Formation of a DNA Layer on Langmuir−Blodgett Films and Its Enzymatic Digestion

Abstract

Here, we report a system we have developed where long double-stranded DNAs (dsDNAs) are immobilized on a monolayer of Zn−arachidate. We have applied the Langmuir−Blodgett technique to form the monolayer of Zn−arachidate where Zn(II) is bound to arachidic acid through charge neutralization. Because tetrahedral Zn(II) participates in DNA recognition through coordination, we have been able to layer DNA over the Zn−arachidate monolayer. The DNA layer shows a typical compression and expansion cycle in a concentration-dependent fashion. Interestingly, the DNA monolayer is available for enzymatic degradation by DNaseI. The detection of DNA and its accessibility towards biological reaction is demonstrated by imaging through fluorescence microscopy. The conformation of the DNA, immobilized on the monolayer, was studied with the help of atomic force microscopy (AFM). We observed that the dsDNAs were aligned in a stretched manner on the surface. To investigate further, we also demonstrate here that the small single-stranded DNA (ssDNA) immobilized on the air−water interface can act as a target molecule for the complementary ssDNA present in the subphase. The study of DNA hybridization done with the help of fluorescence spectroscopy clearly supports the AFM characterization.

Supramolecular Langmuir monolayers and multilayered vesicles of self-assembling DNA–lipid surface structures and their further implications in polyelectrolyte-based cell transfections

“…The main objective of these measurements was to study the complexation behavior of DNA with previously organized DPPC monolayers in the presence and in the absence of divalent metal cations for comparison with other reports (Hianik et al 2003;Bhaumik et al 2004;Gromelski and Brezesinski 2006;Erokhina et al 2007;Cristofolini et al 2007;Castano et al 2009;Campen et al 2010). DPPC lipids were used due to their well-known physicochemical properties and due to their wide use in pharmaceutical lipoplex formulations for therapeutic gene delivery trials.…”

Transcription of T7 DNA immobilised on latex beads and Langmuir–Blodgett film

“…Images were captured using same method reported earlier [22]. Acquisition of fluorescent micrograph of beads bound DNA was performed as reported earlier [8].…”

Adsorption of DNA to octadecylamine monolayers at the air–water interface

“…The reason why its interaction with monolayers is becoming of great importance comes from the mimetic structure with cell membranes that aids a deeper knowledge of the interactions in cellular membranes concerning for example DNA delivery in gene therapy [30] in cancer, VIH, Ebola or heart infarction [31][32][33]. Moreover, anchoring of DNA in a Langmuir-Blodgett film has made possible its immobilization [34][35][36] and the construction of DNA chips [37]. Most of these studies were developed at a lipidic interface, while surface behavior of fatty amines [38][39][40][41][42] has received few research efforts compared with other lipidic matrices.…”