8 results about "Longitudinal Relaxation Rate" patented technology

The invention discloses a highly inert Gd-DOTA-based contrast agent with a hydrophobic side chain as well as a preparation method and application of the highly inert Gd-DOTA-based contrast agent, and two novel Gd-DOTA-based contrast agents Gd-L1 and Gd-L2 are successfully developed by respectively connecting hydrophobic 3-phenyl propylamine and 3, 3-diphenyl propylamine to Gd-DOTABA. The two novel Gd-DOTA-based contrast agents remarkably improve the chemical inertness of the complex, the dissociation half-life period of the complex in a 1 M HCl solution at 37 DEG C is about 5 times that of Gd-DOTA, and a powerful guarantee is provided for clinical safety; the MRI (Magnetic Resonance Imaging) performance of the liver in a mouse shows that Gd-L1 is equivalent to commercially available Gd-BOPTA and is suitable for imaging of a liver and gall system; after the Gd-L2 is combined with the human serum albumin, the longitudinal relaxation rate is obviously increased (r1 = 14.8 mM <-1 > s <-1 >, 1.4 T, 37 DEG C), the blood elimination half-life period in a rabbit model is about 18 minutes, and the Gd-L2 is suitable for vascular MRI (Magnetic Resonance Imaging). The two contrast agents avoid the spleen residual problem, the organ accumulation possibility is reduced, and a safer and more efficient MRI diagnostic tool is provided for clinic.

The application discloses a kind of pre-targeting probe combination for in vivo unstable iron pool imaging and its preparation method and application, and the pre-targeting probe combination includes Fe 2+ Responsive paramagnetic probe GdEpTz and fluorescent signal reporter probe 2E-Tco-Hcy, Fe 2+ Responsive paramagnetic probe GdEpTz and Fe 2+ And after interaction with endogenous protein, by generating free radicals and covalent crosslinking, induce longitudinal relaxation rate (r1) significantly increase about 104.1%, while realizing the efficient enrichment of tetrazine group Tz in lesion part, and the enriched Tz is captured by efficient IEDDA bioorthogonal reaction fluorescent signal reporter probe 2E-Tco-Hcy, trigger fluorescent signal to produce 155.5-fold significant enhancement.The application introduces the bioorthogonal pre-targeting strategy based on reverse electron Diels-Alder (IEDDA) reaction, aims to realize the high selectivity, high contrast synchronous visualization monitoring of dynamic change in deep tissue Fe 2+ Target-induced activation" and "bioorthogonal chemistry".

The present application relates to the technical field of nanoprobes, and particularly relates to a near-infrared fluorescence / magnetic resonance dual-mode probe and a preparation method and application thereof. The present application adopts a Brij98 amphiphilic molecule to wrap an IR824Et-PhDTA-Gd near-infrared fluorescence / magnetic resonance dual-response molecule to prepare the probe, so that the probe has an absorption wavelength of 650-850 nm, generates a fluorescence signal under excitation of 785 nm laser, and the generated fluorescence wavelength can reach 1000 nm, which is in a near-infrared region (780-1700 nm); the probe has good positive magnetic resonance response characteristics, and a longitudinal relaxation rate (r1) of the probe is 28 mM ‑1 s ‑1 , which is 7 times of that of a clinically used Magnevist; the probe can be applied in the fields of fluorescence and / or magnetic resonance imaging, and has a wide application prospect. The preparation method of the near-infrared fluorescence / magnetic resonance dual-mode probe is simple in operation and low in cost.

This invention discloses a pre-targeting probe assembly for in vivo unstable iron pool imaging, its preparation method, and its application. The pre-targeting probe assembly includes Fe... 2+ Response paramagnetic probe GdEpTz and fluorescent reporter probe 2E-Tco-Hcy, Fe 2+ Response paramagnetic probe GdEpTz with Fe 2+ Following interaction with endogenous proteins, free radicals are generated and covalent cross-linking occurs, significantly increasing the longitudinal relaxation rate (r1) by approximately 104.1%. Simultaneously, tetrazine-based Tz is efficiently enriched in the lesion region. The enriched Tz captures the fluorescent signal reporter probe 2E-Tco-Hcy via a highly efficient IEDDA bioorthogonal reaction, triggering a 155.5-fold significant enhancement of the fluorescence signal. This invention introduces a bioorthogonal pre-targeting strategy based on the reverse electron demand Diels-Alder (IEDDA) reaction, aiming to achieve Fe in deep tissues through the organic integration of "target-induced activation" and "bioorthogonal chemistry." 2+ Dynamically changing, highly selective, and high-contrast synchronous visual monitoring.

The invention discloses a gadolinium-based magnetic resonance / near-infrared fluorescence bimodal probe as well as preparation and application thereof, and relates to the field of nano materials and medical engineering. The bimodal probe comprises nanoparticles formed by coordination and self-assembly of gadolinium ions and indocyanine green through sulfonic acid groups, and the molar ratio of the gadolinium ions to the indocyanine green is (2-10): 1. The bimodal probe shows the relaxation performance which is obviously superior to that of other clinical common contrast agents in a 9.4 T ultrahigh field magnetic resonance system, and the longitudinal relaxation rate of the bimodal probe can reach 22.3 mM <-1 > s <-1 >. The bimodal probe can be directly produced on a large scale on the basis of clinically approved drugs, and the bimodal probe has excellent imaging performance and blood-brain barrier penetrating power and provides a very potential strategy for image-guided biomedical application.

The application provides a surface-modified gadolinium-based covalent organic framework magnetic resonance contrast agent and a preparation method and application thereof, characterized in that: tetra-(p-aminophenyl porphyrin) is used as a monomer to prepare Gd(III)-porphyrin, and then the Gd-porphyrin-based covalent organic framework polymer Gd-PCOFs contrast agent is connected by forming an imine bond with a dialsyl compound. Then, the surface of the Gd-PCOFs is modified by a molecule containing a mercapto group, so that a magnetic resonance contrast agent with uniform particle size and good dispersity is obtained, and the longitudinal relaxation rate can reach 126.35 s ‑ 1 mM ‑1 , which can be used for super-sensitive magnetic resonance imaging of solution, cells and living bodies.

The invention belongs to the technical field of medical contrast agents, and discloses a preparation method of a superfine gadolinium oxide T1-MRI contrast agent, which comprises the following steps: S1, preparing hydrophobic gadolinium oxide nanoparticles Gd2O3-OA with stable surface oleic acid by adopting a high-temperature thermal decomposition method; s2, the Gd2O3-OA and gallic acid are subjected to a reaction, and Gd2O3-GA nano particles are obtained; and S3, carrying out a reaction on the Gd2O3-GA and citric acid under an alkaline condition to obtain the ultrafine gadolinium oxide nanoparticles Gd2O3-CA modified by the citric acid. The Gd2O3-CA nano-particles prepared by the method in the scheme are uniform in particle size and superfine in particle size, and have better water dispersibility and stability. The nanoparticles have higher longitudinal relaxation rate and better in-vivo radiography effect, and can realize rapid removal through kidney metabolism at the same time, so that the risk of gadolinium ion deposition is reduced.