Tuneable pH-regulated supramolecular copolymerisation by mixing mismatched dendritic peptide comonomers

Charged phenylalanine-rich dendritic peptides form highly stable and pH-switchable rod-like supramolecular copolymers, when co-assembled with a matching oppositely charged dendritic comonomer. Here, we demonstrate that by mismatching a strong with a weak β-sheet encoded comonomer, both the stability and the pH-triggered disassembly of the copolymers shifts drastically from pH 4.2 to biologically relevant pH 5.8.

Kinetically Controlled Sequential Growth of Surface-Grafted Chiral Supramolecular Copolymers.

We report a facile strategy to grow supramolecular copolymers on Au surfaces by successively exposing a surface-anchored monomer to solutions of oppositely charged peptide comonomers. Charge regulation on the active chain end of the polymer sufficiently slows down the kinetics of the self-assembly process to produce kinetically trapped copolymers at near-neutral pH. We thereby achieve architectural control at three levels: The β-sheet sequences direct the polymerization away from the surface, the height of the supramolecular copolymer brushes is well-controlled by the stepwise nature of the alternating copolymer growth, and 2D spatial resolution is realized by using micropatterned initiatin…

Wavelength-Selective Softening of Hydrogel Networks.

Photoresponsive hydrogels hold key potential in advanced biomedical applications including tissue engineering, regenerative medicine, and drug delivery, as well as intricately engineered functions such as biosensing, soft robotics, and bioelectronics. Herein, the wavelength-dependent degradation of bio-orthogonal poly(ethylene glycol) hydrogels is reported, using three selective activation levels. Specifically, three chromophores are exploited, that is, ortho-nitrobenzene, dimethyl aminobenzene, and bimane, each absorbing light at different wavelengths. By examining their photochemical action plots, the wavelength-dependent reactivity of the photocleavable moieties is determined. The wavele…

Inside Back Cover: Kinetically Controlled Sequential Growth of Surface-Grafted Chiral Supramolecular Copolymers (Angew. Chem. Int. Ed. 25/2016)

Probing the self-assembly and stability of oligohistidine based rod-like micelles by aggregation induced luminescence.

OA hybrid The synthesis and self-assembly of a new C2-symmetric oligohistidine amphiphile equipped with an aggregation induced emission luminophore is reported. We observe the formation of highly stable and ordered rod-like micelles in phosphate buffered saline, with a critical aggregation concentration below 200 nM. Aggregation induced emission of the luminophore confirms the high stability of the anisotropic assemblies in serum.

Innenrücktitelbild: Kinetisch kontrolliertes, sequenzielles Wachstum von chiralen supramolekularen Copolymeren auf Oberflächen (Angew. Chem. 25/2016)

Kinetisch kontrolliertes, sequenzielles Wachstum von chiralen supramolekularen Copolymeren auf Oberflächen

Wir berichten uber eine einfache Strategie zur Herstellung supramolekularer Copolymere an Goldoberflachen durch sukzessive Inkubation einer initiatorbeschichteten Oberflache mit Losungen aus gegensatzlich geladenen peptidischen Comonomeren. Ein ladungsreguliertes Wachstum des Polymers verlangsamt die Kinetik der Selbstorganisation in dem Mase, dass kinetisch gehemmte Copolymere im nahezu neutralen pH-Bereich gebildet werden. Auf diese Weise erreichen wir eine Kontrolle der Polymerarchitektur auf drei Ebenen: Die β-faltblattkodierte Peptidsequenz steuert eine Wachstumsrichtung der Polymere senkrecht zur Oberflache, die Hohe der supramolekularen Copolymerbursten wird durch den schrittweisen A…

Tuning the pH-Switch of Supramolecular Polymer Carriers for siRNA to Physiologically Relevant pH

The preparation of histidine enriched dendritic peptide amphiphiles and their self-assembly into multicomponent pH-switchable supramolecular polymers is reported. Alternating histidine and phenylalanine peptide synthons allow the assembly/disassembly to be adjusted in a physiologically relevant range of pH 5.3-6.0. Coassembly of monomers equipped with dendritic tetraethylene glycol chains with monomers bearing peripheral primary amine groups leads to nanorods with a tunable cationic surface charge density. These surface functional supramolecular polycations are able to reversibly bind short interfering RNA (siRNA). The nanorod-like supramolecular polymers, their complexation with siRNA, and…