Time-dependent phenotypic response of a model osteoblast cell line (hFOB 1.19, ATCC,
and CRL-11372) to substrata with varying surface chemistry and topography is reviewed
within the context of extant cell-adhesion theory. Cell-attachment and proliferation
kinetics are compared using morphology as a leading indicator of cell phenotype. Expression
of (alpha2, alpha3, alpha4, alpha5, alphav, beta1, and beta3) integrins, vinculin,
as well as secretion of osteopontin (OP) and type I collagen (Col I) supplement this
visual assessment of hFOB growth. It is concluded that significant cell-adhesion events-contact,
attachment, spreading, and proliferation-are similar on all surfaces, independent
of substratum surface chemistry/energy. However, this sequence of events is significantly
delayed and attenuated on hydrophobic (poorly water-wettable) surfaces exhibiting
characteristically low-attachment efficiency and long induction periods before cells
engage in an exponential-growth phase. Results suggest that a 'time-cell-substratum-compatibility-superposition
principle' is at work wherein similar bioadhesive outcomes can be ultimately achieved
on all surface types with varying hydrophilicity, but the time required to arrive
at this outcome increases with decreasing cell-substratum-compatibility. Genomic and
proteomic tools offer unprecedented opportunity to directly measure changes in the
cellular machinery that lead to observed cell responses to different materials. But
for the purpose of measuring structure-property relationships that can guide biomaterial
development, genomic/proteomic tools should be applied early in the adhesion/spreading
process before cells have an opportunity to significantly remodel the cell-substratum
interface, effectively erasing cause and effect relationships between cell-substratum-compatibility
and substratum properties. IMPACT STATEMENT: This review quantifies relationships
among cell phenotype, substratum surface chemistry/energy, topography, and cell-substratum
contact time for the model osteoblast cell line hFOB 1.19, revealing that genomic/proteomic
tools are most useful in the pursuit of understanding cell adhesion if applied early
in the adhesion/spreading process.