Enhancing colloidal stability of anisotropic magnetic nanodiscs through mesoporous silica and P(NIPAM/MAA) copolymer coatings

Donnarumma PR, Macchione MA, Wasner F, Kocar E, Duran Toro V, Marzini Irranca S, Gutiérrez Pineda E, Thongsom S, Gregurec D, Moya SE (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Nanoscale Royal Society of Chemistry

DOI: 10.1039/d5nr03822g

Abstract

Magnetic nanodiscs (MNDs), a class of anisotropic magnetite nanomaterials, have attracted considerable attention in smart actuation as they can generate heat through hysteretic losses and their discoidal shape can be tuned to exhibit vortex magnetization and generate mechanical stimuli. Despite near-zero net magnetization, at high concentrations, interparticle forces become dominant leading to MND aggregation. Here, we have optimized a previously reported synthetic approach based on the synthesis of hematite templates subsequently converted into a magnetite phase. We show that removal of oleic acid (OA) during the reduction step results in the same colloidal stability as in the presence of OA but avoids erosion of the MNDs associated with OA. We introduce a thin mesoporous silica coating on the surface of hematite, effectively diminishing aggregation during reduction while allowing complete conversion into magnetite. This silica layer facilitates subsequent silane chemistry and the grafting of poly(N-isopropylacrylamide-co-methacrylic acid) P(NIPAM/MMA) coatings with 80 : 20 and 50 : 50 ratios, yielding highly stable aqueous suspensions of MNDs, both in aqueous and cell culture media. These findings establish a versatile pathway toward colloidally stable MNDs, thereby broadening their applicability in biomedical research.

Authors with CRIS profile

Franziska Wasner Lehrstuhl für Aroma- und Geruchsforschung Elif Kocar Juniorprofessur für Sensory Sciences Vicente Duran Toro Juniorprofessur für Sensory Sciences Danijela Gregurec Juniorprofessur für Sensory Sciences

Related research project(s)

Bidirectional remote deep brain control with magnetic anisotropic nanomaterials (BRAINMASTER) Jan. 1, 2024 - Dec. 31, 2028 Wireless deep BRAIN STimulation thrOugh engineeRed Multifunctinal nanomaterials (BRAINSTORM) Wireless deep BRAIN STimulation thrOugh engineeRed Multifunctinal nanomaterials April 1, 2023 - March 31, 2027

Involved external institutions

CIC biomaGUNE (Centro de Investigación Cooperativa en Biomateriales) ES Spain (ES) Universidad Nacional de Córdoba AR Argentina (AR)

How to cite

APA:

Donnarumma, P.R., Macchione, M.A., Wasner, F., Kocar, E., Duran Toro, V., Marzini Irranca, S.,... Moya, S.E. (2025). Enhancing colloidal stability of anisotropic magnetic nanodiscs through mesoporous silica and P(NIPAM/MAA) copolymer coatings. Nanoscale. https://doi.org/10.1039/d5nr03822g

MLA:

Donnarumma, P. Rafael, et al. "Enhancing colloidal stability of anisotropic magnetic nanodiscs through mesoporous silica and P(NIPAM/MAA) copolymer coatings." Nanoscale (2025).

BibTeX: Download