Latex nanoparticles for multimodal imaging and detectionin vivo

Abstract

The aim of the present work was to develop a multimodal imaging and detection approach to study the behaviour of nanoparticles in animal studies. Highly carboxylated 144 nm-sized latex nanoparticles were labelled with 68 Ga for positron emission tomography, 111 In for quantitative gamma scintigraphy or Gd 3+ for magnetic resonance imaging. Following intravenous injection into rats, precise localization was achieved revealing the tracer in the blood compartment with a time-dependent accumulation in the liver. In addition, rhodamine B was also incorporated to examine specific interactions with blood cells. Flow cytometry and fluorescent microscopy show uptake of nanoparticles by leucocytes and, unexpectedly, thrombocytes, but not erythrocytes. Cellular internalization was an active and selective process. Further incorporation of polyethylene glycol into the nanoparticle corona could prevent uptake by thrombocytes but not macrophages or monocytes. Our data demonstrate the feasibility of a multimodal approach and its usefulness to analyse the fate of nanoparticles at the macroscopic and cellular level. It will facilitate the development of functionalized nanocarrier systems and extend their biomedical applications.

Radiolabeled Nanoplatforms: Imaging Hot Bullets Hitting their Target

“…Surprisingly, the trivalent metal cations bound quickly to latex nanoparticles in water without the need for a BFC, although with low specific activity (220 kBq/mg NP for both radiometals and 10 g/mg NP for Gd) [75]. This finding was explained with the formation of strong coordination bonds between the metal ions and multiple carboxylic groups on the NP surface.…”

“…This finding was explained with the formation of strong coordination bonds between the metal ions and multiple carboxylic groups on the NP surface. However, the in vivo data reported by Cartier et al [75] were limited to 1 hour post NP injection. In another interesting study, Häfeli et al [76] labeled magnetic microspheres prepared from metallic iron and activated carbon by directly mixing the particles with 111 InCl 3 , 111 In-oxine, 111 In-DOTA, and 111 In-Abz-DOTA (an amino benzyl derivative of DOTA).…”

“…Recently, Cartier and co-workers [75] reported also the direct labeling of NPs with 111 InCl 3 , 68 GaCl 3 , and GdCl 3 . Surprisingly, the trivalent metal cations bound quickly to latex nanoparticles in water without the need for a BFC, although with low specific activity (220 kBq/mg NP for both radiometals and 10 g/mg NP for Gd) [75].…”

Gallium-68 radiotracers for Alzheimer’s plaque imaging

“…There are few examples of nanoparticles using gallium-chemistry in literature [34]. Some of these nanoparticles were composed from organic polymers and iron oxide nanoparticles also utilising chelators such as NODAGA and NOTA for catching Gallium(III)-cation ( Figure 3) [18][19][33][34][35][36].…”

“…Some of these nanoparticles were used as multimodal imaging agents for MRI and PET. It is important to mention that to our knowledge, there is no published work for a pre-radiolabelling approach using nanoparticles with Gallium-68 yet [18][19][33][34][35][36].…”