Nanoparticulate compositions for diagnostic imaging
The present invention provides a trialkoxysilanes having structure I wherein R 1 and R 2 are independently at each occurrence a C 1 -C 3 alkyl group; R 3 is independently at each occurrence a hydrogen or a C 1 -C 3 alkyl group; R 4 is a C 1 -C 5 aliphatic radical, a C 7 -C 12 aromatic radical, or a C 5 -C 10 cycloaliphatic group; n is 0, 1, 2 or 3; q is 1, 2 or 3; and X − represents a charge balancing counterion. The trialkoxysilanes are useful for the preparation of nanoparticulate diagnostic imaging agent compositions.
1. A nanoparticle composition comprising nanoparticles having idealized structure II, the nanoparticles comprising a functionalized nanoparticulate metal oxide and a positively charged trioxysilane ligand
wherein R 2 is independently at each occurrence a C 1 -C 3 alkyl group; R 3 is independently at each occurrence a hydrogen or a C 1 -C 3 aliphatic group; R 4 is a C 1 -C 5 aliphatic radical, a C 7 -C 12 aromatic radical, or a C 5 -C 10 cycloaliphatic group; n is 0, 1, 2 or 3; q is 1, 2 or 3; X − represents a charge balancing counterion; and the functionalized nanoparticulate metal oxide comprises nanoparticulate tantalum oxide.
2. The nanoparticulate composition according to claim 1 , wherein each R 2 is methyl, each R 3 is hydrogen, and R 4 is tertiary butyl.
3. The nanoparticulate composition according to claim 1 , wherein each R 2 is methyl, each R 3 is hydrogen, and R 4 is 2-methyl-2-butyl.
4. The nanoparticulate composition according to claim 1 , wherein X − represents bromide ion.
5. The nanoparticulate composition according to claim 1 , wherein the functionalized nanoparticulate metal oxide consists essentially of tantalum oxide.
6. The nanoparticulate composition according to claim 1 , wherein each R 2 is methyl, each R 3 is hydrogen, R 4 is tertiary butyl, n is 1, q is 1; and the nanoparticulate metal oxide consists essentially of nanoparticulate tantalum oxide.