Multifunctional Fe₃O₄@Polydopamine Core–Shell Nanocomposites for Intracellular mRNA Detection and Imaging-Guided Photothermal Therapy

TLDR

Multifunctional nanocomposites can integrate sensing, diagnosis, and therapy, and PDA coatings provide near‑infrared absorption, strong fluorescence quenching, and functionalization sites. The study demonstrates Fe3O4@PDA nanocomposites as theranostic agents for intracellular mRNA detection and imaging‑guided photothermal therapy. Fe3O4@PDA nanocomposites were synthesized by in‑situ self‑polymerization of dopamine onto Fe3O4 nanoparticles, forming a PDA shell. The Fe3O4@PDA nanocomposites effectively detect intracellular mRNA and enable imaging‑guided photothermal therapy, underscoring PDA’s potential for multifunctional biomedical nanocomposites.

Abstract

Multifunctional nanocomposites have the potential to integrate sensing, diagnostic, and therapeutic functions into a single nanostructure. Herein, we synthesize Fe3O4@polydopamine core–shell nanocomposites (Fe3O4@PDA NCs) through an in situ self-polymerization method. Dopamine, a melanin-like mimic of mussel adhesive proteins, can self-polymerize to form surface-adherent polydopamine (PDA) films onto a wide range of materials including Fe3O4 nanoparticles used here. In such nanocomposites, PDA provides a number of advantages, such as near-infrared absorption, high fluorescence quenching efficiency, and a surface for further functionalization with biomolecules. We demonstrate the ability of the Fe3O4@PDA NCs to act as theranostic agents for intracellular mRNA detection and multimodal imaging-guided photothermal therapy. This work would stimulate interest in the use of PDA as a useful material to construct multifunctional nanocomposites for biomedical applications.