McLoughlin Shannon T, Wilcox Paige, Caccamese John F, Fisher John P
Center for Engineering Complex Tissues, University of Maryland, College Park, Maryland, USA.
Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland, USA.
Tissue Eng Part A. 2025 Apr 21. doi: 10.1089/ten.tea.2025.0038.
The periosteum serves as a local source of osteoprogenitor cells and vasculature, therefore influencing the key processes of osteogenesis and neovascularization during bone healing. However, it is often not considered in traditional bone tissue engineering strategies. The periosteum consists of two stratified cell layers, including an inner cambium layer, which serves as a local source of osteoblasts (OBs) and osteoprogenitor cells, and an outer fibrous layer, which hosts vasculature, collagen fibers, and support cells. While several studies have investigated different methodologies to produce tissue-engineered periosteum (TEP) substitutes, few have evaluated the roles of specific cell types within the inner cambium layer and their patterning in 3D environments on underlying bone tissue development. Therefore, we sought to investigate whether mesenchymal stem cells (MSCs) alone, OBs alone, or a 1:1 mixture of the two would result in increased osteogenic differentiation of bone layer MSCs in a 3D bioprinted periosteum-bone coculture model . We first evaluated these effects in a 2D transwell model, demonstrating that OB-containing cultures, either alone or in a mixed population with MSCs, upregulated alkaline phosphatase activity and runt-related transcription factor 2 () expression. In the 3D bioprinted model, the mixed population showed higher levels of expression and calcium deposition, indicating increased osteogenic differentiation within the bone layer. Results obtained from this study provide evidence that a mixed population of MSCs and OBs within the inner cambium layer of TEP can increase bone regeneration.
骨膜作为骨祖细胞和脉管系统的局部来源，因此影响骨愈合过程中的成骨和新血管形成的关键过程。然而，传统的骨组织工程策略中通常不考虑骨膜。骨膜由两层分层细胞组成，包括内层的形成层，它作为成骨细胞（OBs）和骨祖细胞的局部来源，以及外层的纤维层，其中包含脉管系统、胶原纤维和支持细胞。虽然有几项研究调查了生产组织工程骨膜（TEP）替代物的不同方法，但很少有研究评估内层形成层内特定细胞类型的作用及其在三维环境中对下层骨组织发育的模式。因此，我们试图研究单独的间充质干细胞（MSCs）、单独的OBs或两者1:1的混合物是否会在三维生物打印的骨膜-骨共培养模型中导致骨层MSCs的成骨分化增加。我们首先在二维Transwell模型中评估了这些影响，结果表明含OBs的培养物，无论是单独的还是与MSCs混合的群体，都上调了碱性磷酸酶活性和 runt相关转录因子2（）的表达。在三维生物打印模型中，混合群体显示出更高水平的表达和钙沉积，表明骨层内的成骨分化增加。本研究获得的结果提供了证据，表明TEP内层形成层内的MSCs和OBs混合群体可以增加骨再生。
