Ozawa S, Kasugai S
Department of Maxillo-Facial Prosthetics, Life Science of Maxillo-Facial Systems, Tokyo, Japan.
Biomaterials. 1996 Jan;17(1):23-9. doi: 10.1016/0142-9612(96)80751-4.
Bone marrow stromal cells of femora from young adult rats produce bone-like mineralized tissue in culture. We evaluated three implant materials (hydroxyapatite (HA), glass-ceramics (GC) and commercial pure titanium (Ti)), as to their ability to provide an environment for marrow cells to differentiate into osteoblasts and function as suitable for mineralized tissue formation. We did this by measuring the DNA content, alkaline phosphatase (ALP) activity and calcium (Ca) content in culture, and the expression of osteopontin and bone sialoprotein by means of analysis of gene expression using Northern hybridization. DNA measurement showed no difference between each material, but ALP activity and Ca content in the culture on HA and GC were higher than on Ti and the control. An analysis of the gene expression revealed the highest expression of osteopontin and bone sialoprotein in the culture on HA. Mineralized nodule formation (both in area and number) was the most predominant on HA, followed by that on GC. These results showed that HA and GC provided a favourable situation for marrow cells to differentiate osteoblasts, resulting in a large amount of mineralized tissue formation on these surfaces. Present in vitro results could explain the rapid bone bonding of HA and GC in vivo.
年轻成年大鼠股骨的骨髓基质细胞在培养中可产生类骨矿化组织。我们评估了三种植入材料（羟基磷灰石（HA）、玻璃陶瓷（GC）和商业纯钛（Ti））为骨髓细胞分化成成骨细胞并形成适合矿化组织的环境提供条件的能力。我们通过测量培养物中的DNA含量、碱性磷酸酶（ALP）活性和钙（Ca）含量，以及利用Northern杂交进行基因表达分析来检测骨桥蛋白和骨唾液蛋白的表达，从而实现这一目的。DNA测量结果显示各材料之间无差异，但HA和GC培养物中的ALP活性和Ca含量高于Ti及对照组。基因表达分析显示，HA培养物中骨桥蛋白和骨唾液蛋白的表达最高。矿化结节形成（面积和数量方面）在HA上最为显著，其次是GC。这些结果表明，HA和GC为骨髓细胞分化成成骨细胞提供了有利条件，从而在这些表面形成了大量矿化组织。目前的体外实验结果可以解释HA和GC在体内的快速骨结合现象。
