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Objective:To develop a tetramer probe targeting fibroblast activation protein (FAP), named 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-4P(FAP inhibitor (FAPI)) 4, evaluate its biodistribution and PET image in FAP-positive-tumor bearing nude mice, and explore its feasibility as a novel radio-regent for treatment of FAP-positive tumor. Methods:FAP tetramer probe was constructed on the FAPI-46 motif with four mini-polyethylene glycol (PEG)(PEG 3) spacers between the four FAPI motifs, denoted as 4P(FAPI) 4. DOTA was used as the chelator for radiolabeling with 68Ga and 177Lu. The FAP binding characteristics were test by in vitro cell competitive binding experiment. Small-animal PET, in vivo biodistribution, and radionuclide targeting therapy were performed in HT-1080-FAP tumor bearing nude mice ( n=39). Independent-sample t test was performed to analyze tumor uptake data, and two-factor repeated measures analysis of variance was utilized to compare tumor volume data in radioactive isotope therapy. Results:Cell experiment showed that FAPI-tetramer and FAPI-monomer had similar half maximal inhibitory concentration values (3.29 and 2.15 nmol/L). 68Ga/ 177Lu radiolabeled FAPI-tetramer had better tumor uptake and retention than FAPI-monomer in small-animal PET and in vivo biodistribution experiment, with the tumor uptake for 177Lu-DOTA-4P(FAPI) 4 and 177Lu-FAPI-46 at 48 h of (18.72±1.32) vs (2.72±1.20) percentage activity of injection dose per gram of tissue (%ID/g) ( t=15.55, P<0.001). 177Lu-DOTA-4P(FAPI) 4 group showed best anti-tumor efficacy compared with 177Lu-FAPI-46 and control group in radionuclide targeting therapy. On the 2nd day after the start of treatment, the tumor volume in the tetramer treatment group was significantly smaller than that in the control group (mean difference 67.19 mm 3, P=0.049); on the 14th day after the start of treatment, the tumor volume in the tetramer treatment group was significantly smaller than that in the monomer treatment group (mean difference 414.33 mm 3, P=0.005). Conclusion:FAPI-tetramer can improve tumor uptake and retention ability compared with FAPI-46, and 177Lu-DOTA-4P(FAPI) 4 can be a promising radio-agent for FAP-positive tumor therapy.
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Objective:To explore the application potential of 18F-Asp-Glu-val-Asp (DEVD)-Cys(StBu)-PPG(CBT)-AmBF 3 ( 18F-1; PPG: propargyl-glycine; CBT: 2-cyanobenzothiazole; AmBF 3: ammoniomethyl-trifluoroborate) PET imaging in early monitoring of triple-negative breast cancer (TNBC) radiotherapy response. Methods:Ten MDA-MB-231 tumor bearing nude mice models were constructed and divided into radiotherapy group ( n=5) and non-radiotherapy group ( n=5) by random sampling method. The radiotherapy group was treated with single irradiation at a dose of 8 Gy. 18F-1 microPET imaging was performed in the radiotherapy and non-radiotherapy groups, and the tumor uptake and muscle uptake in 2 groups at different time points (2.5, 7.5, 12.5, 17.5, 22.5, 27.5, 32.5, 37.5, 42.5, 47.5, 52.5, 57.5 min after injection) were analyzed. The specific uptake of the probe in apoptotic cells was verified by radioautography, HE staining and immunofluorescent staining. Repeated measures analysis of variance and one-way analysis of variance were used to analyze data. Results:18F-1 microPET imaging showed that there was significant difference between tumor uptake and muscle uptake in radiotherapy group ( F=20.27, P=0.011). The uptake of radiotherapy group was the highest at 7.5 min after injection ((4.64±0.35) percentage activity of injection dose per gram of tissue(%ID/g)). There was no significant difference between tumor uptake and muscle uptake in the non-radiotherapy group ( F=1.81, P=0.215). The tumor/muscle (T/M) ratio of radiotherapy group was higher than that of non-radiotherapy group ( F=31.95, P=0.005), with the highest at 47.5 min after injection (2.49±0.46). Radioautography showed that the tumor radioactivity in radiotherapy group was higher than that of muscle in radiotherapy group, and was also higher than tumor and muscle radioactivies in non-radiotherapy group ( F=116.79, P<0.001). HE staining and immunofluorescent staining verified that 18F-1 could specifically detect the activity of caspase-3 activated in tumor cells after radiotherapy. Conclusion:18F-1 can specifically recognize the activated caspase-3 after TNBC radiotherapy, and monitor radiotherapy response at the molecular level by apoptosis PET imaging.
