The present invention relates to a novel 18F labeled positron emission tomography (PET) molecular probe and a preparation method therefor, and particularly, to an [18F]AlF labeled prostate specific membrane antigen (PSMA) targeting molecular probe and a preparation method therefor, and belongs to the technical field of radiolabeled compounds.
Positron emission tomography (PET) technology is a tip technology in the field of contemporary nuclear medicine, and also one of the state-of-the-art technical means for human beings to study life phenomena in the 21st century. It is a non-invasive, dynamic, and quantitative imaging technique that utilizes positron emitting drugs as molecular probes to evaluate physiological and biochemical changes in vivo, and has been widely used in the differential diagnosis and efficacy monitoring of diseases such as tumors, cardiovascular and cerebrovascular diseases, and neurological diseases. Wherein positron drugs are the “soul” of PET imaging, and their development and clinical translation are the key to the development of PET diagnostic techniques. Positron drugs refer to drugs labeled with positron emitting radioactive nuclides for clinical PET imaging.
Positron nuclides commonly used for PET imaging are 11C (half-life T1/2=20.3 min), 18F (half-life T1/2=109.8 min), 68Ga (half-life T1/2=68.1 min), etc. 18F is currently the most widely used positron nuclide in clinical application, and has good nuclear chemistry properties. 18F labeled compound has been the focus of positron molecular probe development.
Prostate cancer is a urinary malignancy severely threatening the health of elderly men. With the development of population aging and popularization of prostate specific antigen (PSA) screening, incidence and mortality of prostate cancer in China grows year-by-year, and metastatic castration-resistant prostate cancer resulting from progressive prostate cancer is a leading cause of death. Early and accurate diagnosis of prostate cancer patients may allow for timely therapeutic interventions and personalized therapeutic regimens and thus reduce the mortality of prostate cancer.
Prostate-specific membrane antigen (PSMA) is a highly specific epithelial cell membrane antigen of the prostate, and it is an important diagnostic and therapeutic target for prostate cancer. PET imaging technology has the characteristics of precision and non-invasive. In recent years, various 68Ga-labeled PSMA-targeted PET imaging drugs have been reported in literature, represented by the unpatented 68Ga-PSMA-11. Hank F. Kung Laboratories developed a new generation of 68Ga-labeled radiopharmaceutical P16-093 based on existing PSMA targeting molecular probes,
68Ga-P16-093 is coordinated with 68Ga3+ (coordination constant˜38.5) by using HBED-CC as a bifunctional linker, which labeling method is simple, high stability in vivo, has significant radioactive enrichment in tumor metastatic sites of patients and promising properties for imaging. Phase I/II clinical study data showed that the patient did not experience significant toxic side effects after injection of 68Ga-P16-093. Compared with 68Ga-PSMA-11, 68Ga-P16-093 showed a significant decrease in radiation uptake in urinary organs such as the bladder, and PET/CT imaging of the lesion site were more clear. As a novel PSMA targeting molecular probe, 68Ga-P16-093 can be used in the diagnosis and research of prostate cancer and kidney cancer. It has entered phase II clinical trial in United States (Clinical Trials. gov Identifier: NCT034444444).
Compared with 68Ga, 18F is currently the most widely used positron nuclide in clinical application and has good nuclear chemistry properties. 18F labeled compounds have always been the focus in the development of positron molecular probes.
To date, no researcher has conducted 18F labeling studies of P16-093. The inventor attempted to label P16-093 with 18F-AlF, and found that the labeling could be realized by adjusting the reaction conditions. The obtained 18F compound has superior biological properties and has the potential to be a new generation of PSMA positron molecular probes.
An object of the present invention is to overcome the deficiencies of the prior art and provide a [18F]AlF labeled PSMA targeting molecular probe.
The aforementioned object of the present invention is realized through the following technical solutions:
A [18F]AlF labeled PSMA targeting molecular probe, comprises a PSMA-targeting group and the bifunctional linker HBED-CC, wherein the probe has a formula as below:
Another object of the present invention is to provide a preparation method for the aforementioned [18F]AlF labeled PSMA targeting molecular probe.
The aforementioned object of the present invention is realized by the following technical solutions:
A preparation method for the aforementioned [18F]AlF labeled PSMA targeting molecular probe, comprising the steps as below:
Preferably, step (1) was as follows: 6 mg of P16-093 was dissolved in 2 mL of 0.05N sodium acetate buffer, and sodium hydroxide solution was added , adjusted the pH value to 5, and obtained a P16-093 sodium acetate solution at concentration of 3 mg/mL.
Preferably, step (2) was as follows: a sep-pak QMA column was pre-treated with 10 mL of 0.5M NaOAc solution and deionized water, and 18F− was prepared on a cyclotron by nuclear reaction 18O(p,n)18F and then enriched on the sep-pak QMA column, rinsed with deionized water to remove the metal impurity ions adsorbed on the sep-pak QMA column, and eluted with 0.2˜1 mL of saline to obtain 1˜2 GBq of a saline solution.
Preferably, step (3) was as follows: 4 μL of sodium acetate buffer of AICl3 was added in a reaction vessel, and 100 μL of the saline solution prepared in step (2) was added and mixed evenly, and then the P16-093 sodium acetate solution prepared in step (1) and 124 μL of ethanol were added. The mixture was shaken evenly and reacted at 50-80° C. for 10-30 min, then cooling to ambient temperature, the labeling yield was measured by high performance liquid chromatography (HPLC) to obtain a [18F]AlF-P16-093 labeled reaction solution.
