Limits...
Multimodal near-infrared-emitting PluS Silica nanoparticles with fluorescent, photoacoustic, and photothermal capabilities

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.


Comparison of PA properties of NIR-PluS NP preparations.Notes: Representative PA spectra of 0.5 µM NIR-PluS NP suspensions in (A) PBS and (B) blood. Spectra were measured over the wavelength range of 680–970 nm. (C) Imaging comparison of PA amplitudes of 0.5 µM NIR-PluS NP suspensions in blood (NP-4, NP-7, NP-6, and NP-5). Multispectral unmixing method was applied to the PA data to visualize the contribution of each dye.Abbreviations: PA, photoacoustic; NIR, near infrared; NIR-PluS NPs, NIR-emitting pluronic-silica nanoparticles; PBS, phosphate-buffered saline; NP, nanoparticle.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC5036595&req=5

f4-ijn-11-4865: Comparison of PA properties of NIR-PluS NP preparations.Notes: Representative PA spectra of 0.5 µM NIR-PluS NP suspensions in (A) PBS and (B) blood. Spectra were measured over the wavelength range of 680–970 nm. (C) Imaging comparison of PA amplitudes of 0.5 µM NIR-PluS NP suspensions in blood (NP-4, NP-7, NP-6, and NP-5). Multispectral unmixing method was applied to the PA data to visualize the contribution of each dye.Abbreviations: PA, photoacoustic; NIR, near infrared; NIR-PluS NPs, NIR-emitting pluronic-silica nanoparticles; PBS, phosphate-buffered saline; NP, nanoparticle.

Mentions: These results clearly support the potential of using NIR-PluS NPs as bright fluorescent probes in cellular imaging. Of note, besides the enhanced and tunable fluorescence emission properties useful for optical imaging, NIR-PluS NPs can convert the absorbed light into heat via a series of nonradiative processes. The photophysical properties discussed so far are thus also suitable to produce a large PA signal. In particular, as shown in Figure 4A, the PA spectral profiles of NIR-PluS NP preparations indicated their excellent PA signal intensities in PBS. As expected, the PA spectra of NP-5, NP-6, and NP-7 showed two very intense peaks at 680 nm and 820 nm, corresponding to the absorption of Cy5.5 and Cy7, respectively. The PA signals were also measured in blood to account for the effect of red blood cells absorption (Figure 4B).


Multimodal near-infrared-emitting PluS Silica nanoparticles with fluorescent, photoacoustic, and photothermal capabilities
Comparison of PA properties of NIR-PluS NP preparations.Notes: Representative PA spectra of 0.5 µM NIR-PluS NP suspensions in (A) PBS and (B) blood. Spectra were measured over the wavelength range of 680–970 nm. (C) Imaging comparison of PA amplitudes of 0.5 µM NIR-PluS NP suspensions in blood (NP-4, NP-7, NP-6, and NP-5). Multispectral unmixing method was applied to the PA data to visualize the contribution of each dye.Abbreviations: PA, photoacoustic; NIR, near infrared; NIR-PluS NPs, NIR-emitting pluronic-silica nanoparticles; PBS, phosphate-buffered saline; NP, nanoparticle.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036595&req=5

f4-ijn-11-4865: Comparison of PA properties of NIR-PluS NP preparations.Notes: Representative PA spectra of 0.5 µM NIR-PluS NP suspensions in (A) PBS and (B) blood. Spectra were measured over the wavelength range of 680–970 nm. (C) Imaging comparison of PA amplitudes of 0.5 µM NIR-PluS NP suspensions in blood (NP-4, NP-7, NP-6, and NP-5). Multispectral unmixing method was applied to the PA data to visualize the contribution of each dye.Abbreviations: PA, photoacoustic; NIR, near infrared; NIR-PluS NPs, NIR-emitting pluronic-silica nanoparticles; PBS, phosphate-buffered saline; NP, nanoparticle.
Mentions: These results clearly support the potential of using NIR-PluS NPs as bright fluorescent probes in cellular imaging. Of note, besides the enhanced and tunable fluorescence emission properties useful for optical imaging, NIR-PluS NPs can convert the absorbed light into heat via a series of nonradiative processes. The photophysical properties discussed so far are thus also suitable to produce a large PA signal. In particular, as shown in Figure 4A, the PA spectral profiles of NIR-PluS NP preparations indicated their excellent PA signal intensities in PBS. As expected, the PA spectra of NP-5, NP-6, and NP-7 showed two very intense peaks at 680 nm and 820 nm, corresponding to the absorption of Cy5.5 and Cy7, respectively. The PA signals were also measured in blood to account for the effect of red blood cells absorption (Figure 4B).

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.