Nakaoka Ryusuke, Ahmed Saifuddin, Tsuchiya Toshie
Division of Medical Devices, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
J Biomed Mater Res A. 2005 Aug 1;74(2):181-6. doi: 10.1002/jbm.a.30328.
The aseptic loosening of artificial joints with associated periprosthetic bone resorption may be partly due to the suppression of osteoblast function to form new bone by wear debris from the joint. To assess the effect of wear debris on osteoblasts, effects of model wear debris on gap junctional intercellular communication (GJIC) of normal human osteoblasts were estimated. The GJIC activity of the osteoblasts after a 1-day incubation with the microspheres was similar to that of normal osteoblasts. However, hydroxy apatite particles, which have been reported to enhance the differentiation of osteoblasts in contact with them, enhanced the GJIC function of the osteoblasts. From RT-PCR studies, not only connexin 43 but also connexin 45 is suggested to play a role in the GJIC of the osteoblasts in an early stage of coculture with the microspheres, although it is still unclear how these connexins work and are regulated in the GJIC and differentiation. However, this study suggests that there is a relationship between the early levels of GJIC and the differentiation of the cells. Therefore, estimating the effect of biomaterials, even in the microsphere form, on the GJIC of model cells, with which the biomaterials may be in contact in vivo, can provide important information about their biocompatibility.
人工关节无菌性松动并伴有假体周围骨吸收，可能部分归因于关节磨损碎屑抑制成骨细胞形成新骨的功能。为评估磨损碎屑对成骨细胞的影响，我们评估了模型磨损碎屑对正常人成骨细胞缝隙连接细胞间通讯（GJIC）的影响。微球孵育1天后，成骨细胞的GJIC活性与正常成骨细胞相似。然而，据报道能增强与其接触的成骨细胞分化的羟基磷灰石颗粒，增强了成骨细胞的GJIC功能。从逆转录聚合酶链反应（RT-PCR）研究来看，与微球共培养早期阶段，不仅连接蛋白43，连接蛋白45也被认为在成骨细胞的GJIC中发挥作用，尽管目前仍不清楚这些连接蛋白在GJIC和分化过程中是如何起作用及受到调控的。然而，本研究表明GJIC的早期水平与细胞分化之间存在关联。因此，评估生物材料（即使是微球形式）对模型细胞GJIC的影响（生物材料在体内可能与这些模型细胞接触），可为其生物相容性提供重要信息。
