Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8565, Japan.
J Biomed Sci. 2011 Aug 23;18(1):62. doi: 10.1186/1423-0127-18-62.
Safe and efficient gene transfer systems are needed for tissue engineering. We have developed an apatite composite layer including the bone morphogenetic protein-2 (BMP-2) gene and fibronectin (FB), and we evaluated its ability to induce bone formation.
An apatite composite layer was evaluated to determine the efficiency of gene transfer to cells cultured on it. Cells were cultured on a composite layer including the BMP-2 gene and FB, and BMP-2 gene expression, BMP-2 protein concentrations, alkaline phosphatase (ALP) activity, and osteocalcin (OC) concentrations were measured. A bone defect on the cranium of rats was treated with hydroxyapatite (HAP)-coated ceramic buttons with the apatite composite layer including the BMP-2 gene and FB (HAP-BMP-FB). The tissue concentration of BMP-2, bone formation, and the expression levels of the BMP-2, ALP, and OC genes were all quantified.
The apatite composite layer provided more efficient gene transfer for the cultured cells than an apatite composite layer without FB. The BMP-2 concentration was approximately 100-600 pg/mL in the cell-culture medium. Culturing the cells on the apatite composite layer for 27 days increased ALP activity and OC concentrations. In animal experiments, the tissue concentrations of BMP-2 were over 100 pg/mg in the HAP-BMP-FB group and approximately 50 pg/mg in the control groups. Eight weeks later, bone formation was more enhanced in the HAP-BMP-FB group than in the control groups. In the tissues surrounding the HAP button, the gene expression levels of ALP and OC increased.
The BMP-2 gene-FB-apatite composite layer might be useful for bone engineering.
组织工程需要安全有效的基因转移系统。我们已经开发了一种包括骨形态发生蛋白-2（BMP-2）基因和纤维连接蛋白（FB）的磷灰石复合层，并评估了其诱导骨形成的能力。
评估磷灰石复合层以确定其对培养在其上的细胞的基因转移效率。将细胞培养在包含 BMP-2 基因和 FB 的复合层上，并测量 BMP-2 基因表达、BMP-2 蛋白浓度、碱性磷酸酶（ALP）活性和骨钙素（OC）浓度。用含有 BMP-2 基因和 FB 的磷灰石复合层（HAP-BMP-FB）处理大鼠颅骨上的骨缺损。定量测定组织中的 BMP-2 浓度、骨形成以及 BMP-2、ALP 和 OC 基因的表达水平。
与不含 FB 的磷灰石复合层相比，磷灰石复合层为培养细胞提供了更有效的基因转移。细胞培养培养基中的 BMP-2 浓度约为 100-600pg/mL。在磷灰石复合层上培养细胞 27 天可增加 ALP 活性和 OC 浓度。在动物实验中，HAP-BMP-FB 组的组织中 BMP-2 浓度超过 100pg/mg，而对照组约为 50pg/mg。8 周后，HAP-BMP-FB 组的骨形成明显高于对照组。在 HAP 按钮周围的组织中，ALP 和 OC 的基因表达水平增加。
BMP-2 基因-FB-磷灰石复合层可能有助于骨工程。
