The purposes of this study were to construct a novel tissue engineered bone composed of 3D-printed bioactive glass block/chitosan nanoparticles (BD/CSn) composites loaded with Nel-like Type I molecular-1 DNA (pDNA-NELL1) and/or bone marrow mesenchymal stem cells (BMSCs), and study their osteogenic activities by repairing bone defects in rhesus monkeys. CSn with NELL1 gene plasmid and rhesus monkey BMSCs were composited with a BD scaffold to prepare the tissue-engineered bone. Four adult female rhesus monkeys with 10- to 12-years old and 5-7 kg in weight were used in animal experiments. The first and second premolar teeth from four regions of each monkey were removed to form bone defects with size of 10 × 10 × 5 mm, which were then implanted with above-mentioned tissue engineered bone. At 12 weeks after the implantation, gross observations, X-ray and micro-CT observations revealed that the new bone was extremely close to normal bone in mass, density, hardness, and structure. The bony cortex was smooth and closely connected to the surrounding normal bone. Histological observations revealed moderate inflammation in the repair area, and the new bone tissues were similar to normal ones. In conclusion, tissue engineered bone of this study exhibited good osteoconductivity for promoting the formation of new alveolar bone tissue, and NELL1 gene played a promotional role in bone regeneration.

中文翻译：

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使用负载 NELL1 基因的 3D 打印纳米生物活性玻璃进行组织工程修复牙槽骨缺损。

本研究的目的是构建一种新型组织工程骨，该骨由 3D 打印的生物活性玻璃块/壳聚糖纳米颗粒 (BD/CSn) 复合材料组成，负载有类似 Nel 的 I 型分子 1 DNA (pDNA-NELL1) 和/或骨骨髓间充质干细胞（BMSC），并通过修复恒河猴的骨缺损来研究其成骨活性。将携带NELL1基因质粒的CSn与恒河猴BMSCs与BD支架复合，制备组织工程骨。动物实验采用4只10～12岁、体重5～7kg的成年雌性恒河猴。将每只猴子的四个区域的第一和第二前磨牙去除，形成尺寸为10×10×5毫米的骨缺损，然后植入上述组织工程骨。植入后12周，粗略观察，X射线和显微CT观察显示，新骨的质量、密度、硬度和结构与正常骨极其接近。骨皮质光滑，与周围正常骨连接紧密。组织学观察显示修复区域有中度炎症，新骨组织与正常骨组织相似。综上所述，本研究的组织工程骨表现出良好的骨传导性，有利于促进新牙槽骨组织的形成，且NELL1基因对骨再生起到促进作用。新骨组织与正常骨组织相似。综上所述，本研究的组织工程骨表现出良好的骨传导性，有利于促进新牙槽骨组织的形成，且NELL1基因对骨再生起到促进作用。新骨组织与正常骨组织相似。综上所述，本研究的组织工程骨表现出良好的骨传导性，有利于促进新牙槽骨组织的形成，且NELL1基因对骨再生起到促进作用。