ter Brugge Petra J, Wolke Joop G C, Jansen John A
Department of Biomaterials, University Medical Center Nijmegen, The Netherlands.
Clin Oral Implants Res. 2003 Aug;14(4):472-80. doi: 10.1034/j.1600-0501.2003.00886.x.
The aim of this study was to investigate the effect of calcium phosphate coating crystallinity and composition on the proliferation and differentiation of rat bone marrow (RBM) cells. Grit-blasted titanium substrates were provided with thin sputter-coated calcium phosphate (Ca-P) films of different composition. The Ca-P-coated substrates were used as-sputtered or were heat-treated. XRD measurements showed that the as-sputtered coatings had an amorphous structure, whereas the heat-treated substrates showed an amorphous-crystalline structure. RBM cells were cultured on these substrates and on noncoated titanium substrates. After specific culture times, the expression of osteogenic markers by the cells was studied. On the amorphous-crystalline coatings as well as on titanium substrates, RBM cells proliferated, expressed alkaline phosphatase and showed mineralization. More mineralization was found on the amorphous-crystalline coatings than on the titanium substrates. Some precipitation was also found on substrates that were incubated in complete culture medium without cells. This precipitate disappeared after prolonged incubation. Alkaline phosphatase expression differed on the various amorphous-crystalline Ca-P-coated substrates, but no difference was found in the mineralization on these substrates. The amorphous Ca-P coatings showed extensive dissolution and some signs of precipitation after longer culture periods. Proliferation and differentiation of RBM cells was not seen on the amorphous coatings, regardless of Ca-P composition. We conclude that amorphous-crystalline Ca-P coatings stimulate differentiation of RBM cells, with only limited differences between coatings of various composition. In contrast, Ca-P coatings with an amorphous structure inhibit the growth and differentiation of RBM cells. This effect was found on all amorphous substrates, regardless of Ca-P composition.
本研究的目的是探究磷酸钙涂层的结晶度和组成对大鼠骨髓（RBM）细胞增殖和分化的影响。对喷砂处理的钛基底进行不同组成的薄溅射磷酸钙（Ca-P）膜涂覆。Ca-P涂覆的基底直接使用溅射态的或经过热处理。X射线衍射（XRD）测量表明，溅射态涂层具有非晶结构，而热处理后的基底呈现非晶-结晶结构。将RBM细胞培养在这些基底以及未涂覆的钛基底上。在特定培养时间后，研究细胞中成骨标志物的表达情况。在非晶-结晶涂层以及钛基底上，RBM细胞均发生增殖、表达碱性磷酸酶并出现矿化现象。在非晶-结晶涂层上发现的矿化现象比在钛基底上更多。在不含细胞的完全培养基中孵育的基底上也发现了一些沉淀。长时间孵育后这种沉淀消失。不同非晶-结晶Ca-P涂覆基底上的碱性磷酸酶表达存在差异，但这些基底上的矿化情况未发现差异。经过较长培养期后，非晶Ca-P涂层出现大量溶解并伴有一些沉淀迹象。无论Ca-P组成如何，在非晶涂层上均未观察到RBM细胞的增殖和分化。我们得出结论，非晶-结晶Ca-P涂层可刺激RBM细胞的分化，不同组成的涂层之间差异有限。相比之下，具有非晶结构的Ca-P涂层会抑制RBM细胞生长和分化。在所有非晶基底上均发现了这种效应，与Ca-P组成无关。
