Programmable Cyclic Peptide-PEG Nanoarchitectures: Concentration-Controlled Antifreeze Materials

Abstract

Inspired by natural antifreeze proteins (AFPs) that enable subzero survival through specific ice surface binding, we developed biomimetic cyclic peptide-PEG (CP-PEG) conjugates incorporating ice-binding residues (threonine, valine, serine). Our system exhibits concentration-dependent self-assembly: forming one-dimensional nanotube networks above the critical aggregation concentration (CAC) and two-dimensional nanosheets near CAC. β-sheet formation was confirmed via fluorescence spectroscopy, FTIR, and circular dichroism (CD). Threonine-functionalized nanotubes demonstrated superior ice recrystallization inhibition (IRI), ice nucleation inhibition (INI), and distinctive dynamic ice shaping (DIS) behavior. Surface analysis using AFM, TEM, and WAXS revealed precise supramolecular architectures mimicking natural AFP structures. This programmable platform offers crucial insights for developing optimized cryopreservatives for biological preservation applications.