Beta-cyclodextrin-appended giant amphiphile: aggregation to vesicle polymersomes and immobilisation of enzymes.

A giant amphiphile consisting of polystyrene end-capped with permethylated beta-cyclodextrin was synthesised and found to form vesicular structures when injected as a solution in THF into water. The ability of the cyclodextrins on the surface of the polymersomes to form inclusion complexes with hydrophobic compounds was tested by carrying out a competition experiment with a fluorescent probe sensitive to the polarity of the surrounding medium. It was found that 1-adamantol can displace the fluorescent probe from the cavities of the cyclodextrin moieties of the polymersomes. The recognition of molecules by cell membranes in nature is often based on interactions with specific membrane receptors. To mimic this behaviour, the enzyme horseradish peroxidase was modified with adamantane groups through a poly(ethylene glycol) spacer and its interaction with the polymersomes was investigated. It was established that the presence of adamantane moieties on each enzyme allowed a host-guest interaction with the multifunctional surface of the polymersomes.