CN106977714A - Positive electron marking nano probe68Ga NOTA DGL Ac and preparation method thereof and purposes - Google Patents

Abstract

The invention discloses a kind of compound⁶⁸Ga NOTA DGL Ac and preparation method thereof, the compound⁶⁸Ga NOTA DGL Ac have very high radiochemicsl purity, good vitro stability and water solubility, are conducive to⁶⁸Blood circulations of the Ga NOTA DGL Ac in mouse live body.It is of the present invention⁶⁸Ga NOTA DGL Ac preparation method, by synthesizing tree-like macromolecular poly-D-lysine derivative DGL NOTA Ac, and uses positron radionuclide⁶⁸Ga is marked, and explores a simple, positive electron marking nano molecular probe approach that quick, putting yield is high, passs to release for gene therapy, medicine and provides new research direction with bio-imaging.

Description

Positron-labeled nanoprobe 68Ga-NOTA-DGL-Ac and its preparation method and application

technical field

The invention relates to a positron-labeled nanometer probe ^68Ga -NOTA-DGL-Ac, a preparation method and application thereof, and belongs to the medical field.

Background technique

Nanomaterials refer to a class of materials with a one-dimensional space size <100nm. Due to their special volume and structure, they have some special properties, such as good surface activity, low toxicity, high catalytic ability, and are not easy to accept various substances in the body and cells. enzymatic degradation, etc. There are many types of nanomaterials. Nanomaterials used in the field of molecular imaging research can be divided into two categories: organic and inorganic. Organic nanomaterials include dendrimers, liposomes, micelles, ferritin, etc.; inorganic nanomaterials Materials include quantum dots, iron oxide, gold nanoparticles, superparamagnetic rare earth ions, etc. Dendrimers are a new class of polymer materials independently developed in 1985 by Tomalia et al. of the Michigan Institute of Chemistry and Newkome et al. of the University of South Florida almost simultaneously. From its birth to the present, although it has only been 30 years, it has attracted much attention due to its novel structure, unique performance and potential application prospects.

Dendrigraft poly-L-lysine (DGL) is a newly developed dendritic polymer in recent years. In addition to possessing the common characteristics of dendritic polymers, such as amphiphilicity, internal cavity and Positively charged, it is also easy to degrade into bioavailable amino acids, has good biocompatibility, antibacterial properties, no immunogen, and low toxicity. Furthermore, their dendritic frameworks are able to carry large amounts of molecules due to the less crowded structure. For example, the recent use of DGL as a nano-MRI contrast agent (mixed with gadolinium complexes), as a gene delivery vehicle across the blood-brain barrier, or transport through liposomes and cell membranes, these examples indicate that this new class of macromolecules can be used in large Some dendrimers are developed for applications such as gene therapy, drug delivery and bioimaging.

In recent years, positron emitters of ⁶⁸ Ga-labeled polypeptides have begun to be applied. ⁶⁸ Ga does not rely on accelerator production. It is prepared by a ⁶⁸ Ge/ ⁶⁸ Ga generator. The preparation method is simple and can achieve a radiolabeling yield of more than 95% within 15 minutes, and the half-life of ⁶⁸ Ga is 67.6 minutes. Its nuclide properties are excellent. The blood is cleared quickly, and the radiation received by the patient is relatively small, so it has become the key research object of positron drug research in recent years. There are few studies on radioactive labeling in dendrimer polylysine, so this study discusses the method of ⁶⁸ Ga labeling DGL.

Contents of the invention

The purpose of the present invention is to overcome the above defects and provide a novel positron-labeled nanoprobe ^68Ga -NOTA-DGL-Ac, which has good stability and biocompatibility and can circulate in the blood of a living body , The radiochemical yield is high, and the preparation method of the positron-labeled nanometer molecular probe is simple and fast.

In order to achieve the above object, the technical scheme adopted by the present invention is: a compound ⁶⁸ Ga-NOTA-DGL-Ac.

In addition, the present invention discloses a preparation method of compound ⁶⁸ Ga-NOTA-DGL-Ac, which uses ⁶⁸ Ga to radioactively label the precursor DGL-NOTA-Ac to obtain compound ⁶⁸ Ga-NOTA-DGL-Ac.

