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Purpose: The integration of nanotechnology into biomedical imaging has significantly advanced diagnostic and theranostic capabilities. However, nanoparticle detection in imaging relies on functionalization with appropriate probes. In this work, a new approach to visualize free-label nanoparticles using MRI and MRS techniques is described, consisting of detecting by 1 H CSI specific proton signals belonging to the components naturally present in most of the nanosystems used in preclinical and clinical research., Methods: Three different nanosystems, namely lipid-based micelles, liposomes, and perfluorocarbon-based nanoemulsions, were synthesized, characterized by high resolution NMR and then visualized by 1 H CSI at 300 MHz. Subsequently the best 1 H CSI performing system was administered to murine models of cancer to evaluate the possibility of tracking the nanosystem by looking at its proton associated signal. Furthermore, an in vitro comparison between 1 H CSI and 19 F MRI was carried out., Results: The study successfully demonstrates the feasibility of detecting nanoparticles using MRI/MRS without probe functionalization, employing 1 H CSI. Among the nanosystems tested, the perfluorocarbon-based nanoemulsion exhibited the highest SNR. Consequently, it was evaluated in vivo, where its detection was achievable within tumors and inflamed regions via 1 H CSI, and in lymph nodes via PRESS., Conclusions: These findings present a promising avenue for nanoparticle imaging in biomedical applications, offering potential enhancements to diagnostic and theranostic procedures. This non-invasive approach has the capacity to advance imaging techniques and expand the scope of nanoparticle-based biomedical research. Further exploration is necessary to fully explore the implications and applications of this method., (© 2024 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Macrocyclic chelators play a central role in medical imaging and nuclear medicine owing to their unparalleled metal cation coordination abilities. Their functionalization by fluorinated groups is an attractive design, to combine their properties with those of 18 F for Positron Emission Tomography (PET) or natural 19 F for Magnetic Resonance Imaging (MRI), and access potential theranostic or smart medical imaging probes. For the first time, a compact fluorinated macrocyclic architecture has been synthesized, based on a cyclen chelator bearing additional pyridine coordinating units and simple methyltrifluoroborate prosthetic groups. This ligand and its corresponding model Zn(ii) complex were investigated to evaluate the 18 F-PET or 19 F MRI abilities provided by this novel molecular structure. The chelator and the complex were obtained via a simple and high-yielding synthetic route, present excellent solvolytic stability of the trifluoroborate groups at various pH, and provide facile late-stage 18 F-radiolabeling (up to 68% radiochemical yield with high activity) as well as a satisfying detection limit for 19 F MRI imaging (low mM range)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The most prominent pathophysiological hallmark of Alzheimer's disease is the aggregation of amyloid-β (Aβ) peptides into senile plaques. Curcumin and its derivatives exhibit a high affinity for binding to Aβ fibrils, effectively inhibiting their growth. This property holds promise for both therapeutic applications and diagnostic molecular imaging. In this study, curcumin was functionalized with perfluoro- tert -butyl groups to create candidate molecular probes specifically targeted to Aβ fibrils for use in 19 F-magnetic resonance imaging. Two types of fluorinated derivatives were considered: mono-substituted (containing nine fluorine atoms per molecule) and disubstituted (containing eighteen fluorine atoms). The linker connecting the perfluoro moiety with the curcumin scaffold was evaluated for its impact on binding affinity and water solubility. All mono-substituted compounds and one disubstituted compound exhibited a binding affinity toward Aβ fibrils on the same order of magnitude as reference curcumin. The insertion of a charged carboxylate group into the linker enhanced the water solubility of the probes. Compound Curc-Glu-F9 (with one L-glutamyl moiety and a perfluoro- tert -butyl group), showed the best properties in terms of binding affinity towards Aβ fibrils, water solubility, and intensity of the 19 F-NMR signal in the Aβ oligomer bound form.