Chemistry Reference
In-Depth Information
Table 1.3
Examples of
in
vivo
applications of silicone
polymers [
3
,
110
-
112
]
Body region
Biomedical device
Head
Ear/nose cartilage replacement
Replacement for vitreous humour in the eye
Hydrocephalus shunt
Dura membrane
Eustachian tube
Tracheal stent
Tracheostomy vent
Synthetic eyeball
Orbital floor implant
Mandibular prosthesis
Torso
Breast implants
Penile implants
Heart valves
Pacemaker leads
Artificial skin
Anti-reflux cuff
Urethral cuffs
Vaginal stents
Ureteral stent
Oviductal plugs
Testicular prosthesis
Upper limb
Finger joints
Wrist joints
Artificial nail
Elbow joint cap
Lower limb
Knee joints
Hip joint impact cup
Toe joints
• silicones have a very low glass transition temperature (146 K) when compared to
their hydrocarbon analogues (200 K for polyisobutylene)
• gases (oxygen, nitrogen, and water vapor) have a high degree of solubility and
high diffusion coefficient in silicones
• silicones have a great deal of compressibility
• silicones are relatively bioinert
• silicones possess properties that cannot be achieved with purely organic poly-
mers
Silicone polymers, typically as elastomers, have found utility in a number of
in vivo
applications as illustrated in Table
1.3
. Silicone biomaterials were first developed
