Authors: Y-H Lee and C-A Peng
Affilation: University of Southern California, United States
Pages: 168 - 171
Keywords: gene delivery, resonant acoustic fields
Enhancement of DNA delivery efficiency has been improved by several physical and chemical approaches in the past decade. However, the application of those methods is hampered by large-scaled configurations. To augment gene delivery efficiency with scalable settings, the potential of resonant acoustic fields (RAF) to facilitate DNA delivery was explored. We reasoned that, driven by the primary acoustic radiation force, suspended cells agglomerated on the pressure nodal planes first and formed cell bands. Nanometer-sized DNA vectors, circulated between nodal planes by acoustic microstreaming, then used the pre-formed cell bands as the nucleating sites to attach on. As a result, the encounter opportunity between DNA vectors and target cells was increased and further enhanced the gene delivery efficiency. In this talk, delivery efficacy of DNA ferried by retroviral or nonviral vector was examined applying RAF. For the viral vector part, our results showed that mega-hertz RAF brought K562 erythroleukemia cells (106 cells/mL) and vesicular stomatitis virus G protein (VSV-G) pseudotyped retroviruses (titer of 5x106 CFU/mL) into close contact at the pressure nodal planes, yielding a 4-fold increment of eGFP transgene expression after 5-min RAF exposure in the presence of 8 ìg/mL Polybrene (see Fig.1). Furthermore, with a fixed titer of retrovirus, the transduction rate was augmented with the increase of cell concentration. For the nonviral vector part, to avoid electrostatic repulsion and facilitate binding to cell surface, eGFP-encoding DNA plasmids (2 ìg/mL) were complexed with polycationic polyethylenimine (PEI) prior to mixing with K562 cells (106 cells/mL) in an acoustic chamber. After 5-min of RAF exposure, our results showed that PEI/DNA complexes were brought into close contact with K562 cells at the pressure nodal planes, and yielding a 10-fold increment of eGFP transgene expression (see Fig. 2). Taken all together, we demonstrated that RAF is a potential operating technique to enhance gene delivery efficiency. Moreover, it offers a feasible approach for delivering DNA to cells in large-scale settings.