Preferably, the preparation method of the compound ⁶⁸ Ga-NOTA-DGL-Ac comprises the following steps: (1) take an appropriate amount of dilute hydrochloric acid to rinse the germanium-gallium generator, collect the eluent, and select the eluent with the highest activity solution; (2) add sodium acetate solution in the eluent with the maximum activity of step (1) gained, adjust pH, then join in DGL-NOTA-Ac sodium acetate buffer solution; (3) step (2) The resulting mixed solution was subjected to a light-shielding reaction, and ⁶⁸ Ga-NOTA-DGL-Ac was obtained upon completion of the reaction.

Preferably, the concentration of dilute hydrochloric acid in the step (1) is 0.05 mol/L, and the rinsing flow rate for rinsing the germanium-gallium generator is 1 ml/min.

Preferably, the concentration of sodium acetate solution in the step (2) is 1.0mol/L.

Preferably, the pH is adjusted to 4.0-4.2 in the step (2).

Preferably, the conditions for the reaction in the dark in the step (3) are to react in the dark at 70° C. for 10 minutes.

Preferably, the preparation method of the precursor DGL-NOTA-Ac comprises the following steps: (1) dissolving DGL G3 in DMSO, stirring and mixing until completely dissolved; (2) dissolving NOTA-NHS in DMSO, stirring Mix until completely dissolved; (3) mix DGL G3 dissolved in step (1) with NOTA-NHS dissolved in step (2), and react in the dark at room temperature; (4) then add to step (3) Add excess triethylamine to the obtained mixed solution, stir at room temperature in the dark, then add excess acetic anhydride, continue the reaction under the same reaction conditions, and obtain the precursor DGL-NOTA-Ac after the reaction is completed.

Preferably, the preparation method of the precursor DGL-NOTA-Ac also includes step (5) after the reaction is completed, dialyzing the precursor obtained in step (4) in 0.5mol/L, pH=4.0 sodium acetate buffer solution, namely A relatively pure precursor DGL-NOTA-Ac can be obtained.

On the other hand, the present invention discloses the application of a compound ⁶⁸ Ga-NOTA-DGL-Ac as a positron-labeled nanoprobe in gene therapy, drug delivery and bioimaging.

The beneficial effect of the present invention is that: the compound ⁶⁸ Ga-NOTA-DGL-Ac of the present invention has very high radiochemical purity, good in vitro stability and water solubility, which is beneficial to the expression of ⁶⁸ Ga-NOTA-DGL-Ac in mice Blood circulation in a living body. The preparation method of ⁶⁸ Ga-NOTA-DGL-Ac described in the present invention explores a simple and convenient method by synthesizing dendrimer polylysine derivative DGL-NOTA-Ac and labeling it with positron nuclide ⁶⁸ Ga. The rapid and high radiochemical yield of positron-labeled nanomolecular probes provides a new research direction for gene therapy, drug delivery and bioimaging.

Description of drawings

Fig. 1 is the synthesizing schematic diagram of DGL-NOTA-Ac;

Fig. 2 is the ultraviolet absorbance measurement result of DGL-NOTA-Ac, and the black arrow points to 320nm place;

Fig. 3 is the detection result of the Malvern nano particle size potentiometer of DGL-NOTA-Ac;

Figure 4 shows the paper chromatography detection results of ⁶⁸ Ga-NOTA-DGL-Ac, wherein R _{f (} ⁶⁸ _{Ga-NOTA-DGL-Ac)} = 38/200 = 0.19, R _{f (} ⁶⁸ _{Ga ion)} = 101/200 =0.505;

Fig. 5 is the in vitro stability test result of ⁶⁸ Ga-NOTA-DGL-Ac;

Figure 6 shows the uptake and elution results of ^68Ga -NOTA-DGL-Ac in A459 cells and U87MG cells;

Figure 7 is the biodistribution result of ⁶⁸ Ga-NOTA-DGL-Ac in normal mice;

