also: Polysiloxanes

Chemistry: Polymers that include any inert, synthetic compound made up of repeating units of siloxane, which is a chain of alternating silicon atoms and oxygen atoms, frequently combined with carbon and/or hydrogen.

In implants it is used for glaucoma drain, artificial iris, cochlear prosthesis, ear tubes, breast implants, hernia mesh and intrauterine devices (IUD).

Silicone is used in microfluidics, seals, gaskets, shrouds, and other applications requiring high biocompatibility.
The gel form is used in breast implants, testicle implants, pectoral implants and some other medical uses.

Polydimethylsiloxane (PDMS, aka dimethylpolysiloxane or dimethicone) has been used as the hydrophobic block of amphiphilic synthetic block copolymers used to form the vesicle membrane of polymersomes.
It is the most widely used silicon-based organic polymer. PDMS is optically clear, and, in general, inert, non-toxic, and non-flammable.
It is one of several types of silicone oil (polymerized siloxane).
Its applications range from contact lenses and medical devices to elastomers.