Development of Absorbable, Ultra High Strength Poly(lactides)
A new process called “Orientrusion” has been developed which forms fibrils in a semi-crystalline polymeric matrix in such a way that the resulting structure is a fiber reinforced composite of very high strength. To achieve high strength, parameters determining the rate of crystallization and the rate of molecular orientation have been balanced. When this process was applied to poly(lactide) the strength of the poly(lactide) was increased by about 700%, compared to unoriented poly(lactide). This material was shown to be biocompatible and body absorbable. Orthopedic implants made from this material were shown to be strong enough initially and to retain enough strength after they have been implanted in animals for a long enough time for the bone to heal. Investigational device exemption application for the human clinical testing of the oriented poly(lactide) screw has recently been approved by the FDA.
KeywordsStrength Retention Differential Scanning Calorimetric Analysis Stainless Steel Screw High Molecular Weight Poly Bovine Cancellous Bone
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