Modulation of human osteoblasts by metal surface chemistry

Abstract

The use of metal implants in dental and orthopedic surgery is continuously expanding and highly successful. While today longevity and load-bearing capacity of the implants fulfill the expectations of the patients, acceleration of osseointegration would be of particular benefit to shorten the period of convalescence. To further clarify the options to accelerate the kinetics of osseointegration, within this study, the osteogenic properties of structurally identical surfaces with different metal coatings were investigated. To assess the development and function of primary human osteoblasts on metal surfaces, cell viability, differentiation, and gene expression were determined. Titanium surfaces were used as positive, and surfaces coated with gold were used as negative controls. Little differences in the cellular parameters tested for were found when the cells were grown on titanium discs sputter coated with titanium, zirconium, niobium, tantalum, gold, and chromium. Cell number, activity of cell layer-associated alkaline phosphatase (ALP), and levels of transcripts encoding COL1A1 and BGLAP did not vary significantly in dependence of the surface chemistry. Treatment of the cell cultures with 1,25(OH)2 D3 /Dex, however, significantly increased ALP activity and BGLAP messenger RNA levels. The data demonstrate that the metal layer coated onto the titanium discs exerted little modulatory effects on cell behavior. It is suggested that the microenvironment regulated by the peri-implant tissues is more effective in regulating the tissue response than is the material of the implant itself.

The progress on physicochemical properties and biocompatibility of tantalum-based metal bone implants

“…Compared with Ta, Ti cell proliferation was significantly increased after 4 days, the average cell area of Cr decreased and the proliferation ability was poor [71]. This is slightly different from the results of Hofstetter et al's in vitro study on the metal coating, which prepared 6 kinds of coatings by plasma vapor deposition (PVD), among them, Ta is more effective than Ti in cell proliferation, and similarly, Cr has the lowest surface proliferation [72]. From these results, it can be seen that the biocompatibility of Cr is poor.…”

“…The morphological expansion, proliferation, and differentiation of cells on the surface of biomaterials are related to the expression of a series of genes and proteins after the cells are stimulated by the surface of the biomaterial. Some studies have shown that Ta has better osteogenic differentiation ability than Ti in prosthesis and implant coating, and the structural and chemical properties of the material surface have a significant influence on cell behavior, as well as the subsequent bone induction and integration [70][71][72]. The expression of ALP is a marker of osteoblast differentiation, expression analysis of bonerelated genes is also used to evaluate the osteogenic differentiation ability of cells, for example, type I collagen COL1A1 is the main component of the extracellular matrix of bone cells, and BGLAP is a marker of late osteoblast differentiation [72].…”

Porous titanium and Ti–35Nb alloy: effects on gene expression of osteoblastic cells derived from human alveolar bone

“…The expression of genes and proteins involved in bone growth and repair are valuable markers for demonstrating the osteoblast phenotype in vitro. Studies of variable composition and surface topographies of new developed material investigate gene expression of osteoblasts to prove their biocompatibility [33,35,37,44].…”

Magnesium‐based bone implants: Immunohistochemical analysis of peri‐implant osteogenesis by evaluation of osteopontin and osteocalcin expression

“…Other non-dietary elements included in current alloys, as zirconium, neodymium and "trace" rare earth elements, are supposed as low toxic; they are able to exert insignificant effects on osteoblasts. 7,34 Anyway, it is quite difficult to isolate and elucidate the specific impact of elements with small concentrations, which overlapped with the impact of magnesium and mechanical impact due to continuous corrosion and third-body wear formation on peri-implant osteogenesis in vivo.…”