Magnetic resonance imaging contrast agent and preparation method and application thereof

Abstract

The invention discloses a magnetic resonance imaging contrast agent and a preparation method and application thereof. The preparation method comprises the following steps: reacting alpha,omega-biscystamine polyethylene glycol with alpha-cyclodextrin to form pseudopolyrotaxane; then terminating pseudopolyrotaxane with Z-tyrosine to obtain Z-tyrosine terminated polyrotaxane; then reacting the Z-tyrosine terminated polyrotaxane with propargyl carbonylimidazole to form polyrotaxane surface-modified by alkynyl groups and capable of being quickly reduced and cracked; reacting the polyrotaxane surface-modified by alkynyl groups with a lysine second-generation dendrimer with azide as an end group by means of click chemistry so as to form lysine second-generation dendrimer-grafted cleavable polyrotaxane; and bonding the lysine second-generation dendrimer-grafted cleavable polyrotaxane with a gadolinium chelate, and loading gadolinium to form the gadolinium chelate-modified lysine second-generation dendrimer-grafted cleavable polyrotaxane. The magnetic resonance imaging contrast agent is good in biocompatibility, low in toxicity and high in relaxation rate; and in addition, an AS1411 aptameris introduced as a targeting molecule to realize multivalent targeting of tumor cells and tumors with cell membrane overexpression of nucleolin, so in-vivo magnetic resonance imaging of tumors is facilitated.

Description

technical field

[0001] The invention relates to a contrast agent for magnetic resonance imaging and its preparation method, as well as the application of the magnetic resonance imaging contrast agent in the preparation of products with tumor detection function, belonging to the technical field of pharmaceutical preparation. Background technique

[0002] With the development of science and technology, magnetic resonance imaging has become an effective means of clinical detection of diseases. Compared with other clinical imaging techniques, magnetic resonance imaging has many advantages in revealing anatomical structures, especially in detecting inflammatory tissues and solid tumors. In addition, magnetic resonance imaging also has no ionizing radiation damage, and multi-parameter imaging provides doctors with a large amount of diagnostic information and three-dimensional positioning capabilities. However, in order to further improve the sensitivity and accuracy of imaging, c...

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