Perfluorocarbon nanoemulsions with fluorescent, colloidal and magnetic properties

Abstract

Bimodal imaging agents that combine magnetic resonance imaging (MRI) and nearinfrared (NIR) imaging formulated as nanoemulsions became increasingly popular for imaging inflammation in vivo. Quality of in vivo imaging using nanoemulsions is directly dependent on their integrity and stability. Here we report the design of nanoemulsions for bimodal imaging, where both photostability and colloidal stability are equally addressed. A highly chemically and photo stable quaterrylenediimide dye was introduced into perfluoro-15-crown-5 ether (PCE) nanoemulsions. The nanoemulsions were prepared with PCE and Miglyol 812N mixed at 1:1 v/v ratio as internal phase stabilized by non-ionic surfactants. Data shows exceptional colloidal stability demonstrated as unchanged droplet size (~130 nm) and polydispersity (<0.15) after 182 days follow up at both 4 and 25 °C. Nanoemulsions also sustained the exposure to mechanical and temperature stress, and prolonged exposure to light without changes in droplet size, 19F signal or fluorescence signal. No toxicity was observed in vitro in model inflammatory cells upon 24 h exposure while confocal microscopy showed that nanoemulsions droplets accumulated in the cytoplasm. Overall, our data demonstrates that design of bimodal imaging agents requires consideration of stability of each imaging component and that of the nanosystem as a whole to achieve excellent imaging performance.

Development and Characterization of Resveratrol Nanoemulsions Carrying Dual-Imaging Agents

“…Therefore, the reported nanoemulsion colloidal stablility was also tested under three cell culturerelevant conditions: serum-free medium, 10 and 20% serum containing medium, all at 37°C. Nanoemulsions were tested against DI water as a control, and all measurements were performed using DLS [21]. These evaluations help determine nanoemulsion stability under in vitro biological testing conditions, and serve as additional quality control prior to in vivo experiments.…”

“…Macrophage viability upon exposure to increasing concentrations of nanoemulsion was assessed using Cell TiterGlo ® luminescence assay as reported earlier [21].…”

“…Nanoemulsion size distribution and ζ-potential were measured with dynamic light scattering (DLS) using Zetasizer Nano (Malvern Instruments, Worcestershire, UK), as reported earlier [21].…”

“…DiR is a well-known, commercially available lipid tracer and was loaded into the nanoemulsion oil phase to levels that assure complete solubilization. In earlier studies we reported extensive optical evaluations of commercial dyes and custom synthesized dyes in perfluorocarbon/hydrocarbon mixed oil nanoemulsions [21]. DiD-loaded nanoemulsions with similar composition to those reported here have been extensively evaluated in previous studies, and it was demonstrated that there was no loss of DiD dye [22][23][24].…”

Antibody-functionalized peptidic membranes for neutralization of allogeneic skin antigen-presenting cells

“…Nanoemulsions were produced using microfluidization by adapting our earlier described published procedures [24–30]. Briefly, the lipophilic payload, NIR dye (DiR) was dissolved at room temperature in Miglyol® 812N (synthetic hydrocarbon oil).…”