Cell type-specific delivery of short interfering RNAs by dye-functionalised theranostic nanoparticles

Abstract

Efficient delivery of short interfering RNAs reflects a prerequisite for the development of RNA interference therapeutics. Here, we describe highly specific nanoparticles, based on near infrared fluorescent polymethine dye-derived targeting moieties coupled to biodegradable polymers. The fluorescent dye, even when coupled to a nanoparticle, mimics a ligand for hepatic parenchymal uptake transporters resulting in hepatobiliary clearance of approximately 95% of the dye within 45 min. Body distribution, hepatocyte uptake and excretion into bile of the dye itself, or dye-coupled nanoparticles can be tracked by intravital microscopy or even non-invasively by multispectral optoacoustic tomography. Efficacy of delivery is demonstrated in vivo using 3-hydroxy-3-methyl-glutaryl-CoA reductase siRNA as an active payload resulting in a reduction of plasma cholesterol levels if siRNA was formulated into dye-functionalised nanoparticles. This suggests that organ-selective uptake of a near infrared dye can be efficiently transferred to theranostic nanoparticles allowing novel possibilities for personalised silencing of disease-associated genes.

Cargo–carrier interactions significantly contribute to micellar conformation and biodistribution

“…Such at first glance subtle differences might result in significant off-target actions and might determine whether such micelles can be applied safely as a carrier to deliver drugs selectively to hepatic parenchymal cells. 25 On the basis of spectroscopic data and in vitro/in vivo experiments, we propose two different chain conformations of PEO-b-PAGE COOHb-PtBGE during encapsulation, depending on the solution pH, and with that also the localization of V19 within the micelles differs. These effects in turn affect cell-type-specific release within the liver acinus.…”

“…24 In addition, cells were incubated for some experiments in fetal calf serumfree media containing 25 μM Pitstop-2 (Abcam, Cambridge, UK) for 12 min as previously described. 25 In brief, after washing the cells twice with Hanks' balanced salt solution, 480 μl OptiMEM (Gibco, Thermo Scientific-both Langenselbold, Germany) or full-growth media was added. Cells were imaged in a humidified chamber at 37°C, 5% CO 2 .…”

“…A correction factor was measured and calculated as previously described 25 using a fluorescent plate reader (Tecan Infinite Pro200, Crailsheim, Germany) to compare between different micelles loaded with the same probe.…”

Long Circulation Red‐Blood‐Cell‐Mimetic Nanoparticles with Peptide‐Enhanced Tumor Penetration for Simultaneously Inhibiting Growth and Lung Metastasis of Breast Cancer

“…Then, we examined the bioactivity of CD47 and other membrane proteins presenting on the surface of the RVPNs', in particular, the ability to escape from the capture with the macrophage phagocytosis. We fi rst labeled the PNs with a hydrophobic fl uorescence probe Nile red (NR) (Ex/Em 580/630 nm) [ 20 ] and then incubated the NR-labeled RVPNs with the mouse macrophage RAW264.7 cells. The cells were then examined using confocal fl uorescence laser scanning (CLSM) microscopy 1h post RVPN …”

Oligonucleotide-Based Theranostic Nanoparticles in Cancer Therapy

“…Press et al used poly(lactic-co-glycolic acid) nanoparticles covalently conjugated with fluorescent polymethine dyes for organ-selective imaging and siRNA delivery in mice [170]. Dyes with four sulfonic residues underwent preferential renal elimination, and dyes with only one sulfonic residue underwent hepatobiliary excretion.…”