Muerza-Cascante Maria Lourdes, Shokoohmand Ali, Khosrotehrani Kiarash, Haylock David, Dalton Paul D, Hutmacher Dietmar W, Loessner Daniela
Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
The University of Queensland, UQ Centre for Clinical Research, Brisbane, QLD, Australia; The University of Queensland, UQ Diamantina Institute, Translational Research Institute, Brisbane, QLD, Australia.
Acta Biomater. 2017 Apr 1;52:145-158. doi: 10.1016/j.actbio.2016.12.040. Epub 2016 Dec 22.
Tissue engineering technology platforms constitute a unique opportunity to integrate cells and extracellular matrix (ECM) proteins into scaffolds and matrices that mimic the natural microenvironment in vitro. The development of tissue-engineered 3D models that mimic the endosteal microenvironment enables researchers to discover the causes and improve treatments for blood and immune-related diseases. The aim of this study was to establish a physiologically relevant in vitro model using 3D printed scaffolds to assess the contribution of human cells to the formation of a construct that mimics human endosteum. Melt electrospun written scaffolds were used to compare the suitability of primary human osteoblasts (hOBs) and placenta-derived mesenchymal stem cells (plMSCs) in (non-)osteogenic conditions and with different surface treatments. Using osteogenic conditions, hOBs secreted a dense ECM with enhanced deposition of endosteal proteins, such as fibronectin and vitronectin, and osteogenic markers, such as osteopontin and alkaline phosphatase, compared to plMSCs. The expression patterns of these proteins were reproducibly identified in hOBs derived from three individual donors. Calcium phosphate-coated scaffolds induced the expression of osteocalcin by hOBs when maintained in osteogenic conditions. The tissue-engineered endosteal microenvironment supported the growth and migration of primary human haematopoietic stem cells (HSCs) when compared to HSCs maintained using tissue culture plastic. This 3D testing platform represents an endosteal bone-like tissue and warrants future investigation for the maintenance and expansion of human HSCs.
This work is motivated by the recent interest in melt electrospinning writing, a 3D printing technique used to produce porous scaffolds for biomedical applications in regenerative medicine. Our team has been among the pioneers in building a new class of melt electrospinning devices for scaffold-based tissue engineering. These scaffolds allow structural support for various cell types to invade and deposit their own ECM, mimicking a characteristic 3D microenvironment for experimental studies. We used melt electrospun written polycaprolactone scaffolds to develop an endosteal bone-like tissue that promotes the growth of HSCs. We combine tissue engineering concepts with cell biology and stem cell research to design a physiologically relevant niche that is of prime interest to the scientific community.
组织工程技术平台为将细胞和细胞外基质（ECM）蛋白整合到体外模拟自然微环境的支架和基质中提供了独特机会。开发模拟骨内膜微环境的组织工程三维模型，使研究人员能够发现血液和免疫相关疾病的病因并改进治疗方法。本研究的目的是使用3D打印支架建立一个生理相关的体外模型，以评估人类细胞对构建模拟人类骨内膜结构的贡献。使用熔体静电纺丝书写支架比较原代人成骨细胞（hOBs）和胎盘来源的间充质干细胞（plMSCs）在（非）成骨条件下以及不同表面处理时的适用性。在成骨条件下，与plMSCs相比，hOBs分泌致密的ECM，骨内膜蛋白如纤连蛋白和玻连蛋白以及成骨标志物如骨桥蛋白和碱性磷酸酶的沉积增加。在来自三个个体供体的hOBs中可重复鉴定出这些蛋白质的表达模式。磷酸钙涂层支架在成骨条件下培养时可诱导hOBs表达骨钙素。与使用组织培养塑料培养的造血干细胞（HSCs）相比，组织工程骨内膜微环境支持原代人HSCs的生长和迁移。这个3D测试平台代表一种骨内膜样组织，值得对人类HSCs的维持和扩增进行进一步研究。
这项工作是受近期对熔体静电纺丝书写技术的关注所推动，该技术是一种用于生产用于再生医学中生物医学应用的多孔支架的3D打印技术。我们的团队一直是构建用于基于支架的组织工程的新型熔体静电纺丝设备的先驱之一。这些支架为各种细胞类型提供结构支持，使其能够侵入并沉积自身的ECM，模拟用于实验研究的特征性三维微环境。我们使用熔体静电纺丝书写的聚己内酯支架来开发促进HSCs生长的骨内膜样组织。我们将组织工程概念与细胞生物学和干细胞研究相结合，设计出一个科学界极为关注的生理相关生态位。
