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 osteoblastlike
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 mm. Samples were prepared as 11010mm3 tiles withpolish ed or roughsurfaces, 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 eachsurface at an initial concentration of 4500 cells/cm2 for 1, 3, or 7 days. At eachtime 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.
r 2003 Elsevier Ltd. All rights reserved.
Keywords: Alkaline phosphatase; Cell proliferation; Composite;