Polymers

Polymers (from Greek poly = much, meros = part) are giant molecules consisting of chains of subunits (monomers). A polymer contains on average 10,000 and 100,000 monomer units. Since a polymer is usually not linear, but is connected in a net-like manner, the polymer has a very high elasticity: under load it simply stretches like a rubber band.

In polymers of different monomers, the sequence can be ordered or random(copolymers), or blocks from one monomer unit with the same structure can be coupled to the blocks of another monomer unit. (Block copolymers: copolymers in which two longer sequences or blocks of single monomers follow each other (AAAAAAAAABBBBBBBBBB...). Depending on the number of blocks, these are also called diblock, triblock, ..., copolymers. Furthermore, there are branched, ring-shaped, comb-like or cross-linked polymers. Rubber, for example, is an irregular polymer network whose characteristic high elasticity is determined by the polymer structure between the cross-linking points.

Polymer-based transport systems play an important role in siRNA therapeutics.