Understanding the ability of a protein to stick to a surface is important in many industrial and
biological applications. The ability to create a protein repellent surface and prevent biofouling
is of great interest in areas such as marine coatings and design of diverse medical devices.
One approach to enable this would be to create a surface system where the interactions with
water are so favourable that proteins are excluded and not bound.
One possible option is to use zwitterionic materials:
molecules that contain both a positive and negative charge.
This study, published in PCCP, studied dizwitterionic
molecules, incorporating two zwitterionic sections at each
end of an alkyl-chain spacer. The researchers investigated
what happened to the water molecules surrounding the
dizwitterionic molecule when the length of the alkyl-chain
spacer was changed.
They found that, for all chain lengths, each zwitterion end
attracted a shell of about fifty water molecules. This high
hydration activity suggests that this type of system may be
suitable in applications where a protein-repellent is required.
Related publication: “Hydration of sulfobetaine dizwitterions as a function of alkyl spacer length.” Phys. Chem. Chem.
Phys., 22, 16040-16050 (2020)