Figure 8 is the Micro-PET imaging of normal KM mice injected with ⁶⁸ Ga-NOTA-DGL-Ac through the tail vein for 120 minutes;

Figure 9 shows the biological distribution results of ⁶⁸ Ga-NOTA-DGL-Ac in U87MG tumor-bearing mice;

Figure 10 shows the Micro-PET/CT imaging results of ⁶⁸ Ga-NOTA- ^DGL -Ac tumor-bearing nude mice ^. Imaging 120 minutes after NOTA-DGL-Ac, the arrow points to the tumor.

detailed description

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

1. Materials and methods

1.1 Synthesis of precursor DGL-NOTA-Ac

Take 10mg of DGL G3 dissolved in 6mL of anhydrous DMSO, take 8.6mg of NOTA-NHS dissolved in 20mL of anhydrous DMSO, mix the two, and stir at room temperature for 24h in the dark. After the reaction was completed, excess triethylamine was added and stirred at room temperature in the dark for 0.5 h, then excess acetic anhydride was added, and the reaction was continued for 24 h under the same reaction conditions. After the reaction, dialyze in 0.5mol/L sodium acetate buffer solution with pH=4.0 (for 3 days, change the solution 5 times) to obtain a concentration of 1mg/mL, wherein the synthesis diagram of DGL-NOTA-Ac is shown in Figure 1 .

1.2 Preparation of ⁶⁸ Ga-NOTA-DGL-Ac

Take 2.5ml of 0.05mol/L HCl to rinse the germanium-gallium generator at a flow rate of 1ml/min, and collect the eluate, 5 tubes of 0.5ml each. Carry out activity detection respectively, select the eluent with the highest activity, add 32.5μL 1.0mol/L sodium acetate solution, adjust the pH to 4.0-4.2, and then add 200μL DGL-NOTA-Ac sodium acetate buffer solution for 70 ⁶⁸ Ga-NOTA-DGL-Ac was obtained by reacting in the dark for 10 minutes at ℃.

1.3 Identification and purification of ⁶⁸ Ga-NOTA-DGL-Ac

Thin Layer Chromatography (TLC) was used to identify markers, and PD10 purification column was used for separation and purification. Take 1 μL of markers for spotting, and the developing agent is 0.9% saline. Equilibrate the PD10 column with 25 mL of 0.01 mol/L PBS solution, add 500 μL of the reaction mixture, and then rinse with 2 mL of 0.9% saline. Take 5 EP tubes, numbered 1-5 respectively, and each EP tube is connected with 0.5mL of eluent. After rinsing, the radioactivity of each EP tube was measured, and the eluate with the highest radioactivity was used to determine the radiochemical purity by Radio-TLC. If the radiochemical purity was >99%, biological experiments in vivo and in vitro were performed.

1.4 Determination of basic physical and chemical properties

Dissolve the prepared radioactive nanomolecular probe in PBS buffer, observe its color, clarity, and transparency visually, and take a small amount of sample to analyze its pH value with standard pH test paper.

1.5 Determination of fat-water partition coefficient

Take 10 μL of separated and purified ⁶⁸ Ga-NOTA-DGL-Ac, add them to three EP tubes (containing 0.5 mL n-octanol and 0.5 mL 0.01 mol/L PBS buffer solution), seal and vortex at room temperature for 2 min , 3000r/min centrifugation for 5 minutes. Take 10 μL each of the organic phase and the aqueous phase from the three EP tubes sequentially with a sampling gun, place them in γ counting tubes, perform γ counting, and repeat three times. Average Log P values were calculated using the formula Log P = Log(γ count n-octanol/γ count PBS).

1.6 In vitro stability evaluation of ⁶⁸ Ga-NOTA-DGL-Ac

Take 20μL (about 2.03MBq) of ^68Ga -NOTA-DGL-Ac solution, put it in 0.5mL of PBS buffer (pH=7.4, 0.01mol/L), incubate at 37℃ for 30min, 60min, 90min and 120min Take 100 μL to measure its radiochemical purity to observe its stability in PBS buffer, and repeat three times. In order to test the stability of ⁶⁸ Ga-NOTA-DGL-Ac solution in calf serum, it was also incubated at 37°C for 30min, 60min, 90min and 120min, and then dilute fetal bovine serum with an equal volume of PBS, sealed and kept at room temperature Vortex for 2 min, centrifuge at 1000 r/min for 5 min, and take the supernatant for analysis by Radio-TLC.

