Photoresponsive Supramolecular Architectures Based on Polypeptide Hybrids

Abstract

Self-aggregation has recently emerged as an efficient tool for the production of well-ordered supramolecular structures at the nanometric scale. In this framework, peptides offer important advantages as building blocks because of their biocompatibility and 3D-structural/functional diversities. The chemical diversity of peptides may be further expanded by use of noncoded amino acids. In the present work, we focused our attention on two known photoswitchable azobenzene-containing alpha-amino acids and used them as initiators for the reversible modulation of the cis/trans conformational states of two poly(gamma-benzyl-L-glutamate)-based hybrid molecules with either C2 or C3 symmetry. The microscopic photoresponsive self-assembly of these compounds was examined in detail. Moreover, these hybrids were exploited in the construction of macroscopic supramolecular architectures via the electrospinning technique. Finally, after appropriate thiol functionalization, we fabricated and characterized dimeric and trimeric gold nanoparticle/polypeptide hybrid systems

Progress in Photo-Responsive Polypeptide Derived Nano-Assemblies

“…In the case of O -nitrobenzyl, the UV-induced photo-redox cleavage would generate O -nitrosobenzaldehyde that cannot reform the original O -nitrobenzyl moiety. To further pursue efficient and reversible photo-responsiveness of polypeptide nano-assemblies, some research groups have designed smart nanoparticle systems, which rely on photo-isomerizable functionalities, such as azobenzene and spiropyran [ 40 , 75 , 76 , 77 , 78 , 90 , 91 , 92 ].…”

“…To date, azobenzene derivatives have been extensively incorporated into many peptides, either in the side chains or in the backbone. In a report by Moretto, azobenzene served as a central linker for diblock poly( γ -benzyl- l -glutamate) (PBLG) ( Figure 6 A,B) [ 76 ]. Before UV irradiation, diblock PBLG trans- isomer vesicles were observed, as evidenced by TEM and SEM ( Figure 6 C,D).…”

“… ( A ) Reversible geometry change of azobenzene-containing polypeptide via UV and visible light; ( B ) UV-Vis absorptions of cis- and trans- isomers; ( C , D ) TEM and SEM images of vesicles arising from self-assembly of trans- isomer of polypeptides; ( E ) cartoon representation of vesicular structure based on trans- polypeptide; and ( F – I ) time-dependent UV-induced degradation of vesicles. Reproduced with permission from [ 76 ]. …”

Recent Advances in Photo-Responsive Polypeptide Derived Nano-Assemblies

“…To date, azobenzene derivatives have been extensively incorporated into many peptides, either in the side chains or in the backbone. In a report by Moretto, azobenzene served as a central linker for diblock poly(γ-benzyl-L-glutamate) (PBLG) [89]. Before UV irradiation, diblock PBLG trans-isomer nanoparticles as evidenced by TEM (Figure 6).…”

Size Switchable Supramolecular Nanoparticle Based on Azobenzene Derivative within Anionic Pillar[5]arene

“…So the supramolecular assemblies involved azobenzene have various applications in intelligent membranes1415, optical memories161718 and biological systems192021 and so on. A large number of photo-responsive systems based on the azobenzene and macrocycles have been reported2223242526, such as, a photo regulable ion-extraction and ion-transport based on azobenzene-crown ethers27, a photo-responsive artificial muscle based on host-guest complex of α-cyclodextrin and azobenzene2829, and a dual stimuli-responsive self-assembly supramolecular nanoparticles based on the ternary host-guest complexation between cucurbit[8]uril, a methyl viologen polymer, and mono- and multivalent azobenzene functionalized molecules30.…”