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Objective:To observe the inhibitory effects of Huangqi Jiedu Decoction on lung metastasis of breast cancer in nude mice; To explore the mechanism of intervening epithelial mesenchymal transformation (EMT) induced by Wnt/β-catenin signaling pathway.Methods:Totally 30 nude mice were divided into model group, adriamycin group and Huangqi Jiedu Decoction low-, medium-, and high-dosage groups according to random number table method. Each group was injected subcutaneously with mouse breast cancer 4T1 cells to construct tumor - bearing nude mice model. Huangqi Jiedu Decoction low-, medium- and high-dosage groups were intragastrically administrated with Huangqi Jiedu Decoction 17.82, 35.64 and 71.28 g/kg; adriamycin group was injected intraperitoneally adriamycin 0.05 g/kg; model group was intragastrically administrated with normal saline of the same volume for 21 d. Tumor volume was measured at 9, 15, and 21 days after modeling. After the end of administration, the tumor tissue was separated, the tumor weight was measured, and the tumor inhibition rate was calculated. The lung tissue was Isolated,, the number of lung metastatic nodules and the inhibition rate of lung metastasis was counted. HE staining was used to observe the tissue morphology and evaluate the effectiveness of the model. The protein expressions of β-catenin, E-Cadherin and Vimentin in lung tissue were detected by Western Blot. The mRNA levels of β-catenin, E-Cadherin and Vimentin in lung tissue were detected by real-time fluorescent quantitative PCR.Results:Compared with the model group, the tumor volume and mass of Huangqi Jiedu Decoction low-, medium- and high-dosage groups decreased ( P<0.01); the number of pulmonary metastasis nodules in Huangqi Jiedu Decoction high-dosage group significantly decreased ( P<0.01); the mRNA and protein expressions of β-catenin and Vimentinm decreased in the Huangqi Jiedu Decoction low-, medium- and high-dosage groups ( P<0.01), and the protein and mRNA expressions of E-Cadherin increased in the Huangqi Jiedu Decoction high-dosage group ( P<0.01). Conclusion:Huangqi Jiedu Decoction can effectively inhibit the growth and lung metastasis of breast cancer transplanted tumor, and the mechanism may be to down-regulate the expression of key molecules in the Wnt/β-catanin signaling pathway, thereby inhibiting the EMT process, so as to inhibit the lung metastasis of breast cancer.
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Objective:Enriching and isolating breast cancer stem cells from breast cancer transplantation tumors in nude mice.Methods:Human breast cancer MDA-MB-231 cells were injected into the right axilla subcutaneous of 20 nude mice, and the tumor growth was observed .After 30 days, tumors were isolated and stained with hematoxylin and eosin, and then tumor cells from tissues were isolated. DMEM medium containing serum was used to cultivate isolated transplantation tumor cells, cell morphology and growth were also observed. Flow cytometry was used to detect the proportion of stem cells (CD44 +/CD24 -/low cells) in transplantation tumor cells. Serum-free DMEM medium containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF) and B27 cell supplement were used to cultivate transplantation tumor cells and to obtain cell microspheres. The proportion of stem cells on the 10th day in cell microspheres was detected by using flow cell sorter and stem cells were isolated according to the markers of cell surface. Results:After subcutaneously injecting MDA-MB-231 cells into 20 nude mice for 9 days, 17 nude mice had subcutaneous tumors with more parenchymal cells, little interstitial cells, arranged cords tumor cells, large volume of the cell and abundant cytoplasm, the nuclei in different sizes and hyperchromatic state, mitotic more common, the nucleoli clear and obvious pleomorphy. After cultivating transplantation tumor cells with DMEM medium containing serum, the cells began to grow adherent after 24 h, and the adherent proportion rose to 60% after 3 days; after 7 days, the cell proliferation was accelerated; and the cell morphology was more consistent, most of which were spindle shaped and were not significantly different from MDA-MB-231 cells; the proportion of stem cells in transplantation tumor cells was (0.10±0.02)%. After cultivating transplantation tumor cells with serum-free DMEM medium containing cell cultured supplement, the cells grow in spherical patterns, the proportion of stem cells in cell microspheres got up to (70.47±2.03)% on the 10th day.Conclusions:Subcutaneously injecting MDA-MB-231 cells in nude mice can build breast cancer nude mice ectopic transplantation tumor model. Breast cancer stem cells in the transplantation tumors can be enriched from isolated transplantation tumor cells through serum-free medium, and more stem cells can be isolated to provide the research basis for the biological characteristics of breast cancer stem cells.
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Objective:To evaluate the effects of adipose-derived stem cells (ADSCs) and ADM microparticle on diabetic wound healing.Methods:ADSCs was co-cultured with ADM microparticle in vitro. The models of diabetic nude mice were established by intraperitoneal injection of STZ and the full-thickness skin defects were designed on the back. All 24 diabetic mice were randomly divided into 4 group: experimental groups were transplanted with ADSCs and ADM microparticle and the other groups were transplanted with ADSCs, ADM microparticle and blank control group was set up. On the 7th and 14 th days, the wound healing rate of 3 mice randomly selected from each group was calculated, and the thickness between dermis and epidermis was measured by hematoxylin and eosin staining. The density of neovascularization was measured by immunohistochemical staining. The differences were compared between the groups.Results:Compared to the ADSCs groups, the mice of the experimental groups showed higher cell survival rate. The wound healing rate in the experimental groups was (86.0±2.7)% (7 days) and (98.5±1.1)% (14 days), thicker dermis-epidermis distance was (99.1±1.8) μm (7 days) and (124.3±4.3) μm (14 days) ( P<0.05), and higher density of neovascularization was noted. Conclusions:The transplantation with active ADM microparticle can significantly promote neovascularization and wound healing of diabetic wound.
