Adsorption behavior of DNA onto a cationic surfactant monolayer at the air–water interface

Adsorption characteristics of Cytochrome c/DNA complex Langmuir molecular assemblies at the air–water interface: a surface area-normalized isotherm study

“…Langmuir-Blodgett (LB) method has long been acknowledged as an excellent approach to study the surface activity of protein and nucleic acids 21,22 at air-water interface and to prepare their stable ultrathin lms onto solid substrates. It is well known that protein molecules have high tendency to accumulate at their phase boundary at the surfaces.…”

“…The highly hydrophilic DNA molecule has been adsorbed onto oppositely charged surfactant monolayer at air-water interface and the resultant complex assemblies is easily immobilized onto solid substrate via LB method. 22,24 In a recent work it is observed that only DNA can also form a well-ordered molecular network at air-water interface by means of LB technique. 25 However, the reason for this unusual phase behaviour of DNA molecules at air-water interface is not yet clearly explored.…”

Adsorption of a water soluble cationic dye into a cationic Langmuir monolayer

“…DNA-surfactant complexation is a non-viral method of gene delivery into the cell. In a recent work the adsorption of DNA into the preformed Langmuir monolayer of cationic surfactant ODA at the air-water interface has been studied [3]. The incorporation of water soluble anionic surface active enzyme Pepsin (PEP) within an insoluble cationic ODA Langmuir monolayer was investigated by changing various parameters [9].…”

Changes in Interfacial Tension of a Lipid Membrane Formed at the Water/Chloroform Interface upon DNA Complex Formation

“…7 In recent years, many reports have featured a method that measures the free energy change that occurs upon the adsorption of DNA to a lipid membrane, which results in changes in membrane tension. [9][10][11] It is technically difficult to measure tension changes in a micro region at the cellular level; thus, as a model system, a Langmuir-Blodgett (LB) membrane formed at an air/water interface is often used. Many of these studies base their discussions on changes in the surface pressure-area (π-A) isotherms in the presence/absence of DNA, and examples that have measured changes in tension over time are limited.…”

“…Hansda et al added DNA solution to the subphase of an octadecylamine LB membrane formed at the air/water interface, and studied the interaction of the lipid and DNA via the temporal changes in the surface pressure and Brewster angle microscopy (BAM) images. 9 Cárdenas et al observed the changes in BAM images accompanying surface pressure responses when DNA was added to a cationic lipid (dioctadecyldimethylammonium bromide) membrane formed at the air/water interface, as well as changes in the domains of a complex at the air/water interface. 10 The time scale of these studies investigating the tension changes associated with complex formation was on the order of minutes.…”