Interfacial phenomena: Anin vitro study of the effect of calcium phosphate (Ca-P) ceramic on bone formation

Abstract

In previous studies we developed a RF magnetron sputter technique for the production of thin Ca-P coatings. With this technique coatings can be produced that vary in Ca/P ratio as well as in structural appearance. The aim of this investigation was to obtain more understanding of the biological behavior of these coatings by way of in vitro experiments. The effect of noncoated titanium (Ti) and three different Ca-P-sputtered surfaces on the proliferation and differentiation (morphology and matrix production) of osteoblast-like cells was studied. Proliferation was determined using counting procedures; morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fluorescent markers and energy-dispersive X-ray microanalysis (EDX) were used to obtain quantitative and compositional information about the resultant calcified extracellular matrix (ECM). Results demonstrated that proliferation of the osteoblast-like cells was significantly (p < 0.05) higher on noncoated than on Ca-P-coated samples. On the other hand, more mineralized ECM was formed on the coated surfaces. In addition, TEM confirmed that the cells on the coated substrates were surrounded by ECM with collagen fibers embedded in crystallized, needle-shaped structures. On the basis of these findings, we concluded that: (1) the investigated Ca-P sputter coatings possess the capacity to activate the differentiation and expression of osteogenic cells, and (2) bone formation proceeds faster on Ca-P surfaces than on Ti substrates. Further, this bone-inductive effect appeared to be dependent on the Ca-P ratio of the deposited coatings.

The effect of alkali- and heat-treated titanium and apatite-formed titanium on osteoblastic differentiation of bone marrow cells

“…25 Furthermore, Hulshoff et al reported that the bone marrow cells formed more mineralized extracellular matrices on magnetron-sputtered Ca-P coating titanium than pure titanium, and the proliferation of the cells was significantly higher on the pure titanium than the coated titanium. 41 Our results are consistent with these data. Apatite formed on titanium probably promotes adsorption of proteins from the serum, which are then subsequently utilized by the osteoblasts to form a mineralized extracellular matrix, as previously described.…”

Application of magnetron sputtering for producing bioactive ceramic coatings on implant materials

“…With RF magnetron sputter technique coatings can be produced that vary in Ca/P ratio as well as in structural appearance (Hulshoff et al 1998). All heat-treated coatings appeared to be stable in simulated body fluid (Yonggang Yan et al 2006).…”

Initial interfacial healing events around calcium phosphate (Ca‐P) coated oral implants

“…The advan tages of this process are that the deposited films are very thin (100 nm -4 pm), well-defined in structure and composition, and strongly bonded to the underlying metal substrate. Previous cell cul ture and animal experiments (Hulshoff et aL 1995(Hulshoff et aL , 1996b already showed the biological feasibility of this type of coating.…”