Implants, biodegradable/bioabsorbable

There is an important additional advantage of using (n-s) polymer-CD-ICs to nucleate the melt-crystallization of polymers. Because CDs are nontoxic, biocompatible, and biodegradable, they may be safely utilized in (n-s) polymer-CD-IC nucleants to fabricate both permanent and biodegradable/bioabsorbable implants that are also nontoxic. 

Those membranes, however, have a drawback as a second surgical entry is needed to remove the membrane after tissue regeneration has been achieved, if the membranes are not biodegradable. In order to preclude the surgical removal of an implant after doing its task, membranes made of bioabsorbable material, such as microfibrillar collagen, PLA, and poly(galactin) have been used. 

In the treatment of vascular disease such as arteriosclerosis, intracoronary stent placement is a common adjimct to balloon angioplasty (74). Stents, however, can also cause imdesirable side effects. For example, the continued exposure of a stent to blood can lead to thrombus formation and the presence of a stent in a blood vessel can over time cause the blood vessel wall to weaken creating the potential for arterial rupture or formation of aneurisms. A stent can also become overgrown by tissue after its implantation such that its utility is diminished or eliminated while its continued presence may lead to a variety of complications such as the foregoing. To ameliorate the above situation, stents can be fabricated from materials that are biodegradable and, if desired, bioabsorbable (74). 

K. Gorona, S. Gogolewski, Novel biodegradable polyurethanes for medical applications, in Synthetic Bioabsorbable Polymers for Implants, ed. by C.M. Agrawal, J.E. Parr, S.T. Lin (ASTM special technical publication, UK, 2000), pp. 39-57... 

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