Self-assembly of cyclic peptides for controlled ice crystal growth

Abstract

Antifreeze proteins (AFPs) enable subzero survival through specific ice surface binding. Drawing inspiration from AFPs, we report a biomimetic approach using rationally designed cyclic peptides (CPs) incorporating ice-binding amino acids (threonine, valine, and serine), conjugated with 4-arm polyethylene glycol. Our designed system exhibits concentration- dependent self-assembly, forming either nanotubes or two-dimensional nanosheets depending on peptide concentration. The formation of β-sheet structures was confirmed through spectroscopic analysis, including fluorescence, FTIR, and circular dichroism, and ice-binding effectiveness was evaluated through ice recrystallization inhibition (IRI), thermal hysteresis (TH), and dynamic ice formation (DIS) measurements. This investigation provides crucial insights for developing optimized cryopreservativesfor biological sample preservation.