From hollow shells to artificial cells: biointerface engineering on polyelectrolyte capsules

Biomimetic composites can be fabricated by coating hollow polyelectrolyte capsules with biological interfaces such as a phospholipid membrane and proteins. Polyelectrolyte capsules have been templated applying the Layer-by-Layer technique of polyelectrolyte assembled on decomposable cores, which are destroyed after the assembly of the polyelectrolyte multilayer. Phospholipid vesicles of 200-300 nm size are spreaded on the capsule wall forming a continuous lipid membrane. Further functionalisation of the outer capsule wall can be achieved with fused virions and recrystallised S-layers. Compartimentation of the capsule interior with lipid vesicles has been possible by using a solvent exchange method. The functionalisation of the outer capsule surface with biomolecules, together with the creation of internal compartments in the capsule, open new nanobiotechnological challenges towards the fabrication of artificial cells.