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Objective:To investigate the value of 18F-FDG total-body PET/CT dynamic imaging in evaluating the efficacy of early radiotherapy for MDA-MB-231 breast cancer bearing nude mice. Methods:MDA-MB-231 breast cancer bearing nude mice were established and divided into control group and radiotherapy group based on the random number table method ( n=10 for each group). 18F-FDG total-body PET/CT dynamic imaging was performed before and after the radiotherapy. The SUV max and the maximum tracer uptake net influx constant ( Kimax) of tumors, and the target-to-background ratio (TBR) were calculated. The change of tumor volume was recorded. The value of 18F-FDG total-body PET/CT dynamic imaging in evaluating the efficacy of radiotherapy was accessed using pathological findings as the reference. Paired t test, independent-sample t test and Pearson correlation analysis were used for data analysis. Results:After radiotherapy, SUV max and Kimax(4.66±0.46 and 0.14±0.03) were reduced in the radiotherapy group compared with those before radiotherapy (5.30±0.52 and 0.19±0.03; t values: 4.61, 8.31, P values: 0.001, <0.001), while the SUV max (5.94±0.74 vs 5.24±0.50) and Kimax (0.23±0.03 vs 0.19±0.02) were increased compared with baseline in the control group ( t values: 4.77, 6.87, P values: 0.001, <0.001). TBR Ki was significantly higher than TBR suv based on all images of the 2 groups (14.11±5.58 vs 5.91±1.60; t=8.92, P<0.001). The tumor volume in the radiotherapy group decreased compared with that before radiotherapy, but the difference was not statistically significant ((0.74±0.12) vs (0.81±0.08) cm 3; t=2.24, P=0.052). The results of immunohistochemistry showed that glucose transport protein (Glut)1 was highly expressed in tumors, and the Glut1 positive cell percentage of the radiotherapy group was significantly lower than that of the control group ((38.30±6.18)% vs (69.78±5.37)%; t=12.17, P<0.001). The expression of Glut1 was significantly positively correlated with SUV max and Kimax(the control group: rsuv=0.75, P=0.012; rKi=0.77, P=0.010; the radiotherapy group: rsuv=0.67, P=0.035; rKi=0.77, P=0.010). The apoptosis index (AI) of tumor cells in the radiotherapy group was higher than that in the control group ((24.15±4.00)% vs (10.15±3.05)%; t=8.85, P<0.001). Conclusion:18F-FDG total-body PET/CT dynamic imaging can sensitively monitor the effect of early radiotherapy in MDA-MB-231 breast cancer bearing nude mice.
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Objective:Apt-A10-3.2 (aptamer of prostate specific membrane antigen (PSMA)) can be used as a specific ligand for early diagnosis and targeted treatment of prostate cancer. Mouse double minute 2 homolog (MDM2) is closely related to the malignancy of prostate cancer, and MDM2 small interfering RNA (siRNA) can silence MDM2 gene through RNA interference. To design a novel chimera of PSMA Apt-MDM2 siRNA and combine it with docetaxel (DTX) to explore a new diagnosis and treatment model combining targeted therapy of PSMA-positive prostate cancer with 99Tc m-chimera imaging monitoring. Methods:Apt-siRNA were obtained by covalent connection of PSMA Apt-A10-3.2 and MDM2 siRNA, which was combined with DTX to treat PSMA-positive prostate cancer cell lines (22RV1 and LNCaP). Cell lines were treated with Apt-siRNA alone or in combination with DTX. The levels of MDM2 and apoptosis-related proteins (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), poly ADP-ribose polymerase (PARP), caspase-3) were detected by Western blot, which were used to evaluate the therapeutic effect. Fifteen BALB/c mice bearing 22RV1 xenografts were treated with PBS, DTX+ Apt-siRNA (200 pmol) and DTX+ Apt-siRNA (400 pmol), respectively. Tumor volume and MDM2 level were observed, and 99Tc m-Apt-siRNA SPECT imaging was performed to obtain the tumor/muscle (T/M) ratio. One-way analysis of variance, Tukey′s test and linear regression analysis were used for data analysis. Results:The levels of MDM2 protein were significantly decreased by Apt-siRNA (0.25±0.02, F=183.40, P<0.001; 0.56±0.03, F=37.15, P<0.001) in 22RV1 and LNCaP cells. After the treatment of Apt-siRNA+ DTX, the levels of Bcl-2 were significantly decreased, and the levels of Bax, PARP and caspase-3 were significantly increased. MDM2 protein level (400 pmol: 0.59±0.12; F=49.99, P=0.023) and tumor volume (400 pmol: (0.22±0.07) cm 3;F=71.30, P=0.039) were significantly inhibited by Apt-siRNA+ DTX in mice bearing 22RV1 xenografts. As for 99Tc m-Apt-siRNA SPECT imaging in vivo, T/M ratio of treatment group was significantly decreased (400 pmol: 2.07±0.22; F=34.99, P=0.022), and there was a linear regression relationship between T/M ratio and the expression level of MDM2 ( R2=0.875, P<0.001). Conclusion:Apt-siRNA combined with DTX can effectively inhibit the progression of prostate cancer, and realize visual targeted diagnosis and treatment of PSMA-positive prostate cancer by coupling radionuclide technetium.
