Fe₃O₄@polydopamine Composite Theranostic Superparticles Employing Preassembled Fe₃O₄ Nanoparticles as the Core

Abstract

Iron oxide (Fe3O4), polydopamine (PDA), and in particular their composites are examples of the safest nanomaterials for developing multifunctional nanodevices to perform noninvasive tumor diagnosis and therapy. However, the structures and performances of Fe3O4-PDA nanocomposites should be further perfected to enhance the theranostic efficiency. In this work, we demonstrate the fabrication of PDA-capped Fe3O4 (Fe3O4@PDA) superparticles (SPs) employing preassembled Fe3O4 nanoparticles (NPs) as the cores. Owing to the collective effect of preassembled Fe3O4 NPs, the superparamagnetism and photothermal performance of Fe3O4@PDA SPs are greatly enhanced, thus producing nanodevices with improved magnetic resonance imaging (MRI)-guided photothermal efficiency. Systematical studies reveal that the molar extinction coefficient of the as-assembled Fe3O4 SPs is 3 orders of magnitude higher than that of individual Fe3O4 NPs. Also due to the high aggregation degree of Fe3O4 NPs, the T2-weighted MRI contrast is greatly enhanced for the SPs with r2 relaxivity of 230.5 mM(-1) s(-1), which is ∼2.5 times larger than that of individual Fe3O4 NPs. The photothermal stability, physiological stability, and biocompatibility, as well as the photothermal performance of Fe3O4 SPs, are further improved by enveloping with PDA shell.

Iron oxide nanoparticles promote the migration of mesenchymal stem cells to injury sites

“…Nanoparticles were prepared as previously described. 31 Briefly, SDS-capped Fe 3 O 4 nanoparticles were fabricated by emulsification. 32,41 Under mechanical stirring and nitrogen atmosphere at room temperature, 4.0 mL of 7.0 mg/mL oleic acid-stabilized Fe 3 O 4 nanoparticles were injected into SDS aqueous solution (12.5 mL; 14 mg/mL).…”

“…Due to the collective effect of the preassembled Fe 3 O 4 nanoparticles, utilization of a PDA shell greatly enhanced the superparamagnetism, physiological stability, and biocompatibility of the Fe 3 O 4 core. 31 The high degree of aggregation of Fe 3 O 4 nanoparticles frequently reduces Brownian motion and precludes cellular uptake of the aggregates due to their size. 45 Accordingly, PDA encapsulation reduced Fe 3 O 4 aggregation and increased their uptake by cells.…”

“…29,30 PDA-capped Fe 3 O 4 (Fe 3 O 4 @ PDA) and their composites are among the safest nanomaterials used for clinical diagnosis and therapy. 31 Given the cell uptake necessary for cell therapeutics, the size and shape of the spherical, self-assembled structures comprising hundreds of nanoparticles (also known as superparticles) make them highly suitable for such applications. 32 Additionally, PDA can spontaneously form a conformal layer through in situ polymerization in an alkaline dopamine solution.…”

Dual-responsive dithio-polydopamine coated porous CeO₂ nanorods for targeted and synergistic drug delivery

“…30,31 Polydopamine (PDA)-based substrate-independent coating, due to its adhesive property, 32 has been comprehensively applied in nanomedicine for drug delivery systems (DDS). [33][34][35][36] One valuable feature of PDA lies in its chemical structure that incorporates many functional groups such as catechol, amine, and imine, which further realize the emergence of diverse hybrid materials. [37][38][39][40] Frank's group immobilized pH-cleavable polymer-drug in PDA capsules via robust thiol-catechol reactions for intracellular drug delivery, which realized the application of pH stimuli-responsive PDA capsules as DDS.…”

Preparation and characterization of magnetic hollow Fe3O4/P(GMA‐EGDMA)‐SO3H/Au‐PPy recyclable catalyst for catalytic reduction of 4‐nitrophenol

“…Therefore, it is usually necessary to coat a magnetic support with a coating to avoid the interaction between the magnetic core and the external substrate. Such magnetic supports are usually coated with silica, carbon or organic polymers . However, the nanoparticles might detach from the surface of the coating layer when exposed directly to a reaction solution.…”