Gd₃N@C₈₄(OH)_x: A New Egg-Shaped Metallofullerene Magnetic Resonance Imaging Contrast Agent

Abstract

Water-soluble derivatives of gadolinium-containing metallofullerenes have been considered to be excellent candidates for new magnetic resonance imaging (MRI) contrast agents because of their high relaxivity and characteristic encapsulation of the lanthanide ions (Gd(3+)), preventing their release into the bioenvironment. The trimetallic nitride template endohedral metallofullerenes (TNT EMFs) have further advantages of high stability, high relative yield, and encapsulation of three Gd(3+) ions per molecule as illustrated by the previously reported nearly spherical, Gd3N@I(h)-C80. In this study, we report the preparation and functionalization of a lower-symmetry EMF, Gd3N@C(s)-C84, with a pentalene (fused pentagons) motif and an egg-shaped structure. The Gd3N@C84 derivative exhibits a higher (1)H MR relaxivity compared to that of the Gd3N@C80 derivative synthesized the same way, at low (0.47 T), medium (1.4 T), and high (9.4 T) magnetic fields. The Gd3N@C(s)-C84 derivative exhibits a higher hydroxyl content and aggregate size, as confirmed by X-ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS) experiments, which could be the main reasons for the higher relaxivity.

Endohedral Clusterfullerenes: Future Perspectives

“…For example, some water-soluble derivatives of gadolinium-containing metallofullerenes have shown great promise in innovative medical positron emission tomography/magnetic resonance (PTE/MR) simultaneous imaging techniques. 23 In vivo tests of a Gd 3 N@C 80 derivative confirmed its effectiveness in providing contrast for tumor imaging. 24 Similar metallofullerenes, once chemically optimized, will likely serve as low-toxicity, highly specific medical imaging agents.…”

Facile Synthesis of an Extensive Family of Sc2O@C2n (n = 35–47) and Chemical Insight into the Smallest Member of Sc2O@C2(7892)–C70

“…These endohedrals are potentially useful in the fields of molecular electronics, hydrogen storage, medical and material sciences. [17][18][19][20][21][22][23] Particularly, it has been approved that most group 2-3 elements and lanthanides can be trapped inside a fullerene cage in the form of M x (x=1-3) [24][25][26][27] or a cluster of metal carbide M x C 2 (x=2-4), 28-32 20 metal nitride M 3 N, 33 [42][43][44] giving rise to the formation of endohedral metallofullerenes (EMFs). For bulk 3 preparations of EMFs, the Krätschmer-Huffman generator has been widely used since 1991, 45 in which a graphite anode containing metal oxide or metallic alloy is evaporated in an electric arc under a lowpressure helium atmosphere.…”

Real-time monitoring of tumor vascular disruption induced by radiofrequency assisted gadofullerene

“…1b, the FTIR spectrum of GFNCs exhibits several peaks, in which the main peak at 3,400 cm −1 is assigned to the characteristic vibration bands of -OH and the middle peak at 1,598 cm −1 belongs to the skeletal vibration frequency of C=C of fullerenes. The peaks locating at 1,465-1,340 cm −1 are attributed to the asymmetric stretching bands of -C-OM (M=H, C), suggesting the existence of -C-OH and -C-O-C groups [40,41]. The height and the diameter of GFNCs were approximately 30 nm and 80 nm as observed by AFM (Fig.…”