COMPARISON OF GROWTH AND METABOLISM OF AVIAN OSTEOBLASTS ON POLISHED DISKS VERSUS THIN-FILMS OF TITANIUM-ALLOY

The purpose of this study was to evaluate the efficacy of using high v acuum, thermal evaporation to deposit thin films of Ti-6Al-4V onto pla tes for subsequent cell culture investigations. Osteoblastic response to thin-film coated plates was compared to that of cells grown on Ti a lloy disk inserts and uncoated culture plates. The Ti alloy disks were polished, cleaned, and passivated following a commercial protocol for orthopedic implants. Mean surface roughness was 262 nm for the Ti all oy disks and 4.756 nm for the coated culture plates. Osteoblasts isola ted from 16-day chick embryo calvariae were cultured on polystyrene, t hin films, and disks. At confluence, the cells were cultured an additi onal 48 h and were evaluated for cell number (DNA content), rate of gl ycolysis (lactate production), alkaline phosphatase activity (ALPase), and collagenous (H-3-proline hydroxylation) and noncollagenous protei n synthesis. Cell morphology was similar for the controls, disks, and thin-film groups. DNA, lactate, cell layer ALPase, H-3-hydroxyproline, and noncollagenous protein were not different (p > 0.05) among the co ntrol, thin-film, and disk groups. Medium ALPase was lower (p < 0.05) in the thin-film group compared to the control group. Although aluminu m and vanadium percentages varied from nominal in the thin-film groups (11A1-2V as opposed to 6A1-4V), avian osteoblasts responded similarly to the Ti alloy thin films, disks, and uncoated culture plates for th e smooth surfaces tested. The thin-film cell culture system used for e lemental material studies appears to offer a promising method for the investigation of cellular response to alloyed biomaterials as well. Pr oper adjustments in alloy percentages before deposition, however, need to be made if thermal evaporation is utilized. (C) 1998 John Wiley & Sons, Inc.