Polymersome

Polymersomes are artificial vesicles, which are used in biochemistry and biotechnology to entrapment. The term was coined in reference to liposomes. In contrast to liposomes, polymersomes are made of amphiphilic block copolymers and therefore consist of long-chain polymers such as bioplastics. Therefore, they are more stable and less permeable.

Properties

Polymersomes have radii between 50 nm and 5 microns. Most of the aqueous solutions are included in polymersomes to protect components dissolved within such as proteins, DNA, RNA or small molecules against a metabolism. Areas of application are, for example, drug targeting, depot dosage forms, nanoreactors and artificial cells.

Include polymersomes transport proteins such as ion channels, they are also referred to as Synthosome. Such a semi-permeable membrane polymersomes can selectively accumulate molecules inside. Are enzymes previously been included in the polymersomes, a specific metabolism of the molecule selectively taken up can be achieved. By choosing suitable additives in the polymer Omen properties such as permeability and stability, and thus the rate of delivery can be selectively altered. Similar to liposomes, by a coating of the polymersomes with polyethylene glycol, the immunogenicity can be reduced, which increases the biological half-life.

Production

Most linear polymers are used as diblock and triblock copolymers. By the use of hydrophilic and hydrophobic copolymer in an alternating sequence, the polymers obtained have amphiphilic properties. Comb-like copolymers can be used to produce branched polymers. In this case there are those with hydrophilic and hydrophobic ridge extensions or those with hydrophobic and hydrophilic comb extensions. By crosslinking portable powder can be produced.

In a triblock copolymer, a hydrophobic middle block is selected most flanked by two hydrophilic copolymer, so that a single layer ( monolayer Sheet ) forms. Some of the preparation of the polymer the polymer is similar to liposomes.

The following blocks are approved in the U.S. by the USFDA:

Hydrophilic blocks

• Polyethylene glycol ( PEG / PEO)
• Poly (2- methyloxazoline )

Hydrophobic blocks

• Polydimethylsiloxane (PDMS)
• Polycaprolactone ( PCL)
• Polylactides (PLA)
• Poly ( methyl methacrylate ) (PMMA)