scholarly journals Small Molecule Optoacoustic Contrast Agents: An Unexplored Avenue for Enhancing In Vivo Imaging

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2766 ◽  
Author(s):  
Matt Laramie ◽  
Mary Smith ◽  
Fahad Marmarchi ◽  
Lacey McNally ◽  
Maged Henary
Keyword(s):  
Contrast Agents ◽  
Fluorescence Imaging ◽  
Small Molecule ◽  
Fluorescent Dyes ◽  
Molecular Design ◽  
Imaging Technique ◽  
Structural Features ◽  
Optoacoustic Imaging ◽  
Information Gap

Almost every variety of medical imaging technique relies heavily on exogenous contrast agents to generate high-resolution images of biological structures. Organic small molecule contrast agents, in particular, are well suited for biomedical imaging applications due to their favorable biocompatibility and amenability to structural modification. PET/SPECT, MRI, and fluorescence imaging all have a large host of small molecule contrast agents developed for them, and there exists an academic understanding of how these compounds can be developed. Optoacoustic imaging is a relatively newer imaging technique and, as such, lacks well-established small molecule contrast agents; many of the contrast agents used are the same ones which have found use in fluorescence imaging applications. Many commonly-used fluorescent dyes have found successful application in optoacoustic imaging, but others generate no detectable signal. Moreover, the structural features that either enable a molecule to generate a detectable optoacoustic signal or prevent it from doing so are poorly understood, so design of new contrast agents lacks direction. This review aims to compile the small molecule optoacoustic contrast agents that have been successfully employed in the literature to bridge the information gap between molecular design and optoacoustic signal generation. The information contained within will help to provide direction for the future synthesis of optoacoustic contrast agents.

scholarly journals LDL-mimetic lipid nanoparticles prepared by surface KAT ligation for in vivo MRI of atherosclerosis

2020 ◽  
Vol 11 (44) ◽  
pp. 11998-12008
Author(s):  
Alessandro Fracassi ◽  
Jianbo Cao ◽  
Naoko Yoshizawa-Sugata ◽  
Éva Tóth ◽  
Corey Archer ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Fluorescent Dyes ◽  
Lipid Nanoparticles ◽  
Mri Contrast Agents ◽  
Mri Contrast ◽  
Mimetic Peptide

LDL-mimetic lipid nanoparticles, decorated with MRI contrast agents and fluorescent dyes, were prepared by the covalent attachments of an apoB100-mimetic peptide, Gd(iii)-chelate, and rhodamine to enhance atherosclerosis in the in vivo imaging.

One small molecule as a theranostic agent: naphthalimide dye for subcellular fluorescence localization and photodynamic therapy in vivo

MedChemComm ◽  
2016 ◽  
Vol 7 (6) ◽  
pp. 1171-1175 ◽  
Author(s):  
Lei Zhang ◽  
Kecheng Lei ◽  
Jingwen Zhang ◽  
Wenlin Song ◽  
Yuanhong Zheng ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Fluorescence Imaging ◽  
Small Molecule ◽  
Single Molecule ◽  
Therapeutic Treatment ◽  
Agent Based ◽  
Theranostic Agent ◽  
Bright Fluorescence ◽  
Naphthalimide Dye

A small single-molecule theranostic agent based on naphthalimide was developed, which possessed both bright fluorescence imaging and effective photodynamic therapeutic treatment.

Design of AIEgens for Near-Infrared IIb Imaging Through Structural Modulation at Molecular and Morphological Levels

2019 ◽  
Author(s):  
yuanyuan li ◽  
Zhaochong Cai ◽  
shunjie liu ◽  
Haoke Zhang ◽  
sherman Wong ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Fluorescence Imaging ◽  
Near Infrared ◽  
Molecular Design ◽  
Organic Dyes ◽  
Tissue Imaging ◽  
Deep Penetration ◽  
Structural Modulation ◽  
Organic Fluorophore

<p>Fluorescence imaging in near-infrared IIb (NIR-IIb, 1500-1700 nm) spectrum holds a considerable promise for tissue imaging with deep penetration and high spatial resolution owing to the minimized autofluorescence and suppressed photon scattering. While few inorganic NIR-IIb fluorescent probes have been reported, their organic counterparts are still underdeveloped, possibly due to the lack of efficient materials with long emission wavelength. Herein, we propose a new molecular design philosophy to develop organic NIR-IIb fluorophores with high quantum yield (QY) by manipulation of the effects of twisted intramolecular charge transfer and aggregation-induced emission at the molecular and morphological levels. A pure organic fluorescent dye emitting up to 1600 nm with a QY of 14.2% in the NIR-II region (1000-1600 nm) is developed. For the first time, NIR-IIb fluorescence imaging of blood vessels and deeply-located intestinal tract of live mice based on organic dyes is achieved. The results show that organic fluorophore performs superb imaging ability in both superficial blood vessels and internal organs with high resolution and enhanced signal-to-background ratio in NIR-IIb region. We hope this groundbreakingly study will inspire further research on the evolution of pure organic NIR-IIb probes for in vivo imaging.</p>

Comparison between optical coherence tomography imaging and histological sections of peripheral nerves

2019 ◽  
pp. 1-8
Author(s):  
Anne E. Carolus ◽  
Jens Möller ◽  
Martin R. Hofmann ◽  
Johannes A. P. van de Nes ◽  
Hubert Welp ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Peripheral Nerves ◽  
Imaging Technique ◽  
Structural Features ◽  
Weighted Averaging ◽  
Optical Coherence ◽  
Myelinated Axons ◽  
Averaging Filter ◽  
Perineural Fibrosis

