Sulfobetaine-Phosphonate Block Copolymer Coated Iron Oxide Nanoparticles for Genomic Locus Targeting and Magnetic Micromanipulation in the Nucleus of Living Cells

TL;DR

This paper introduces sulfobetaine-phosphonate coated iron oxide nanoparticles that can specifically target and manipulate genomic loci within the nucleus of living cells using magnetic fields, enabling new cellular biophysics studies.

Contribution

Development of stealthy, targetable magnetic nanoparticles capable of intracellular nuclear targeting and magnetic manipulation in living cells, a novel achievement in nanobiotechnology.

Findings

Successful synthesis of sulfobetaine-phosphonate block copolymer ligands.

Efficient nuclear targeting of magnetic nanoparticles demonstrated.

Magnetic micromanipulation of specific genomic loci achieved in living cells.

Abstract

Exerting forces on biomolecules inside living cells would allow us to probe their dynamic interactions in their native environment. Magnetic iron oxide nanoparticles represent a unique tool capable of pulling on biomolecules with the application of an external magnetic field gradient; however, their use has been restricted to biomolecules accessible from the extracellular medium. Targeting intracellular biomolecules represents an additional challenge due to potential nonspecific interactions with cytoplasmic or nuclear components. We present the synthesis of sulfobetaine-phosphonate block copolymer ligands, which provide magnetic nanoparticles which are stealthy and targetable in living cells. We demonstrate for the first time their efficient targeting in the nucleus and their use for magnetic micromanipulation of a specific genomic locus in living cells. We believe that these stable and furtive magnetic nanoprobes represent a promising tool to manipulate specific biomolecules in living cells and probe the mechanical properties of living matter at the molecular scale.