ABSTRACT
Many types of surgically implantable devices that only function for a relatively short time in vivo can be made from polymers that are eliminated from the body by hydrolytic degradation and subsequent metabolism after serving their intended purpose. Although the first application for such bioabsorbable polymers was surgical suture, additional uses have been developed including clips, staples, pins, and mesh. Other applications of a more demanding nature such as fracture fixation implants and drug delivery devices are the subject of ongoing research. Copolymers and homopolymers of glycolide and lactide form an important class of bioabsorbable polymers as a result of their proven toxicological safety and commercial availability. Rates of strength loss and bioabsorption can be controlled by selecting an appropriate copolymer and processing the material under conditions that optimize the desired polymer morphology. Proprietary bioabsorbable polymer systems such as the “bioerodible” poly(ortho esters) appear well suited for zero-order drug delivery applications while stereocomplex blends of poly-L-lactide with poly-D-lactide offer superior mechanical properties needed for the fabrication of high-strength implants for orthopedic surgery.
