Targeted Fluorescence Imaging Research Articles

Affibody-Attached Hyperbranched Conjugated Polyelectrolyte for Targeted Fluorescence Imaging of HER2-Positive Cancer Cell

A hyperbranched conjugated polyelectrolyte (HCPE) with a core-shell structure is designed and synthesized via alkyne polycyclotrimerization and click chemistry. The HCPE has an emission maximum at 565 nm with a quantum yield of 12% and a large Stokes shift of 143 nm in water. By virtue of its poly(ethylene glycol) shell, this polymer naturally forms spherical nanoparticles that minimize nonspecific interaction with biomolecules in aqueous solution, consequently allowing for efficient bioconjugation with anti-HER2 affibody via carbodiimide-activated coupling reaction. The resulting affibody-attached HCPE can be utilized as a reliable fluorescent probe for targeted cellular imaging of HER2-overexpressed cancer cells such as SKBR-3. Considering its low cytotoxicity and good photostability, the HCPE nanoprobe holds great promise in practical imaging tasks. This study also provides a molecular engineering strategy to overcome the intrinsic limitations of traditional fluorescent polymers (e.g., chromophore-tethered polymers and linear conjugated polyelectrolytes) for bioconjugation and applications.

Conjugated oligoelectrolyte-polyhedral oligomeric silsesquioxane loaded pH-responsive nanoparticles for targeted fluorescence imaging of cancer cell nucleus

We report conjugated oligoelectrolyte-polyhedral oligomeric silsesquioxane (COE-POSS) loaded and pH-triggered chitosan/poly(ethylene glycol) nanoparticles with folic acid functionalization for targeted imaging of cancer cell nucleus.

In Vivo Targeted Cancer Imaging, Sentinel Lymph Node Mapping and Multi-Channel Imaging with Biocompatible Silicon Nanocrystals

Quantum dots (QDs) have size-dependent optical properties that make them uniquely advantageous for in vivo targeted fluorescence imaging, traceable delivery, and therapy. The use of group II-VI (e.g., CdSe) QDs for these applications is advancing rapidly. However, group II-VI QDs contain toxic heavy metals that limit their in vivo applications. Thus, replacing these with QDs of a biocompatible semiconductor, such as silicon (Si), is desirable. Here, we demonstrate that properly encapsulated biocompatible Si QDs can be used in multiple cancer-related in vivo applications, including tumor vasculature targeting, sentinel lymph node mapping, and multicolor NIR imaging in live mice. This work overcomes dispersibility and functionalization challenges to in vivo imaging with Si QDs through a unique nanoparticle synthesis, surface functionalization, PEGylated micelle encapsulation, and bioconjugation process that produces bright, targeted nanospheres with stable luminescence and long (>40 h) tumor accumulation time in vivo. Upon the basis of this demonstration, we anticipate that Si QDs can play an important role in more sophisticated in vivo models, by alleviating QD toxicity concerns while maintaining the key advantages of QD-based imaging methods.

Fluorophore−Quencher Based Activatable Targeted Optical Probes for Detecting in Vivo Cancer Metastases

In vivo molecularly targeted fluorescence imaging of tumors has been proposed as a strategy for improving cancer detection and management. Activatable fluorophores, which increased their fluorescence by 10-fold after binding tumor cells, result in much higher target to background ratios than conventional fluorophores. We developed an in vivo targeted activatable optical imaging probe based on a fluorophore-quencher pair, bound to a targeting moiety. With this system, fluorescence is quenched by the fluorophore-quencher interaction outside cancer cells, but is activated within the target cells by dissociation of the fluorophore-quencher pair. We selected the TAMRA (fluorophore)-QSY7 (quencher) pair and conjugated it to either avidin (targeting the D-galactose receptor) or trastuzumab (a monoclonal antibody against the human epithelial growth factor receptor type2 (HER2/neu)) and evaluated their performance in mouse models of cancer. Two probes, TAMRA-QSY7 conjugated avidin (Av-TM-Q7) and trastuzumab (Traz-TM-Q7) were synthesized. Both demonstrated better than similar self-quenching probes. In vitro fluorescence microscopic studies of SHIN3 and NIH/3T3/HER2+ cells demonstrated that Av-TM-Q7 and Traz-TM-Q7 produced high intracellular fluorescent signal. In vivo imaging with Av-TM-Q7 and Traz-TM-Q7 in mice enabled the detection of small tumors. This molecular imaging probe, based on a fluorophore-quencher pair conjugated to a targeting ligand, successfully detected tumors in vivo due to its high activation ratio and low background signal. Thus, these activatable probes, based on the fluorophore-quencher system, hold promise clinically for "see and treat" strategies of cancer management.

Development and validation of receptor targeted fluorescence imaging for tumor detection and assessment of therapeutic response

Development and validation of receptor targeted fluorescence imaging for tumor detection and assessment of therapeutic response

Development and validation of receptor targeted fluorescence imaging for tumor detection and assessment of therapeutic response

Imaging, in particular, biological imaging techniques offer an effective means to evaluate and understand various biological process in living animals and human. Furthermore it has a crucial role in cancer diagnosis, delineation of tumor target, and assessment of therapeutic response. In is work, we report our experience in developing and validating a novel receptor targeted fluorescent imaging technique and explore its potential applications for radiation oncology research.