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Objective:To exploring the uptake of fibroblast activation protein (FAP) inhibitor (FAPI) in pancreatic cancer through 68Ga-FAPI-04 PET/CT imaging, and provide a basis for the FAP-targeted imaging of pancreatic cancer. Methods:Pancreatic cancer-patient-derived tumor xenograft (PDX) mouse models ( n=8) were developed, then 68Ga-FAPI-04 and 18F-FDG microPET/CT imaging were performed (4 in each group). The differences of percentage activity of injection dose per gram of tissue (%ID/g) of 68Ga-FAPI-04 and 18F-FDG were analyzed by independent-sample t test. 68Ga-FAPI-04 and 18F-FDG PET/CT imaging were performed in 5 patients (4 males, 1 female, age: 46-74 (63.0±11.9) years) with pancreatic cancer, and the maximum standardized uptake value (SUV max) of 68Ga-FAPI-04 and 18F-FDG in primary pancreatic cancer and the SUV max ratio of liver metastases to liver tissue were compared by paired t test. Results:MicroPET/CT imaging showed that 68Ga-FAPI-04 was obviously uptaken at all time points in the tumor of PDX mice. The uptake of 68Ga-FAPI-04 in PDX mice 60 min after injection was significantly higher than that of 18F-FDG ((6.58±0.44) and (4.29±0.13) %ID/g; t=4.152, P=0.008 9). PET/CT showed that the SUV max of 68Ga-FAPI-04 in pancreatic cancer was significantly higher than that of 18F-FDG (16.82±3.08 and 5.14±2.20; t=6.893, P=0.000 1) and the SUV max ratio of liver metastases to liver tissue of 68Ga-FAPI-04 was also significantly higher than that of 18F-FDG (4.57±1.47 and 1.30±0.16; t=3.803, P=0.019 1). Conclusion:68Ga-FAPI-04 can be highly uptaken in pancreatic cancer, suggesting that FAP can be a potential target for PET/CT imaging of pancreatic cancer.
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Objective:To prepare 68Ga-2-(4, 7-bis(carboxymethyl)-1, 4, 7-triazonan-1-yl)pentanedioic acid (NODAGA)-YHWYGYTPQNVI (GE11) and evaluate its feasibility of PET imaging for pancreatic cancer. Methods:GE11 peptide was conjugated with NODAGA and then labeled with 68Ga. The labeling yield, radiochemical purity, hydrophilicity, stability and specificity in vitro were determined. Human pancreatic cancer BxPC3 nude mice models ( n=9) were established. MicroPET imaging was then obtained after 30 and 90 min, and mice were sacrificed at 90 min to acquire the radioactivity distribution of main organs and tumors. Pair t test was used to analyze the data. Results:The labeling yield was (73.5±5.4)% and radiochemical purity was more than 98%. After incubation 120 min in mouse serum at 37 ℃, radiochemical purity was more than 92%. The uptake was specific in BxPC3 cell lines. MicroPET images showed that 68Ga-NODAGA-GE11 could accumulate quickly in tumor. Value of tumor uptake was significantly higher than that of normal pancreas at 90 min ((1.38±0.25) vs (0.49±0.07) %ID/g; t=12.67, P<0.05), and the radio-uptake of blood, muscle and bone was lower than that of tumor. Conclusions:68Ga-NODAGA-GE11 is easy to be prepared with high radiochemical purity and good stability, and can specifically target BxPC3 xenograft tumor. However, due to the high uptake in the kidneys and liver, the value of 68Ga-NODAGA-GE11 in PET imaging for pancreatic tumor needs further study.
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Objective: To observe the effect of 125I on T24 transitional cell carcinoma of nude mouse. Methods: Totally 40 T24 transplanted tumor nude mice were divided into high, medium, low activity and control groups (each n=10), and 125I seeds with activity of 0.9 mCi (33. 3 MBq), 0.6 mCi (22. 2 MBq), 0.3 mCi (11. 1 MBq) and 0 mCi (nuclide free) were implanted in the tumor center, respectively. The 90% target absorbed dose (D90), tumor inhibition rate (IR), radiation reaction grade (RRG) of HE staining, apoptosis index and B-cell lymphoma-2 (Bcl-2) protein expression were analyzed and compared among groups 10 days and 20 days after implantation. Results: D90 and IR of nude mice with high, medium and low activity groups decreased gradually 10 and 20 days after 125I seed implantation (all P<0.05). The necrosis was obvious within 5 mm around the tumor, and the higher the seed activity, the longer the time, the wider the ranges of necrosis. RRG of high activity group 10 and 20 days after 125I seed implantation were higher than that in low activity group and control group (all P<0.05). Meanwhile, the apoptotic index of high, medium and low activity groups gradually decreased, the expression of Bcl-2 protein gradually increased (all P<0.05). Conclusion: 125I seeds can significantly inhibit the growth of T24 metastatic cell carcinoma in nude mouse. Promoting the apoptosis of tumor cells may be one of the mechanisms.
