Characterization of Cationic Vector-Based Gene Delivery Vehicles Using Isothermal Titration and Differential Scanning Calorimetry

Abstract

Within the past 10 years, major advances in the design and development of differential scanning calorimeters (DSC) (1) and isothermal titration calorimeters (ITC) (2) have resulted in an unparalleled level of sensitivity, stability, and reproducibility in calorimetric measurements of large molecules. These improvements have allowed the thermal stability and ligand binding processes of biological macromolecules to be thermodynamically characterized with speed, accuracy, and convenience. With their increasing commercial availability, experiments that were previously limited to specialist calorimetry laboratories can now be routinely performed by most investigators.

Infrared Spectroscopic Characterization of the Interaction of Cationic Lipids with Plasmid DNA

“…Thus, our findings are consistent with a direct interaction of the lipid headgroup with the phosphate and the concomitant displacement of hydrogen-bonded water. This observation is also consistent with previous studies suggesting that the release of bound water and counterions is the driving force for complex formation (37,38). Additionally, the release of bound water from the lipid interface upon complexation of DNA with cationic lipids has been reported using both fluorescence techniques and differential scanning calorimetry (12).…”

The Potential Role of Proteoglycans in Cationic Lipid-mediated Gene Delivery

“…4A). This favorable entropic signature is consistent with an electrostatic character to the interaction (31,32). Additional entropic contributions from apolar interactions (e.g.…”

Differential scanning calorimetric studies of the thermal stability of plasmid DNA complexed with cationic lipids and polymers

“…8,9 A thermodynamic analysis of the thermal disruption of SC DNA employing DSC is limited because the supercoiled component and native base pairing cannot be restored upon cooling. 10 This irreversibility prevents a quantitative thermodynamic analysis of the heat capacity function that renders the enthalpic and entropic contributions to the transition unavailable. The application of DSC to synthetic gene delivery vectors, however, can provide general empirical insight into the effects of formulation variables on the thermal stability of such complexes.…”