OBJECTIVEOptical coherence tomography (OCT) is an imaging technique that uses the light-backscattering properties of different tissue types to generate an image. In an earlier feasibility study the authors showed that it can be applied to visualize human peripheral nerves. As a follow-up, this paper focuses on the interpretation of the images obtained.METHODSTen different short peripheral nerve specimens were retained following surgery. In a first step they were examined by OCT during, or directly after, surgery. In a second step the nerve specimens were subjected to histological examination. Various steps of image processing were applied to the OCT raw data acquired. The improved OCT images were compared with the sections stained by H & E. The authors assigned the structures in the images to the various nerve components including perineurium, fascicles, and intrafascicular microstructures.RESULTSThe results show that OCT is able to resolve the myelinated axons. A weighted averaging filter helps in identifying the borders of structural features and reduces artifacts at the same time. Tissue-remodeling processes due to injury (perineural fibrosis or neuroma) led to more homogeneous light backscattering. Anterograde axonal degeneration due to sharp injury led to a loss of visible axons and to an increase of light-backscattering tissue as well. However, the depth of light penetration is too small to allow generation of a complete picture of the nerve.CONCLUSIONSOCT is the first in vivo imaging technique that is able to resolve a nerve’s structures down to the level of myelinated axons. It can yield information about focal and segmental pathologies.

Acceptor Engineering of Small Molecule Fluorophores for NIR-II Fluorescent and NIR-I Photoacoustic Imaging

2021 ◽  
Author(s):  
Yaxi Li ◽  
Hongli Zhou ◽  
Renzhe Bi ◽  
Xiuting Li ◽  
Menglei Zha ◽  
...  
Keyword(s):  
Fluorescence Imaging ◽  
Small Molecule ◽  
Near Infrared ◽  
Photoacoustic Imaging ◽  
High Sensitivity ◽  
Tissue Penetration ◽  
Deep Tissue ◽  
Infrared Window

Fluorescence imaging in the second near-infrared window (NIR-II) has been an emerging technique in diverse in vivo applications with high sensitivity/resolution and deep tissue penetration. To date, the designing principle...

Design of AIEgens for Near-Infrared IIb Imaging Through Structural Modulation at Molecular and Morphological Levels

2019 ◽  
Author(s):  
yuanyuan li ◽  
Zhaochong Cai ◽  
shunjie liu ◽  
Haoke Zhang ◽  
sherman Wong ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Fluorescence Imaging ◽  
Near Infrared ◽  
Molecular Design ◽  
Organic Dyes ◽  
Tissue Imaging ◽  
Deep Penetration ◽  
Structural Modulation ◽  
Organic Fluorophore

<p>Fluorescence imaging in near-infrared IIb (NIR-IIb, 1500-1700 nm) spectrum holds a considerable promise for tissue imaging with deep penetration and high spatial resolution owing to the minimized autofluorescence and suppressed photon scattering. While few inorganic NIR-IIb fluorescent probes have been reported, their organic counterparts are still underdeveloped, possibly due to the lack of efficient materials with long emission wavelength. Herein, we propose a new molecular design philosophy to develop organic NIR-IIb fluorophores with high quantum yield (QY) by manipulation of the effects of twisted intramolecular charge transfer and aggregation-induced emission at the molecular and morphological levels. A pure organic fluorescent dye emitting up to 1600 nm with a QY of 14.2% in the NIR-II region (1000-1600 nm) is developed. For the first time, NIR-IIb fluorescence imaging of blood vessels and deeply-located intestinal tract of live mice based on organic dyes is achieved. The results show that organic fluorophore performs superb imaging ability in both superficial blood vessels and internal organs with high resolution and enhanced signal-to-background ratio in NIR-IIb region. We hope this groundbreakingly study will inspire further research on the evolution of pure organic NIR-IIb probes for in vivo imaging.</p>

scholarly journals Molecular Design of Conjugated Small Molecule Nanoparticles for Synergistically Enhanced PTT/PDT

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Shao ◽  
Chuang Yang ◽  
Fangyuan Li ◽  
Jiahe Wu ◽  
Nan Wang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Singlet Oxygen ◽  
Small Molecule ◽  
Energy Gap ◽  
Molecular Design ◽  
High Mass ◽  
Triplet Energy ◽  
Donor Acceptor

AbstractSimultaneous photothermal therapy (PTT) and photodynamic therapy (PDT) is beneficial for enhanced cancer therapy due to the synergistic effect. Conventional materials developed for synergistic PTT/PDT are generally multicomponent agents that need complicated preparation procedures and be activated by multiple laser sources. The emerging monocomponent diketopyrrolopyrrole (DPP)-based conjugated small molecular agents enable dual PTT/PDT under a single laser irradiation, but suffer from low singlet oxygen quantum yield, which severely restricts the therapeutic efficacy. Herein, we report acceptor-oriented molecular design of a donor–acceptor–donor (D–A–D) conjugated small molecule (IID-ThTPA)-based phototheranostic agent, with isoindigo (IID) as selective acceptor and triphenylamine (TPA) as donor. The strong D–A strength and narrow singlet–triplet energy gap endow IID-ThTPA nanoparticles (IID-ThTPA NPs) high mass extinction coefficient (18.2 L g−1 cm−1), competitive photothermal conversion efficiency (35.4%), and a dramatically enhanced singlet oxygen quantum yield (84.0%) comparing with previously reported monocomponent PTT/PDT agents. Such a high PTT/PDT performance of IID-ThTPA NPs achieved superior tumor cooperative eradicating capability in vitro and in vivo.

Sign in / Sign up

Export Citation Format

Share Document