RT Journal Article
T1 Predicting the Dominant Role of Dense Aggregates in Magnetic Hyperthermia via Intracellular-Mimetic Nanoparticle Models
A1 García Acevedo, Pelayo
A1 Paz Castro, Alba
A1 Estébanez Pisonero del Pozo, Jorge
A1 Piñeiro Redondo, Yolanda
A1 Rivas Rey, José
K1 Aggregation effects
K1 Magnetic hyperthermia
K1 Magnetic interactions
K1 Magnetic nanoparticles
AB Dense aggregation of magnetic nanoparticles (MNPs) in cellular environments is a major contributor to reduced magnetic hyperthermia (MH) efficiency; however, in situ magnetic characterization remains challenging, necessitating reliable extracellular models to predict such behavior. In this study, soft and dense aggregates (≈200 nm) are engineered using 10 nm iron oxide MNPs, encapsulated in polymeric (soft) or inorganic (dense) shells, with morphological features and strong magnetic dipolar interactions confirming their similarity to nanoparticle assemblies found in living cells. Unlike previous studies that induced aggregation by modifying the surrounding medium, the approach enables controlled, invariant aggregation states, allowing systematic evaluation of the transition from soft to dense aggregation under both aqueous and high-viscosity, cell-mimicking conditions. Results demonstrate that dense aggregation leads to a >20% reduction in specific absorption rate (SAR), primarily due to decreased remanent magnetization (MR), highlighting the critical role of aggregate structure. Viscosity is found to have a non-negligible effect once MNPs are aggregated, suggesting dominant Néel relaxation modulated by dipolar interactions. A strong SAR–MR correlation is observed, while SAR–coercivity (HC) dependence is disrupted by aggregation. These findings offer new insights for optimizing MH efficiency and guiding the design of magnetic nanoactuators for MH therapy.
PB Wiley
SN 1613-6810
YR 2025
FD 2025-08-29
LK https://hdl.handle.net/10347/43548
UL https://hdl.handle.net/10347/43548
LA eng
NO References  García-Acevedo, P., Paz-Castro, A., Estébanez, J., Piñeiro, Y., & Rivas, J. (2025). Predicting the Dominant Role of Dense Aggregates in Magnetic Hyperthermia via Intracellular-Mimetic Nanoparticle Models. Small, 21(41), e06620. 10.1002/smll.202506620
NO P.G.-A. thanks to Axencia Galega de Innovación (Spain) for his Posdoctoral Grant (Axudas de apoio á etapa de formación posdoutoral - IN606B-2024.1). This work was partially funded by Project PLEC2022-009217, within the framework of the State Plan for Scientific, Technical, and Innovation Research 2021–2023 and the Recovery, Transformation, and Resilience Plan of the Spanish Ministry of Science, Innovation, and Universities.
DS Minerva
RD 25 abr 2026