Hydrophilic Cyanine Dyes as Contrast Agents for Near-infrared Tumor Imaging: Synthesis, Photophysical Properties and Spectroscopic In vivo Characterization¶

Tissue is translucent to shortwave infrared (SWIR) light, rendering optical imaging superior in this region. However, the widespread use of optical SWIR imaging has been limited, in part, by the lack of bright, biocompatible contrast agents that absorb and emit light above 1000 nm. J-aggregation offers a means to transform stable, near-infrared (NIR) fluorophores into red-shifted SWIR contrast agents. Here we demonstrate that hollow mesoporous silica nanoparticles (HMSNs) can template the J-aggregation of NIR fluorophore IR-140 to result in nanomaterials that absorb and emit SWIR light. The J-aggregates inside PEGylated HMSNs are stable for multiple weeks in buffer and enable high resolution imaging <i>in vivo</i>with 980 nm excitation.

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Recent Experiences and Advances in Contrast-Enhanced Subharmonic Ultrasound

BioMed Research International ◽

10.1155/2015/640397 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

John R. Eisenbrey ◽

Anush Sridharan ◽

Ji-Bin Liu ◽

Flemming Forsberg

Keyword(s):

Contrast Agents ◽

Tumor Imaging ◽

Three Dimensional ◽

Ultrasound Contrast Agents ◽

Surrounding Tissue ◽

Contrast Enhanced Ultrasound ◽

Ultrasound Contrast ◽

Contrast Enhanced ◽

Subharmonic Response

Nonlinear contrast-enhanced ultrasound imaging schemes strive to suppress tissue signals in order to better visualize nonlinear signals from blood-pooling ultrasound contrast agents. Because tissue does not generate a subharmonic response (i.e., signal at half the transmit frequency), subharmonic imaging has been proposed as a method for isolating ultrasound microbubble signals while suppressing surrounding tissue signals. In this paper, we summarize recent advances in the use of subharmonic imagingin vivo. These advances include the implementation of subharmonic imaging on linear and curvilinear arrays, intravascular probes, and three-dimensional probes for breast, renal, liver, plaque, and tumor imaging.

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Bright and stable near-infrared Pluronic–silica nanoparticles as contrast agents for in vivo optical imaging

Journal of Materials Chemistry B ◽

10.1039/c6tb01234e ◽

2016 ◽

Vol 4 (33) ◽

pp. 5560-5566 ◽

Cited By ~ 19

Author(s):

Lesan Yan ◽

Huiquan Wang ◽

Anqi Zhang ◽

Calvin Zhao ◽

Yongping Chen ◽

...

Keyword(s):

Lymph Node ◽

Sentinel Lymph Node ◽

Contrast Agents ◽

Optical Imaging ◽

Silica Nanoparticles ◽

Near Infrared ◽

Circulation Time ◽

In Vivo Optical Imaging

The IR780@NPs exhibited excellent characteristics for in vivo imaging with a long circulation time and high retention in tumor and sentinel lymph node.

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Spectroscopically Well-Characterized RGD Optical Probe as a Prerequisite for Lifetime-Gated Tumor Imaging

Molecular Imaging ◽

10.2310/7290.2011.00018 ◽

2011 ◽

Vol 10 (6) ◽

pp. 7290.2011.00018 ◽

Cited By ~ 15

Author(s):

Julia Eva Mathejczyk ◽

Jutta Pauli ◽

Christian Dullin ◽

Joanna Napp ◽

Lutz-F. Tietze ◽

...

Keyword(s):

Fluorescence Lifetime ◽

Nude Mice ◽

Near Infrared ◽

Tumor Imaging ◽

Specific Binding ◽

Optical Probe ◽

Detection Sensitivity ◽

Rgd Peptides ◽

Emissive Probes

Labeling of RGD peptides with near-infrared fluorophores yields optical probes for noninvasive imaging of tumors overexpressing αvβ3 integrins. An important prerequisite for optimum detection sensitivity in vivo is strongly absorbing and highly emissive probes with a known fluorescence lifetime. The RGD-Cy5.5 optical probe was derived by coupling Cy5.5 to a cyclic arginine–glycine–aspartic acid–d-phenylalanine–lysine (RGDfK) peptide via an aminohexanoic acid spacer. Spectroscopic properties of the probe were studied in different matrices in comparison to Cy5.5. For in vivo imaging, human glioblastoma cells were subcutaneously implanted into nude mice, and in vivo fluorescence intensity and lifetime were measured. The fluorescence quantum yield and lifetime of Cy5.5 were found to be barely affected on RGD conjugation but dramatically changed in the presence of proteins. By time domain fluorescence imaging, we demonstrated specific binding of RGD-Cy5.5 to glioblastoma xenografts in nude mice. Discrimination of unspecific fluorescence by lifetime-gated analysis further enhanced the detection sensitivity of RGD-Cy5.5-derived signals. We characterized RGD-Cy5.5 as a strongly emissive and stable probe adequate for selective targeting of αvβ3 integrins. The specificity and thus the overall detection sensitivity in vivo were optimized with lifetime gating, based on the previous determination of the probes fluorescence lifetime under application-relevant conditions.

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