Smart Cysteine Peptide Self-Assembles into ROS-Responsive Antioxidant Platform

Oxidative stress, caused by an imbalance of reactive oxygen species (ROS), contributes significantly to the progression of numerous chronic diseases and accelerated aging processes. While a plethora of antioxidant compounds exist, a persistent challenge lies in developing smart, targeted delivery systems that can activate their therapeutic function precisely when and where oxidative stress is present. This study addresses the crucial need for novel, multi-functional antioxidant platforms capable of dynamically responding to and mitigating oxidative environments, drawing inspiration from principles found in natural medicine.

The cysteine-rich peptide successfully demonstrated remarkable chiral self-assembly, forming stable and well-defined nanostructures under simulated physiological conditions. Crucially, it exhibited potent multi-functional antioxidant activity, effectively scavenging a broad spectrum of reactive oxygen species (ROS), including hydroxyl radicals and superoxide anions, in experimental setups. This robust activity highlights its intrinsic therapeutic potential. The peptide's most groundbreaking finding was its novel SH-mediated ROS-responsive disassembly, where the presence of oxidative stress triggered a complete and rapid breakdown of its self-assembled structures. This unique disassembly mechanism was highly efficient, leading to a swift release of its active components or a significant change in its functional state precisely in response to the oxidative environment, thereby enabling highly on-demand activation or degradation.