A First Step in De Novo Synthesis of a Living Pulp Tissue Replacement Using Dental Pulp MSCs and Tissue Growth Factors, Encapsulated within a Bioinspired Alginate Hydrogel
A First Step in De Novo Synthesis of a Living Pulp Tissue Replacement Using Dental Pulp MSCs and Tissue Growth Factors, Encapsulated within a Bioinspired Alginate Hydrogel
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DOI：
10.1016/j.joen.2015.03.006
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发表时间：
2015-07-01
影响因子：
4.2
通讯作者：
Green, David W.
中科院分区：
文献类型：
--
作者：
Bhoj, Manasi;Zhang, Chengfei;Green, David W.
前言：一种活体、自持的体外牙髓组织移植是一项诱人但尚未满足的生物工程挑战。我们的目标是创造基于藻酸盐的三维微环境，复制杜仲胶的形状，并包含祖细胞增殖和生长因子释放的关键元素。方法：以RGD为载体，以1：1的比例包裹牙髓干细胞和人脐静脉内皮细胞，并保留和传递血管内皮生长因子121和成纤维细胞生长因子两种关键生长因子。然后设计了一种方法，在定制的热敏性N-异丙基丙烯酰胺模具中使用RGD海藻酸盐复制杜仲胶的形状。在1至14天内，对含有不同排列的基于生长因子的胶囊的海藻酸盐塞进行了活性、增殖和释放动力学的测试和评估。结果：通过扫描电子显微镜和共聚焦显微镜观察，包裹的人内皮细胞和牙髓干细胞在整个构建过程中分布频繁和广泛。在所有测试环境中也有很高水平的生存能力。此外，以生长因子为基础的组的细胞增殖更高。两者的生长因子释放动力学也有显著差异。有趣的是，血管内皮生长因子和成纤维细胞生长因子的组合协同作用显著上调细胞增殖。结论：RGD-藻酸盐支架可以通过简单的模板制作成填充牙髓间隙的形状。在RGD-藻酸盐支架内的干细胞共培养中加入双重生长因子，可以创造出显著促进牙髓干细胞/人脐静脉内皮细胞组合增殖的微环境。
Introduction: A living, self-supporting pulp tissue replacement in vitro and for transplantation is an attractive yet unmet bioengineering challenge. Our aim is to create 3-dimensional alginate-based microenvironments that replicate the shape of gutta-percha and comprise key elements for the proliferation of progenitor cells and the release of growth factors. Methods: An RGD-bearing alginate framework was used to,encapsulate dental pulp stem cells and human umbilical vein endothelial cells in a ratio of 1:1. The alginate hydrogel also retained and delivered 2 key growth factors, vascular endothelial growth factor-121 and fibroblast growth factor, in a sufficient amount to induce proliferation. A method was then devised to replicate the shape of gutta-percha using RGD alginate within a custom-made mold of thermoresponsive N-isopropylacrylamide. Plugs of alginate containing different permutations of growth factor-based encapsulates were tested and evaluated for viability, proliferation, and release kinetics between 1 and 14 days. Results: According to scanning electron microscopic and confocal microscopic observations, the encapsulated human endothelial cells and dental pulp stem cell distribution were frequent and extensive throughout the length of the construct. There were also high levels of viability in all test environments. Furthermore, cell proliferation was higher in the growth factor-based groups. Growth factor release kinetics also showed significant differences between them. Interestingly, the combination of vascular endothelial growth factor and fibroblast growth factor synergize to significantly up-regulate cell proliferation. Conclusions: RGD-alginate scaffolds can be fabricated into shapes to fill the pulp space by simple templating. The addition of dual growth factors to cocultures of stem cells within RGD-alginate scaffolds led to the creation of microenvironments that significantly enhance the proliferation of dental pulp stem cell/human umbilical vein endothelial cell combinations.