| An enhanced strength retention poly(glycolic acid)-poly(L-lactic acid) copolymer for internal fixation: in vitro characterization of hydrolysis. | |
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MedLine Citation:
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PMID: 19816292 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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In general, most bioabsorbable polymers used for internal fixation are composed of copolymers of glycolic acid and lactic acid (L and/or DL). Within this family of polymers resides the latitude to design materials with specific degradation properties to meet a variety of clinical needs. One material with an extensive clinical history is LactoSorb copolymer, which is composed of a molar ratio of 82:18 poly(L-lactic acid)-poly(glycolic acid). Fixation devices derived from this copolymer have been used in orthopedic and craniofacial surgeries. With a strength loss profile of approximately 12 weeks, it mirrors the profile of normal healing; however, in cases in which delayed healing is anticipated, a copolymer with a longer strength retention profile may be desirable. This study compared the hydrolytic degradation, in vitro, of the 82:18 copolymer with a related 85:15 poly(L-lactic acid)-poly(glycolic acid) copolymer. In addition to a difference in the copolymer ratio, the latter had a larger inherent viscosity (molecular weight) and a smaller polydispersity (molecular weight distribution). This copolymer had an equivalent initial tensile modulus as the 82:18 copolymer (0.8 GPa) but a strength retention profile that spanned 44 weeks. The activation energy of hydrolysis for the 85:15 copolymer was 38.8 kcal/mol, which was greater than the 23.8 kcal/mol historical value for the 82:18 copolymer. This suggests that hydrolysis of the 85:15 copolymer is more temperature-sensitive than that of the 82:18 copolymer. These results were interpreted in the context of the differences in the compositions of these 2 copolymers. |
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Authors:
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William S Pietrzak; Mukesh Kumar |
Publication Detail:
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Type: Comparative Study; Journal Article |
Journal Detail:
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Title: The Journal of craniofacial surgery Volume: 20 ISSN: 1536-3732 ISO Abbreviation: J Craniofac Surg Publication Date: 2009 Sep |
Date Detail:
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Created Date: 2009-10-09 Completed Date: 2010-01-28 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9010410 Medline TA: J Craniofac Surg Country: United States |
Other Details:
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Languages: eng Pagination: 1533-7 Citation Subset: D |
Affiliation:
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Biomet, Inc., 56 E Bell Drive, Warsaw, IN 46581, USA. bill.pietrzak@biomet.com |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Absorbable Implants* Biocompatible Materials / chemistry* Elastic Modulus Hot Temperature Humans Hydrolysis Internal Fixators* Lactic Acid / chemistry* Materials Testing Molecular Weight Polyglycolic Acid / chemistry* Prosthesis Design Stress, Mechanical Tensile Strength Time Factors Transition Temperature Viscosity Water / chemistry |
| Chemical | |
Reg. No./Substance:
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0/Biocompatible Materials; 0/polylactic acid-polyglycolic acid copolymer; 26009-03-0/Polyglycolic Acid; 50-21-5/Lactic Acid; 7732-18-5/Water |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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