1.7 Uptake and elution experiments of ⁶⁸ Ga-NOTA-DGL-Ac in A549 and U87MG cells

(1) Cell uptake experiment: Add ⁵ ×104 human lung adenocarcinoma cell line A549 or human glioma cell line U87MG to each well of a 24-well plate, culture overnight to allow the cells to adhere to the wall, remove the medium the next day, Add 5 μL PBS solution containing 185KBq ⁶⁸ Ga-NOTA-DGL-Ac to each well, add 5 μL PBS solution (without ⁶⁸ Ga-NOTA-DGL) to the blank control group, and incubate at 37°C for 20min, 40min, 80mim and 120min respectively. Each well was washed 3 times with 0.5mL frozen PBS, and then the cells were digested with 0.25% trypsin/0.02% EDTA, and the radioactive count was measured with a gamma counter after collecting the cell suspension. The cell uptake data were all expressed by the cell binding rate after attenuation correction, that is, the percentage of the added dose. The experiment was set in three parallels and repeated 3 times.

(2) Cell elution experiment: add 5×10 ⁴ A549 or U87MG to each well of a 24-well plate, and incubate with 185 KBq/well of ⁶⁸ Ga-NOTA-DGL-Ac at 37°C for 1 hour to fully internalize . Then remove the culture medium, wash with frozen PBS for 3 times, then add serum-free medium and incubate at 37°C for 0min, 20min, 40min, 80min and 120min. Afterwards, each well was washed three times with 0.5 mL of frozen PBS, and finally the cells were digested with 0.25% trypsin/0.02% EDTA, and the radioactive count was measured with a gamma counter after collecting the cell suspension. The cell elution data were all expressed by the cell retention rate after the attenuation correction, that is, the percentage of the added dose. The experiment was set in three parallels and repeated 3 times.

Biodistribution of 1.8 ⁶⁸ Ga-NOTA-DGL-Ac in normal mice

The Kunming mice were fasted for 12 hours, and the normal mice were marked and grouped (12 in total, divided into 4 groups, 3 in each group), and the counting tubes were labeled and weighed. Draw 100 μL tracer into the syringe, measure the radioactivity, and number each syringe, and the number is consistent with the number of the mouse. The mice were anesthetized with 2% isoflurane, then the tails of the mice were wiped with alcohol, and the tracer was injected through the tail vein. Blood was collected from the eyeball 5 minutes, 30 minutes, 60 minutes and 120 minutes after the injection of the tracer, and then executed by neck dislocation and the main organs (heart, lung, liver, spleen, kidney, stomach, intestine, pancreas, brain, muscle, bone, fur) were dissected, washed with PBS buffer and dried, and then placed in corresponding numbered empty counting tubes. Weigh all the counting tubes with organ tissues, organ tissue weight=total weight−empty counting tube weight. Gamma counting was carried out on the counting tube containing the organs and tissues with a gamma counter, and the radioactive count per gram of tissue was calculated after attenuation correction, expressed as percent injected dose per gram of tissue (ID%/g).

Micro-PET imaging of 1.9 ⁶⁸ Ga-NOTA-DGL-Ac in normal mice

Micro-PET acquisition and image analysis were performed with Siemens Inevon small animal PET/CT. Normal mice were anesthetized by intraperitoneal injection of chloral hydrate solution and injected 250 μL (12.7MBq) ⁶⁸ Ga-NOTA-DGL-Ac through the tail vein of the rats. The experimental animals were fixed in the prone position, and static images were collected 120 minutes after the injection of the imaging agent. , data reconstruction is performed after the scan is completed.

