Cell architecture-cell function dependencies on titanium arrays with regular geometry.

Knowledge about biocomplexity of cell behavior in dependence on topographical characteristics is of clinical relevance for the development of implant designs in tissue engineering. The aim of this study was to find out cell architecture-cell function dependencies of human MG-63 osteoblasts on titanium (Ti) arrays with regular geometry. We compared cubic pillar structures (SU-8, dimension 3 x 3 x 5 and 5 x 5 x 5 mum) with planar samples. Electrochemical surface characterization revealed a low amount of surface energy (including polar component) for the pillar-structured surfaces, which correlated with a reduced initial cell adhesion and spreading. Confocal microscopy of cell's actin cytoskeleton revealed no stress fiber organization instead, the actin was concentrated in a surface geometry-dependent manner as local spots around the pillar edges. This altered cell architecture resulted in an impaired MG-63 cell function - the extracellular matrix proteins collagen-I and bone sialo protein (BSP-2) were synthesized at a significantly lower level on SU-8 pillar structures; this was accompanied by reduced beta3-integrin expression. To find out physicochemical factors pertaining to geometrically microstructured surfaces and their influence on adjoining biosystems is important for the development of biorelevant implant surfaces. Copyright 2010 Elsevier Ltd. All rights reserved.