Imaging of red-shifted photons from bioluminescent tumours using fluorescence by unbound excitation from luminescence

AbstractEarly detection of tumours is today a major challenge and requires sensitive imaging methodologies coupled with new efficient probes. Bioluminescence imaging has been widely used in the field of oncology and several cancer cell lines have been genetically modified to provide bioluminescence signals. However, photons that are emitted by the majority of commonly used luciferases are usually in the blue part of the visible spectrum, where tissue absorption is still very high, making deep tissue imaging non-optimal and calling for optimised optical imaging methodologies. We have previously shown that red-shifting of bioluminescence signal by Fluorescence Unbound Excitation from Luminescence (FUEL) is a mean to increase bioluminescence signal sensitivity detection in vivo. Here, we applied FUEL to tumour detection in two different subcutaneous tumour models: the auto-luminescent human embryonic kidney (HEK293) cell line and the murine B16-F10 melanoma cell line previously transfected with the plasmid Luc2. Tumour size and bioluminescence were measured over time and tumour vascularization characterized. We then locally injected near infrared emitting Quantum Dots (NIR QDs)in the tumour site and observed a red-shifting of bioluminescence signal by (FUEL) indicating that FUEL could be used to allow deeper tumour detection.

Download Full-text

mRhubarb: Engineering of monomeric, red-shifted, and brighter variants of iRFP using structure-guided multi-site mutagenesis

Scientific Reports ◽

10.1038/s41598-019-52123-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Oliver C. Rogers ◽

Dorothy M. Johnson ◽

Elad Firnberg

Keyword(s):

Near Infrared ◽

Fluorescent Proteins ◽

Visible Spectrum ◽

Tissue Imaging ◽

Imaging Studies ◽

Near Ir ◽

Site Mutagenesis ◽

Light Absorbance ◽

Reduced Light

Abstract Far-red and near-infrared fluorescent proteins (FPs) enable in vivo tissue imaging with greater depth and clarity compared to FPs in the visible spectrum due to reduced light absorbance and scatter by tissues. However current tools are limited by low brightness, limited red-shifting, and a non-ideal dimeric oligomerization state. In this study we developed a monomeric variant of iRFP, termed mRhubarb713, and subsequently used a targeted and expansive multi-site mutagenesis approach to screen for variants with red-shifted spectral activity. Two monomeric variants were discovered, deemed mRhubarb719 and mRhubarb720, with red-shifted spectra and increased quantum yield compared to iRFP. These tools build on previously developed near-IR FPs and should enable improved in vivo imaging studies with a genetically encoded reporter.

Download Full-text

Five-nanometer ZnSn2O4:Cr,Eu ultra-small nanoparticles as new near infrared-emitting persistent luminescent nanoprobes for cellular and deep tissue imaging at 800 nm

Nanoscale ◽

10.1039/c7nr02468a ◽

2017 ◽

Vol 9 (25) ◽

pp. 8631-8638 ◽

Cited By ~ 21

Author(s):

Jin-Lei Li ◽

Jun-Peng Shi ◽

Cheng-Cheng Wang ◽

Peng-Hui Li ◽

Zhen-Feng Yu ◽

...

Keyword(s):

Near Infrared ◽

Tissue Imaging ◽

Deep Tissue ◽

Deep Tissue Imaging ◽

Small Nanoparticles

Schematic illustration of the synthesis, functionalization and repeated in vivo simulated deep tissue imaging of ZSO NPLNPs.

Download Full-text

A microrobotic system guided by photoacoustic computed tomography for targeted navigation in intestines in vivo

Science Robotics ◽

10.1126/scirobotics.aax0613 ◽

2019 ◽

Vol 4 (32) ◽

pp. eaax0613 ◽

Cited By ~ 73

Author(s):

Zhiguang Wu ◽

Lei Li ◽

Yiran Yang ◽

Peng Hu ◽

Yang Li ◽

...

