title: The magnetic, relaxometric, and optical properties of gadolinium-catalyzed single walled carbon nanotubes.
abstract: We report the magnetic behavior, relaxometry, phantom magnetic resonance imaging (MRI), and near-infrared (NIR) photoluminescence spectroscopy of gadolinium (Gd) catalyzed single-walled carbon nanotubes (Gd-SWCNTs). Gd-SWCNTs are paramagnetic with an effective magnetic moment of 7.29μB. Gd-SWCNT solutions show highr1andr2relaxivities at very low (0.01 MHz) to clinically relevant (61 MHz) magnetic fields (r1≥ 130 mM-1s-1,r2≥ 160 mM-1s-1). Analysis of nuclear magnetic resonance dispersion profiles using Solomon, Bloembergen, and Morgan equations suggests that multiple structural and dynamic parameters such as rotational correlation time [Formula: see text], rate of water exchange [Formula: see text], and the number of fast-exchanging water molecules within the inner sphereqmay be responsible for the increase inr1andr2relaxivity. TheT1weighted MRI signal intensity (gradient echo sequence; repetition time (TR) = 66 ms, echo time (TE) = 3 ms, flop angle = 108°) of Gd-SWCNT phantom solution is 14 times greater than the Gd-based clinical MRI contrast agent Magnevist. Additionally, these nanotubes exhibit near infrared fluorescence with distinct E11transitions of several semiconducting SWCNTs. Taken together, these results demonstrate that Gd-SWCNTs have potential as a novel, highly efficacious, multimodal MRI-NIR optical imaging contrast agent.
authors: Balaji
authors: B
authors: Sitharaman
authors: Barry D
authors: BD
authors: Jacobson
authors: Youssef Z
authors: YZ
authors: Wadghiri
authors: Henry
authors: H
authors: Bryant
authors: Joseph
authors: J
authors: Frank
references: Nano Lett. 2008 Jan;8(1):232-6
references: 18088153
references: Nat Nanotechnol. 2010 Nov;5(11):815-21
references: 20972435
references: Q J Nucl Med. 1997 Jun;41(2):155-62
references: 9203854
references: Int J Nanomedicine. 2012;7:1953-64
references: 22619533
references: Breast Cancer Res. 2001;3(1):41-6
references: 11250744
references: Tissue Eng Part C Methods. 2011 Jan;17(1):19-26
references: 20666611
references: Science. 2002 Jul 26;297(5581):593-6
references: 12142535
references: Nano Lett. 2007 Aug;7(8):2272-5
references: 17638391
references: Contrast Media Mol Imaging. 2007 May-Jun;2(3):139-46
references: 17583898
references: J Magn Reson Imaging. 1999 Feb;9(2):348-52
references: 10077036
references: J Am Chem Soc. 2005 Jan 19;127(2):799-805
references: 15643906
references: J Biomed Mater Res A. 2010 Jun 15;93(4):1454-62
references: 19927368
references: Acc Chem Res. 2009 Jul 21;42(7):938-47
references: 19505089
references: Invest Radiol. 2005 Nov;40(11):715-24
references: 16230904
references: Int J Nanomedicine. 2006;1(3):291-5
references: 17717970
references: Chem Rev. 1999 Sep 8;99(9):2293-352
references: 11749483
references: Inorg Chem. 1998 Aug 10;37(16):4104-4113
references: 11670530
references: Chem Commun (Camb). 2011 Feb 7;47(5):1607-9
references: 21113509
references: J Biol Inorg Chem. 2007 Sep;12(7):939-49
references: 17659368
references: Chem Rev. 2008 Jun;108(6):2064-110
references: 18543879
references: Nano Lett. 2007 Apr;7(4):861-7
references: 17335265
references: Radiology. 1999 Sep;212(3):609-14
references: 10478223
references: Acc Chem Res. 2008 Feb;41(2):235-43
references: 18281946
references: Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2011 Mar-Apr;3(2):162-73
references: 20860051
references: Chem Commun (Camb). 2005 Aug 21;(31):3915-7
references: 16075070
references: J Org Chem. 2001 Nov 16;66(23):7745-50
references: 11701031
references: Eur J Pharm Biopharm. 2009 Jun;72(2):397-404
references: 18940253
references: Nanotechnology. 2011 Jul 22;22(29):295103
references: 21693804