PET and NIR optical imaging using self-illuminating 64 Cu-doped chelator-free gold nanoclusters

Abstract

Self-illuminating fluorescence imaging without autofluorescence background interference has recently aroused more research interests in molecular imaging. Currently, only a few self-illuminating probes were developed, based mainly on toxic quantum dots such as CdSe, CdTe. Herein, we report a novel design of nontoxic self-illuminating gold nanocluster (64Cu-doped AuNCs) for dual-modality positron emission tomography (PET) and near-infrared (NIR) fluorescence imaging based on Cerenkov resonance energy transfer (CRET). PET radionuclide 64Cu was introduced by a chelator-free doping method, which played dual roles as the energy donor and the PET imaging source. Meanwhile, AuNCs acted as the energy acceptor for NIR fluorescence imaging. 64Cu-doped AuNCs exhibited efficient CRET-NIR and PET imaging both in vitro and in vivo. In a U87MG glioblastoma xenograft model, 64Cu-doped AuNCs showed high tumor uptake (14.9%ID/g at 18 h) and produced satisfactory tumor self-illuminating NIR images in the absence of external excitation. This self-illuminating nanocluster with non-toxicity and good biocompatibility can be employed as a novel imaging contrast agent for biomedical applications, especially for molecular imaging.

Polymer Nanoassemblies With solvato- and halo-fluorochromism for Drug Release Monitoring and Metastasis Imaging

“…However, many fluorescent dyes can provide false signals during imaging assays unless used carefully. Theranostics for tumor metastasis using fluorescence must consider signal-to-noise ratios, quantum yields and photo-bleaching during their development [18]. Fluorescent dyes often change fluorescenceemitting spectra and quantum yields based on solvent polarity (solvato-fluorochromism) and pH (halofluorochromism) [19].…”

Synthesis and application of strawberry-like Fe 3 O 4 -Au nanoparticles as CT-MR dual-modality contrast agents in accurate detection of the progressive liver disease

“…Au nanoclusters with a size less than 2 nm have been widely studied because of their strong fluorescence, which make them promising potential labels for cellular and molecular imaging application [40,41]. In this work, the gold nanoclusters on the surface of the Fe 3 O 4 -Au NPs had a mean size about 1.0 nm, which might also possess fluorescent property.…”

Review of biomedical Čerenkov luminescence imaging applications

“…This field is at an embryonic stage, and while the actual uses are likely to be in niche areas, the amount of physical chemistry research appears to be growing. Enhancement of the Čerenkov signal is possible via interaction with radiation absorbing media, such as gold or copper based nanoparticles [70][71][72]. Several innovative designs in nanoparticle material science have shown that a carefully designed particle can enhance the signal, or this effect could be used for microenvironment sensing [73].…”