面向组织工程反应器构建的上皮细胞高分化功能的微环境调控研究

The tissue engineering bioreactors of epithelium organ have been widely used as bioartificial devices and drug screening platform. However, their much lower functions than the in vivo organs largely limited their applications. The limitations may be due to the lack of the regulative mechanism on epithelial cell functions, leading to the ineffective design on bioreactors. Based on our previous finding that both cell self-assembly and monolayer culture on specific 3D lumen upregulated the epithelial cell functions, this project will try to investigate the regulation of various lumens in PEG and RGD modified PEG hydrogel on cell self-assembly and adhesion. The effect of different microenvironment on cell functions will be detected. Then, we establish the methodology to detect the mechanical force in 3D cultured cells inside the PEG/RGD-PEG hydrogel lumen. The relationship between mechanical force and cell functions will be investigated. Finally, under the guidance by the regulative rules of cell function via microenvironment and mechanical force, the micro-bioreactors with high expressed cell functions will be designed. As a whole, this project will illustrate the scientific relationship among functions, mechanical force and microenvironment of epithelia cells, and thus propose a possible design principle of tissue engineering bioreactors. This will promote the rational development of such bioreactors in field of tissue engineering.

具有上皮器官功能的组织工程反应器已被广泛应用于人工器官和新药筛选等领域，然而其功能远低于体内器官，无法满足应用要求。分析其原因，可能在于上皮细胞功能的调控规律尚未被阐明，导致了反应器设计缺乏指导原则。本项目基于前期发现的细胞自组装和特殊空腔单层贴壁均能上调分化功能的现象，首先研究PEG水凝胶空腔对细胞自组装与分化功能的影响，以及RGD修饰PEG水凝胶空腔对细胞单层贴壁与分化功能的影响，获得空腔微环境调节细胞功能的规律；随后，建立三维细胞应力检测方法，比较有无RGD修饰时空腔对细胞应力的影响规律，探索细胞应力与分化功能之间的内在联系；最后，以细胞功能受空腔微环境和细胞应力调控的规律为指导，构建高表达细胞功能的微型组织工程反应器。本研究拟阐释上皮细胞功能、细胞应力和培养微环境三者之间关系的科学问题，并提出组织工程反应器设计的新理念，使其设计更趋理性，进而推动组织工程相关领域的发展。

上皮器官功能的组织工程反应器已被广泛应用于人工器官和新药筛选等领域，然而其功能远低于体内器官，无法满足应用要求。其原因可能在于上皮细胞功能的调控规律尚未被阐明，导致了反应器设计缺乏指导原则。本项目较为系统地研究了微环境化学和力学性质对上皮细胞形态和功能的影响。结果发现，随着表面曲率的增加，细胞受到的应力增加，其分化功能也随之上升；表面粘附性的适度降低，也有助于提高细胞功能，同时降低了对蛋白和药物分子的吸附。根据这些发现的规律，我们设计了基于胶原水凝胶空腔的肾细胞反应器，发现肾细胞能形成类似肾脏的小管结构，并高表达肾功能；此外，我们还设计了基于3D打印技术的Caco-2细胞悬挂培养模型，用于药物口服吸收的评价，并可实现高通量筛选。因此，本研究阐释了上皮细胞功能、细胞应力和培养微环境三者之间关系，并提出组织工程反应器设计的新理念，使其设计更趋理性，进而推动组织工程相关领域的发展。