Pramod Kumar Avti1, Henry Bryant2, Youssef Zaim Wadghiri3, Joseph Frank2, Kenneth Shroyer4, Balaji Sitharaman5
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States; 2Frank Laboratory, Radiology & Imaging Sciences, National Institutes of Health,, Bethesda, MD 20892, United States; 3Radiology, New York University, Langone Medical Center, New York, New York 10016, United States; 4Pathology, Stony Brook University Medical Center, Stony Brook, New York 11794-8691, United States; 5Biomedical Engineering, Stony Brook University Medical Center, Stony Brook, New York 11794-5281, United States
We report the in vitro cell labeling and in vivo biological response of novel water-solubilized gadolinium-catalyzed single-walled carbon nanotubes (Gd-SWCNTs). The Gd-SWCNT show 25-fold greater relaxivities (at 1.5 T, r1 (Gd-SWCNT) = 126 mM-1s-1 vs. r1(Magnevist) = 4.5 mM-1s-1, [Gd3+] = 0.2 mM), and are uptaken by NIH 3T3 cells at Gd-SWCNT concentrations upto 25 g/ml without inducing cytotoxicity. Intravenous injection of the Gd-SWCNT into rats (dosage = 0.5 mg/kg) reveal distribution into various organs with no signs of inflammation or tissue architectural damage. In conclusion, Gd-SWCNTs show potential for future development as magnetic labels for cellular MRI.