Ice Recrystallization Inhibition via 2D Janus Peptide Nanosheets

Abstract

Antifreeze proteins (AFPs) play a key role in the survival of polar organisms by selectively binding to specific ice crystal facets and regulating their growth. To mimic this mechanism, a series of amphiphilic peptides were developed incorporating aromatic residues, anionic groups, and hydrophobic tails. These peptides spontaneously self-assembled into two-dimensional Janus nanosheets. At the nanoscale peptide binds to ice crystal surfaces to block their growth, while at the macroscale hydrophobic face prevents water access to inhibit ice recrystallization. Cryo in-situ imaging revealed binding between the nanosheets and ice surfaces. These findings highlight the potential of amphiphilic peptide nanosheets as efficient cryoprotective agents for the preservation of sensitive biological materials such as sperm, oocytes, and stem cells.