Order from disorder with intrinsically disordered peptide amphiphiles

TL;DR

This paper introduces intrinsically disordered peptide amphiphiles (IDPA) that undergo a pH-triggered shape transition, offering new possibilities for stimuli-responsive biomedical applications through tailored peptide interactions.

Contribution

The study presents novel IDPA molecules with a sharp pH-induced micellar shape transition and a theoretical model describing this behavior, advancing design strategies for responsive amphiphilic systems.

Findings

IDPA exhibits a sharp pH-induced transition from spheres to worm-like micelles

Experimental characterization of the phase transition was performed

A theoretical model explains the pH-response mechanism

Abstract

Amphiphilic molecules and their self-assembled structures have long been the target of extensive research due to their potential applications in fields ranging from materials design to biomedical and cosmetic applications. Increasing demands for functional complexity have been met with challenges in biochemical engineering, driving researchers to innovate in the design of new amphiphiles. An emerging class of molecules, namely, peptide amphiphiles, combines key advantages and circumvents some of the disadvantages of conventional phospholipids and block-copolymers. Herein, we present new peptide amphiphiles comprised of an intrinsically disordered peptide conjugated to two variants of hydrophobic dendritic domains. These molecules termed intrinsically disordered peptide amphiphiles (IDPA), exhibit a sharp pH-induced micellar phase-transition from low-dispersity spheres to extremely elongated worm-like micelles. We present an experimental characterization of the transition and propose a theoretical model to describe the pH-response. We also present the potential of the shape transition to serve as a mechanism for the design of a cargo hold-and-release application. Such amphiphilic systems demonstrate the power of tailoring the interactions between disordered peptides for various stimuli-responsive biomedical applications.