Patent ID: 8568690
Filing Date: 2013-10-29
Classification: A61K,C12N,C12Q

Abstract:
1. An MRI contrast agent, comprising: (i) MRI contrast agent particles that are biocompatible and biodegradable in vivo, (ii) oligonucleotides, attached to the particles, wherein the oligonucleotides have one end attached to the particles and a second free end; and (iii) an aptamer comprising an oligonucleotide sequence that is complementary to the free end of two oligonucleotides attached to different particles, wherein the aptamer is hybridized to the free end of the two oligonucleotides thereby forming a bridge between the particles, wherein the particles, the oligonucleotides, and the aptamer, together form aggregates in absence of the effector and wherein the aptamer, specific for an effector, undergoes a conformational change when bound to the effector, causing the particles to disaggregate.