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Biological Targeting of Plasmonic Nanoparticles Improves Cellular Imaging via the Enhanced Scattering in the Aggregates Formed.

Aioub M, Kang B, Mackey MA, El-Sayed MA - J Phys Chem Lett (2014)

Bottom Line: Nuclear-targeted AuNPs showed the greatest scattering due to the formation of denser nanoparticle clusters (i.e., increased localization).We also obtained a dynamic profile of AuNP localization in living cells, indicating that nuclear localization is directly related to the number of nuclear-targeting peptides on the AuNP surface.Increased localization led to increased plasmonic field coupling, resulting in significantly higher scattering intensity.

View Article: PubMed Central - PubMed

Affiliation: Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.

ABSTRACT
Gold nanoparticles (AuNPs) demonstrate great promise in biomedical applications due to their plasmonically enhanced imaging properties. When in close proximity, AuNPs plasmonic fields couple together, increasing their scattering cross-section due to the formation of hot spots, improving their imaging utility. In the present study, we modified the AuNPs surface with different peptides to target the nucleus and/or the cell as a whole, resulting in similar cellular uptake but different scattering intensities. Nuclear-targeted AuNPs showed the greatest scattering due to the formation of denser nanoparticle clusters (i.e., increased localization). We also obtained a dynamic profile of AuNP localization in living cells, indicating that nuclear localization is directly related to the number of nuclear-targeting peptides on the AuNP surface. Increased localization led to increased plasmonic field coupling, resulting in significantly higher scattering intensity. Thus, biochemical targeting of plasmonic nanoparticles to subcellular components is expected to lead to more resolved imaging of cellular processes.

No MeSH data available.


Related in: MedlinePlus

Real-time Rayleighscattering spectra of AuNP uptake and localizationwithin living cells for (A) RGD-AuNPs, (B) RGD1/NLS1-AuNPs, and (C) RGD1/NLS10-AuNPs. Thedeconvoluted peaks show the plasmonic scattering bands of single nanoparticles(538 nm), small AuNP clusters (641 nm), and large AuNP clusters (745nm) and the center of the Gaussian fits are denoted by dashed lines.
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fig2: Real-time Rayleighscattering spectra of AuNP uptake and localizationwithin living cells for (A) RGD-AuNPs, (B) RGD1/NLS1-AuNPs, and (C) RGD1/NLS10-AuNPs. Thedeconvoluted peaks show the plasmonic scattering bands of single nanoparticles(538 nm), small AuNP clusters (641 nm), and large AuNP clusters (745nm) and the center of the Gaussian fits are denoted by dashed lines.

Mentions: From these Rayleigh scattering dark-field images, our PERSIStechniqueallows us to obtain Rayleigh scattering spectra of AuNPs in livingcells. Accordingly, spectra were collected for the various AuNPs testedover a 24 h period as shown in Figure 2. Theentire spectrum obtained at each time point was integrated to givethe total scattering intensity for each different surface modifiedAuNP, and is shown in Figure 3. From theseintegrated scattering intensities, we calculated a scattering half-time(see Supporting Information) for each differentsurface-modified AuNP to estimate the rate at which the AuNPs localizewithin cells. RGD-AuNPs were found to have a scattering half-timeof 11.4 h, while RGD1/NLS1-AuNPs exhibited afaster scattering half-time of 6.7 h. RGD1/NLS10-AuNPs had the fastest scattering half-time of just 2.9 h. In additionto the faster half-time, indicating more rapid AuNP localization withincells, the RGD1/NLS10-AuNPs exhibit a significantlyhigher overall scattering intensity after 24 h, compared to that ofRGD-AuNPs and RGD1/NLS1-AuNPs. This indicatesthat higher concentrations of NLS on the AuNP surface leads to anincreased concentration of localized AuNPs at the perinuclear region,as evidenced by their more rapid increase in scattering, greater scatteringintensity, and greater interparticle coupling of the plasmonic fields(i.e., greater intensity of the red-shifted plasmon peaks).


