Salt Responsive Morphologies of ssDNA‐Based Triblock Polyelectrolytes in Semi‐Dilute Regime: Effect of Volume Fractions and Polyelectrolyte Length

Abstract

A comprehensive study is reported on the effect of salt concentration, polyelectrolyte block length, and polymer concentration on the morphology and structural properties of nanoaggregates self-assembled from BAB single-strand DNA (ssDNA) triblock polynucleotides in which A represents polyelectrolyte blocks and B represents hydrophobic neutral blocks. A morphological phase diagram above the gelation point is developed as a function of solvent ionic strength and polyelectrolyte block length utilizing an implicit solvent ionic strength method for dissipative particle dynamics simulations. As the solvent ionic strength increases, the self-assembled DNA network structures shrinks considerably, leading to a morphological transition from a micellar network to worm-like or hamburger-shape aggregates. This study provides insight into the network morphology and its changes by calculating the aggregation number, number of hydrophobic cores, and percentage of bridge chains in the network. The simulation results are corroborated through cryogenic transmission electron microscopy on the example of the self-assembly of ssDNA triblocks.

Controlled Organization of Inorganic Materials Using Biological Molecules for Activating Therapeutic Functionalities

“…Computational modeling provides fundamental understanding of how experimental and environmental variables control the self-assembly process, resulting in changes in the organization of the QDs. Here, we use the mesoscale modeling technique dissipative particle dynamics (DPD) to understand these materials on the size and time scales relevant to the experiment. , The technique has been successful in predicting and explaining the self-assembly of polymer-based materials, including block copolymers, polyelectrolytes, and DNA. − Computational modeling of QD and DNA assemblies as a function of DNA length and salt concentration was performed using our implicit solvent ionic strength method (ISIS-DPD) model and provides key insights into the driving forces of the resulting morphologies. The initial system (Figure A) consists of 24 QDs decorated with 12 ssDNAs each based on the experimentally determined number of binding sites per QD …”

Biomaterials for vaccine-based cancer immunotherapy

“…As such, plasmid DNA can be designed to act as both antigen and adjuvant[56]. However, due to its low molecular weight and negatively charged backbone, naked DNA typically yields low cellular uptake, off-target effects, and systemic dissemination[57–60]. Therefore, various efforts have focused on developing methods of effectively introducing plasmid DNA into antigen presenting cells (APCs).…”

Self-assembly of amphiphilic polyelectrolytes in trivalent salt solution

“…In addition to the significance of an external electric field, varying the salt concentration is also a powerful mechanism to tune the assembled structures of PEs. 16–18 The assembled structures of PEs in monovalent salt solutions were extensively investigated. For the quenched PE chains, an increase in the salt concentration led to an increase in the aggregation number in micelles and a weak decrease of the radius of micellar coronas, which were attributed to the enhanced electrostatic screening reducing electrostatic repulsion between PE chains.…”

“…For the quenched PE chains, an increase in the salt concentration led to an increase in the aggregation number in micelles and a weak decrease of the radius of micellar coronas, which were attributed to the enhanced electrostatic screening reducing electrostatic repulsion between PE chains. 16,17 Morphological changes of copolymer micelles were observed by varying the ionic strength and PE block length. After increasing the solvent ionic strength, a morphological transition from a micellar network to worm-like hamburger-shape aggregates was found for the triblock system, 16 and a spherical to cylindrical to lamellar aggregation was observed for the diblock system.…”

“…16,17 Morphological changes of copolymer micelles were observed by varying the ionic strength and PE block length. After increasing the solvent ionic strength, a morphological transition from a micellar network to worm-like hamburger-shape aggregates was found for the triblock system, 16 and a spherical to cylindrical to lamellar aggregation was observed for the diblock system. 18…”