CN111281986A

CN111281986A - A kind of18Application of F-fluorine labeled sulfone compound and preparation method of blood pool tracer

Info

Publication number: CN111281986A
Application number: CN202010065277.8A
Authority: CN
Inventors: 陈跃; 王力; 张心怡; 黄占文; 蔡亮; 张莉; 刘会攀; 张蜀茂; 傅文会; 徐婷婷
Original assignee: Affiliated Hospital of Southwest Medical University
Current assignee: Affiliated Hospital of Southwest Medical University
Priority date: 2020-01-20
Filing date: 2020-01-20
Publication date: 2020-06-16
Anticipated expiration: 2040-01-20
Also published as: CN111281986B

Abstract

The invention discloses¹⁸An application of F-fluorine labeled compound and a preparation method of a blood pool tracer agent belong to the technical field of radiopharmaceuticals and nuclear medicine, and solve the problems that the blood pool tracer agent in the prior art is poor in imaging capability and stability and the imaging process is influenced by glucose metabolism. The invention is shown as formula I¹⁸The use of an F-fluorine labelled compound or a salt thereof in the preparation of a blood pool tracer agent,

according to the invention¹⁸The preparation method of the F fluorine labeled blood pool tracer comprises the steps of adding a buffer solution of a compound shown in the formula I into an RBC buffer solution, incubating, centrifuging, collecting erythrocyte precipitates, adding the buffer solution, and mixing to obtain the F fluorine labeled blood pool tracer. The blood pool tracer agent has obvious stability, good heart blood pool imaging capability and prolonged effectHeart blood pool residence time; can not penetrate blood brain barrier and has small influence on brain tissue.

Description

A kind of18Application of F-fluorine labeled sulfone compound and preparation method of blood pool tracer

Technical Field

The invention belongs to the technical field of radiopharmaceuticals and nuclear medicine, and particularly relates to a radiopharmaceuticals¹⁸An application of a F-fluorine labeled sulfone compound in preparation of a blood pool tracer agent and a preparation method of the blood pool tracer agent.

Background

The blood pool tracer is a macromolecular substance marked by radioactive nuclide, and can be completely mixed in blood after intravenous injection to achieve balance, and can be used for scanning or taking pictures by using related instruments to obtain the form of heart large vessel and the imaging of the relation between peripheral tissues and organs thereof, and also can be used for obtaining heart function information by quantitative analysis, and can be used for diagnosing diseases such as coronary heart disease, cardiomyopathy, congenital heart disease, valvular heart disease and the like, and has important significance for monitoring the toxic reaction of drugs to heart, diagnosing chronic intermittent bleeding, particularly lower gastrointestinal bleeding and the like.

With the continuous development of cardiovascular nuclear medicine, new blood pool tracers continue to emerge, but each has its drawbacks and deficiencies. Such as¹³¹The I-labeled Human Serum Albumin (HSA) needs to seal the thyroid three days before imaging, the radiation dose of a patient is large, the nuclide energy is high, and the application of a gamma camera is not facilitated. Applications of^99mTc-labeled HSA and Red Blood Cells (RBC) avoid the above problems and improve imaging quality. The blood pool tracer agent used in clinic at present is mainly adopted^99mTc-labeled autologous red blood cells predominate. RBC is the highest-content visible component in blood and is easy to beThe in vitro separation operation and culture have good imaging quality. But do not^99mThe labeling rate of Tc-RBC is often unstable and is greatly influenced by the type and dosage of the applied medicine.^99mTc-HSA tends to decrease in blood radioactivity within 15 minutes of injection, while the radioactivity in the liver increases. After 90 minutes, the radioactivity in blood is obviously reduced, the radioactivity of liver and lung is higher, and the imaging of heart blood pool is influenced. Moreover, the imaging agent needs SPECT for detection, and has lower receiving efficiency and poor image quality compared with images obtained by PET/CT imaging. There are also reports related to the use of radioactive nuclides (such as fluorine-18, copper-64, gallium-68, etc.) and evans blue complex (NOTA-EB) labeled HSA as a blood pool tracer, and because the radionuclide needs to be combined with HSA for imaging, the effect is not ideal and the stability is poor. At present, there are¹⁸F-FDG labeled RBC, but because FDG is influenced by glucose metabolism, the labeling process requires fasting, glucose consumption, and the like.

