title: Poly(D,L-lactic acid) coated 45S5 Bioglass-based scaffolds: processing and characterization.
abstract: A comparative investigation has been carried out on the mechanical properties and bioactivity of Bioglass-based foams, before and after applying a poly(D,L-lactic acid) (PDLLA) coating layer on the foam struts. It was found that the bioactivity of foams upon immersion in simulated body fluid (SBF) was maintained in the PDLLA-coated foams; however, the transformation kinetics in SBF of the crystalline phase (Na(2)Ca(2)Si(3)O(9)) in the foam struts to an amorphous calcium phosphate phase was retarded by PDLLA coating. The compressive and three-point bending strengths of the Bioglass-based foams were slightly improved by the PDLLA-coating, and the work-of-fracture of the foams was considerably enhanced, as indicated by stress-strain curves. Immersion in SBF for 4 weeks led to a large decrease of the mechanical strength of as-sintered foams decreased (from 0.3 to 0.03 MPa), because of the transformation of the crystalline phase to an amorphous calcium phosphate. On the other hand, the mechanical strength was well-maintained in PDLLA-coated foams after immersion in SBF for 8 weeks. This behavior was attributed to the in-situ formation of a nanocomposite PDLLA/calcium phosphate film on the strut surfaces upon immersion in SBF.
authors.affiliation: Department of Materials, Imperial College London, London SW7 2BP, United Kingdom.
authors.forename: Q Z
authors.initials: QZ
authors.lastname: Chen
authors.forename: A R
authors.initials: AR
authors.lastname: Boccaccini
mesh_terms: D018786:Bone Substitutes / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D005898:Glass; D019344:Lactic Acid / Q000737:chemistry*; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*
chemical_list: D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D011091:Polyesters; D011108:Polymers; C425330:bioactive glass 45S5; D019344:Lactic Acid; C033616:poly(lactide)