Exploitation of the Coil−Globule Plasmid DNA Transition Induced by Small Changes in Temperature, pH Salt, and Poly(ethylene glycol) Compositions for Directed Partitioning in Aqueous Two-Phase Systems

Abstract

In this study, the interplay of two linked equilibria is examined, one concerning an aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and salt employed to partition plasmid DNA (pDNA), and the other a potential structural transition of pDNA depending on PEG and salt concentration and other system parameters. The boundary conditions for pDNA partitioning are set by PEG and salt concentrations, PEG molecular weight, pH, and temperature. While investigating these parameters, it was found that a small increase/decrease of the respective values led to a drastic and significant change in pDNA behavior. This behavior could be attributed to a coil-globule transition of the pDNA triggered by the respective phase conditions. The combination of this structural change, aggregation effects linked to the transition process, and the electrostatic potential difference found in PEG-salt systems thus offers a sensitive way to separate nucleic acid forms on the basis of their unique property to undergo coil-globule transitions under distinct system properties.

Promoting DNA loading on magnetic nanoparticles using a DNA condensation strategy

“…We ascribe the observed enhancement of DNA loading capacity on ASMNPs to the DNA condensation phenomenon provoked by PEG/NaCl through an excluded volume mechanism [16,18]. To confirm this, a standard sedimentation study was conducted [43,44], where without using MNPs, DNA was mixed with PEG 8000 (0-30%)/NaCl (1 M) at room temperature for 10 min prior to sample centrifugation for 20 min at 15,000 × g to separate the precipitated DNA. Finally, the DNA concentration in the supernatant of each sample was analysed and the percentage of DNA in the precipitate was calculated.…”

Advancing Nonviral Gene Delivery: Lipid- and Surfactant-Based Nanoparticle Design Strategies

“…into globular structures at high lipid concentrations (positively charged particles); in this case, multivalent cationic lipids produced smaller-sized globules than did monovalent lipids [99,196,197]. For systems with charge ratios close to one (i.e., near stochiometry), aggregation and precipitation are common and large heterogeneously shaped structures are usually formed.…”

Block copolymer as a novel functional phase in an aqueous biphasic system for species selective iodine extraction

“…1,2 As both phases in an ABS are strictly made up of water, it is regarded as environmentally benign alternative for conventional liquid/liquid (l/l) extractions. 1,2 As both phases in an ABS are strictly made up of water, it is regarded as environmentally benign alternative for conventional liquid/liquid (l/l) extractions.…”