A new ex vivo method to evaluate the performance of candidate MRI contrast agents: a proof-of-concept study

Table 1 Gd-GNPs studied, percentage of Gd (in g of Gd per 100 g of nanoparticle), relaxivity values (r ₁ , r ₂ and r ₂ /r ₁ ) and relative contrast enhancement (RCE) values

Contrast agent Gd-GNP (Glyco-Au-D03A:Gd)^a	% Gd (g of Gd per 100 g of nano particle)	1.4 T r₁relaxivity (s⁻¹ mM⁻¹) (in vitro) (n = 3)	7.0 T r₁relaxivity (s¹ mM⁻¹) (in vitro) (n = 3)	7.0 T r₂relaxivity (s⁻¹ mM⁻¹) (in vitro) (n = 3)	7.0 T r₂/r₁	% RCE postmorten (ex vivo) (n = 3)	% RCE (in vivo**) (n = 3)
GlcC5-DO3AC11 (GNP (E_1))	4.7 ± 0.1	7.4 ± 0.7	2.7 ± 0.40	20.2 ± 0.11	7.48	182.8 ± 10.7*	NM
GlcC2-DO3AC11 (GNP (F))	3.4 ± 0.2	7.1 ± 0.9	2.9 ± 0.04	14.5 ± 2.37	5.00	185.4 ± 17.2	NM
GlcC9-DO3AC11 (GNP (G))	3.2 ± 0.2	7.5 ± 0.6	1.6 ± 0.15	12.7 ± 0.24	7.94	168.7 ± 7.74*	NM
GlcC7-DO3AC11 (GNP (H))	4.1 ± 0.2	7.1 ± 0.9	1.6 ± 0.36	11.2 ± 0.21	7.00	143.6 ± 8.0*	NM
GlcC3-DO3AC11 (GNP (I))	3.3 ± 0.2	6.3 ± 0.7	1.8 ± 0.07	19.9 ± 1.43	11.06	141.5 ± 2.5	NM
GlcC5-DO3AC11 (GNP (E_2))^b	7.0 ± 0.2	11.5 ± 0.1	8.2 ± 0.37	14.5 ± 0.66	1.77	201.9 ± 9.3*	124.9 ± 8.3*
GlcC5-DO3AC11 (GNP (J))	5.0 ± 0.2	8.1 ± 0.3	4.6 ± 0.24	24.4 ± 0.34	5.30	169.1 ± 14.1*	NM
Gadoterate meglumine	NA	3.10^c/3.5^d	2.1 ± 0.42	3.58 ± 0.02	1.70	236.7 ± 8.3	113. 1 ± 2.5

Detailed legend:
^a)Glc = glucose, Gal = galactose. C (number) after the saccharide and the DO3A indicates the number of carbon atoms of the linkers.
^b) GNP (E_2) was obtained from GNP (E_1) after further incubation with a solution of DO3AC11-Gd complex (4 equiv.) during 44 hours as described in [31].
^c) Values taken from [7].
^d) Values taken from [58].
*p < 0.05 versus gadoterate meglumine.
**Mean of RCE values (n = 9 independent measures for 3 animals) measured at the maximum enhancement time, for each of the CA studied in vivo.
NM, not measured. NA, not applicable.
For each value mean and standard deviation are shown.

ISSN: 1477-3155