The automated synthesis of 18F-FL-10 using a microfluidic chip-based synthesizer

1250 Objectives 18F-ML-10 is a novel molecular imaging probe for in vivo apoptotic detection by PET/CT, which presents great potential of clinic translation due to the encouraging results of clinic trials and convenient radiochemical process. Herein, it was aimed to develop the automated synthesis of 18F-ML-10 using a microfluidic chip-based synthesizer to facilitate its basic and translational studies of cancer apoptosis imaging in this study. Methods The microfluidic chip-based synthesizer developed in our lab and semipreparative HPLC system (SP-HPLC) were used to fulfill the automated synthesis and purification of 18F-ML-10, respectively. First, 18F-fluorination between 18F ion and precursor (TPMM) (1.0 mg, 0.1 mL MeCN) was carried out at 120 oC for 10.0 min within the synthesizer. Then hydrolysis was run with aq. NaOH (1.0 M, 0.L ml) at 110 oC for 8.0 min, and neutralization with aq. HCl (1.0 M, 0.L ml) at room temperature. After dilution with water and injection of the mixture into the sample loop, HPLC separation was run with semipreparative C18 column and EtOH/H2O (25/75) as mobile phase at the flow rate of 3.0 ml/min. The radiochemical purity of 18F-ML-10 was measured by analytic radio-HPLC (30% MeCN/H2O with 0.1% TFA, 1.0 ml/min) and radio-TLC (MeCN/H2O (95/5)). Results The microfluidic chip-based synthesizer was very suitable for the automated synthesis of 18F-probes due to the trace consumption of precursors. The automated synthesis of 18F-ML-10 could be fulfilled using this synthesizer plus SP-HPLC purification. As results, 150~200 mCi of 18F-ML-10 could be obtained, starting from the curie level of 18F ion and 1/10 amount of TPMM used before. The total synthesis time was about 65 min including HPLC purification. The radiochemical yield was about 15-20% without decay correction. The radiochemical purity was as high as >98% determined by Radio-HPLC and Radio-TLC. Conclusions The automated synthesis of 18F-ML-10 was successfully developed using the microfluidic chip-based synthesizer with the advantages of low consumption of precursor and good radiochemical yield. Research Support This study was supported by SRF for ROCS, SEM and partly by National Natural Science Foundation of China (No. 11275050, No. 30700188).