develop nanoprobes with theranostic features, including - at the same time - photoacoustic, near-infrared (NIR) optical imaging, and photothermal properties, in a versatile and stable core-shell silica-polyethylene glycol (PEG) nanoparticle architecture.


MATERIALS AND METHODS
We synthesized core-shell silica-PEG nanoparticles by a one-pot direct micelles approach. Fluorescence emission and photoacoustic and photothermal properties were obtained at the same time by appropriate doping with triethoxysilane-derivatized cyanine 5.5 (Cy5.5) and cyanine 7 (Cy7) dyes. The performances of these nanoprobes were measured in vitro, using nanoparticle suspensions in phosphate-buffered saline and blood, dedicated phantoms, and after incubation with MDA-MB-231 cells.


RESULTS
We obtained core-shell silica-PEG nanoparticles endowed with very high colloidal stability in water and in biological environment, with absorption and fluorescence emission in the NIR field. The presence of Cy5.5 and Cy7 dyes made it possible to reach a more reproducible and higher doping regime, producing fluorescence emission at a single excitation wavelength in two different channels, owing to the energy transfer processes within the nanoparticle. The nanoarchitecture and the presence of both Cy5.5 and Cy7 dyes provided a favorable agreement between fluorescence emission and quenching, to achieve optical imaging and photoacoustic and photothermal properties.


CONCLUSION
We obtained rationally designed nanoparticles with outstanding stability in biological environment. At appropriate doping regimes, the presence of Cy5.5 and Cy7 dyes allowed us to tune fluorescence emission in the NIR for optical imaging and to exploit quenching processes for photoacoustic and photothermal capabilities. These nanostructures are promising in vivo theranostic tools for the near future.
['Biffi|Stefania|S|', 'Petrizza|Luca|L|', 'Garrovo|Chiara|C|', 'Rampazzo|Enrico|E|', 'Andolfi|Laura|L|', 'Giustetto|Pierangela|P|', 'Nikolov|Ivaylo|I|', 'Kurdi|Gabor|G|', 'Danailov|Miltcho Boyanov|MB|', 'Zauli|Giorgio|G|', 'Secchiero|Paola|P|', 'Prodi|Luca|L|']
D052160:Benzothiazoles D001943:Breast Neoplasms D002232:Carbocyanines D004396:Coloring Agents D005260:Female D005453:Fluorescence D005456:Fluorescent Dyes D006801:Humans D006979:Hyperthermia, Induced D008823:Micelles D064847:Multimodal Imaging D053758:Nanoparticles D049329:Nanostructures D061848:Optical Imaging D061088:Photoacoustic Techniques D010789:Phototherapy D011092:Polyethylene Glycols D012822:Silicon Dioxide D014407:Tumor Cells, Cultured
optical imaging NIR imaging PEGylated nanoparticles dye-doped nanoparticles photoacoustic imaging photothermal therapy