Keyword(s):

Computed Tomography ◽

Biomedical Applications ◽

Near Infrared ◽

Tissue Imaging ◽

Infrared Light ◽

Precise Control ◽

Deep Imaging ◽

Diverse Environment ◽

Deep Tissue Imaging

Recently, tremendous progress in synthetic micro/nanomotors in diverse environment has been made for potential biomedical applications. However, existing micro/nanomotor platforms are inefficient for deep tissue imaging and motion control in vivo. Here, we present a photoacoustic computed tomography (PACT)–guided investigation of micromotors in intestines in vivo. The micromotors enveloped in microcapsules are stable in the stomach and exhibit efficient propulsion in various biofluids once released. The migration of micromotor capsules toward the targeted regions in intestines has been visualized by PACT in real time in vivo. Near-infrared light irradiation induces disintegration of the capsules to release the cargo-loaded micromotors. The intensive propulsion of the micromotors effectively prolongs the retention in intestines. The integration of the newly developed microrobotic system and PACT enables deep imaging and precise control of the micromotors in vivo and promises practical biomedical applications, such as drug delivery.

Download Full-text

DNA-based nanocarriers to enhance the optoacoustic contrast of tumors in vivo

10.1101/2020.08.07.235705 ◽

2020 ◽

Author(s):

James Joseph ◽

Kevin N. Baumann ◽

Alejandro Postigo ◽

Laura Bollepalli ◽

Sarah E. Bohndiek ◽

...

Keyword(s):

Near Infrared ◽

Tumor Imaging ◽

Signal Generation ◽

Tissue Imaging ◽

Optoacoustic Tomography ◽

Synthetic Strategy ◽

Deep Tissue Imaging ◽

Spatio Temporal ◽

Tumor Accumulation

AbstractOptoacoustic tomography (OT) enables non-invasive deep tissue imaging of optical contrast at high spatio-temporal resolution. The applications of OT in cancer imaging often rely on the use of molecular imaging contrast agents based on near infrared dyes to enhance contrast at the tumor site. While these agents afford excellent biocompatibility and minimal toxicity, they present limited optoacoustic signal generation capability and rapid renal clearance, which can impede their tumor imaging efficacy. In this work, a synthetic strategy to overcome these limitations utilizing biodegradable DNA-based nanocarrier (DNA-NC) platforms is introduced. DNA-NCs enable the incorporation of near infrared dyes (in this case, IRDye 800CW) at precise positions to enable fluorescence quenching and maximize optoacoustic signal generation. Furthermore, these DNA-NCs show a prolonged blood circulation compared to the native fluorophores, facilitating tumor accumulation by the Enhanced Permeability and Retention (EPR) effect. In vivo imaging of tumor xenografts in mice following intravenous administration of DNA-NCs revealed enhanced OT signals at 24h when compared to free fluorophores, indicating promise for this method to enhance the optoacoustic signal generation capability and tumor uptake of clinically relevant near infrared dyes.

Download Full-text

Improvement in Tracing Quantum Dot-Conjugated Nanospheres forIn VivoImaging by Eliminating Food Autofluorescence

Journal of Nanomaterials ◽

10.1155/2015/894353 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Chul-Kyu Park ◽

Hoonsung Cho

Keyword(s):

Fluorescence Imaging ◽

Near Infrared ◽

Signal To Noise Ratio ◽

Tissue Imaging ◽

Fluorescence Probes ◽

Infrared Range ◽

Long Term Stability ◽

Magnetic Nanospheres ◽

Deep Tissue Imaging

Fluorescence imaging using fluorescent probes has demonstrated long-term stability and brightness suitable forin vivodeep-tissue imaging, but it also allows intense background fluorescence associated with food in the near-infrared (IR) range. We investigated effects of changing rodent diet on food autofluorescence, in the presence of quantum dots-conjugated magnetic nanospheres (QD-MNSs). Replacement of a regular rodent diet with a purified diet has great improvement in removing autofluorescence in the near-infrared range ideal forin vivofluorescence imaging. By feeding a purified diet for eliminating ingredients impairing desirable fluorescence signals in the near-IR range, food autofluorescence was clearly eliminated and fluorescence probes, QD-MNSs, introduced by i.v. injection were effectively traced in a mouse by a distinctive signal-to-noise ratio.

