Controlling amphiphilic copolymer self-assembly morphologies based on macrocycle/anion recognition and nucleotide-induced payload release

Abstract

We report here a new approach to creating diversiform copolymer-derived self-assembly morphologies that relies on macrocycle/anion recognition in aqueous media. This approach exploits the anion binding features of a water-soluble form of the so-called ‘Texas-sized’ molecular box. When this tetracationic receptor is added to an aqueous solution of an amphiphilic copolymer bearing tethered carboxylate anion substituents, binding occurs to form a macrocycle/polymer complex. As the concentration of the box-like receptor increases, the relative hydrophilic fraction of the copolymer complex likewise increases. This leads to changes in the overall morphology of the self-assembled ensemble. The net result is an environmentally controllable system that mimics on a proof-of-concept level the structural evolution of organelles seen in living cells. The macrocycle/anion interactions respond in differing degrees to three key biological species, namely ATP, ADP, and AMP, which may be used as “inputs” to induce disassembly of these vehicles. As a result of this triggering and the nature of the morphological changes induced, the present copolymer system is capable of capturing and releasing in controlled manner various test payloads, including hydrophobic and hydrophilic fluorophores. The copolymer displays low inherent cytotoxicity as inferred from cell proliferation assays involving the HUVEC and HepG2 cell lines.

Redox and pH Dual-Responsive Supramolecular Micelles with a Traditional Polymer Block and a Supramolecular Block for Drug Controlled Release

“…Supramolecular micelles mediated by noncovalent bonds such as host-guest interactions will be of interest in completely releasing of the drugs. [3][4][5][6][7][8][9][10] Furthermore, the common ferrocene-terminated polymers are typically used to build redox-responsive supramolecular micelles. However, there are no reports using a traditional polymer block and a supramolecular block using cyclodextrin to prepare redox-responsive supramolecular micelles.…”

Encoding, Reading, and Transforming Information Using Multifluorescent Supramolecular Polymeric Hydrogels

“…This system, designated as G3‐2 to distinguish it from the nonresponsive rhodamine B ester ( RE ) hydrogel ( G3‐1 ), was found to produce a red fluorescence in its native state but emitted blue after exposure to ammonia vapor. All these hydrogels encode for tertracationic imidazolium macrocycle/alkyl sulfonate anion interactions, both within the interior of the hydrogel and at the surface . Thus, they can be used to produce different multicolor fluorescent patterns when pushed together manually on a black nitrile substrate.…”

“…Prior work with the tetracationic imidazolium derived “box” used in this study, as well as a range of predicative studies involving it and acrylate propyl sulfonate ester carried out in the context of this study (cf. Figures S1–S7, Supporting Information), provided support for the notion that this receptor–anion combination would interact strongly in aqueous media.…”

“…Methacrylate or styrene monomers containing coumarin, BODIPY, and rhodamine B functionalities were also prepared as detailed in the Supporting Information. G0 was then prepared by free radical copolymerization of acrylamide, MBAAm (a covalent cross‐linker), 1 , and acrylate propyl sulfonate ester, using azobisisobutyronitrile (AIBN) in aqueous media (Scheme S2, Supporting Information). For G1 , G2 , and G3 ( G3‐1 and G3‐2 ), the corresponding fluorescent monomers were used, respectively, in addition to the components used to prepare G0 .…”

Probing membrane asymmetry of ABC polymersomes

“…25 The packing parameter is very sensitive to slight changes in the block ratio caused by the variation of hydrophilicity/hydrophobicity under external stimuli or chemical modification. For example, structures assembled from stimulusresponsive polymers may undergo order-order transitions (e.g., polymersome-to-worm, polymersome-to-micelle) upon the change of temperature [26][27][28][29][30][31][32][33] or pH, [34][35][36] in the presence of enzymes, 37 by host-guest recognition 38 or in the presence of a cross-linking agent, 39 etc. Moreover, even the modification of only end-groups already induces morphological transitions.…”