Bone tissue engineering on calcium phosphate-coated titanium plates utilizing cultured rat bone marrow cells: A preliminary study

The use of osteoinductive in vitro tissue-coated implants in orthopaedic an d dental surgery (e.g. revision hip arthroplasty), could result in a better fixation of these implants. However, this tissue engineering technology ha s only proved to be effective in porous materials and not on flat implant s urfaces. In this study we have demonstrated that calcium phosphate-coated t itanium plates with a layer of cultured osteogenic cells and their extracel lular matrix can initiate bone formation in vivo. Both primary and subcultu red rat bone marrow cells were grown on to biomimetic calcium phosphate-coa ted titanium plates. After 7 d of cu Itu re, in the presence or absence of dexamethasone, the implants were subcutaneously im planted in nude mice for 4 wk. Control samples, which consisted of calcium phosphate-coated plates without cultured cells and porous calcium phosphate particles with or witho ut cultured cells, were also implanted subcutaneously. At autopsy, no bone formation could be detected on any of the control samples without cells and samples with subcultured cells, which were primary cultured in medium with out dexamethasone. In contrast, clear de novo bone formation could be obser ved on the calcium phosphate-coated plates and in the porous calcium phosph ate particles with primary or subcultured cells, which had been continuousl y cultured in medium with dexamethasone. These results indicate that this h ybrid technology offers great potential for the fixation of flat bone repla cement implants (e.g. artificial hips) in inferior bone in the future. (C) 1998 Kluwer Academic Publishers.