The use of micromachined surfaces to investigate the cell behavioural factors essential to osseointegration.

OBJECTIVE

Although currently available implants can be used to achieve osseointegration under well-defined conditions, a greater understanding of cell behaviour is required to improve the designs and embark on actual tissue engineering.

MATERIALS AND METHODS

We employed micromachined substrata to investigate some of the main behavioural responses of osteoblasts from rat fetal calvaria to surface topography. In particular, confocal laser scanning microscopy (CLSM), differential interference contrast microscopy, time-lapse cinemicrography, immunofluorescence, digital radiography and image analysis were used to investigate cell adhesion, cell shape and cytoskeleton distribution, tissue organization, cell differentiation, and microenvironment.

RESULTS AND CONCLUSIONS

A grooved surface permitted the attachment of more cells than a smooth one. Cell shape and cytoskeleton were strikingly influenced as early as 20 min after cell attachment, when the cytoskeleton begins to align with the topography. Some grooved surfaces appeared to promote osteogenesis in vitro as assessed by the production of bone-like nodules. Moreover, these nodules align with the topography in vitro, and preliminary results indicate that bone-like tissue also aligns with grooves when such surfaces are implanted in vivo.