Therefore, providing a blood pool tracer with good visualization ability for heart blood pool and good stability is a problem to be solved by those skilled in the art.

Disclosure of Invention

The technical problem solved by the invention is as follows: providing a compound of formula I¹⁸The application of the F-fluorine labeled sulfone compound or salt thereof in the preparation of the blood pool tracer agent solves the problems of poor imaging capability and poor stability of the blood pool tracer agent in the prior art.

The invention also provides a method for preparing the blood pool tracer by using the compound shown in the formula I as a raw material.

The technical scheme adopted by the invention is as follows:

the invention is shown as formula I¹⁸The use of an F-fluorine labelled compound or a salt thereof in the preparation of a blood pool tracer agent,

wherein n is 0 to 5.

The invention relates to¹⁸A process for the preparation of F fluorine labelled blood pool tracers by buffering a compound of formula IAdding the solution into RBC buffer solution, incubating, centrifuging, collecting erythrocyte precipitate, adding buffer solution, and mixing to obtain the final product¹⁸F fluorine labelled blood pool tracers.

In the technical scheme of the invention, the buffer solution of the compound of the formula I is 1-fold PBS solution containing the compound of the formula I, the pH value is 6-8, and preferably the pH value is 7.4;

or/and the RBC buffer solution is 1-fold PBS buffer solution containing RBC, and the pH value is 6-8, preferably the pH value is 7.4.

In the technical scheme of the invention, when the compound in the buffer solution of the compound in the formula I is 1-20 mCi, the red blood cell count in the RBC buffer solution is 0.8^ 9-2 ^ 9.

In the technical scheme of the invention, the incubation condition is incubation for 30-60 min at 35-38 ℃; preferably, the incubation is carried out at 37 ℃ for 45 min.

In the technical scheme of the invention, the centrifugation is performed under a low-temperature condition.

The temperature of the centrifugation is below 20 ℃.

In the technical scheme of the invention, the centrifugal force is 300-400 Xg during centrifugation.

According to the technical scheme, the collected erythrocyte sediment is added into PBS buffer solution to be repeatedly centrifuged for 2-4 times.

In the technical scheme of the invention, the¹⁸The concentration of the red blood cells in the F fluorine marked blood pool tracer is 3^12/L to 6^ 12/L.

It should be noted that when the blood pool tracer agent of the invention is used in human, the red blood cells used in the preparation process are human autologous red blood cells; when the blood pool tracer agent is used for animals, the red blood cells used in the preparation process are the red blood cells of the animals.

The preparation method of the RBC buffer solution comprises the following steps: mixing blood with 5-10 times volume of PBS (phosphate buffer solution) containing 2-8 mM EDTA to obtain diluted blood solution, dropping the diluted blood solution on 15mL of leukocyte separation solution (rho is 1.077g/mL), and centrifuging at 20 ℃ at 300-400 Xg for 30 min; eliminating all the upper liquid to leave the RBS layer undisturbed; adding 20-30 mL of PBS (containing 5mM EDTA) solution to fill a centrifuge tube, and gently blowing and beating the uniform RBS by a pipette; centrifuging at 300-400 Xg for 20-60 min at 20 ℃; all buffers were removed and the appropriate amount of PBS buffer was added to the cell pellet to obtain RBC buffer.

Compared with the prior art, the invention has the following beneficial effects:

the invention has scientific design and simple method. The invention creatively adopts fluorine-18 labeled sulfone compounds to prepare the blood pool tracer, and compared with the method for labeling by complexing metal radionuclides (gallium-68, copper-64 and technetium-99) by using macrocyclic polyamine chelating groups (such as NOTA), the blood pool tracer has obvious stability and advantages by forming stable carbon-fluorine-18 chemical bond labeled blood pool tracer.

Blood pool observation shows that the imaging agent has good imaging capability on the heart blood pool after being injected into mammals.

The labeling method is simple, the precursor is easy to obtain, the observation of the heart blood pool of the mammal can be simply and effectively realized, meanwhile, the blood sugar is not influenced (fasting is not needed), and the imaging effect is good; compared with the existing heart blood pool tracer, the tracer prolongs the retention time in the heart blood pool, is mainly excreted by the kidney and the bladder, has higher excretion speed, and reduces the nephrotoxic effect; can not penetrate blood brain barrier and has small influence on brain tissue.

