title: Proliferation and differentiation of osteoblast-like cells on apatite-wollastonite/polyethylene composites.
abstract: Glass-ceramic apatite-wollastonite (A-W)/high-density polyethylene composite (AWPEX) materials have been designed to match the mechanical strength of human cortical bone and to provide favourable bioactivity, with potential use in many orthopaedic applications. To better understand AWPEX properties, the effects of surface finish and ceramic filler size and content on osteoblast-like cell attachment, proliferation, and differentiation were examined. Glass-ceramic content was tested at 30 and 50 vol% and median particle size at 4.5 and 7.7 microm. Samples were prepared as 1 x 10 x 10 mm(3) tiles with polished or rough surfaces, sterilized by gamma irradiation (2.5 Mrad), and characterized by scanning electron microscopy (SEM) and surface profilometry. Saos-2 human osteoblast-like cells were cultured on each surface at an initial concentration of 4500 cells/cm(2) for 1, 3, or 7 days. At each time point, adenosine triphosphate and alkaline phosphatase levels were measured to assess cell number and osteoblast differentiation. SEM imaging of cells on the composite surfaces showed preferential cell attachment to filler particles within the polymer matrix. Significant biochemical assay differences were found at 7 days, confirmed by ANOVA post-hoc testing using Bonferroni's correction. Overall, increased exposure of the glass-ceramic A-W phase in AWPEX through surface polishing, higher volume fraction and/or larger particle size was found to lead to an improved cell response.
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, Pembroke St., Cambridge CB2 3QZ, UK. smr31@cam.ac.uk
authors.forename: S M
authors.initials: SM
authors.lastname: Rea
authors.forename: R A
authors.initials: RA
authors.lastname: Brooks
authors.forename: S M
authors.initials: SM
authors.lastname: Best
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: W
authors.initials: W
authors.lastname: Bonfield
mesh_terms: D001031:Apatites / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D002516:Ceramics / Q000737:chemistry*; D006801:Humans; D008420:Manufactured Materials / Q000032:analysis; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology*; D020959:Polyethylene / Q000737:chemistry*; D012824:Silicic Acid / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001031:Apatites; D018786:Bone Substitutes; C077777:apatite-wollastonite-containing glass ceramic; D012824:Silicic Acid; D020959:Polyethylene