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Objective@#To prepare manganese-doped carbon quantum dots (Mn-CDs) dual-modal nanoprobe for fluorescent-magnetic imaging, and evaluate its characteristics and potential on fluorescence imaging and MRI.@*Methods@#Mn-CDs were synthesized at 150 ℃. The form, diameter, component, fluorescent capability, T1 relaxation rate, stability and cytotoxicity of Mn-CDs in vivo were verified. The fluorescence imaging of HO-8910 tumor-bearing mice was performed on small animal imager, and the whole-body enhanced imaging was performed on 3.0 T MRI scanner. One-way analysis of variance was used to analyze the data.@*Results@#The Mn-CDs with the diameter of (4.64±0.85) nm showed a well-defined spherical morphology. The fluorescent spectra of Mn-CDs exhibited that the excitation maximum was at 360 nm and the emission maximum was at 440 nm. The T1 relaxation rate was (3.26±0.04) mmol·L-1·s-1. The Mn-CDs had good stability of fluorescent and magnetic imaging capability at 0, 0.25, 0.5, 0.75, 1.0 and 2 months at room temperature with no significant differences of fluorescent and magnetic signals (F=1.566 and 0.987, both P>0.05). After injection of 200 μl Mn-CDs (15 g/L), mice were all alive and had no viscera damage. The tumor could be observed obviously on fluorescence imaging at 5 min. Enhanced MRI showed that the tumor was unevenly enhanced and Mn-CDs were mainly cleared away through urinary system.@*Conclusion@#Mn-CDs are stable and have good potential on fluorescence imaging and MRI, which provides a promising multimodal imaging method for tumor detection and monitoring.
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Objective To develop the automated preparation of 18F-Alfatide II using newly-designed 18F-minireactor and perform 18F-Alfatide D microPET/CT imaging in tumor.Methods The automated preparation of 18F-Alfatide H was developed by using 18F-microreactor and water phase Al18F-chelating method,and the radiochemical yield and quality analysis were measured.The nude mice bearing breast tumor ZR-75-1 and nasopharyngeal tumor CNE1 were established(n = 3 respectively).MicroPET/CT imaging was performed at 0.5,1.0 and 2.0 h after the injection of 18F-Alfatide II.The region of interest(ROI)was depicted and the tumor/muscle(T/M)ratio was calculated.Results 18F-Alfatide II was automatically prepared with the total synthesis time of 40 min,the radiochemical yield of(28±6)%(no decay corrected,n=11),and the radiochemical purity >97%.All quality analysis indexes accorded with the radiopharmaceutical requirements.18F-Alfatide II microPET/CT images of ZR-75-1 and CNE1 tumors were clear due to the high radioactivity uptake of tumor lesions(T/M ratio was greater than 4.0 at 1.0 h after injection).Conclusion Based on the 18F-minireactor,the,8F-Alfatide II can be prepared successfully with short synthesis time and high radiochemical yield,which can help the application studies in 18F-Alfatide II microPET/CT imaging.
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Objective@#To construct 131I-the fifth generation polyamidoamine (PAMAM(G5.0)) with targeting peptide Ser-Arg-Glu-Ser-Pro-His-Pro (SRESPHP; SR) or Gly-Pro-Leu-Pro-Leu-Arg (GPLPLR; GP) and double targeting peptide SR/GP, and evaluate the targeting ability in medullary thyroid carcinoma (MTC) model.@*Methods@#PAMAM(G5.0), PAMAM(G5.0)-SR, PAMAM(G5.0)-GP and PAMAM(G5.0)-SR/GP were radiolabeled with 131I by chloramine T method. The radiolabeled yield and radiochemical purity were determined by thin layer chromatography. MTC xenografts were developed and the percentage radio-activity of injection dose per gram of tissue (%ID/g) in tumor and organs was measured at 24 h post-injection. Region of interest (ROI) was drawn and the tumor/non-tumor (T/NT) ratios at 4, 8 and 24 h post-injection were calculated and compared among different groups. One-way analysis of variance, repetitive measurement analysis of variance and Dunnett-t test were used to compare the data of different groups. The relationship between %ID/g and T/NT was analyzed with Pearson correlation.@*Results@#The radiolabeled yield was more than 75% and radiochemistry purity was more than 90%. The difference of %ID/g at 24 h post-injection was significant (F=14.400, P<0.001) in tumors of all groups. The radioactive uptake in tumor of 131I-PAMAM(G5.0)-SR group was the highest at 24 h post-injection((1.80±0.18) %ID/g). There were significant differences of T/NT ratios among different groups(F=4.776, P<0.05)and between different time points(F=8.630, P<0.05). Compared with negative control group (Na131I), the T/NT ratios significantly increased in 131I-PAMAM(G5.0)-SR group at 4, 8 and 24 h post-injection (t=4.169, 7.123 and 4.032, all P<0.05) and in 131I-PAMAM(G5.0)-GP group at 4 h post-injection (t=5.893, P<0.05). The T/NT ratio in 131I-PAMAM(G5.0)-SR group was higher than that in 131I-PAMAM(G5.0)-GP group at 24 h post-injection (t=2.871, P<0.05).@*Conclusions@#PAMAM(G5.0)-SR, PAMAM(G5.0)-GP and PAMAM(G5.0)-SR/GP can target the MTC models. 131I-PAMAM(G5.0)-SR has the best biological properties and may provide a new precision method for MTC diagnosis, treatment and prognosis evaluation.
