ABSTRACT
Objective:To produce 68Ga and automatically synthesize 68Ga-labeled drugs based on low-energy medical cyclotron solid target system. Methods:68Zn was electroplated on the surface of the target by electrodeposition. According to the principle of 68Zn(p, n) 68Ga nuclear reaction, 68Zn was irradiated by the 10 MeV medical cyclotron solid target system (30 μA, 30 min) to produce 68Ga, and the activity, nuclear purity, half-life and content of metal impurities of purified product were determined. 68Ga-prostate specific membrane antigen (PSMA)-11 and 68Ga-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid- D-Phe1-Tyr3-Thr8-octreotide (DOTATATE) were synthesized automatically using 68Ga respectively, and the quality control analyses of drug properties, concentration, pH, radiochemical purity, sterility and bacterial endotoxin were carried out. Results:The electroplating mass of 68Zn was (43.71±0.87) mg ( n=35), the yield of 68Ga after irradiation was (10.96±0.67) GBq ( n=35), and the measured half-life was (67.64±0.06) min ( n=7). Only 511 keV energy peak was detected by the gamma spectrometer. After purification, (6.85±0.12) GBq ( n=35) of pure 68Ga was obtained, and the purification efficiency was (62.46±0.96)% (non-attenuated correction, n=35). The metal impurity contents of Zn and Fe were (0.18±0.06) and (1.25±0.43) μg/GBq ( n=5), which met the requirements of European Pharmacopoeia. Three batches of 68Ga-PSMA-11 and 68Ga-DOTATATE were automatically synthesized, with the yield, concentration and radiochemical purity of (3.54±0.14) and (2.74±0.20) GBq, (294.97±11.58) and (228.17±16.32) GBq/L, (99.73±0.11)% and (99.45±0.25)%, respectively. Both sterility and bacterial endotoxin were qualified. Conclusion:High-yield and qualified nuclide 68Ga and 68Ga-labeled drugs are successfully prepared through the low-energy medical cyclotron solid target system and the automated purification and synthesis module, which provide a strong guarantee for clinical practice.
ABSTRACT
Objective:To prepare 89Zr labeled Daratumumab and evaluate its feasibility in the imaging diagnosis of multiple myeloma (MM). Methods:According to the principle of 89Y (p, n) 89Zr nuclear reaction, 89Zr was produced by cyclotron solid target system (30 μA, 1.5 h) and automatic purification module. The radionuclide purity, half-life and impurity metal ion concentration were detected. Desferrioxamine (DFO) was coupled with Daratumumab and then chelated with 89Zr to prepare 89Zr-DFO-Daratumumab. The quality control analyses of three consecutive batches were carried out. Pharmacokinetic evaluation and 89Zr-DFO-Daratumumab microPET/CT imaging were performed in normal rabbits and orthotopic myeloma mouse models, respectively. The SUV in situ myeloma and that in normal bone were compared by independent-sample t test. Results:About 560 MBq of 89Zr was obtained, and there were only two characteristic energy peaks of 89Zr (909 keV and 511 keV) by γ spectrometer. The half-life of 89Zr was 78.2 h, and the content of metal impurities was small. 89Zr-DFO-Daratumumab was prepared with pH of 7.2, radiochemical purity of more than 99%, good stability in vitro, and sterility and endotoxin tests were passed. Pharmacokinetic studies in rabbits showed that 89Zr-DFO-Daratumumab was gradually distributed from blood to liver, spleen, kidney and bone joints over time and metabolism. The results of microPET/CT imaging in orthotopic myeloma mouse models showed that the SUVs of 89Zr-DFO-daratumumab in situ myeloma were significantly higher than those in normal bone (2 h: 0.22±0.02 vs 0.06±0.00; 1 d: 0.38±0.01 vs 0.08±0.00; t values: 8.89, 21.90, both P=0.001). Conclusion:89Zr and 89Zr-DFO-daratumumab are successfully prepared, and relevant quality control and biological evaluation in vivo and in vitro are completed, which verify the feasibility of 89Zr-DFO-Daratumumab in the imaging diagnosis of MM, thus laying a foundation for clinical transformation.
ABSTRACT
CeO2-Co3 O4 composite nanofibers were prepared by the double jets electrospinning method. The nanofibers were then deposited onto the surface of a ω-type heating coil as cataluminescence material to prepare a new cataluminescence ( CTL ) type formaldehyde gas sensor. The crystalline phase and microstructure of CeO2-Co3 O4 composite nanofibers were characterized by X-ray diffraction ( XRD) and scanning electron microscope (SEM), and the cataluminescence mechanism and electrochemical characteristic of formaldehyde on the surface of CeO2-Co3 O4 nanofibers were analyzed by H2 temperature programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). Under the optimal conditions (500 nm of wavelength, 0. 2 L/ min of flow rate and 550℃), there was a good relationship between the CTL intensity of this formaldehyde gas sensor (Ce30) and formaldehyde concentration in the range of 1. 2 -50 μg / m3 , the sensitivity was 40. 04 a. u. / (μg / m3 ), the detection limit was 1. 2 μg / m3 , the dynamic response time and recover time of formaldehyde gas were 2. 4 s and 3. 5 s, respectively. The formaldehyde sensor was successfully applied to the determination of formaldehyde in the automotive exhaust, with relative errors of 0. 39% -1. 07% and relative standard deviations of less than 3% .
