A Block Copolymer for Functionalisation of Polymersome Surfaces

A block copolymer was designed to functionalise the surface of polystyrene‐based polymersomes via coaggregation. An α,ω‐diacetylene‐functionalised poly(ethylene glycol) (PEG) was coupled to an azide‐terminated polystyrene via a Cu(I)‐catalysed cycloaddition to produce a PS‐b‐PEG polymer with an acetylene at its hydrophilic extremity. Incorporation of this ‘anchor’ compound in the bilayer of a polymersome places its bio‐orthogonal group at the surface of this aggregate. Its accessibility was demonstrated using an azido‐functionalised Candida antarctica Lipase B (CalB), which retained its activity while immobilised on the polymersome.