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Are quantum dots ready for in vivo imaging in human subjects?

Cai W, Hsu AR, Li ZB, Chen X - Nanoscale Res Lett (2007)

Bottom Line: Numerous studies on QDs have resulted in major advancements in QD surface modification, coating, biocompatibility, sensitivity, multiplexing, targeting specificity, as well as important findings regarding toxicity and applicability.For in vitro applications, QDs can be used in place of traditional organic fluorescent dyes in virtually any system, outperforming organic dyes in the majority of cases.With new advances in QD technology such as bioluminescence resonance energy transfer, synthesis of smaller size non-Cd based QDs, improved surface coating and conjugation, and multifunctional probes for multimodality imaging, it is likely that human applications of QDs will soon be possible in a clinical setting.

View Article: PubMed Central - PubMed

Affiliation: The Molecular Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484, USA.

ABSTRACT
Nanotechnology has the potential to profoundly transform the nature of cancer diagnosis and cancer patient management in the future. Over the past decade, quantum dots (QDs) have become one of the fastest growing areas of research in nanotechnology. QDs are fluorescent semiconductor nanoparticles suitable for multiplexed in vitro and in vivo imaging. Numerous studies on QDs have resulted in major advancements in QD surface modification, coating, biocompatibility, sensitivity, multiplexing, targeting specificity, as well as important findings regarding toxicity and applicability. For in vitro applications, QDs can be used in place of traditional organic fluorescent dyes in virtually any system, outperforming organic dyes in the majority of cases. In vivo targeted tumor imaging with biocompatible QDs has recently become possible in mouse models. With new advances in QD technology such as bioluminescence resonance energy transfer, synthesis of smaller size non-Cd based QDs, improved surface coating and conjugation, and multifunctional probes for multimodality imaging, it is likely that human applications of QDs will soon be possible in a clinical setting.

No MeSH data available.


Related in: MedlinePlus

RGD Peptide-conjugated QD705 successfully targets the tumor vasculature in vivo. Mouse on the left was injected with QD705-RGD and the mouse on the right was injected with QD705. Arrows indicate tumors. From [45]
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Figure 8: RGD Peptide-conjugated QD705 successfully targets the tumor vasculature in vivo. Mouse on the left was injected with QD705-RGD and the mouse on the right was injected with QD705. Arrows indicate tumors. From [45]

Mentions: We reported the first in vivo targeted imaging of tumor vasculature using peptide-conjugated QDs [45]. Cell adhesion molecule integrin αvβ3 is highly expressed on activated endothelial cells and tumor cells but is not readily detectable in resting endothelial cells and most normal organ systems [157,158]. Previous reports have demonstrated that integrin αvβ3 is an excellent tumor-related target [157-165]. The fact that integrin αvβ3 is over-expressed on both tumor vasculature and tumor cells makes it a prime target for in vivo targeted imaging using QDs, as extravasation is not required to observe tumor signal. Arginine–glycine–aspartic acid (RGD; potent integrin αvβ3 antagonist) containing peptides were conjugated to QD705 (emission maximum at 705 nm) and QD705-RGD exhibited high affinity integrin αvβ3 specific binding in cell culture and ex vivo. In vivo NIR fluorescence (NIRF) imaging was carried out on athymic nude mice bearing subcutaneous integrin αvβ3-positive U87MG human glioblastoma tumors (Fig. 8) [45]. Tumor fluorescence intensity reached a maximum at 6 h post-injection with good contrast. The size of QD705-RGD (∼20 nm) prevented efficient extravasation, thus QD705-RGD mainly targeted tumor vasculature instead of tumor cells. Immunofluorescence staining of the tumor vessels confirmed that the majority of the QD fluorescence signal in the tumor colocalizes with the tumor vessels. Successful in vivo tumor imaging using QD conjugates has introduced new perspectives for targeted NIRF imaging and may aid in cancer detection and management including image-guided surgery. This probe may also have great potential as a universal NIRF probe for detecting tumor vasculature in living subjects.


