Enhancement of in vitro osteogenesis on titanium by chemically produced nanotopography

Abstract

The surface characteristics of biomaterials can influence protein adsorption, cellular functions, and ultimately tissue formation. Controlled chemical oxidation of titanium-based surfaces with a mixture of H(2)SO(4)/H(2)O(2) creates a nanopatterned surface that has been shown to affect early osteogenic events. The objective of this study was to evaluate the effect over time of this nanopattern on various key parameters of osteogenesis, and determine whether these effects ultimately translate into more mineralized matrix production. Osteogenic cells were obtained by enzymatic digestion of newborn rat calvaria and grown on treated and untreated titanium discs for periods of up to 14 days. Alkaline phosphatase activity peaked earlier and cell number was higher as of day 7 on the nanopatterned discs. Immunofluorescence showed that the treated surface favored early bone sialoprotein and osteopontin secretion, and fibronectin accumulation. Alizarin red staining revealed that, at days 10 and 14, there were significantly more mineralized nodules on treated than on untreated discs. These results demonstrate that simple chemical treatment of titanium with H(2)SO(4)/H(2)O(2) accelerates the in vitro osteogenic potential of calvaria-derived cells. They also suggest that this treatment may represent an advantageous approach for producing "intelligent surfaces" that stimulate bone formation and enhance bone-implant contact.

The role of well-defined nanotopography of titanium implants on osseointegration: cellular and molecular events in vivo

“…stem cells (MSCs) has largely been provided in vitro. 3,[19][20][21][22][23][24][25][26] Nanostructures support the anabolic path of bone formation, but less information is available with respect to the effect of nanostructures on osteoclasts. The latter is likely of equal importance by virtue of the important role of osteoblastosteoclast coupling and regulation of bone formation and remodeling during osseointegration.…”

“…Previous in vitro studies show that nanofeatures stimulate osteoblasts and their progenitors, including the osteogenic differentiation of MSCs. 10,[19][20][21]25,26,[44][45][46] However, many of these studies use osteogenic differentiation media in the culture, and so the effect of nanotopography would be considered as an adjunctive effect. It is therefore interesting that in absence of differentiation media, surface nanotopography did neither induce differentiation nor lineage-specific gene expression changes of MSCs.…”

Differentiation of MC3T3-E1 on poly(4-styrenesulfonic acid-co-maleic acid)sodium salt-coated films

“…Currently, a variety of strategies have been proposed to modify the surface of titanium-based implants in order to enhance bone growth and implant initial stability. These strategies include immobilization of bioactive protein or peptides (such as fibronectin 6) and RGD peptides 7) ), chemical treatment 8,9) , thermal treatment 10) , coating with hydroxyapatite, electrochemical method (also known as anodization or anodic oxidation 11) ), plasma surface treatment, micro-arc oxidation (MAO) 12) , sol-gel process 13) and polyelectrolyte multilayer (PEM) film.…”

Nanoscale Oxidative Patterning of Metallic Surfaces to Modulate Cell Activity and Fate

“…These surfaces have been shown to have beneficial effects on both initial and subsequent osteogenic (bone-forming) events in vitro. [24][25][26] The rationale for using H 2 SO 4 /H 2 O 2 to nanotexture metals was to permit simultaneous etching and oxidation of the surface in a controlled manner. 29 This method is effective, but the range of nanoporosity achieved so far is narrow.…”