Polyalkylimide

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Polyalkylimide is a polymer which belongs to the family of acryl derivatives. Its polymeric structure does not contain free monomers.

It is also the active ingredient in a permanent dermal filler called Bio-Alcamid® (manufactured by Polymekon, Brindisi, Italy) which is a 3% polyalkylimide suspension in water used medically to treat soft tissue deficits like facial lipoatrophy and lipodystrophy, Poland syndrome, Pectus excavatum (sunken chest), gluteal atrophy, acne scars etc.. In plastic and reconstructive surgery it is used for building up facial volume in areas like the cheeks, chin, jaw and for lip augmentation.

It is injected subcutaneously through a syringe, mostly under local anesthesia (like lidocaine). After being injected, a thin layer (0,02 mm) of collagen forms naturally around it (takes around 4-8 weeks), which completely surrounds the gel, isolating it from the host tissues and making it an endogenous prosthesis. It is radio-transparent (for x-rays), although it can be located by using ultrasound.

Also large quantities can be injected in one session without an immune response. Amounts of 5ml to 20ml are normally injected into the face. Its manufacturer says that it should not degrade or move and that it can also be removed through aspiration or puncture and manual pressure.

While infection is always a possibility with the use of any implanted material, no other complications have been reported so far. But long-term safety data has not been established yet.

Bio-Alcamid® comes in pre-filled syringes (1cc, 3cc and 5cc). It has a CE mark. Doctors charge around US$150 to US$300 per ml of the product injected, depending on the quantity needed.

Bio-Alcamid® is commercially available since 2000 and used by doctors in Europe and Mexico. The Food and Drug Administration (FDA) has not yet approved its use in the United States. In Canada it is available only under provisions of the Special Access Program, which involves application on a patient by patient basis.