title: Liquid-crystalline aromatic-aliphatic copolyester bioresorbable polymers.
abstract: The synthesis and characterisation of a series of liquid-crystalline aromatic-aliphatic copolyesters are presented. Differential scanning calorimetry showed these polymers have a glass transition temperature in the range 72 degrees C-116 degrees C. Polarised optical microscopy showed each polymer exhibits a nematic mesophase on heating to the molten state at temperatures below 165 degrees C. Melt processing is demonstrated by the production of injection moulded and compression moulded specimens with Young's modulus of 5.7 +/- 0.3 GPa and 2.3 +/- 0.3 GPa, respectively. Wide-angle X-ray scattering data showed molecular orientation is responsible for the increase of mechanical properties along the injection direction. Degradation studies in the temperature range 37 degrees C-80 degrees C are presented for one polymer of this series and a kinetic constant of 0.002 days(-1) is obtained at 37 degrees C assuming a first order reaction. The activation energy (83.4 kJ mol(-1)) is obtained following the Arrhenius analysis of degradation, showing degradation of this material is less temperature sensitive compared with other commercially available biodegradable polyesters. In vitro and in vivo biocompatibility data are presented and it is shown the unique combination of degradative, mechanical and biological properties of these polymers may represent in the future an alternative for medical device manufacturers.
authors.affiliation: Smith & Nephew Research Centre, York Science Park, Heslington, York, UK. horacio.montesdeoca@smith-nephew.com
authors.forename: Horacio Montes
authors.initials: HM
authors.lastname: de Oca
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Wilson
authors.forename: Andrew
authors.initials: A
authors.lastname: Penrose
authors.forename: David M
authors.initials: DM
authors.lastname: Langton
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Dagger
authors.forename: Melissa
authors.initials: M
authors.lastname: Anderson
authors.forename: David F
authors.initials: DF
authors.lastname: Farrar
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Lovell
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ries
authors.forename: Ian M
authors.initials: IM
authors.lastname: Ward
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Wilson
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cowling
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Saez
authors.forename: John W
authors.initials: JW
authors.lastname: Goodby
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008297:Male; D008422:Materials Testing; D051379:Mice; D015394:Molecular Structure; D008970:Molecular Weight; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012542:Scattering, Radiation; D013314:Stress, Mechanical; D013696:Temperature; D046509:Tissue Culture Techniques
chemical_list: D001672:Biocompatible Materials; D006841:Hydrocarbons, Aromatic; D011091:Polyesters; D011108:Polymers