1.10 Micro-PET imaging of ⁶⁸ Ga-NOTA-DGL-Ac in mice bearing U87MG tumor

Under 2% isoflurane anesthesia, U87MG tumor-bearing mice were injected with about 3.7 MBq (100 μCi) and 1.11 MBq (30 μCi) of ⁶⁸ Ga-NOTA-DGL-Ac through the tail vein and intratumorally, respectively, and the imaging agent was injected for 15 minutes. , 60min, and 120min later collect static images. On the attenuation-corrected coronal images of the whole body, the regions of interest of the tumor and major organs were delineated, and the radioactive uptake value was measured, expressed as %ID/g. After the PET imaging was completed, the animals were sacrificed by neck dislocation, following the principles of animal welfare.

1.11 Biological distribution of ⁶⁸ Ga-NOTA-DGL-Ac in mice bearing U87MG tumor

Under 2% isoflurane anesthesia, each U87MG tumor-bearing mouse was injected with about 3.7 MBq (100 μCi) of ⁶⁸ Ga-NOTA-DGL-Ac through the tail vein. One hour after the injection of the imaging agent, the U87MG tumor-bearing mice were killed by neck dissection, and the tumor and major organs were dissected and separated, and put into an empty counting tube for weighing (total weight), and then the radioactivity was measured with a gamma counter Counting, radioactive uptake by tumors and normal organs is represented by ID%/g, and the specific experimental steps are as in 1.8.

2. Conclusion

2.1 Characterization of DGL-NOTA-Ac

Take 1 mg of DGL nanocarrier, NOTA-NHS and the reacted DGL-NOTA lyophilized product, respectively, and dissolve them in 2 mL of ultrapure water for ultraviolet absorbance detection. The results show that the nanocarrier DGL has no ultraviolet absorption at 200-500nm wavelength, while NOTA-NHS has an ultraviolet absorption peak at 320nm wavelength, and the synthesized product has an ultraviolet absorption peak at about 320nm at the corresponding position (Figure 2), indicating that DGL- NOTA-Ac was successfully synthesized, and the synthetic product DGL-NOTA-Ac was tested for its particle size in water by a Malvern nanometer particle size potentiometer. The results showed that the particle size of DGL-NOTA-Ac was (35.02±1.53) nm( image 3).

2.2 Labeling and quality control of ⁶⁸ Ga-NOTA-DGL-Ac

As shown in Figure 4, the radiochemical yield of ⁶⁸ Ga-NOTA-DGL-Ac can reach 96%, the radiochemical purity after separation and purification by PD10 purification column is greater than 98%, and the pH value is between 4.0-4.2 and it is colorless , Transparent, clear solution, no other heavy metal pollution. 250 μL of ⁶⁸ Ga-NOTA-DGL-Ac probe was injected into normal KM mice (n=3) through the tail vein, and observed for 7 days, no KM mice died, indicating that the nanoprobe has no obvious toxicity .

2.3 Determination of fat-water partition coefficient

The lipid-water partition coefficient experiment is to measure the degree of lipophilicity, and the LogP=Log[(lipid phase γ count-background average γ count)/(water phase γ count-background average γ count) of ⁶⁸ Ga-NOTA-DGL-Ac is measured. )]=-1.62, indicating that the nanomolecular probe is hydrophilic.

2.4 Radio-TLC analysis and in vitro stability test of ⁶⁸ Ga-NOTA-DGL-Ac

Radio-TLC analysis results showed that the R _f value of GaCl ₃ was 0.505, and the R _f value of ⁶⁸ Ga-NOTA-DGL-Ac was 0.19. The results of the in vitro stability study are shown in Figure 5. After standing in 0.01mol/L PBS solution with a pH value of 7.4 and calf serum for 2 hours, the radiochemical purity was >95%. The above experiments show that ⁶⁸ Ga-NOTA-DGL-Ac has good in vitro stability, and the specific activity of the labeled compound is 30 GBq/μmol.

2.5 Cell uptake and elution experiments

In order to determine the cell binding and cell retention properties of ⁶⁸ Ga-NOTA-DGL-Ac, A549 and U87MG were used for cell uptake and elution experiments, respectively. The results show that A549 and U87MG cells can quickly and efficiently bind ⁶⁸ Ga-NOTA-DGL-Ac, as shown in Figure 6, and as the incubation time prolongs, the binding force of the imaging agent to the two cells is further enhanced. reach the peak. In the cell elution experiment, ⁶⁸ Ga-NOTA-DGL-Ac showed a slow decrease with the extension of time in both types of cells, indicating that ⁶⁸ Ga-NOTA-DGL-Ac was excreted slowly in the cells, and remained at the end of 2 hours. There is developer retention.

2.6 ⁶⁸ Biological distribution of Ga-NOTA-DGL-Ac in normal mice

The biodistribution results of ⁶⁸ Ga-NOTA-DGL-Ac in normal Kunming mice are shown in Figure 7. The results showed that the radioactivity in the blood was significantly lower than 5 minutes after the imaging agent was injected for 30 minutes, each being (3.43±1.93) ID%/g and (8.73±1.21) ID%/g indicated that ⁶⁸ Ga-NOTA-DGL-Ac cleared faster in blood. After injection of imaging agent for 5min, 30min, 60min and 120min, the radioactive uptake mainly accumulated in the liver and spleen, and the radioactive uptake in the liver increased with time, while that in the spleen decreased with time. The radioactive uptake values of both kidneys were lower at each time point, while the radioactive uptake values of the liver were higher at each time point, indicating that ⁶⁸ Ga-NOTA-DGL-Ac was metabolized by the liver rather than excreted by the kidneys.

2.7 Micro-PET imaging of ⁶⁸ Ga-NOTA-DGL-Ac in normal mice

The Micro-PET imaging results of ⁶⁸ Ga-NOTA-DGL-Ac in normal KM mice after 120 min of tail vein injection (Figure 8) showed that the probe ⁶⁸ Ga-NOTA-DGL-Ac was mainly distributed in the liver, followed by the spleen , a small amount of uptake in the bladder, no significant uptake in the kidneys and other organs.

2.8 Biological distribution of ⁶⁸ Ga-NOTA-DGL-Ac in U87MG tumor-bearing mice

Figure 9 shows the degree of radioactive uptake of the nanomolecular probe ⁶⁸ Ga-NOTA-DGL-Ac in U87MG tumor mice via tail vein injection for 1 hour in tumor tissues and major organs. The results showed that: 1 hour after the injection of the imaging agent, the uptake value of U87MG tumor tissue was (0.19±0.02) ID%/g, which was lower than that of other major organs. The radioactive uptake of the imaging agent was higher in the liver and spleen, which were (65.75±0.10) ID%/g and (9.79±0.58) ID%/g, respectively.

2.9 Micro-PET imaging of ⁶⁸ Ga-NOTA-DGL-Ac in U87MG tumor-bearing mice

The in vivo pharmacokinetic properties of ⁶⁸ Ga-NOTA-DGL-Ac in U87MG tumor-bearing mice can be observed by Micro PET/CT imaging. It can be seen from Figure 10 that after injection of ⁶⁸ Ga-NOTA-DGL-Ac , the imaging agent was mainly distributed in the liver, followed by the heart, and no obvious uptake was seen in the tumor nodules. The uptake values of tumor tissue were (6.18±1.44), (7.58±1.88) and (5.93±0.48) after injection of imaging agent for 15min, 60min and 120min, respectively. The results of intratumoral injection showed that the imaging agent ⁶⁸ Ga-NOTA-DGL-Ac was mainly distributed in the tumor nodules, and there was no significant uptake in other tissues and organs throughout the body. After intratumoral injection of imaging agent for 15 minutes, 60 minutes and 120 minutes, the uptake values of tumor tissues were (29.82±1.88), (27.68±3.78) and (27.28±2.65), respectively.

