title: Macromolecular design of aliphatic polyesters with maintained mechanical properties and a rapid, customized degradation profile.
abstract: An innovative type of triblock copolymer that maintains and even increases the mechanical properties of poly(l-lactide) (PLLA) and poly(ε-caprolactone) (PCL) with a controlled, predictable, and rapid degradation profile has been synthesized. Elastic triblock copolymers were formed from the hydrophobic and crystalline PLLA and PCL with an amorphous and hydrophilic middle block of poly(but-2-ene-1,4-diyl malonate) (PBM). The polymers were subjected to degradation in PBS at 37 °C for up to 91 days. Prior to degradation, ductility of the PLLA-PBM-PLLA was approximately 4 times greater than that of the homopolymer of PLLA, whereas the modulus and tensile stress at break were unchanged. A rapid initial hydrolysis in the amorphous PBM middle block changed the microstructure from triblock to diblock with a significant reduction in ductility and molecular weight. The macromolecular structure of the triblock copolymer of PLLA and PBM generates a more flexible and easier material to handle during implant, with the advantage of a customized degradation profile, demonstrating its potential use in future biomedical applications.
authors.affiliation: Department of Fibre and Polymer Technology, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Malberg
authors.forename: Anders
authors.initials: A
authors.lastname: Hoglund
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Albertsson
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000378:metabolism; D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D055119:Elastic Modulus; D004548:Elasticity; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008314:Malonates / Q000737:chemistry*; D008422:Materials Testing; D015394:Molecular Structure; D008970:Molecular Weight; D011090:Polyenes / Q000737:chemistry*; D011091:Polyesters / Q000138:chemical synthesis* / Q000378:metabolism; D058105:Polymerization; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D008314:Malonates; D011090:Polyenes; D011091:Polyesters; C016240:polycaprolactone; C033616:poly(lactide); C008952:polybutene