Confinement and compartmentalisation are two of the most important prerequisites for the complexity of life. These two essential concepts are used by synthetic biologists to reverse-engineer life in order to understand its complexity and/or to exploit its efficiency in the production of (bio)molecules. As we advance our understanding of biological confinement and engineer new ways of mimicking this situation, we realise that the interaction between molecules and macromolecules is substantially affected by the complexity and diversity of their environment. This is particularly true for proteins, where their functionality is strongly correlated to their macromolecular structure.
Figure 3. Functional hybrid nanocontainers composed of polymersomes (middle) are assembled from amphiphilic block copolymers (left) and membrane spanning DNA nanopores (right). The containers are of size-selective permeability and permit transport of organic enzyme substrate through DNA nanopores while retaining bioactive encapsulated enzyme
We developed a new method toe encapsulated biological macromolecules into preformed polymersomes by controlled temporary destabilization of the vesicle membrane using pulsed AC electrical fields (see figure 1). In collaboration with Voit and Appelhans we made pH-sensitive polymersomes stabilised by UV cross-linking after incorporation of an enzyme in a synthetic bio-nanoreactor without transmembrane proteins. This stabilization allows the reversible swelling and deswelling of the polymersomes upon changes in the pH value. The controlled reaction of the enclosed enzyme could be monitored selectively at pH 6 when the substrate could penetrate the membrane (see figure 2). More recently, in collaboration with the Howorka group at UCL, we combine our expertise on polymersomes with their ability to design DNA origami and DNA nanopores in particular (See figure 3) to create a nanoreactor able to differentiate molecules in terms of size.
- D. Cecchin and G. Battaglia Protein stabilisation by polymersome entrapment arXiv, 2016, arXiv:1607.08886 [q-bio.BM]
- L. Messager, J. Kim, J. Burns, D. Cecchin, J. Hindley, J. Gaitzsch, G. Battaglia*, S. Howorka* Biomimetic nanoreactors composed of polymersomes, membrane spanning DNA nanopores, and encapsulated enzymes Angew. Chem. Int. Ed, 2016, in the press
- L. Wang, L. Chierico, D. Little, N. Patikarnmonthon, Z. Yang, M. Azzouz, J. Madsen, S. P. Armes, G. Battaglia Encapsulation of Biomacromolecules within Polymersomes via Electroporation Angew. Chem. Int. Ed. 2012, 51, 11122-11125
- J. Gaitzsch, D. Appelhans, L. Wang, G. Battaglia, and B. Voit Synthetic bionanoreactor: Mechanical and chemical control of polymersome membrane permeability Angew. Chem. Int. Ed. 2012, 51, 4448–4451