High surface energy enhances cell response to titanium substrate microstructure

TLDR

Titanium implants rely on a biocompatible TiO₂ oxide layer, yet its low surface energy from adsorbed hydrocarbons and roughness limits osteogenic activity, although complex microtopography can enhance bone contact and osteoblast differentiation. The authors created hydroxylated/hydrated TiO₂ surfaces to preserve high surface energy. Osteoblasts on the modified surfaces showed enhanced differentiation markers and cytokine production, and 1α,25(OH)₂D₃ synergistically amplified these effects, indicating that high surface energy promotes bone formation. © 2005 Wiley Periodicals, Inc., J Biomed Mater Res, 2005.

Abstract

Abstract Titanium (Ti) is used for implantable devices because of its biocompatible oxide surface layer. TiO 2 surfaces that have a complex microtopography increase bone‐to‐implant contact and removal torque forces in vivo and induce osteoblast differentiation in vitro . Studies examining osteoblast response to controlled surface chemistries indicate that hydrophilic surfaces are osteogenic, but TiO 2 surfaces produced until now exhibit low surface energy because of adsorbed hydrocarbons and carbonates from the ambient atmosphere or roughness induced hydrophobicity. Novel hydroxylated/hydrated Ti surfaces were used to retain high surface energy of TiO 2 . Osteoblasts grown on this modified surface exhibited a more differentiated phenotype characterized by increased alkaline phosphatase activity and osteocalcin and generated an osteogenic microenvironment through higher production of PGE 2 and TGF‐β1. Moreover, 1α,25(OH) 2 D 3 increased these effects in a manner that was synergistic with high surface energy. This suggests that increased bone formation observed on modified Ti surfaces in vivo is due in part to stimulatory effects of high surface energy on osteoblasts. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005