Known as the third domain of life, the archaea is a group of single-celled microorganisms which have long been famous for their ability to thrive in extreme conditions, including high pressures, high temperatures, high or low pH values and high salinity. Of these extremophiles, the acidophilic adaptions of thermoacidophilic archaeons have been most extensively studied, which flourish in hot acid springs with pH value below 3, while maintain the internal pH near to neutral. Several mechanisms have been suggested to act synergistically to maintain the pH homeostasis, but a deeper understanding of this phenomenon is still hindered in part due to the lack of proper tools.

Recently, a group of researchers from Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (SINANO), designed a biomimetic membrane to study the role of sugar coating in proton-defenses. In this work, a surface-tethered OH-rich polymer - poly(oligo(ethylene glycol) methacrylate) (poly(OEGMA)) – was synthesized as a mimic of the sugar coating on the surface of acidophilic archaea. Using acid-sensitive self-assembled monolayer as a probe, this OH-rich poly(OEGMA) membrane was shown to raise pH from 1.0 to > 5.0. The study presents strong evidence for sugar coating’s effect on proton resistance and pinpoints the effective site at OH groups. This bioinspired proton shelter had also been finely-tuned by means of block- and co-polymerization. This biomimetic study may be expanded for the development of biocompatible anti-acid strategies, such as tooth protection and drug-carriers that withstand gastric acid digestion. The work has been published on Scientific Reports (2：892，2012)

(Information source: Suzhou Institute of Nano-Tech and Nano-Bionics of CAS)