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Objective@#To synthesis 177Lu-prostate specific membrane antigen (PSMA)-I&T with automated module, evaluate the biodistribution and pharmacokinetics in mice and study the targeting property in human prostate cancer cell line LNCaP Clone FGC.@*Methods@#The iQS-TS automated module was applied in labeling 177Lu-PSMA-I&T. Radiochemical purity and stability were determined with high performance liquid chromatography (HPLC). The biodistribution was observed in normal ICR mice and U-SPECT/CT imaging was performed in LNCaP Clone FGC tumor-bearing mice. Independent-sample t test was used to analyze the data.@*Results@#177Lu-PSMA-I&T was stable in vitro and in vivo, with the radiolabeled yield of (91.5±4.9)% and radiochemical purity >99%. The half maximal inhibitory concentration (IC50) of 177Lu-PSMA-I&T binding to LNCaP Clone FGC cells was (26.74±3.53) nmol/L. The uptake of 177Lu-PSMA-I&T by LNCaP Clone FGC cells increased with time and significantly decreased after the inhibitor addition (t values: 4.301-27.483, all P<0.05). 177Lu-PSMA-I&T was cleared from blood rapidly and predominantly excreted by kidneys. Significant radioactive uptake was observed in tumors with a long retention time.@*Conclusion@#177Lu-PSMA-I&T can be produced in a convenient and efficient procedure using iQS-TS automated module, with good biological properties and excellent affinity and targeting property towards prostate cancer cells, which making it a potential radiopharmaceutical for prostate cancer therapy.
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Objective To prepare manganese-doped carbon quantum dots ( Mn-CDs) dual-modal nanoprobe for fluorescent-magnetic imaging, and evaluate its characteristics and potential on fluorescence imaging and MRI. Methods Mn-CDs were synthesized at 150 ℃. The form, diameter, component, fluo-rescent capability, T1 relaxation rate, stability and cytotoxicity of Mn-CDs in vivo were verified. The fluores-cence imaging of HO-8910 tumor-bearing mice was performed on small animal imager, and the whole-body enhanced imaging was performed on 3.0 T MRI scanner. One-way analysis of variance was used to analyze the data. Results The Mn-CDs with the diameter of (4.64±0.85) nm showed a well-defined spherical morpholo-gy. The fluorescent spectra of Mn-CDs exhibited that the excitation maximum was at 360 nm and the emission maximum was at 440 nm. The T1 relaxation rate was (3.26±0.04) mmol·L-1·s-1. The Mn-CDs had good stability of fluorescent and magnetic imaging capability at 0, 0.25, 0.5, 0.75, 1.0 and 2 months at room tem-perature with no significant differences of fluorescent and magnetic signals ( F=1. 566 and 0. 987, both P>0. 05) . After injection of 200 μl Mn-CDs ( 15 g/L) , mice were all alive and had no viscera damage. The tumor could be observed obviously on fluorescence imaging at 5 min. Enhanced MRI showed that the tumor was unevenly enhanced and Mn-CDs were mainly cleared away through urinary system. Conclusion Mn-CDs are stable and have good potential on fluorescence imaging and MRI, which provides a promising multimodal im-aging method for tumor detection and monitoring.
