AVS 46th International Symposium
    Biomaterial Interfaces Group Wednesday Sessions
       Session BI-WeP

Paper BI-WeP3
Osteoblast and Monocyte Response to Nanometre Surface Topography In Vitro

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: P. Hanarp, Chalmers University of Technology, Sweden
Authors: P. Hanarp, Chalmers University of Technology, Sweden
J. Rice, University of Liverpool, UK
J.A. Hunt, University of Liverpool, UK
J.A. Gallagher, University of Liverpool, UK
D.S. Sutherland, Chalmers University of Technology, Sweden
J. Gold, Chalmers University of Technology, Sweden
Correspondent: Click to Email
It is well known that cells adhering to surfaces are influenced by micron-sized chemical and topographical features, but very little is known about cell behaviour on surfaces with smaller, nanometre-sized features. We have used a method based on adsorption of colloidal particles to produce surfaces with well-controlled nanotopography. Surfaces of silicon wafers, pre-coated with 30 nm of thermally evaporated Ti, were treated with aluminium chloride hydroxide giving a net positive charge at neutral pH. Then the surfaces were exposed to dilute aqueous solutions of 110 nm polystyrene particles, and the negatively charged particles adsorbed onto the positively charged surfaces randomly by electrostatic interactions. A submonolayer of particles was obtained with coverage controlled either by salt concentration in the colloidal solution for equilibrium adsorptions, or particle concentration and adsorption time in interrupted (non-equilibrium) adsorptions. To produce chemically homogenous surfaces, a film of titanium (82.5nm) was evaporated on top of the particle films. The titanium film was naturally oxidised in air. The response of primary human osteoblasts and monocytes to these surfaces has been investigated. The cells were cultured in contact with the samples, 1) flat titanium oxide, 2) 10% and 3) 20% coverage of 110 nm particles coated in titanium oxide, for 1 and 7 days. They were examined using fluorescent cytoskeletal staining, confocal microscopy and lactate dehydrogenase assays in conjunction with flow cytometry. At each time point, both osteoblasts and monocytes cultured on the flat titanium oxide and the 20% coverage surfaces showed a greater affinity for adherence than at the 10% surfaces. SEM analysis of the samples after cell culture showed that the surfaces are still intact. This work is ongoing, but these preliminary results indicate that osteoblasts and monocytes are influenced by nanotopography in vitro.