Download Full-text

Evaluation of Red CdTe and Near Infrared CdHgTe Quantum Dots by Fluorescent Imaging

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.18163 ◽

2008 ◽

Vol 8 (3) ◽

pp. 1155-1159 ◽

Cited By ~ 5

Author(s):

Jun Zhang ◽

Junfeng Su ◽

Li Liu ◽

Yalou Huang ◽

Ralph P. Mason

Keyword(s):

Fluorescent Probes ◽

Near Infrared ◽

Fluorescent Imaging ◽

Tissue Imaging ◽

Antibody Conjugates ◽

Deep Tissue Imaging ◽

Membrane Antigens ◽

Preclinical Animal Models

Non-invasive fluorescent imaging of preclinical animal models in vivo is a rapidly developing field with new emerging technologies and techniques. Quantum dot (QD) fluorescent probes with longer emission wavelengths in red and near infrared (NIR) emission ranges are more amenable to deep-tissue imaging, because both scattering and autofluorescence are reduced as wavelengths are increased. We have designed and synthesized red CdTe and NIR CdHgTe QDs for fluorescent imaging. We demonstrated fluorescent imaging by using CdTe and CdHgTe QDs as fluorescent probes both in vitro and in vivo. Both CdTe and CdHgTe QDs provided sensitive detection over background autofluorescence in tissue biopsies and live mice, making them attractive probes for in vivo imaging extending into deep tissues or whole animals. The studies suggest a basis of using QD-antibody conjugates to detect membrane antigens.

Download Full-text

Two-Dimensional Near-Infrared and Shortwave Infrared Molecular Aggregates: Taking Kasha’s Model to the Next Dimension

10.26434/chemrxiv.7699358.v3 ◽

2019 ◽

Author(s):

Arundhati Deshmukh ◽

Danielle Koppel ◽

Chern Chuang ◽

Danielle Cadena ◽

Jianshu Cao ◽

...

Keyword(s):

Near Infrared ◽

Photophysical Properties ◽

Satellite Telemetry ◽

Transition Dipole Moment ◽

Short Wave ◽

Tissue Imaging ◽

Transition Dipole ◽

Deep Tissue Imaging ◽

Excitonic States ◽

Shortwave Infrared

Technologies which utilize near-infrared (700 – 1000 nm) and short-wave infrared (1000 – 2000 nm) electromagnetic radiation have applications in deep-tissue imaging, telecommunications and satellite telemetry due to low scattering and decreased background signal in this spectral region. However, there are few molecular species, which absorb efficiently beyond 1000 nm. Transition dipole moment coupling (e.g. J-aggregation) allows for redshifted excitonic states and provides a pathway to highly absorptive electronic states in the infrared. We present aggregates of two cyanine dyes whose absorption peaks redshift dramatically upon aggregation in water from ~ 800 nm to 1000 nm and 1050 nm with sheet-like morphologies and high molar absorptivities (e ~ 105 M-1cm-1). To describe this phenomenology, we extend Kasha’s model for J- and H-aggregation to describe the excitonic states of 2-dimensional aggregates whose slip is controlled by steric hindrance in the assembled structure. A consequence of the increased dimensionality is the phenomenon of an intermediate “I-aggregate”, one which redshifts yet displays spectral signatures of band-edge dark states akin to an H-aggregate. We distinguish between H-, I- and J-aggregates by showing the relative position of the bright (absorptive) state within the density of states using temperature dependent spectroscopy. Our results can be used to better design chromophores with predictable and tunable aggregation with new photophysical properties.

Download Full-text

Real-time observation of tetrapyrrole binding to an engineered bacterial phytochrome

Communications Chemistry ◽

10.1038/s42004-020-00437-3 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yusaku Hontani ◽

Mikhail Baloban ◽

Francisco Velazquez Escobar ◽

Swetta A. Jansen ◽

Daria M. Shcherbakova ◽

...

Keyword(s):

Real Time ◽

Rational Design ◽

Near Infrared ◽

Fluorescent Proteins ◽

Covalent Bond ◽

Binding Pocket ◽

Tissue Imaging ◽

Covalent Attachment ◽

Time Resolved

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.

Download Full-text