Differential uptake of antisense oligonucleotides in mouse hepatocytes and macrophages revealed by simultaneous 2P-fluorescence and CARS

Abstract

Antisense oligonucleotides (ASOs), a novel paradigm in modern therapeutics, modulate cellular gene expression by binding to complementary RNA sequences. Triantennary N-acetyl galactosamine (GN)-conjugated ASOs show greatly improved potency via Asialoglycoprotein receptor (ASGR)-mediated uptake in hepatocytes. Here, we compare the uptake kinetics and subsequent distribution of untargeted ASOs to that of GN-ASOs in mouse macrophages and hepatocytes using simultaneous coherent anti-Stokes Raman scattering (CARS) and two-photon excited fluorescence imaging. While the CARS modality captured the changing lipid distributions and overall morphology of the cell, two-photon fluorescence imaging measured the uptake and the subsequent distribution of the fluorescently labeled (Alexa-488) ASOs inside the cells.