Correction: Structural, magnetic and hyperthermia properties and their correlation in cobalt-doped magnetite nanoparticles.

[This corrects the article DOI: 10.1039/D1RA07407E.].

Correction: Sensitive MnFe2O4-Ag hybrid nanoparticles with photothermal and magnetothermal properties for hyperthermia applications.

[This corrects the article DOI: 10.1039/D1RA03216J.].

Sensitive MnFe2O4-Ag hybrid nanoparticles with photothermal and magnetothermal properties for hyperthermia applications.

In this study, we present an experiment showing that designing multifunctional MnFe2O4-Ag nanoparticles to act as a dual hyperthermia agent is an efficient route for enhancing their heating ability. Interestingly, the specific absorption rate of the heteromeric MnFe2O4-Ag nanoparticles increased 2.7 times under simultaneous irradiation of a 100 Oe magnetic field and 0.14 W cm-2 laser compared to the action by the magnetic field alone, and more interestingly, is 30% higher than the sum of the two individual actions. The synergistic benefit of the magneto- and photo-thermal properties of the heteromeric structure can reduce the strengths of the magnetic field and laser intensities as well as their irradiation time to levels lower than those required in their hyperthermia applications individually. In vitro cytotoxicity analysis performed on HepG2 liver cancer and Hela cervical cancer cell lines showed that IC50 values were 83 ± 5.6 µg mL-1 (for HepG2) and 122.6 ± 19.8 µg mL-1 (for Hela cells) after 48 h of incubation, therefore, the nanoparticles are moderately cytotoxic and nontoxic to HepG2 and Hela cells, respectively; which offers the potential of safe therapy.

Structural, magnetic and hyperthermia properties and their correlation in cobalt-doped magnetite nanoparticles.

Cobalt doped magnetite nanoparticles (Co x Fe3-x O4 NPs) are investigated extensively because of their potential hyperthermia application. However, the complex interrelation among chemical compositions and particle size means their correlation with the magnetic and heating properties is not trivial to predict. Here, we prepared Co x Fe3-x O4 NPs (0 ≤ x ≤ 1) to investigate the effects of cobalt content and particle size on their magnetic and heating properties. A detailed analysis of the structural features indicated the similarity between the crystallite and particle sizes as well as their non-monotonic change with the increase of Co content. Magnetic measurements for the Co x Fe3-x O4 NPs (0 ≤ x ≤ 1) showed that the blocking temperature, the saturation magnetization, the coercivity, and the anisotropy constant followed a similar trend with a maximum at x = 0.7. Moreover, 57Fe Mössbauer spectroscopy adequately explained the magnetic behaviour, the anisotropy constant, and saturation magnetization of low Co content samples. Finally, our study shows that the relaxation loss is a primary contributor to the SAR in Co x Fe3-x O4 NPs with low Co contents as well as their potential application in magnetic hyperthermia.