Multifunctional Fe3O4 Cored Magnetic-Quantum Dot Fluorescent Nanocomposites for RF Nanohyperthermia of Cancer Cells

• Published in: Journal of physical chemistry. C 2010-03, Vol.114 (11), p.5020-5026
• Main Authors: Xu, Yang, Karmakar, Alokita, Wang, Daoyuan, Mahmood, Meena W, Watanabe, Fumiya, Zhang, Yongbin, Fejleh, Ashley, Fejleh, Phillip, Li, Zhongrui, Kannarpady, Ganesh, Ali, Syed, Biris, Alexandru R, Biris, Alexandru S
• Format: Article
• Language: English
• Subjects: C: Surfaces, Interfaces, Catalysis
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp9103036

Highly biocompatible luminescent superparamagnetic nanocomposites have been synthesized from Fe3O4/SiO2−QDs (IQ). Fe3O4 nanoparticles coated with a silica shell, Fe3O4/SiO2 (IOS), and water-soluble CdSe−ZnS quantum dots (QDs) were assembled together by the conjugation of an SH group. X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), UV−vis absorption and emission spectroscopy, and magnetometry were applied to characterize the nanocomposites. The nanocomposites exhibited multifunctional superparamagnetic and photoluminescent properties. Bright orange IQ nanoparticles were found to be successfully uptaken into pancreatic human cancer cells (Panc-1) after 24 h incubation. The IQ nanocomposites showed virtually no cytotoxicity toward the Panc-1 cells when the exposure concentration was below 50 μg/mL or 200 μg/mL as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) or lactate dehydrogenase (LDH) release measurements. After the inclusion of a very low dose (1.66 μg /ml) of fluorescent magnetic nanocomposites and exposure to a radio frequency (RF) treatment for only 2 min, most of the Panc-1 cells (99.2%) were found to die. The apoptosis process can be traceable because of the unique optical properties of the water-soluble IQs. It was also confirmed that the structure-controlled IQ nanocomposites have reasonable magnetic properties, self-heating temperature-rising characteristics, and high biocompatibility. This suggests that these IQ nanocomposites may be considered as biopotential materials for applications involving in vivo nanohyperthermia and cancer treatment.