Are quantum dots ready for in vivo imaging in human subjects?

Cai W, Hsu AR, Li ZB, Chen X - Nanoscale Res Lett (2007)

RGD Peptide-conjugated QD705 successfully targets the tumor vasculature in vivo. Mouse on the left was injected with QD705-RGD and the mouse on the right was injected with QD705. Arrows indicate tumors. From [45]
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3050636&req=5

Figure 8: RGD Peptide-conjugated QD705 successfully targets the tumor vasculature in vivo. Mouse on the left was injected with QD705-RGD and the mouse on the right was injected with QD705. Arrows indicate tumors. From [45]
Mentions: We reported the first in vivo targeted imaging of tumor vasculature using peptide-conjugated QDs [45]. Cell adhesion molecule integrin αvβ3 is highly expressed on activated endothelial cells and tumor cells but is not readily detectable in resting endothelial cells and most normal organ systems [157,158]. Previous reports have demonstrated that integrin αvβ3 is an excellent tumor-related target [157-165]. The fact that integrin αvβ3 is over-expressed on both tumor vasculature and tumor cells makes it a prime target for in vivo targeted imaging using QDs, as extravasation is not required to observe tumor signal. Arginine–glycine–aspartic acid (RGD; potent integrin αvβ3 antagonist) containing peptides were conjugated to QD705 (emission maximum at 705 nm) and QD705-RGD exhibited high affinity integrin αvβ3 specific binding in cell culture and ex vivo. In vivo NIR fluorescence (NIRF) imaging was carried out on athymic nude mice bearing subcutaneous integrin αvβ3-positive U87MG human glioblastoma tumors (Fig. 8) [45]. Tumor fluorescence intensity reached a maximum at 6 h post-injection with good contrast. The size of QD705-RGD (∼20 nm) prevented efficient extravasation, thus QD705-RGD mainly targeted tumor vasculature instead of tumor cells. Immunofluorescence staining of the tumor vessels confirmed that the majority of the QD fluorescence signal in the tumor colocalizes with the tumor vessels. Successful in vivo tumor imaging using QD conjugates has introduced new perspectives for targeted NIRF imaging and may aid in cancer detection and management including image-guided surgery. This probe may also have great potential as a universal NIRF probe for detecting tumor vasculature in living subjects.

Bottom Line: Numerous studies on QDs have resulted in major advancements in QD surface modification, coating, biocompatibility, sensitivity, multiplexing, targeting specificity, as well as important findings regarding toxicity and applicability.For in vitro applications, QDs can be used in place of traditional organic fluorescent dyes in virtually any system, outperforming organic dyes in the majority of cases.With new advances in QD technology such as bioluminescence resonance energy transfer, synthesis of smaller size non-Cd based QDs, improved surface coating and conjugation, and multifunctional probes for multimodality imaging, it is likely that human applications of QDs will soon be possible in a clinical setting.

View Article: PubMed Central - PubMed

Affiliation: The Molecular Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484, USA.

ABSTRACT
Nanotechnology has the potential to profoundly transform the nature of cancer diagnosis and cancer patient management in the future. Over the past decade, quantum dots (QDs) have become one of the fastest growing areas of research in nanotechnology. QDs are fluorescent semiconductor nanoparticles suitable for multiplexed in vitro and in vivo imaging. Numerous studies on QDs have resulted in major advancements in QD surface modification, coating, biocompatibility, sensitivity, multiplexing, targeting specificity, as well as important findings regarding toxicity and applicability. For in vitro applications, QDs can be used in place of traditional organic fluorescent dyes in virtually any system, outperforming organic dyes in the majority of cases. In vivo targeted tumor imaging with biocompatible QDs has recently become possible in mouse models. With new advances in QD technology such as bioluminescence resonance energy transfer, synthesis of smaller size non-Cd based QDs, improved surface coating and conjugation, and multifunctional probes for multimodality imaging, it is likely that human applications of QDs will soon be possible in a clinical setting.

No MeSH data available.


Related in: MedlinePlus