Release of DNA from surfactant complexes induced by 2-hydroxypropyl-beta-cyclodextrin

Area of Science:

• Biophysical Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• DNA-chitosan complexes are self-assembled structures with potential applications.
• Cyclodextrins (CDs) are known to interact with and modify DNA structures.
• Understanding DNA decompaction mechanisms is crucial for gene delivery and materials science.

Purpose of the Study:

• To investigate the decompaction of DNA-chitosan complexes using 2-hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD) with varying substitution degrees.
• To compare the efficacy of 2-HP-beta-CD with unsubstituted beta-cyclodextrin in DNA release.
• To explore the nature of the DNA decompaction process and phase transitions.

Main Methods:

• Fluorescence microscopy and steady-state fluorescence spectroscopy.
• Density and sound velocity measurements.
• Thermal melting (DNA denaturation) and circular dichroism (DNA conformation).

Main Results:

• 2-HP-beta-CD successfully decompacted DNA-chitosan complexes across all tested substitution degrees.
• Fluorescence spectroscopy indicated that 2-HP-beta-CD is more efficient than alpha- and beta-CD in releasing DNA.
• Dissociation of phase-separated DNA-chitosan complexes was observed with 2-HP-beta-CD, suggesting a non-equilibrium system.
• The globule-to-coil transition in DNA decompaction did not exhibit a coexistence region.

Conclusions:

• 2-HP-beta-CD is a highly effective agent for DNA-chitosan complex decompaction.
• The study provides evidence for the non-equilibrium nature of DNA decompaction processes mediated by cyclodextrins.
• The absence of a coexistence region in the globule-to-coil transition appears to be a general characteristic of CD-mediated DNA decompaction.