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Supramolecular peptide assemblies have been widely used for the development of biomedical, catalytical, and optical materials with chiral nanostructures in view of the intrinsic chirality of peptides. However, the assembly pathway and chiral transformation behavior of various peptides remain largely elusive especially for the transient assemblies under out‐of‐equilibrium conditions. Herein, the N‐fluorenylmethoxycarbonyl‐protected phenylalanine‐tyrosine dipeptide (Fmoc‐FY) was used as a peptide assembly platform, which showed that the assembly proceeds multistep evolution. The original spheres caused by liquid‐liquid phase separation (LLPS) can nucleate and elongate into the formation of right‐handed helices which were metastable and easily converted into microribbons. Interestingly, a bipyridine derivative can be introduced to effectively control the assembly pathway and induce the formation of thermodynamically stable right‐handed or left‐handed helices at different stoichiometric ratios. In addition, the chiral assembly can also be regulated by ultrasound or enzyme catalysis. This minimalistic system not only broadens the nucleation‐elongation mechanisms of protein aggregates but also promotes the controllable design and development of chiral biomaterials. [ABSTRACT FROM AUTHOR]

[Display omitted] Development of peptide-based supramolecular materials with hierarchical morphology and tunable guest loading displays broad potential as drug carrier in view of biocompatibility and biodegradability. Herein, we report a facile Schiff base nanoarchitectonic for supramolecular assembly of diphenylalanine (FF) metastable gel. The addition of trace glutaraldehyde (GA)/H 2 O solution induces the Schiff base reaction between GA and FF accompanying by phase transition from gel to solution. FF nanoparticles and hierarchical beaded nanofibers with autofluorescence properties can be constructed by regulating the competitive assembly between FF-H 2 O and FF-GA oligomer. Moreover, various guest molecules with different hydrophilic and hydrophobic properties can be easily loaded into such assembled particles and its release can be triggered under weak alkaline conditions, which show the potential application of the assembled FF system as drug carriers. [ABSTRACT FROM AUTHOR]

Many solid drugs exist in polycrystalline state, which markedly hinder their pharmacological effectiveness. Given the designability and biocompatibility, the development of peptide-based supramolecular gel that can regulate crystal growth of drug has a strong potential. In this research, the polycrystalline drug carbamazepine (CBZ) was successfully transformed from orthorhombic dihydrate into amorphous form through the introduction of 9-fluorenylmethoxycarbonyl diphenylalanine (FmocFF) gel and co-assembled supramolecular gel was obtained. The intermolecular mechanism of structural transformation was elucidated in detail by various spectral techniques. The dihydrate of CBZ was restrained through the inhibition of hydration of the NH 2 groups and the π-π stacking interaction among the aromatic rings of FmocFF and CBZ. Especially, principal component analysis (PCA), and two-dimensional correlation spectroscopy (2DCOS) techniques were conducted to analyze the time-dependent IR spectra, which indicated that the π-π stacking interaction mainly affected the FmocFF gel fiber elongation after co-assembly with CBZ. In addition, the FmocFF gel matrix significantly influenced the release behavior of CBZ in vitro, which providing theoretical guidance for the development of short-peptide assembly strategies in drug delivery materials. [Display omitted] • Transformation of CBZ from orthorhombic dihydrate into amorphous structure through the regulation of FmocFF gel. • The intermolecular mechanism of structural transformation was elucidated in detail by various spectral techniques. • FmocFF gel as a carrier matrix of CBZ sustained-release. [ABSTRACT FROM AUTHOR]