| The influence of thermal treatment on the mechanical characteristics of a PLLA coiled stent. | |
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MedLine Citation:
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PMID: 19085931 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We studied the effects of thermal treatment on the expansive characteristics of a coil-within-coil Poly(L-lactic acid) (PLLA) fiber stent developed at our institution to improve its mechanical performance and reproducibility. Following fabrication, furled stents were thermally treated at 62 degrees C for 25 min. The mechanical characteristics were measured compared with those of untreated stents when both were expanded via sequential balloon catheter pressure loading up to 12 atm. Treated stents reached full diameter at 3 atm and maintained that diameter despite further pressure increases. Using measurements of pressure, diameter, and axial length, we calculated the sequential mechanical work required to unfurl the stent. The mechanical work for complete unfurling of treated stents was significantly less than that required for untreated controls. Little axial dimensional change was observed for treated stents. Treated stents exhibited higher stiffness than controls at all pressure levels and also demonstrated higher resistance to external pressure-induced collapse, as measured in a special apparatus developed in our laboratory. Differential scanning calorimetry measurements indicated higher crystallinity values for fibers used in treated stents compared with controls. SEM examination of striations revealed that treated stents underwent less twist than controls following balloon-induced unfurling. The results indicate that, thermal treatment improves the reorientation and realignment of fiber crystalline structure, and favorably influences on the fiber stress-strain behavior and the expansive mechanical characteristics of the PLLA fiber stents. |
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Authors:
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Tré R Welch; Robert C Eberhart; Cheng-Jen Chuong |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural |
Journal Detail:
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Title: Journal of biomedical materials research. Part B, Applied biomaterials Volume: 90 ISSN: 1552-4981 ISO Abbreviation: J. Biomed. Mater. Res. Part B Appl. Biomater. Publication Date: 2009 Jul |
Date Detail:
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Created Date: 2009-06-09 Completed Date: 2009-10-02 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 101234238 Medline TA: J Biomed Mater Res B Appl Biomater Country: United States |
Other Details:
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Languages: eng Pagination: 302-11 Citation Subset: IM |
Copyright Information:
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(c) 2008 Wiley Periodicals, Inc. |
Affiliation:
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Bioengineering Department, University of Texas at Arlington, Arlington, Texas 76019, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Lactic Acid* Microscopy, Electron, Scanning Polymers* Reproducibility of Results Stents* |
| Grant Support | |
ID/Acronym/Agency:
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R01 HL53225/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Polymers; 26100-51-6/poly(lactic acid); 50-21-5/Lactic Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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