Intracellular labeling and quantification process by magnetic resonance imaging using iron oxide magnetic nanoparticles in rat C6 glioma cell line.
OBJECTIVE
To assess intracellular labeling and quantification by magnetic resonance imaging using iron oxide magnetic nanoparticles coated with biocompatible materials in rat C6 glioma cells in vitro. These methods will provide direction for future trials of tumor induction in vivo as well as possible magnetic hyperthermia applications.


METHODS
Aminosilane, dextran, polyvinyl alcohol, and starch-coated magnetic nanoparticles were used in the qualitative assessment of C6 cell labeling via light microscopy. The influence of the transfection agent poly-L-lysine on cellular uptake was examined. The quantification process was performed by relaxometry analysis in T1 and T2weighted phantom images.


RESULTS
Light microscopy revealed that the aminosilane-coated magnetic nanoparticles alone or complexed with poly-L-lysine showed higher cellular uptake than did the uncoated magnetic particles. The relaxivities of the aminosilane-coated magnetic nanoparticles with a hydrodynamic diameter of 50nm to a 3-T field were r1=(6.1±0.3)×10(-5) ms-1mL/µg, r2=(5.3±0.1)× 10(-4) ms(-1)mL/µg, with a ratio of r2 / r1 ≅ 9. The iron uptake in the cells was calculated by analyzing the relaxation rates (R1 and R2) using a mathematical relationship.


CONCLUSIONS
C6 glioma cells have a high uptake efficiency for aminosilane-coated magnetic nanoparticles complexed with the transfection agent poly-L-lysine. The large ratio r2 / r1 ≅ 9 indicates that these magnetic nanoparticles are ideal for quantification by magnetic resonance imaging with T2-weighted imaging techniques.
Instituto do Cérebro, Hospital Israelita Albert Einstein, São Paulo, SP, Brazil.
Javier Bustamante
JB
Mamani
Lorena Favaro
LF
Pavon
Liza Aya Mabuchi
LA
Miyaki
Tatiana Tais
TT
Sibov
Fabiana
F
Rossan
Paulo Henrique
PH
Silveira
Walter Humberto Zavala
WH
Cárdenas
Edson
E
Amaro Junior
Lionel Fernel
LF
Gamarra
D000818:Animals; D045744:Cell Line, Tumor; D058948:Cell Tracking; D005290:Ferric Compounds; D005910:Glioma / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D051381:Rats; D013194:Staining and Labeling
D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide