| With the positron emision tomography and computed tomography applicationin the diagnosing and treating of lung cancer, it characterized by noninvasive imaging diagnosis, high sensitivity and distinguishability for detecting tumor. The PET/CT will have better prospects in the clinical applications for early diagnosis, stage, treatment, assessment of efficacy and prognosis of lung cancer.2-18F-fluoro-2-deoxy-D-glucose (18F-FDG) was widespreadly used in clinical diagnosis. However, it is easy to falsepositive that 18F-FDG is not a special tumor angent for tumor which the normal tissues and lesion could uptake 18F-FDG such as nflammation, tuberculosis, inflammatory pseudotumor, radiotherapy, surgery.However, radiolabeledamino acid can make up for the shortcomings of 18F-FDG. In order to solve these problems, the researching project designs the N-(2-18F-fluoropropionyl)-L-arginine acid (18F-FPARG)and evaluates the tracer.The First ChapterMethods:1. This study was based on the previous research that arginine was enriched in lung cancer bearing mice. So, The small molecular imaging probe-18F-FPARG was designed and the synthesisof the standard compound--N-(2-flouroptopionyl)-L-arginine(FPARG) was needed.2. ethyl-2-fluoropropanoate was hydrolyzed by the alkaline conditions and evaporated under vacuum. thesodium 2-fluoropropanoate and Nω-nitro-L-arginine methyl ester hydrochloride(N-NO2-L-ARG-OMe-HCl) formatted to offercrude methyl-2-(2-fluoropropanamido)-5-(3-nitroguanidino)pentanoate by triethylamine (Et3N), 1-hydroxybenzotriazole hydrate (HOBt·H2O) and dicyclohexylcarbodiimide (DCC). After purified by silica gel to get the purification, the methyl-2-(2-fluoropropanamido)-5-(3-nitroguanidino)pentanoate was hydrolyzed by the alkaline conditions. Furthermore, the N2-(2-fluoropropanoyl)-N-nitro-L-arginine was hydrolyzed by the alkaline conditions. The final step was carried out at palladium 5 %on carbon(Pb/C) and acetic acid(ACOH), then freeze-dried by lyophilize to afford FPARG The structure of FPARG was characterized by mass spectrometry and nuclear magnetic resonance spectroscopy.Result:1.We had get the final compoud (FPARG) with 97.8% of purity, which was detected by mass spectrometry(MS) and nuclear magnetic resonance(NMR).The Second ChapterMethods:1.18F-NFP production was first performed in PET-MF-2 V-IT-I module within a lead-shielded hot cell. Anhydrous 18F-NFP was added into the solution of L-arginine ethyl ester dihydrochloride (H-Arg-OEt) in Dimethylsulphoxide (DMSO) and N,N-Diisopropylethylamine (DIPEA). The reaction mixture was heated for 10 min at 50℃. thenthe [18F]FPARG-ethyl ester was was hydrolyzed by the alkaline conditions after it purity it.2. We have detected the radioactive compound by using the radioactive labeled compound and the standard compoundand the build the HPLC method.3.We have detected the by-product radioactive compound(2-18F-fluoropropionic acid,18F-FPA)and the 18F-FPARG by using Rodia-TLC4.Synthesis of 18F-FDG was using the a fully automated synthesis module.Result:1. The uncorrected radiochemical yield of 18F-FPARG was 15±3%(n=10) with more than 98% radiochemical purity.2.18F-FPA and 18F-FPARG can be distinguished by the TLC, because 18F-FPA and 18F-FPARG were not easy to detecte in HPLC.3. The uncorrected radiochemical yield of 18F-FDG was 65± 6%(n= 10) with more than 98%　radiochemical purity.The Third ChapteMethods:1. The mice were anesthetized with 5%　chloral hydrate solution (6 mL/kg) before injection of radiotracer. They were injected with 18F-FPARG in saline through the tail vein. Time points 5,30,60, and 120 min after injection were chosen for determining the distribution of 18F-FPARG in designated organs.2. Three types of mice(SPC-A-ladenocarcinoma cancer, NCI-H1299non small cell lung cancer,NCI-H4601arge cell lung cancer) were imaged by PET/CT scanner after injection with 18F-FPARGvia tail vein at 30,60,90,120 mins.Furthermore, the mice also were imaged with 18F-FDG at 60 min after injection3. HE staining method was used to identify tumor in nude mice bearing tumor.4. The transport assays experiment was detectedamino acids transporter by the six types of inhibitor in the condition that contain sodion or not.Result:1.18F-FPARG distributed rapidly through the whole body after the tail vein injection and uptake occurred primarily in the blood, liver and kidney. The kidney showed high uptake of 18F-FPARG, but it was quickly excreted and eliminated through the urinary bladder. Rapid clearance of the tracer from the blood was observed.The radioactivity of liver and intestinestill have kept hight level after at 120 min post-injection.However, the low uptake in the brain did not show any obvious change over the whole observed time.The heart, lung, pancreas and intestines showed moderate uptake.2. Small-animal PET-CT fused imaging was performed to evaluate the potential of 18F-FPARG as a tumor-imaging agent in mice with lung cancer SPC-A-1.NCI-H1299 and NCI-H460 xenograft cancer.3. The tumors were clearly visible with high contrast to the contralateral background (muscle) for each animal model. However,18F-FPARG had better imaging for the SPC-A-1 than the other NCI-H1299 and NCI-H460 bearing mice.4. In HE staining of tissue sections, a large number of heterogeneous cells appeared in the tumor tissues, which proved that the model was successful.5. The uptake studies in SPC-A-1 cell lines suggested that 18F-FPARG primarily transported through Na+-independent system b0,+ and y+ L, and Na+-dependent system A, ASC.The Fourth ChapterMethods:1. The serum for Kunming mice and the 18F-FPARG was incubated at37℃ for two hours, and the stability of 18F-FPARG was detected by HPLC2.The stability of plasma 18F-FPARG was detected by Radio-TLC, after Kunmingmice injected.3. To determine the extent of protein incorporation of 18F-FPARG, the protein-bound activity was determined at SPC-A-1 cell lineResult:1. Samples, precipitated with trichloroacetic acid after an incubation with 18F-FPARG in SPC-A-1 cells, demonstrated less than 1% of the radioactivity in the acid precipitable fraction. Therefore, no incorporation of 18F-FPARG into protein could be found.2. According to radio-HPLC analysis,18F-FPARG in serum was proven to be stable at two hours.3. According to radio-TLC analysis,60% of 18F-FPARG remained intact in the plasm at 15 min and 30 min... |
PDF Full Text Request