Silica-coated gadolinium-doped lanthanum strontium manganite nanoparticles for self-controlled hyperthermia applications

Abstract

Gadolinium-doped lanthanum strontium manganite (LSM) nanoparticles were synthesized by using a citrate-gel technique. The particles were then annealed at 850 oC to remove defects for a good crystallinity, followed by coating with silica for possible biomedical application to magnetic hyperthermia. The chemical composition was determined to be La0.54Sr0.27Gd0.19MnO3 using an inductively coupled plasma mass spectrometer. The nanoparticles were characterized by X-ray diffraction, transmission electron microscope, and Fourier transform infrared spectrometer to check the perovskite crystalline structure and to observe the particles size and coating status of silica on the surface of the particles. The Curie temperature of the particles was found to be about 280 K. The saturation temperature of the aqueous solution of the particles remained at the hyperthermia target temperature of 42 oC with increasing concentration of particles from 6 to 60 mg/mL in the dispersion. This saturation temperature for a highly concentrated 120-mg/mL-sample increased further, but less than the dangerous temperature of 47 oC for normal tissues. The saturation temperature of the powder sample reached only up to 53 oC. These results showed that the gadolinium-doped LSM nanoparticles can be used for the self-controlled hyperthermia in which the temperature does not exceed the target temperature of hyperthermia even at the tissue site of highly accumulated nanoparticles.

Investigation of gadolinium doped manganese nano spinel ferrites via magnetic hypothermia therapy effect towards MCF-7 breast cancer

“…This behavior can be attributed to the lower curie temperature of the particles. Such heating characteristics of the particles make them suitable for controlled hyperthermia [ 47 ]. The optimal particle concentration for hyperthermia at the cancer site falls between 100 and 200 mg/mL, resulting in a temperature increase of the site to 46 °C.…”

Improvement of the Self-Controlled Hyperthermia Applications by Varying Gadolinium Doping in Lanthanum Strontium Manganite Nanoparticles

“…The synthesis process of silica-encapsulated manganite NPs involves two steps. Firstly, the gadolinium-doped La 1-x-y Sr x Gd y MnO 3 (y = 0.10, 0.15, 0.19) was fabricated using a citrate gel auto-combustion technique based on the previous report [41]. In a typical syn-thesis, the analytical grades of La(NO 3 ) 3 •6H 2 O, Sr(NO 3 ) 2 , Gd(NO 3 ) 3 , and Mn(NO 3 ) 2 in stoichiometric quantities were dissolved in 60 mL of distilled water for intended compositions trailed by the addition of ammonium hydroxide NH 4 OH (25 vol%, Sigma Aldrich, Seoul, Republic of Korea) to peptize the solution into a stable emulsion.…”

Structural studies of silica‐supported spinel magnesium ferrite nanorods for photocatalytic degradation of methyl orange

“…[ 33–36 ] They are widely used to control bacterial pollution and ultimately control many infections. [ 37 ] They are observed in many forms, such as thin films, [ 38 ] Nanopowders, [ 35 ] nanofibers, [ 39 ] nanowires, [ 40 ] nanospheres, even histoarchitecture geometry particles [ 41 ] and cubic spinel‐type of structures also. [ 42 ] However, due to the longer processing time for their application of magnetic nanoparticles as catalysts, they were used for water purification, controlling air pollution, [ 43 ] and many organic transformations as well.…”