Department of Comparative Biomedical Science, University of Teramo, Teramo, Italy.
PLoS One. 2013 May 17;8(5):e63256. doi: 10.1371/journal.pone.0063256. Print 2013.
Evidence has been provided that a cell-based therapy combined with the use of bioactive materials may significantly improve bone regeneration prior to dental implant, although the identification of an ideal source of progenitor/stem cells remains to be determined.
In the present research, the bone regenerative property of an emerging source of progenitor cells, the amniotic epithelial cells (AEC), loaded on a calcium-phosphate synthetic bone substitute, made by direct rapid prototyping (rPT) technique, was evaluated in an animal study.
Two blocks of synthetic bone substitute (∼0.14 cm(3)), alone or engineered with 1×10(6) ovine AEC (oAEC), were grafted bilaterally into maxillary sinuses of six adult sheep, an animal model chosen for its high translational value in dentistry. The sheep were then randomly divided into two groups and sacrificed at 45 and 90 days post implantation (p.i.). Tissue regeneration was evaluated in the sinus explants by micro-computer tomography (micro-CT), morphological, morphometric and biochemical analyses.
The obtained data suggest that scaffold integration and bone deposition are positively influenced by allotransplantated oAEC. Sinus explants derived from sheep grafted with oAEC engineered scaffolds displayed a reduced fibrotic reaction, a limited inflammatory response and an accelerated process of angiogenesis. In addition, the presence of oAEC significantly stimulated osteogenesis either by enhancing bone deposition or making more extent the foci of bone nucleation. Besides the modulatory role played by oAEC in the crucial events successfully guiding tissue regeneration (angiogenesis, vascular endothelial growth factor expression and inflammation), data provided herein show that oAEC were also able to directly participate in the process of bone deposition, as suggested by the presence of oAEC entrapped within the newly deposited osteoid matrix and by their ability to switch-on the expression of a specific bone-related protein (osteocalcin, OCN) when transplanted into host tissues.
有证据表明，细胞疗法与生物活性材料的联合应用可显著提高牙种植前的骨再生效果，尽管理想祖细胞/干细胞来源的确定仍有待研究。
本研究中，通过动物实验评估了一种新兴祖细胞来源——羊膜上皮细胞（AEC）在加载于由直接快速成型（rPT）技术制备的磷酸钙合成骨替代物上的骨再生特性。
将 2 块（约 0.14cm3）合成骨替代物单独或用 1×106 只绵羊来源的 AEC（oAEC）进行工程化处理后，双侧植入 6 只成年绵羊的上颌窦，选择该动物模型是因为其在牙科学中有较高的转化价值。绵羊随后随机分为两组，并在植入后 45 天和 90 天处死。通过微计算机断层扫描（micro-CT）、形态学、形态计量学和生化分析评估窦内标本的组织再生情况。
所得数据表明，同种异体移植的 oAEC 可正向影响支架整合和骨沉积。与未工程化支架组相比，oAEC 工程化支架组的窦内标本显示出较少的纤维组织反应、有限的炎症反应和加速的血管生成过程。此外，oAEC 的存在可通过增强骨沉积或使更多的骨核形成焦点来显著刺激成骨。除了 oAEC 在成功引导组织再生的关键事件中发挥的调节作用（血管生成、血管内皮生长因子表达和炎症）之外，本文数据还表明，oAEC 还可直接参与骨沉积过程，这可通过 oAEC 被包裹在新形成的类骨质基质内以及其在移植入宿主组织时可开启特定骨相关蛋白（骨钙素，OCN）的表达得到证实。
