Role of Oligoethylene Glycol Side Chain Length in Responsive Polymeric Nanoassemblies

Abstract

An oft-desired feature of a responsive nanomaterial is that it should undergo disassembly or morphological change upon application of a specific stimulus. The extent of response has been found to depend on factors such as the nature and the number of responsive functionalities incorporated into these particles. In this work, the length of oligoethylene glycol (OEG) side chains associated with the polymers has been shown to greatly influence the responsive behavior of polymeric nanoparticles. The integrity of these OEG-based polymeric assemblies was found to depend not only on the chemical cross-links but also on the physical cross-links in these aggregates in cases where the polymer chains bear long OEG side chains. The physical cross-linking in longer OEG side chain containing polymeric nanogels is present in the form of crystalline domains. Our results here highlight that these ethylene glycol-based hydrophilic units are not to be ignored as spectator units with water-solubilization characteristics but must be analyzed in the context of assembly stabilization and triggerability with the targeted stimulus.

Luminescent Vesicles Self-assembled Directly from an Amphiphilic Europium Complex in an Ionic Liquid

“…There were also strong interactions between [Bmim]PF 6 and the MEE segment, 36 including H-bonding between the hydrogen atom on the imidazole ring and the oxygen atom on the MEE segment. Furthermore, the previous research has shown that the longer ethoxy chains would provide physical cross-linking and chemical cross-linking, 37 which could increase the area of the hydrophilic region. According to the equation P = V/a o l, the P value may become smaller and the micelles but not vesicles may be generated.…”

A disulfide-based linker for thiol–norbornene conjugation: formation and cleavage of hydrogels by the use of light

“…Disulfide-containing linkers have been studied bearing acrylate or acrylamide terminals, and were either incorporated into polymer networks via thiol-Michael addition with thiol-terminated macromers 45 or by free radical copolymerization with acrylates. 52–54 However, formulations based on Michael-acceptors and thiols have to be handled very skilled and quickly, as gelation sets in fast upon combining of the reactive components, 18 which can be especially challenging when it comes to delicate procedures such as cell encapsulation or molding of complex geometries. Besides, acrylates are cytotoxic.…”

Some Guidelines for the Synthesis and Melting Characterization of Azide Poly(ethylene glycol) Derivatives

“…In the case of using PEG as a modifier, good control of the efficiency of functionalization is therefore fundamental, as well as the knowledge of the effect of the introduction of new end groups on fundamental properties and how such groups may affect characterization methodologies. For other solid-state applications such as in polymer electrolytes, ionic liquids or supercapacitors [ 12 , 13 , 14 ] or in hydrogel scaffolds for tissue engineering [ 15 ], other PEG characteristics—especially crystalline morphology and molecular weight—become important, including how they are influenced by molecular and structural changes [ 16 , 17 , 18 ].…”