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Objective To construct 131 I-the fifth generation polyamidoamine (PAMAM(G5.0)) with targeting peptide Ser-Arg-Glu-Ser-Pro-His-Pro (SRESPHP;SR) or Gly-Pro-Leu-Pro-Leu-Arg (GPLPLR;GP) and double targeting peptide SR/GP,and evaluate the targeting ability in medullary thyroid carcinoma (MTC) model.Methods PAMAM(GS.0),PAMAM(GS.0)-SR,PAMAM(GS.0)-GP and PAMAM(GS.0)-SR/GP were radiolabeled with 131I by chloramine T method.The radiolabeled yield and radiochemical purity were determined by thin layer chromatography.MTC xenografts were developed and the percentage radio-activity of injection dose per gram of tissue (％ID/g) in tumor and organs was measured at 24 h post-injection.Region of interest (ROI) was drawn and the tumor/non-tumor (T/NT) ratios at 4,8 and 24 h post-injection were calculated and compared among different groups.One-way analysis of variance,repetitive measurement analysis of variance and Dunnett-t test were used to compare the data of different groups.The relationship between ％ID/g and T/NT was analyzed with Pearson correlation.Results The radiolabeled yield was more than 75％ and radiochemistry purity was more than 90％.The difference of ％lD/g at 24 h post-injection was significant (F=14.400,P＜0.001) in tumors of all groups.The radioactive uptake in tumor of 131I-PAMAM (G5.0)-SR group was the highest at 24 h post-injection ((1.80± 0.18) ％ID/g).There were significant differences of T/NT ratios among different groups (F =4.776,P＜ 0.05)and between different time points (F =8.630,P＜0.05).Compared with negative control group (Na131 I),the T/NT ratios significantly increased in 131I-PAMAM(G5.0)-SR group at 4,8 and 24 h post-injection (t=4.169,7.123 and 4.032,all P＜0.05) and in 131I-PAMAM(G5.0)-GP group at 4 h post-injection (t =5.893,P＜0.05).The T/NT ratio in 131I-PAMAM (G5.0)-SR group was higher than that in 131 I-PAMAM (G5.0)-GP group at 24 h post-injection (t=2.871,P＜0.05).Conclusions PAMAM(G5.0)-SR,PAMAM(G5.0)-GP and PAMAM(G5.0)-SR/GP can target the MTC models.131I-PAMAM(G5.0)-SR has the best biological properties and may provide a new precision method for MTC diagnosis,treatment and prognosis evaluation.
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Objective To study the reliability of 99Tcm-(hydrazinonicotinamide (HYNIC)-BMS-200261) (tricine) (trisodium triphenylphosphine-3,3',3"-trisulfonate (TPPTS)) as a radiotracer for protease activated receptor-1 (PAR-1) expression in breast cancer.Methods Fifteen nude mice bearing MDA-MB-435,MDA-MB-231 and MCF-7 human breast cancer xenografts (5 mice for each cell line) with different PAR-1 expression were used for 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) γ imaging,and tumor/non-tumor (T/NT) ratios were obtained with region of interest (ROI) technique.Afterwards,the biodistribution of 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) was analyzed in tumor-bearing nude mice,and the radioactivity in tumor (percentage activity of injection dose per gram of tissue,％ID/g) was calculated.The immunostaining was performed to examine PAR-1 expression in tumor tissue and semi-quantitative analysis was used.One-way analysis of variance and Pearson correlation analysis were used to analyze data.Results At 2 h postinjection,the T/NT ratios were 3.03±0.32,2.27±0.25 and 1.51±0.13 respectively in nude mice bearing MDA-MB-435,MDA-MB-231 and MCF-7 xenografts;the tumor uptakes of 99Tcm-(HYNIC-BMS-200261)(tricine)(TPPTS) were (1.03±0.15),(0.56±0.14) and (0.30±0.06) ％ID/g;PAR-1 expression levels were (17.22±2.71) ％,(10.78± 1.95) ％ and (2.80± 1.18) ％,respectively (F values:47.66,46.36,62.35,all P＜0.05).The T/NT ratios and tumor uptake of 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) at 2 h post-injection were correlated with PAR-1 expression (r values:0.934 and 0.929,both P＜0.05).Conclusions 99Tcm-(HYNIC-BMS-200261) (tricine) (TPPTS) imaging could be a noninvasive and effective method for monitoring PAR-1 expression in human breast cancer.
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Objective To synthesize 18F-AlF-1,4,7-triazacyclononane-l,4,7-triacetic acid (NOTA)-c (CGRRAGGSC),which could specifically bind to the α chain of interleukin (IL)-11 receptor (IL-11 R),and evaluate its targeting potential to IL-11 R-positive tumors.Methods Polypeptide c (CGRRAGGSC) was first coupled with NOTA and then labeled with 18F by AlF labeling method.The radiochemical purity and radiochemical yield of 18F-AlF-NOTA-c(CGRRAGGSC) were analyzed by high performance liquid chromatography,and the stability in vitro was evaluated.The tracer biodistribution in tumor-bearing mice (cell line SKOV3) was evaluated by the dynamic imaging with microPET 30 min,1 h,2 h after injection of 18F-AlF-NOTA-c (CGRRAGGSC).The tracer kinetics was performed in normal mice.Pharmacokinetics parameters were calculated using DAS2.0 software.Results The radiochemical purity of 18F-AlF-NOTA-c(CGRRAGGSC) was higher than 95％ and the radiochemical yield was (30.0±7.4)％.It could be stably maintained in phosphatebuffered solution and plasma for at least 2 h.MicroPET imaging showed that 18F-AlF-NOTA-c(CGRRAGGSC)had a good affinity to SKOV3 tumor.The tumor/muscle ratios at 30 min,1 h,2 h after the injection of 18F-AlF-NOTA-c(CGRRAGGSC) were 6.26±2.98,7.19±3.63 and 9.05±4.30,respectively.The tracer was cleared rapidly in blood and mainly excreted by the liver and kidneys.The T1/2α and T1/2β were (0.38±0.14) h and (2.64±0.28) h,respectively.Conclusions 18F-AlF-NOTA-c(CGRRAGGSC) is easy to be synthesized and has a good affinity to IL-11R-positive tumors.It will be a potential IL-11R-targeting imaging agent.