Biological Targeting of Plasmonic Nanoparticles Improves Cellular Imaging via the Enhanced Scattering in the Aggregates Formed.

Aioub M, Kang B, Mackey MA, El-Sayed MA - J Phys Chem Lett (2014)

Real-time Rayleighscattering spectra of AuNP uptake and localizationwithin living cells for (A) RGD-AuNPs, (B) RGD1/NLS1-AuNPs, and (C) RGD1/NLS10-AuNPs. Thedeconvoluted peaks show the plasmonic scattering bands of single nanoparticles(538 nm), small AuNP clusters (641 nm), and large AuNP clusters (745nm) and the center of the Gaussian fits are denoted by dashed lines.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126704&req=5

fig2: Real-time Rayleighscattering spectra of AuNP uptake and localizationwithin living cells for (A) RGD-AuNPs, (B) RGD1/NLS1-AuNPs, and (C) RGD1/NLS10-AuNPs. Thedeconvoluted peaks show the plasmonic scattering bands of single nanoparticles(538 nm), small AuNP clusters (641 nm), and large AuNP clusters (745nm) and the center of the Gaussian fits are denoted by dashed lines.
Mentions: From these Rayleigh scattering dark-field images, our PERSIStechniqueallows us to obtain Rayleigh scattering spectra of AuNPs in livingcells. Accordingly, spectra were collected for the various AuNPs testedover a 24 h period as shown in Figure 2. Theentire spectrum obtained at each time point was integrated to givethe total scattering intensity for each different surface modifiedAuNP, and is shown in Figure 3. From theseintegrated scattering intensities, we calculated a scattering half-time(see Supporting Information) for each differentsurface-modified AuNP to estimate the rate at which the AuNPs localizewithin cells. RGD-AuNPs were found to have a scattering half-timeof 11.4 h, while RGD1/NLS1-AuNPs exhibited afaster scattering half-time of 6.7 h. RGD1/NLS10-AuNPs had the fastest scattering half-time of just 2.9 h. In additionto the faster half-time, indicating more rapid AuNP localization withincells, the RGD1/NLS10-AuNPs exhibit a significantlyhigher overall scattering intensity after 24 h, compared to that ofRGD-AuNPs and RGD1/NLS1-AuNPs. This indicatesthat higher concentrations of NLS on the AuNP surface leads to anincreased concentration of localized AuNPs at the perinuclear region,as evidenced by their more rapid increase in scattering, greater scatteringintensity, and greater interparticle coupling of the plasmonic fields(i.e., greater intensity of the red-shifted plasmon peaks).

Bottom Line: Nuclear-targeted AuNPs showed the greatest scattering due to the formation of denser nanoparticle clusters (i.e., increased localization).We also obtained a dynamic profile of AuNP localization in living cells, indicating that nuclear localization is directly related to the number of nuclear-targeting peptides on the AuNP surface.Increased localization led to increased plasmonic field coupling, resulting in significantly higher scattering intensity.

View Article: PubMed Central - PubMed

Affiliation: Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.

ABSTRACT
Gold nanoparticles (AuNPs) demonstrate great promise in biomedical applications due to their plasmonically enhanced imaging properties. When in close proximity, AuNPs plasmonic fields couple together, increasing their scattering cross-section due to the formation of hot spots, improving their imaging utility. In the present study, we modified the AuNPs surface with different peptides to target the nucleus and/or the cell as a whole, resulting in similar cellular uptake but different scattering intensities. Nuclear-targeted AuNPs showed the greatest scattering due to the formation of denser nanoparticle clusters (i.e., increased localization). We also obtained a dynamic profile of AuNP localization in living cells, indicating that nuclear localization is directly related to the number of nuclear-targeting peptides on the AuNP surface. Increased localization led to increased plasmonic field coupling, resulting in significantly higher scattering intensity. Thus, biochemical targeting of plasmonic nanoparticles to subcellular components is expected to lead to more resolved imaging of cellular processes.

No MeSH data available.


Related in: MedlinePlus