Reversible deformation–formation of a multistimuli responsive vesicle by a supramolecular peptide amphiphile

Abstract

A systematic study of the ternary complex formation process for aromatic amino acids using ucurbit[8]uril (CB[8]) and a viologen amphiphile shows that the affinity of the amino acid needs to be higher or in a comparable range to that of CB[8] for the amphiphile in order to form the ternary complex. Based on these observations, a supramolecular peptide amphiphile and its corresponding vesicle are prepared using a peptide containing an azobenzene moiety. The azobenzene group at the N-terminus of the peptide served as the second guest for CB[8]. The vesicles obtained from this peptide amphiphile show response to a number of external triggers. The trans-cis isomerization of the azobenzene group upon irradiation with UV-light of 365 nm leads to the breakdown of the ternary complex and eventually to the disruption of the vesicle. The deformation-reformation of the vesicle can be controlled by illuminating the disrupted solution with light of 420 nm as it facilitates the cis-trans isomerization. Thus, the vesicle showed a controlled and reversible response to UV-light with the ability for manipulation of the formation-deformation of the vesicle by the choice of an appropriate wavelength. The vesicle showed response to a stronger guest (1-adamantylamine) for CB[8], which displaces both the guests from the CB[8] cavity and consequently ruptures the vesicle structure. 2,6-Dihydroxynaphthalene acts as a competitive guest and thereby behaves as another external trigger for replacing the peptide from the CB[8] cavity by self-inclusion to form the ternary complex. Henceforth, it allows retaining the vesicle structure and results in the release of the peptide from the vesicle.

Dynamic supramolecular polymers built from cucurbit[n]urils and viologens

“…Z/E photoisomerization was also shown to trigger the breakdown of the ternary complex and eventually the disruption of the vesicle (Fig. ) …”

“…On the other hand, Das and co‐workers have established that different aromatic amino acids can form vesicles through ternary complexes with CB[8] and an amphiphilic viologen. They also report that vesicle formation is a peptide‐dependent process, with tryptophan forming stable vesicles while tyrosine and phenylalanine fail to do so . Vesicles generated from adiazobenzene‐containing peptide have been shown to be tunable by a number of external triggers including the trans – cis isomerization of the azobenzene group upon irradiation with UV light of 365 nm.…”

“…Chemical structures of Azo‐AA ((E)‐4‐((4‐aminophenyl)diazenyl)benzoic acid), DEV ( N , N ′‐diethylviologen dibromide), HDEV ( N ‐ethyl‐ N ′‐hexadecylviologen dibromide) and CB[8], a pictorial presentation of the formation of supramolecular peptide amphiphiles and its vesicle as well as responses to various stimuli . Reproduced by permission of the Royal Society of Chemistry.…”

Supramolecular guest relay using host-protein nanocavities: an application of host-induced guest protonation

“…[4][5][6][7][8] One of the most interesting aspects of host-guest complexation is perhaps the unravelling of the dynamical nature of the formation of a very simple and discrete supramolecular assemblies in solution, which is able to modify the chemical reactivity and physical properties of the encapsulated guest. 1-3 Investigation of a simple stimuli-responsive host-guest systems provides us the opportunity to understand the nature of the intermolecular interactions operating in a multicomponent system.…”

Voltage-responsive reversible self-assembly and controlled drug release of ferrocene-containing polymeric superamphiphiles

“…[6][7][8] However, most conventional block polymer amphiphiles need complicated synthesis and purification processes. 10,11 These so-called superamphiphiles are usually made of non-amphiphilic molecules, or non-amphiphilic molecules and amphiphilic small molecules by noncovalent interactions or dynamic covalent bonds in aqueous solution, such as hydrogen-bonding, electrostatic interaction, metal-coordination bonding, π-stacking, and host-guest interaction. 5,9 In recent years, a new concept of superamphiphiles has been well established and received substantial attention in chemist community due to their facile preparation and interesting selfassembly behaviour.…”