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Objective To prepare 99Tcm-succinimidyl-6-hydrazinonicotinate hydrochloride (SHNH)-AC133 and evaluate its targeting ability on CD133 positive colon cancer by Gamma imaging,and to explore its feasibility as a molecular probe for cancer stem cells (CSCs).Methods CD133 expression was detected by immunofluorescence assay and flow cytometry on Lovo cell lines and tumor xenografts.CD133 specific monoclonal antibody (AC133) was conjugated with SHNH,and then labeled with 99Tcm to prepare 99Tcm-SHNH-AC133.The radiolabeled yield and radiochemical purity were investigated.Colon cancer xenografts were developed and Gamma imaging were performed.Region of interest (ROI) was drawn and the tumor/non-tumor (T/NT) ratio was calculated.For the blocking experiment,animals were pre-injected with excess unlabeled AC133.Two-sample t test was used to analyze the data.Results CD133 was expressed on the surface of Lovo cells.And the percentage of CD133 positive cells in Lovo tumor tissues was (29.5±3.4)％.The radiolabeled yield of 99Tcm-SHNH-AC133 was more than 85％ and radiochemistry purity was (97.7±2.4)％.Gamma imaging demonstrated that 99Tcm-SHNH-AC133 could specifically target to Lovo tumors which could be gradually visible after 12 h.The tumor uptake was obvious at 24 h and T/NT ratio was 8.16±0.45.In blocking study,the tumor uptake was significantly reduced by pre-injection of excess unlabeled AC133 (3.52±0.13;t=19.8,P＜0.05).Conclusions 99Tcm-SHNH-AC133 has high labeling yield and radiochemistry purity.The excellent targeting properties of 99Tcm-SHNH-AC133 on CD133 positive colon cancer demonstrate that it is a promising imaging agent for CSCs tracking in vivo.
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Objective To prepare 131I-anti-neuropilin-2-monoclonal antibody (131I-anti-NRP-2-mAb),and investigate its biodistribution and imaging in nude mice bearing xenografted lung adenocarcinoma,in order to evaluate its feasibility as an imaging agent targeting to NRP-2 positive tumors.Methods (1)131I-anti-NRP-2-mAb was prepared by Chloramine-T method under the optimum labeling conditions,then the labeling efficiency,radiochemical purity and stability were determined in vitro.(2) The binding fraction and receptor binding affinity of 131I-anti-NRP-2-mAb were measured in A549 human lung cancer cells by cell uptaking and binding experiments.(3) The A549 tumor-bearing mice were randomly divided into 4 groups with direct sampling method and were sacrificed at 6,24,48,and 72 h,respectively,after tail intravenous injection of 0.37 MBq 131I-anti-NRP-2-mAb.The distribution was measured,and the ratios of tumor/muscle (T/M) and tumor/blood (T/B) were calculated.(4) Gamma imaging was performed in 6 mice,including 3 in the competitive inhibition control group (injected with 3.7 MBq 131I-anti-NRP-2-mAb and 100 μg atniNRP-2-mAb),at 6,24,48,and 72 h post-injection to observe the radioactivity in tumor.Two-sample t test was used for data analysis.Results (1) The labeling yield and radiochemical purity of 131I-anti-NRP-2-mAb were (94.69 ± 3.63) ％ and (98.56± 0.48) ％,respectively.The radiochemical purity was more than 85％ after incubating in phosphate-buffered solution at room temperature for 72 h.(2) At 60,120,180 and 240 min post-injection,the binding ratios of 131I-anti-NRP-2-mAb in A549 cells were (3.95±0.18)％,(5.19±0.65) ％,(6.60± 0.36) ％ and (5.58± 0.63) ％,respectively.When excessive anti-NRP-2-mAb were added,the binding ratios were reduced to (0.94±0.31)％,(1.12±0.17)％,(1.24±0.25)％ and (1.04±0.18) ％,respectively,which were significantly lower than those of non-inhibited group (t values:9.89-19.66,all P＜0.05).131I-anti-NRP-2-mAb bound to NRP-2 with high affinity half maximal inhibitory concentration (IC50 =(410.8±1.2) nmol/L).(3) Biodistribution study demonstrated that the T/M and T/B ratios increased with the time extension and were 3.83±0.18 and 1.10±0.20,respectively,at 72 h post-injection.(4) Gamma imaging studies revealed that 131I-anti-NRP-2-mAb could clearly identify A549 tumors 6 h post-injection,especially at 48 h post-injection.Tumors were not observed clearly in competitive inhibition control group.Conclusion 131I-anti-NRP-2-mAb has been successfully prepared,and it could target to NRP-2 specifically.