Preferably, step (4) was as follows: the [18F]AlF-P16-093 labeled reaction solution prepared in step (3) was purified by solid phase extraction small column, the resulting product was diluted with saline to an ethanol content of less than 10%, its retention time and radiochemical purity were measured by HPLC, and its appearance was observed as a colorless clear transparent liquid to obtain a [18F]AlF labeled PSMA targeting molecular probe.
Preferably, in step (3) and step (4), the first mobile phase was 0.1% aqueous solution of trifluoroacetic acid, the second mobile phase was acetonitrile, the gradient elution conditions were as follows: 0 min, 100% of the first mobile phase; 0˜10 min, 100% ˜0% of first mobile phase; the flow rate of the mobile phase was 1 ml/min.
A further object of the present invention is to provide the use of the aforementioned [18F]AlF labeled PSMA targeting molecular probe.
The aforementioned object of the present invention is realized by the following technical solutions:
Use of [18F]AlF labeled PSMA targeting molecular probe in the diagnosis and detection of prostate cancer.
Preferably, the diagnosis and detection include early diagnosis, preoperative staging, treatment guidance, recurrence, and metastatic lesion detection.
The subject matter of the present invention is further illustrated and described in connection with the example and the corresponding text and figures. There is no intent to limit the protection scope of the present invention.
Unless otherwise specified, the raw material and reagents mentioned in the examples of the present disclosure are the conventional ones that are commercially available, the test methods used are conventional, and the equipment and devices used are all conventional ones in this field.
A preparation method of the [18F]AlF labeled PSMA targeting molecular probe, comprising the following steps:
In high performance liquid chromatography (HPLC) aforementioned in step (1), step (4) and step (5), the first mobile phase was 0.1% aqueous solution of trifluoroacetic acid, the second mobile phase was acetonitrile, the gradient elution conditions were as follows: Omin, 100% of the first mobile phase; 0˜10 min, 100% ˜0% of first mobile phase; the flow rate of the mobile phase was 1 ml/min.
Tumor mouse models of PC3-PIP (overexpressing of PSMA) and PC3 (no expressing of PSMA) were established, the PC3-PIP tumor, PC3 tumor and kidney tissue of the tumor mouse were sectioned at −20° C. with a thickness of 20 μm, the obtained sections were placed on a glass slide and dried in air for in vitro autoradiography studies. 1 mL of [18F]AlF-P16-093 solution was overlaid on the tissue sections, incubated at room temperature for 60 minutes, and rinsed with PBS solution and deionized water for 3 minutes respectively, after drying, the tissue sections were covered with cling film and exposed overnight on a phosphorscreen, and then placed in a Cyclone Storage Phosphor System for imaging analysis.
The results of in vitro autoradiography experiments are illustrated in
PC3-PIP cells (expressing PSMA) and PC-3 cells (no expressing PSMA) were seeded separately in 12-well plates, RPMI 1640 culture fluid and fetal bovine serum FBS (v/v=9/1) were added, after incubation in a CO2 incubator (5% of CO2, 37° C.) for 24 hours, there were approximately 5×105 cells per well plate, the medium was moved, and washed twice with PBS, then PBS solution of [18F]AlF-P16-093 or RPMI 1640 culture fluid was added, after incubation in a CO2 incubator (5% of CO2, 37° C.) for 0-120 minutes, the solution was removed, washed twice with 1 mL of cold PBS (without Ca2+ and Mg2+), the cells and cold PBS radioactive count were measured by a γ-Counter (radioactive counting instrument). Simultaneously, inhibition experiments were conducted, 10 μM MIP-1095 was added per well plate.
The results of the cellular uptake studies of [18F]AlF-P16-093 in Example 1 of the present invention in PC3-PIP cells and PC-3 cells are illustrated in
CD-I nude mice were implanted with PC3-PIP cells in the anterior left extremity axilla and PC3 cells in the anterior right extremity axilla and grown until tumors were 5-8 mm in diameter for biodistribution studies, by tail vein injection of 0.15 mL of [18F]AlF-P16-093 saline (approximately 370 kBq), and tumor bearing nude mice were sacrificed anesthetically at different time points (30min, 60 min and 120 min), dissected, tissue of interest weighed and radioactivity counted;
The results of in vivo biodistribution studies in tumor mice are illustrated in Table 1: [18F]AlF-P16-093 in vivo biodistribution studies in tumor mice (% dose/g, avg±SD, n=4); it can be seen that [18F]AlF-P16-093 uptake was higher in kidneys and PC3-PIP tumors of PSMA-high expressing, rising stepwise with time and reaching a maximum at 60 min; the uptake was lower in PC3 tumors which PSMA did not express; PC3-PIP tumor to muscle ratios were 17, 43 and 63 at 30 min, 60 min and 120 min respectively; PC3-PIP tumor to blood ratios were 11, 29 and 61 respectively.
In the present invention, 18F is used as a radioactive labeled nuclide, and a PSMA targeting molecular probe is labeled by means of [18F]AlF-HBED. The labeled [18F]AlF-P16-093 has two advantages: firstly, the labeled method of [18F]AlF-P16-093 is simple, evaporation and water removal are not required, automatic synthesis is easy to realize, the labeling yield is high, HPLC purification is not required, and commercial application of radiopharmaceuticals in clinical promotion is facilitated; and secondly, by means of the biological characteristic of specifically targeting PSMA of the [18F]AlF -P16-093, the labeled product has important potential clinical values in early diagnosis, preoperative staging, treatment guidance, recurrence and metastasis focus detection of prostate cancer.
It is to be understood that the described examples herein are only some preferred examples of the present invention, there is no intent to limit the scope of implementation of the present invention. Equivalent changes and modifications made according to the patent scope and specification of the present invention should still fall within the scope of the present invention.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/CN2021/078215 | 3/17/2021 | WO |