Microfluidic complexation between plasmid DNA and cationic liposomes for gene delivery

T.A. Balbino, A.R. Azzoni, L.G. de La Torre
University of Campinas, UNICAMP, BR

Keywords: microfluidics, cationic liposomes, DNA, micromixer, gene delivery

Summary:

To evaluate the process parameters for the production of plasmid DNA/cationic liposome (pDNA/CL) complexes in microfluidic systems, we studied two microfluidic devices: one with simple straight hydrodynamic flow focusing (SMD) and a second one with barriers in the mixing microchannel (patterned walls, PMD). The results showed that the incorporation of the pDNA into the CL was different for both microfluidic devices; the temperature influenced the average size of complexes produced by SMD, while it did not influence in PMD. The differences were also observed in pDNA probe accessibility into the complexes. SMD yielded similar quantity of non-electrostatic bound pDNA to that of the bulk mixing method. Interestingly, the complexes produced by PMD presented pDNA probe accessibility decreased in 40% and achieved lower in vitro transfection levels in HeLa cells than the conventional bulk mixing and SMD methods. These differences are most likely consequence on different association between pDNA and CL controlled by the microfluidic devices. This study contributes to the development of rational strategies in controlling the formation of pDNA/CL complexes for further applications in gene and vaccine therapy.