Synthesis, Radiolabelling and In Vitro Imaging of Multifunctional Nanoceramics

Abstract

Molecular imaging has become a powerful technique in preclinical and clinical research aiming towards the diagnosis of many diseases. In this work, we address the synthetic challenges in achieving lab‐scale, batch‐to‐batch reproducible copper‐64‐ and gallium‐68‐radiolabelled metal nanoparticles (MNPs) for cellular imaging purposes. Composite NPs incorporating magnetic iron oxide cores with luminescent quantum dots were simultaneously encapsulated within a thin silica shell, yielding water‐dispersible, biocompatible and luminescent NPs. Scalable surface modification protocols to attach the radioisotopes 64Cu (t1/2=12.7 h) and 68Ga (t1/2=68 min) in high yields are reported, and are compatible with the time frame of radiolabelling. Confocal and fluorescence lifetime imaging studies confirm the uptake of the encapsulated imaging agents and their cytoplasmic localisation in prostate cancer (PC‐3) cells. Cellular viability assays show that the biocompatibility of the system is improved when the fluorophores are encapsulated within a silica shell. The functional and biocompatible SiO2 matrix represents an ideal platform for the incorporation of 64Cu and 68Ga radioisotopes with high radiolabelling incorporation.

Oxygen Sensing, Hypoxia Tracing and in Vivo Imaging with Functional Metalloprobes for the Early Detection of Non-communicable Diseases

“…Various silica matrices such as MSU-3 (Zhang et al, 2008 ) and trimethoxysilane (TEOS) xerogel (Roche et al, 2010 ) were employed in the O 2 sensing devices in the attempt to improve the thermal and photostability, and visible-light optical transparency. Ru(bpy) 2 (Bpy-Si)Cl 2 was synthesized by reacting [Ru(dpy) 2 Cl 2 ] derivatives with a number of organosilicon precursors (Estella et al, 2010 ; Lupo et al, 2010 ; Lledos et al, 2018 ) resulting in a ruthenium(II) polypiridyl complex bearing a silane NH-(CH 2 ) 3 Si(OEt) 3 pendant moiety that allows for the covalent link between the dye and silica glass films (Malins et al, 1999 ; Zhang et al, 2008 ). An alternative to silica sieves and sol-gel matrices was proposed in 2015: anodized alumina oxide was functionalized with the novel polypyridyl Ru(II) complex Ru(dpy) 2 (phen-NH 2 )(PF 6 ) 2 complex (phen-NH 2 = 5-amine-1,10-phenanthroline) (Cui et al, 2015 ).…”

Biocompatible Probes Based on Rare-Earth Doped Strontium Aluminates with Long-Lasting Phosphorescent Properties for In Vitro Optical IMAGING

“…The encapsulation of the SrAlO:Eu,Dy with a silica shell was accomplished using a reverse micelle routine in its acidic variant [ 10 ]. In a typical procedure, 0.1 g of the strontium aluminate nanoparticles were suspended in cyclohexane (1 mg/mL) in a round bottom flask.…”

“…In this context, molecular imaging plays a key role in personalized and targeted medicine [ 8 ] and, particularly, imaging modalities such as optical imaging (including fluorescence imaging), positron emission tomography (PET), and single-photon emission computed tomography (SPECT) have gathered considerable research interest for cancer diagnosis [ 9 ]. This is mainly due to the availability of a wide selection of molecules, with adequate properties, to provide a good signal that can be exploited to image a variety of cancers [ 10 ]. Among these techniques, fluorescence imaging reveals some clear-cut advantages, including superior sensitivity, low energy radiation, the capacity to monitor multiple independent optical biomarker reporters simultaneously (multiplexing), and a relatively simple imaging hardware [ 11 , 12 , 13 ].…”

Hybrid Hierarchical Heterostructures of Nanoceramic Phosphors as Imaging Agents for Multiplexing and Living Cancer Cells Translocation

“…Biomedical imaging is a powerful diagnostic tool for personalized and targeted medicine. 21,22 Industrial and academic research users in this sector require access to advanced and affordable monitoring tools and testing facilities that can also accelerate the development of new and safe medical technologies. Recent studies have demonstrated that the applications of fluorescent labels in biomedical imaging have the potential to address the current ca.…”

“…The fluorescence techniques applied to date employ a number of wellestablished organic molecules further functionalized to be directed to target cancer specifically, such as Rhodamine, derivatives of fluorescein, and more recently NIR-emitting cyanine dyes. 22 The dominant immunoassays used in biosensing clinical, preclinical, and life sciences research are multiplexed ELISA, where different emitting fluorophores anchored onto supports and coated with specific antibodies are responsive for a high precision biomarker detection, additionally to Western Blot (WB), immunofluorescence microscopy (IF), immunohistochemistry (IHC), and flow cytometry (FC) which all have a requirement for enzymatic or fluorescencebased detection methodologies. 25 The majority of the currently available immunoassays are either singleplex or low multiplex (2−4 channels) and in the latter, the extra channels are normally required for providing contextual information such as providing cellular context in imaging applications.…”