Drawings

FIG. 1 is a HPLC chart of a compound of formula I of the present invention using a radioactivity detector;

FIG. 2 is a HPLC plot of a compound of formula I of the present invention using a UV detector;

FIG. 3 is a micro-PET/CT scan image of normal mice injected with 18F-VS1-RBC for 1 hour;

FIG. 4 is a micro-PET/CT scan image of normal mice injected with 18F-VS1-RBC 5 hours later.

FIG. 5 is a graph of organ biodistribution (X. + -. S) (% ID/g) of 18F-VS1-RBC in normal mice.

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are provided for illustration only and are not intended to limit the scope of the present invention, and any equivalent replacement in the field made in the light of the present disclosure is included in the scope of the present invention.

Example 1

This example discloses compounds of formula I according to the invention¹⁸The preparation method of F-VS1 specifically comprises the following steps:

prepared by making accelerator bombs¹⁸Capturing F-fluoride ions with an activated QMA column, and then capturing the QMA column¹⁸F-fluorinion is washed into a multifunctional fluorine synthesis module reaction tube by using 2.5 percent TBAB acetonitrile/water mixed solution, and part of F-fluorinion is taken after the F-fluorinion is dried by anhydrous acetonitrile for three times¹⁸A solution of F-TBAF (about 50mCi) was added to a solution of 2mg of the compound of formula II (n ═ 1) in anhydrous acetonitrile (60 μ L), and after heating under sealed conditions at 95 ℃ for 15min, a portion of the reaction solution was removed and subjected to radio-HPLC separation. The chromatographic conditions are as follows: the elution separation was carried out by using ODS C18 column as a column, 0.1% trifluoroacetic acid in acetonitrile as a mobile phase A, 0.1% trifluoroacetic acid in water as a mobile phase B, and a flow rate of 1mL/min, according to the following table.

Time (min)	Mobile phase A (%)	Mobile phase B (%)
			0	5	95
2	5	95
			22	95	5
28	95	5

The HPLC profiles are shown in FIGS. 1 and 2.

Evaporating acetonitrile from the collected eluent containing the compound of formula I to obtain the compound of formula I, and recording as¹⁸F-VS 1. Taking part of a compound of formula I¹⁸F-VS1 and standard¹⁹F-VS1 solution was analyzed by HPLC mixed injection with consistent peak time.

Example 2

This example discloses the preparation of a blood pool tracer using the compound of formula I prepared in example 1, specifically:

RBC preparation: under isoflurane anesthesia, 200. mu.L of blood was collected after euthanasia of mice due to cervical dislocation, and the blood was mixed with 10-fold volume of PBS containing 5mM EDTA. The diluted blood solution was dropped on 15mL of a leukocyte separation solution (. rho. ═ 1.077g/mL) in a 50mL centrifuge tube, and centrifuged at 1000r/min at 20 ℃ for 30 min. All supernatant liquid was eliminated leaving the RBS layer undisturbed. Add 30mL PBS solution (containing 5mM EDTA) to fill the centrifuge tube and gently pipette the RBCs well. Centrifugation was again carried out at 300Xg1000 r/min for 30min at 20 ℃. All buffers were removed, and 10 to 100. mu.L of a buffer solution of an appropriate amount of PBS was added to the cell pellet as an RBC buffer for use.

The eluent containing the compound of formula I collected in example 1 was evaporated to remove acetonitrile, adjusted to pH 7 to give a 1-fold amount of PBS¹⁸F-VS1 solution was ready for use.

3 to 4mCi¹⁸F-VS1 in PBS was added to the above RBC buffer and incubated at 37 ℃ for 45 min. At 20 ℃ at 30Centrifuging at the rotating speed of 0xg1000 r/min for 5 min. The erythrocyte pellet was collected and mixed with an appropriate amount of 2ml PBS buffer. PBS buffer addition/centrifugation/red blood cell collection was repeated twice. Finally, 150. mu.L of 1-fold PBS buffer was added and mixed to obtain¹⁸F-VS1 labeled blood pool tracer for micro PET/CT imaging.

