Authors acknowledge to Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to
CIMO (UIDB/00690/2020) and for the Base Funding—UIDB/50020/2020 of the Associate Laboratory LSRE-LCM—funded by national
funds through FCT/MCTES (PIDDAC).
Stable artificial vesicles with a tiny membrane enclosing a liquid solution are generically defined as polymersomes.
They are produced using amphiphilic synthetic polymers, usually block copolymers. Often, polymersomes assume a
spherical geometry and their size can range from tens of nanometers up to a few microns (e.g., 50 nm!5 μm). The
thickness of the membrane is generally of the order of a few nanometers (e.g., 5!20 nm) and the most common polymersomes
contain in the core an aqueous solution. Fig. 11.1 depicts a typical polymersome showing a hollow sphere
containing an aqueous solution in the core enclosed by a bi-layer membrane.1 The bi-layer membrane (internal/external
hydrophilic coronas with a hydrophobic separating layer) is formed due to the self-assembly of an amphiphilic copolymer.
The aqueous core can be used to encapsulate hydrophilic therapeutic molecules (e.g., drugs, enzymes, proteins,
DNA, and RNA) while hydrophobic drugs can be loaded in the middle-layer. Homing devices, such as antibodies, can
also be incorporated in the external surface of the polymersomes in order to enhance local drug release.1 Besides surface functionalization, the membrane of polymersomes can also be tailored through polymerization mechanisms such as
crosslinking to enhance its hardness, if desired.
