US 12,324,844 B2
MRI contrast agent including T1 contrast material coated on surface of nanoparticle support
Jin Woo Cheon, Seoul (KR); and Tae Hyun Shin, Yongin-si (KR)
Assigned to INVENTERA PHARMACEUTICALS INC., Seoul (KR)
Filed by INVENTERA PHARMACEUTICALS INC., Cheongju-si (KR)
Filed on Dec. 18, 2020, as Appl. No. 17/126,340.
Application 17/126,340 is a continuation of application No. 14/759,288, abandoned, previously published as PCT/KR2014/000062, filed on Jan. 3, 2014.
Claims priority of application No. 10-2013-0001002 (KR), filed on Jan. 4, 2013.
Prior Publication US 2021/0113717 A1, Apr. 22, 2021
Int. Cl. A61K 49/18 (2006.01); A61K 49/08 (2006.01); A61K 49/12 (2006.01); A61K 49/14 (2006.01)
CPC A61K 49/1878 (2013.01) [A61K 49/08 (2013.01); A61K 49/126 (2013.01); A61K 49/14 (2013.01)] 9 Claims
 
1. A magnetic resonance imaging (MRI) method using an iron-based T1 contrast agent for obtaining T1-weighted images in MRI scan, comprising
(a) introducing the iron-based T1 contrast agent with a T1 relaxivity coefficient (r1) value ranging from approximately 1 mM−1s−1 to 5 mM−1s−1 at 1.5 Tesla on an MRI scanner, into a body fluid of a subject, said iron-based T1 contrast agent producing a bright or positive contrast effect compared to water,
wherein the MRI iron-based T1 contrast agent consists of
(i) a non-magnetic nanoparticle support comprising SiO2, a polysaccharide, or a protein wherein a surface of the nanoparticle support comprises surface functional groups, and
(ii) an iron oxide coating layer having iron oxide bound by coordination bond to the surface functional groups,
wherein a ratio of thickness of the iron oxide coating layer to a diameter of the non-magnetic nanoparticle support is to 1:25 to 1:6; the diameter of the non-magnetic nanoparticle support is 2 to 40 nm; and the thickness of the iron oxide coating layer is 0.1 to 1 nm,
wherein the iron-based T1 contrast agent shortens T1 relaxation time (spin-lattice relaxation time) to induce a positive contrast on T1-weighted images without inducing a negative contrast associated with a T2 contrast agent; and
(b) obtaining T1-weighted images in MRI scan of body parts of the subject.