Example 3

This example discloses a blood pool tracer prepared in example 2¹⁸Imaging experiments of F-VS1 labeled RBC:

placing a normal mouse on a PET/CT scanning bed, maintaining anesthesia and detecting respiration by using isoflurane-oxygen mixed gas with the volume fraction of 1%, and injecting 50-200 mu Ci to the tail vein of the mouse¹⁸F-VS labeled erythrocyte tracer solution. After injection, static imaging of the mice is carried out at different time points, after acquisition and image reconstruction, the myocardium, the blood pool, the liver, the kidney, the brain, the muscle, the bone, the stomach, the small intestine and the brain are sketched on a whole body attenuation correction coronary image by using software Inveon Research Workplace (SIEMENS) provided by a supplier as a region of interest (ROI), and the region of interest (ROI) is obtained by processing data of the Inveon Research Workplace¹⁸F-VS1 labeled erythrocyte tracer solution injected the percent dose per gram of tissue (% ID/g) at this time point.

The results are shown in FIGS. 3 and 4, from the injection¹⁸After the F-VS1 marks the erythrocyte tracer solution, the Micro-PET/CT visualizations and the in vivo distribution of normal mice are seen¹⁸After the F-VS1 marks the erythrocyte tracer solution for 1 hour, the imaging of the mice can see that the radioactivity distribution of the heart and the blood pool is obvious, the radioactivity distribution of the bladder is high, and the radioactivity distribution of the liver, the kidney, the lung, the bone, the brain and the like is slight; after 5h of injection, the radioactivity distribution in the heart blood pool is still clear, the radioactivity distribution in the stomach and the intestine is increased, the radioactivity distribution in the bladder is reduced, and the radioactivity distribution in the liver and other soft tissues is reduced. Description of the invention¹⁸The erythrocyte tracer solution marked by F-VS1 has longer retention time in the heart blood pool, is mainly excreted by the kidney and the bladder, has higher excretion speed, and can reduce the nephrotoxic effect; there is a poor distribution in brain tissue, indicating that it is unable to cross the blood brain barrier.¹⁸Organ biodistribution of F-VS1 in Normal mice (X. + -. S) (% ID/g) is shown in FIG. 5.

The above-mentioned embodiment is only one of the preferred embodiments of the present invention, and should not be used to limit the scope of the present invention, but all the insubstantial modifications or changes made within the spirit and scope of the main design of the present invention, which still solve the technical problems consistent with the present invention, should be included in the scope of the present invention.

Claims

1. As shown in formula I¹⁸The application of the F-fluorine marked sulfone compound or the salt thereof in the preparation of the blood pool tracer agent,

wherein n is 0 to 5.

2. A kind of¹⁸The preparation method of the F fluorine labeled blood pool tracer agent is characterized by adding a buffer solution of the compound shown in the formula I into an RBC buffer solution, incubating, centrifuging, collecting erythrocyte sediment, adding the buffer solution, and mixing to obtain the F fluorine labeled blood pool tracer agent¹⁸F fluorine labelled blood pool tracers.

3. The method of claim 2, wherein the buffer solution of the compound of formula I is a 1-fold PBS solution containing the compound of formula I, and has a pH of 6 to 8, preferably a pH of 7.4;

4. The method of claim 2 or 3, wherein when the compound of formula I is 1-20 mCi in the compound of formula I buffer, the red blood cell count in RBC buffer is 0.8^ 9-2 ^ 9.

5. The method according to claim 2 or 3, wherein the incubation is carried out at 35-38 ℃ for 30-60 min; preferably, the incubation is carried out at 37 ℃ for 45 min.

6. The method of claim 2 or 3, wherein the centrifugation is centrifugation under cryogenic conditions.

7. The method of claim 6, wherein the temperature of the centrifugation is less than 20 ℃.

8. The method according to claim 2 or 3, wherein the centrifugal force is 300 to 400 Xg.

9. The method according to claim 8, wherein the collected erythrocyte pellet is added to PBS buffer solution and centrifuged repeatedly for 2 to 4 times.

10. The method of claim 2, wherein the step of preparing the composition is carried out in a batch process¹⁸The concentration of the red blood cells in the F fluorine marked blood pool tracer is 3^12/L to 6^ 12/L.