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Liposomes are vesicles composed of phospholipids forming a spherical bilayer in an aqueous environment. Liposome membranes are flexible, which makes them a great platform to mimic the physiological plasma membranes of immune cells. While there are many alternative methods to synthesize liposomes, the recent progress in using microfluidics for the synthesis of liposomes enabled better control over the parameters that affect the resulting liposome properties, such as size and polydispersity (PDI). Here we investigated how the two main parameters, the total flow rate (TFR) and the flow rate ratio (FRR), affect the formation of liposomes in two different microfluidic chip designs. Results demonstrated that at a low FRR range (below 15), FRR had an inverse relationship with Z-average. However, as the FRR increased over 15, the Z-average also increased. We also observed that there is a threshold in FRR above which the hydrodynamic focusing is no longer stable, causing uneven mixing of the lipid components and PBS. The PDI increased as FRR increased, regardless of the two tested flow rates or chip designs. These results suggest that maintaining a lower FRR would be most beneficial to synthesize liposomes with uniform sizes below 200 nm in Z-average, which would work best as a model platform to present antigens to immune cells in cell culture.
Chemical and Materials Engineering
College of Engineering
liposomes, microfluidics, hydrodynamic focusing, Z-average, polydispersity, lipids, flow rate
Bell, Anna, "Microfluidic Synthesis of Liposomes for Antigen Presentation in Cell Culture" (2023). Summer Community of Scholars Posters (RCEU and HCR Combined Programs). 444.