ABSTRACT
Objective To develop a polydimethylsiloxane (PDMS) microfluidic chip-based 18F microreactor for the preparation of 18F-labeled probes.Methods The 18F microreactor was composed of PDMS microfluidic chip and customized glass microvessel integrating with stainless capillary tube (D 0.6 mm) as heater/cooler.PDMS chips were fabricated by silk-screen printing technology,a traditional and easily accessible process.18F-FDG and 18F-fluoroacetate(FAC) were synthesized using the 18F microreactor.TLC was applied to measure the 18F-labeling yield and the radiochemical purity of 18F-FDG and 18F-FAC.Results The size of PDMS chip was 40.0 mm (l)×30.0 mm (w)×6.0 mm(h) and the liquid/gas inside channel was 0.3 mm (w)×50.0 μm (h).The customized glass microvessel was about 4.0 mm (D) ×30.0 mm (h) with 200 μl of reaction volume.The capillary tube which wrapped around the microvessel functioned as a heater when electric current was provided,while as a cooler when compressed air went through.The integrated 18F microreactor with a total size of 40.0 mm (l) ×30.0 mm (w) ×15.0 mm (h) was successfully used to prepare 18F-FDG and 18F-FAC,whose radiochemical purity were both higher than 96％ and 18F-labeling yield was 92.5％ and 90.0％ respectively in the first fluorination step.Conclusions A PDMS microfluidic chip-based 18F microreactor is developed and successfully applied to prepare 18F-FDG and 18F-FAC.It has the dual advantages of both microfluidc chip and traditional synthesis module and features of high integration,small total size and low consumption of labeling precursor.