High-Throughput Synthesis of Liposome Using an Injection-Molded Plastic Micro-Fluidic Device

• Main Authors: Sang-Won Woo, Yun Kyong Jo, Yeong-Eun Yoo, Sun Kyoung Kim
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Micromachines
• Subjects: liposome; micro-nozzle array; micro-channel; injection molding; plastic
• Online Access: https://www.mdpi.com/2072-666X/12/2/170

For mass production of liposomes, we designed a plastic micro-channel device on the basis of 5 μm of micro-nozzle array forming T-junction with 100 μm depth of micro-channel. A micro-channel unit for synthesizing liposomes consisted of two micro-nozzle arrays for mixing two solutions as well as delivery and recovery channels for supplying solutions and collecting liposome suspension. The number of micro-nozzles was approximately 2400 for a micro-channel unit, and seven units were applied independently on a micro-channel plate. The plastic micro-channel plate was injection-molded for mass production using a micro-channel stamper previously fabricated by UV lithography and nickel electroforming process. A plastic cover plate with seven pairs of inlet and outlet ports was machined by mechanical milling and drilling and was assembled with a micro-channel plate using a holder to form a liposome synthesizing device. Flow and mixing of solutions in the micro-channels were tested using colored water to check the micro-fluidic characteristics of the device. Finally, a L-α-phosphatidylcholine (SOY PC) liposome was synthesized using EtOH solution of SOY PC (95%) and saline (0.85% NaOH solution) to find that the liposomes were around 230 and 260 nm in diameter, depending on the flow rate of the lipid solution.