Abstract
The mass transport characteristics of cationic, nonviral liposome-DNA plasmid complexes (lipoplexes) were evaluated over a range of fluid shear stresses. The typical case of stagnant flow transfection was expanded to include controlled fluid convection provided by constant flow through a parallel plate flow chamber. Equations describing the transport of lipoplex by sedimentation and convection were derived from theory and solved numerically. Instantaneous lipoplex delivery rate and total lipoplex surface delivery during a 72-h transfection were estimated for two shear stress levels and for static conditions. Theory predicted that lipoplex is delivered to the cell surface more than 12- to 19-fold faster through the addition of convection, at least for physiologic shear stresses of 2.3-9.7 dyn/cm2, respectively. These calculations were tested experimentally using a cell line (ECV-304) transfected with fluorescently labeled plasmid DNA formulated into a lipoplex. Transfections were conducted during cellular exposure to the same known, uniform levels of fluid shear stress presumed in theoretical calculations. Lipoplex delivery was increased by more than nine-fold at 2.3 dyn/cm2 compared to the static case as assessed by flow cytometric measurement. Lipoplex delivery was modestly reduced at the highest fluid shear stress, to six-fold of the static case, consistent with the disruption of lipoplex-cell binding mediated by hydrodynamic forces. The complicated relationship between fluid convection and lipoplex delivery has important implications for nonviral gene therapy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.