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Synthesis and bioconjugation of gold nanoparticles as potential molecular probes for light-based imaging techniques.

Rayavarapu RG, Petersen W, Ungureanu C, Post JN, van Leeuwen TG, Manohar S - Int J Biomed Imaging (2007)

Bottom Line: Further, we have conjugated these gold nanoparticles to a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells.The bioconjugation protocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions of the antibody and the gold surface.We discuss various aspects of the synthesis and bioconjugation protocols and the characterization results of the functionalized nanoparticles.

View Article: PubMed Central - PubMed

Affiliation: Biophysical Engineering Group, Institute for Biomedical Technology (BMTI), Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

ABSTRACT
We have synthesized and characterized gold nanoparticles (spheres and rods) with optical extinction bands within the "optical imaging window." The intense plasmon resonant driven absorption and scattering peaks of these nanoparticles make them suitable as contrast agents for optical imaging techniques. Further, we have conjugated these gold nanoparticles to a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells. The bioconjugation protocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions of the antibody and the gold surface. We discuss various aspects of the synthesis and bioconjugation protocols and the characterization results of the functionalized nanoparticles. Some proposed applications of these potential molecular probes in the field of biomedical imaging are also discussed.

No MeSH data available.


Related in: MedlinePlus

Confocal reflectance images (left) and bright fieldimages (right) of (a) SKBR3 cells incubated with silver-stained HER81/goldsphere conjugates, (b) CHO cells under the same conditions. Care was taken tomaintain the same acquisition parameters in both cases. The silver-stainedbioconjugates are detected at the cell membranes of SKBR3 cells where HER2 islocalized. This indicates successful conjugation and retention of functionalityof the antibody after conjugation. No such accumulation of HER81/gold sphereconjugates is demonstrated in HER2 negative CHO cells.
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fig7: Confocal reflectance images (left) and bright fieldimages (right) of (a) SKBR3 cells incubated with silver-stained HER81/goldsphere conjugates, (b) CHO cells under the same conditions. Care was taken tomaintain the same acquisition parameters in both cases. The silver-stainedbioconjugates are detected at the cell membranes of SKBR3 cells where HER2 islocalized. This indicates successful conjugation and retention of functionalityof the antibody after conjugation. No such accumulation of HER81/gold sphereconjugates is demonstrated in HER2 negative CHO cells.

Mentions: Figure 7(a) show confocal reflectance image (on left)and bright field image (on right) of the HER81 mAb/gold sphere conjugatesincubated with SKBR3 cells. As discussed in the experimental section, silverenhancement was used by which silver is reduced onto the gold particles forminglarge clusters around 500 nm in size. This then enables visualization under themicroscope. The HER2 receptors are localized to the cell membranes of SKBR3cells. The high intensities in both images at the cell membrane are thenevidence of the preservation of the functionality of the antibody and alsoillustrate successful conjugation. The images in Figure 7(b), which show thesituation with the negative control using the CHO cells, display no suchaccumulation of gold particles. Also, adding nonantibody conjugated gold NPs tothe SKBR3 cells did not result in accumulation of the nanorods, indicating thespecificity of the HER81 antibody-nanorod conjugate (data not shown).


Synthesis and bioconjugation of gold nanoparticles as potential molecular probes for light-based imaging techniques.

Rayavarapu RG, Petersen W, Ungureanu C, Post JN, van Leeuwen TG, Manohar S - Int J Biomed Imaging (2007)

Confocal reflectance images (left) and bright fieldimages (right) of (a) SKBR3 cells incubated with silver-stained HER81/goldsphere conjugates, (b) CHO cells under the same conditions. Care was taken tomaintain the same acquisition parameters in both cases. The silver-stainedbioconjugates are detected at the cell membranes of SKBR3 cells where HER2 islocalized. This indicates successful conjugation and retention of functionalityof the antibody after conjugation. No such accumulation of HER81/gold sphereconjugates is demonstrated in HER2 negative CHO cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2266791&req=5

fig7: Confocal reflectance images (left) and bright fieldimages (right) of (a) SKBR3 cells incubated with silver-stained HER81/goldsphere conjugates, (b) CHO cells under the same conditions. Care was taken tomaintain the same acquisition parameters in both cases. The silver-stainedbioconjugates are detected at the cell membranes of SKBR3 cells where HER2 islocalized. This indicates successful conjugation and retention of functionalityof the antibody after conjugation. No such accumulation of HER81/gold sphereconjugates is demonstrated in HER2 negative CHO cells.
Mentions: Figure 7(a) show confocal reflectance image (on left)and bright field image (on right) of the HER81 mAb/gold sphere conjugatesincubated with SKBR3 cells. As discussed in the experimental section, silverenhancement was used by which silver is reduced onto the gold particles forminglarge clusters around 500 nm in size. This then enables visualization under themicroscope. The HER2 receptors are localized to the cell membranes of SKBR3cells. The high intensities in both images at the cell membrane are thenevidence of the preservation of the functionality of the antibody and alsoillustrate successful conjugation. The images in Figure 7(b), which show thesituation with the negative control using the CHO cells, display no suchaccumulation of gold particles. Also, adding nonantibody conjugated gold NPs tothe SKBR3 cells did not result in accumulation of the nanorods, indicating thespecificity of the HER81 antibody-nanorod conjugate (data not shown).

Bottom Line: Further, we have conjugated these gold nanoparticles to a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells.The bioconjugation protocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions of the antibody and the gold surface.We discuss various aspects of the synthesis and bioconjugation protocols and the characterization results of the functionalized nanoparticles.

View Article: PubMed Central - PubMed

Affiliation: Biophysical Engineering Group, Institute for Biomedical Technology (BMTI), Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

ABSTRACT
We have synthesized and characterized gold nanoparticles (spheres and rods) with optical extinction bands within the "optical imaging window." The intense plasmon resonant driven absorption and scattering peaks of these nanoparticles make them suitable as contrast agents for optical imaging techniques. Further, we have conjugated these gold nanoparticles to a mouse monoclonal antibody specific to HER2 overexpressing SKBR3 breast carcinoma cells. The bioconjugation protocol uses noncovalent modes of binding based on a combination of electrostatic and hydrophobic interactions of the antibody and the gold surface. We discuss various aspects of the synthesis and bioconjugation protocols and the characterization results of the functionalized nanoparticles. Some proposed applications of these potential molecular probes in the field of biomedical imaging are also discussed.

No MeSH data available.


Related in: MedlinePlus