Ohgushi H, Dohi Y, Tamai S, Tabata S
Department of Orthopedics, Nara Medical University, Japan.
J Biomed Mater Res. 1993 Nov;27(11):1401-7. doi: 10.1002/jbm.820271107.
Bioactive materials such as hydroxyapatite ceramics (HA) are known to show a stable interfacial bond with tissues (the bone bonding property has been especially well documented). However, the biological phenomenon on the material surface that evoke bone bonding is not well documented. To address this issue, composites of porous HA and rat marrow cells were implanted into ectopic (subcutaneous) sites. At 3 weeks after implantation, active osteoblasts lining the HA surface initiated bone formation, primarily as mature bone (lamellar type). Gene expression study using Northern blot analysis of the composites showed that alkaline phosphatase (ALP) and bone Gla protein (BGP) mRNAs began to appear at 2 weeks and the level of BGP mRNA at 4 weeks was comparable to that of cancerous bone. However, HA implantation without marrow cells did not show bone formation and neither BGP nor ALP mRNA were detected. These results indicate that the HA surface is able to support cell differentiation (osteoblastic phenotype expression of marrow stromal stem cells), as well as cell coordination resulting in mature bone formation that bonds to the HA.
生物活性材料，如羟基磷灰石陶瓷（HA），已知能与组织形成稳定的界面结合（骨结合特性已有充分记录）。然而，材料表面引发骨结合的生物学现象尚无充分记录。为解决这一问题，将多孔HA与大鼠骨髓细胞的复合材料植入异位（皮下）部位。植入后3周，HA表面排列的活跃成骨细胞开始形成骨组织，主要为成熟骨（板层型）。对复合材料进行Northern印迹分析的基因表达研究表明，碱性磷酸酶（ALP）和骨钙蛋白（BGP）mRNA在2周时开始出现，4周时BGP mRNA水平与癌骨相当。然而，未植入骨髓细胞的HA未显示骨形成，也未检测到BGP和ALP mRNA。这些结果表明，HA表面能够支持细胞分化（骨髓基质干细胞的成骨细胞表型表达），以及细胞协调，从而导致与HA结合的成熟骨形成。
