title: Controllable degradation kinetics of POSS nanoparticle-integrated poly(ε-caprolactone urea)urethane elastomers for tissue engineering applications.
abstract: Biodegradable elastomers are a popular choice for tissue engineering scaffolds, particularly in mechanically challenging settings (e.g. the skin). As the optimal rate of scaffold degradation depends on the tissue type to be regenerated, next-generation scaffolds must demonstrate tuneable degradation patterns. Previous investigations mainly focussed on the integration of more or less hydrolysable components to modulate degradation rates. In this study, however, the objective was to develop and synthesize a family of novel biodegradable polyurethanes (PUs) based on a poly(ε-caprolactone urea)urethane backbone integrating polyhedral oligomeric silsesquioxane (POSS-PCLU) with varying amounts of hard segments (24%, 28% and 33% (w/v)) in order to investigate the influence of hard segment chemistry on the degradation rate and profile. PUs lacking POSS nanoparticles served to prove the important function of POSS in maintaining the mechanical structures of the PU scaffolds before, during and after degradation. Mechanical testing of degraded samples revealed hard segment-dependent modulation of the materials' viscoelastic properties, which was attributable to (i) degradation-induced changes in the PU crystallinity and (ii) either the presence or absence of POSS. In conclusion, this study presents a facile method of controlling degradation profiles of PU scaffolds used in tissue engineering applications.
authors.affiliation: Centre for Nanotechnology &Regenerative Medicine, UCL Division of Surgery &Interventional Science, University College London.
authors.forename: Lara
authors.initials: L
authors.lastname: Yildirimer
authors.affiliation: UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK.
authors.forename: Asma
authors.initials: A
authors.lastname: Buanz
authors.affiliation: UCL School of Pharmacy, University College London, 29-39 Brunswick Square, London WC1N 1AX, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Gaisford
authors.affiliation: Department of Chemistry, University of Warwick, CV4 7AL, Coventry, UK.
authors.forename: Edward L
authors.initials: EL
authors.lastname: Malins
authors.affiliation: School of Engineering and Materials Science, Queen Mary University of London, E1 4NS, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Remzi Becer
authors.affiliation: Department of Burns and Plastic Surgery, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, United Kingdom.|The Healing Foundation Children's Burns Research Centre, University of Bristol, Senate House, Tyndall Avenue, Bristol, BS8 1TH, UK.
authors.forename: Naiem
authors.initials: N
authors.lastname: Moiemen
authors.affiliation: Centre for Liver Research &NIHR BRU, Queen Elizabeth Hospital &University of Birmingham.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Reynolds
authors.affiliation: Centre for Nanotechnology &Regenerative Medicine, UCL Division of Surgery &Interventional Science, University College London.|Royal Free Hampstead NHS Trust Hospital, Pond Street, NW3 2QG, London, UK.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Seifalian
mesh_terms: D020341:Absorbable Implants; D055119:Elastic Modulus; D020724:Elastomers / Q000737:chemistry*; D019544:Equipment Failure Analysis; D007700:Kinetics; D008422:Materials Testing; D058726:Nanoconjugates / Q000737:chemistry* / Q000648:ultrastructure; D017646:Organosilicon Compounds / Q000737:chemistry*; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011474:Prosthesis Design; D013718:Tensile Strength; D023822:Tissue Engineering / Q000295:instrumentation; D054457:Tissue Scaffolds; D014520:Urethane / Q000737:chemistry; D014783:Viscosity
chemical_list: D020724:Elastomers; D058726:Nanoconjugates; D017646:Organosilicon Compounds; D011091:Polyesters; C521417:polyhedraloligosilsesquioxane; C016240:polycaprolactone; D014520:Urethane