Partitioning-dependent conversion of polyelectrolyte assemblies in an aqueous two-phase system

Abstract

Partitioning refers to the distribution of solute molecules in the two immiscible phases of a mixture of two solutions, such as an aqueous two-phase system (ATPS). The partitioning of RNA and peptide has been adjusted in situ to facilitate their assembly into intracellular membraneless organelles. Despite the immense potential of this approach in artificial systems, a partitioning-dependent assembly of macromolecules has been limited, due to the sophisticated processing associated with their in situ modification. Here we demonstrate an approach to direct the assembly of polyelectrolytes in an ATPS through varying their partitioning via pH changes. Microcapsules can be converted to microgel particles as the polyelectrolytes selectively partition to different emulsion phases when changing pH. Such partitioning-dependence can also be equally applied for complexing hydrophilic nanoparticles with polyelectrolytes in an ATPS. By enabling access of hydrophilic materials across the aqueous interface freely, the ATPS allows modification of their intrinsic properties in situ; this advantage will inspire more versatile control over the partitioning of hydrophilic materials and will create new multi-functional biomaterials.

Cell‐Inspired All‐Aqueous Microfluidics: From Intracellular Liquid–Liquid Phase Separation toward Advanced Biomaterials

“…This microfluidic method afford a precise control over the complexation of the PEs, and the resultant PE microcapsules show sustained release of encapsulated biomolecules. The concept of using w/w/w emulsion as templates is not restricted to the formation of PE capsules, but also applicable to a broad range of engineered polymers with predesigned surface charges and functionalities …”

All‐Aqueous Freeform Fabrication of Perfusable Self‐Standing Soft Compartments

“…In fact, the assembly of PEs in an ATPS depends not only on the electrostatic interaction between the PE's charged groups, but it is also critically influenced by the affinity and partitioning‐induced distribution of the PEs in the distinct polymer phases. [ 38 ] Based on the theory purposed by Ma et al which states that an increase in pH may enhance hydrogen bonds between polyelectrolytes and the hydroxyl groups of DEX, [ 38 ] we hypothesize that higher pH values in our solutions could have increased the affinity of ALG toward the dissolving phase. Consequently, its availability at the interface would be decreased, culminating in the reduced stability of the produced fibers.…”

Controlled Formation of All-Aqueous Janus Droplets by Liquid–Liquid Phase Separation of an Aqueous Three-Phase System

“…The shape control of the Janus templates offers a versatile platform to study the movements as a function of their morphologies after solidification, extending their applications, such as targeted drug delivery. To facilitate these potential applications, the Janus droplets may be solidified through the following strategies: (1) photo-cross-linking of the Janus The Journal of Physical Chemistry B droplets by converting the DEX and PEtOx into photocurable polymers; 48,49 (2) addition of oppositely charged polyelectrolytes that can complex inside the Janus droplets; 50 (3) addition of other curable polymers that can retain in the Janus droplets. 51 To demonstrate the versatility of generating Janus droplets with the preselected A3PS, the all-aqueous electrospray technique is further applied.…”