3. Conclusion Analysis

The present invention synthesizes the dendrimer polylysine derivative DGL-NOTA-Ac, and successfully labels it with the positron nuclide ⁶⁸ Ga. This method explores a simple, fast, and high radiochemical yield positron Electronically labeled nanomolecular probe pathways. The in vivo biological distribution of normal mice and the Micro-PET imaging of normal mice showed that ⁶⁸ Ga-NOTA-DGL-Ac nano-molecular probes were mainly distributed in the liver and spleen in normal mice, and other organs were not. See overt metabolism. In vivo imaging and in vivo biological distribution of U87MG tumor-bearing mice also showed that the nanoprobes were mainly concentrated in the liver and spleen, and there was no obvious uptake in the tumor. The main reasons may be: 1. ⁶⁸ Ga-NOTA-DGL-Ac is used as a nanoprobe, because the nanometer particle size detected by hydrodynamics is (35.02 ± 1.53) nm, so the probe is easily swallowed by the reticuloendothelial system, resulting in High intake in the liver. 2. ⁶⁸ Ga-NOTA-DGL-Ac nanoprobe has passive tumor targeting, resulting in unsatisfactory tumor uptake and imaging effects.

We will make improvements in the following two aspects in the later research: 1. Select nano-sized molecules with smaller nanometer size as carriers, such as DGL-G2, etc., so that the modified nano-sized molecules are suitable for accumulation in tumor sites, and the maximum possible reduction in liver, spleen and other network uptake by the endothelial system. 2. To increase the active tumor targeting of nanoprobes, RGD and other targeting peptides targeting glioma can be modified on the nanometer surface to increase its tumor targeting.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention can be modified or equivalently replaced without departing from the essence of the technical solution of the present invention.

Claims (10)

1. a kind of compound⁶⁸Ga-NOTA-DGL-Ac。

2. a kind of preparation method of compound as claimed in claim 1, it is characterised in that use⁶⁸Ga is to precursor DGL-NOTA-Ac Radioactive label is carried out, compound is produced⁶⁸Ga-NOTA-DGL-Ac。

3. the preparation method of compound as claimed in claim 2, it is characterised in that the compound⁶⁸Ga-NOTA-DGL-Ac's Preparation method comprises the following steps：(1) take appropriate watery hydrochloric acid to elute germanium-gallium generator, collect eluent, choose activity Maximum eluent；(2) sodium acetate solution is added into the maximum eluent of the activity obtained by step (1), adjusts pH, Ran Houjia Enter into DGL-NOTA-Ac sodium-acetate buffers；(3) mixed solution obtained by step (2) is subjected to lucifuge reaction, reaction end is ⁶⁸Ga-NOTA-DGL-Ac。

4. the preparation method of compound as claimed in claim 3, it is characterised in that the concentration of watery hydrochloric acid is in the step (1) 0.05mol/L, the elution flow rate 1ml/min eluted to germanium-gallium generator.

5. the preparation method of compound as claimed in claim 3, it is characterised in that sodium acetate solution is dense in the step (2) Spend for 1.0mol/L.

6. the preparation method of compound as claimed in claim 3, it is characterised in that adjustment pH to 4.0- in the step (2) 4.2。

7. the preparation method of compound as claimed in claim 3, it is characterised in that the condition that lucifuge is reacted in the step (3) For the lucifuge reaction 10min at 70 DEG C.

8. the preparation method of compound as claimed in claim 2, it is characterised in that the preparation side of the precursor DGL-NOTA-Ac Method comprises the following steps：(1) DGL G3 are dissolved in DMSO, stirred and evenly mixed to being completely dissolved；(2) NOTA-NHS is dissolved in DMSO In, stir and evenly mix to being completely dissolved；(3) by the DGL G3 dissolved in step (1) and the middle NOTA-NHS dissolved of step (2) Mixed, lucifuge is reacted at room temperature；(4) excessive triethylamine and then into mixed solution obtained by step (3) is added, at room temperature Lucifuge is stirred, and then adds excessive acetic anhydride, continues to react under the same reaction conditions, and reaction end produces precursor DGL- NOTA-Ac。

9. the preparation method of compound as claimed in claim 8, it is characterised in that the preparation side of the precursor DGL-NOTA-Ac Method also includes dialysing obtained by step (4) in 0.5mol/L, pH=4.0 sodium-acetate buffer after step (5) reaction terminates Precursor, you can obtain purer precursor DGL-NOTA-Ac.

10. compound as claimed in claim 1 as positive electron marking nano probe gene therapy, medicine pass release and it is biological into Application as in.