Effect of spatial confinement on magnetic hyperthermia via dipolar interactions in Fe3O4 nanoparticles for biomedical applications

Colloidal magnetic nanocrystal clusters: variable length-scale interaction mechanisms, synergetic functionalities and technological advantages

“…Calculation of Néel and Brown relaxation times in the latter unveiled that the Néel relaxation is faster than the Brownian and shorter than the measurement time [145]. These calculations indicated that the Néel relaxation is the leading mechanism together with the hysteresis losses for hyperthermia heating [145,148]. The dissimilar variation of the SLP upon the applied magnetic field strength, namely, being proportional to H for the aminecapped clusters [30] and to H 2 for the PS-encapsulated nanoclusters [145] reveal that the interactions among nanocrystals are mainly present in the first case.…”

“…The SLP has been found enhanced compared to that of individual nanocrystals when superparamagnetic nanoclusters were capped with amine [30], while the opposite effect was observed for superparamagnetic nanocrystals embedded in polystyrene (PS) nanospheres [145]. Calculation of Néel and Brown relaxation times in the latter unveiled that the Néel relaxation is faster than the Brownian and shorter than the measurement time [145]. These calculations indicated that the Néel relaxation is the leading mechanism together with the hysteresis losses for hyperthermia heating [145,148].…”

“…In a fashion analogous to the evolution of MRI relaxivities, a range of morphologies (Figure 20), associated with different magnetic material volume fractions, variable strength dipolar interactions, and emerging microscopic mechanisms (see Section 3.2) were shown to impact heat release. The SLP has been found enhanced compared to that of individual nanocrystals when superparamagnetic nanoclusters were capped with amine [30], while the opposite effect was observed for superparamagnetic nanocrystals embedded in polystyrene (PS) nanospheres [145]. Calculation of Néel and Brown relaxation times in the latter unveiled that the Néel relaxation is faster than the Brownian and shorter than the measurement time [145].…”

“…However, humans cannot tolerate alternating magnetic field with a large H·f product, due to unwanted side effects. An alternative way to attain a better efficiency, with a lower dose and milder magnetic field conditions, is to optimize the size of the magnetic particle mediators [143,144], as well as to improve their magnetic characteristics (M S , H C , K) by tuning the composition [97,130], shape [66], and morphology [30,145]. Broadly speaking, the SLP values go through a maximum at a certain particle size and magnetic anisotropy constant.…”

Multifunctional Nanoplatform for Targeted Laser-induced Hyperthermia and Microscopy of Breast Cancer Cells using SPION-based Gold and Folic Acid Conjugated Nanodendrimers: An in vitro Assay

“…Meanwhile, size and surface characteristics of the nanoparticle are of prime importance in the biodistribution and rapid clearance of nanoparticle from the blood which affects nanoparticle delivery to target sites [25,31]. In recent years much interest has been shown for nanotechnology-based hyperthermia and effective cancer therapy where one of the main goals of is to deliver therapeutic agents to tumor sites, since most anticancer drugs cannot distinguish between healthy and cancerous tissues hence causing some undesirable results [32][33][34][35]. In our previous study, application of doxorubicin loaded magnetic thermosensitive liposomes for laser hyperthermia and chemotherapy of breast cancer was reported [36].…”