Research Center for Nano-Biomaterials, Analytical & Testing Center, Sichuan University, Chengdu, China.
Technology Transfer Center, Kunming Medical University, Kunming, China.
Cell Prolif. 2019 Sep;52(5):e12658. doi: 10.1111/cpr.12658. Epub 2019 Jul 11.
The bone tissue engineering primarily focuses on three-dimensional co-culture systems, which physical and biological properties resemble the cell matrix of actual tissues. The complex dialogue between bone-forming and endothelial cells (ECs) in a tissue-engineered construct will directly regulate angiogenesis and bone regeneration. The purpose of this study was to investigate whether co-culture between osteogenic and angiogenic cells derived by bone mesenchymal stem cells (MSCs) could affect cell activities and new bone formation.
Mesenchymal stem cells were dually induced to differentiate into osteogenic cells (OMSCs) and ECs; both cell types were co-cultured at different ratios to investigate their effects and underlying mechanisms through ELISA, RT-qPCR and MTT assays. The selected cell mixture was transplanted onto a nano-hydroxyapatite/polyurethane (n-HA/PU) scaffold to form a cell-scaffold construct that was implanted in the rat femoral condyles. Histology and micro-CT were examined for further verification.
ELISA and gene expression studies revealed that co-cultured OMSCs/ECs (0.5/1.5) significantly elevated the transcription levels of osteogenic genes such as ALP, Col-I and OCN, as well as transcription factors Msx2, Runx2 and Osterix; it also upregulated angiogenic factors of vascular endothelial growth factor (VEGF) and CD31 when compared with cells cultured alone or in other ratios. The optimized OMSCs/ECs group had more abundant calcium phosphate crystal deposition, further facilitated their bone formation in vivo.
The OMSCs/ECs-scaffold constructs at an optimal cell ratio (0.5/1.5) achieved enhanced osteogenic and angiogenic factor expression and biomineralization, which resulted in more effective bone formation.
骨组织工程主要侧重于三维共培养系统，其物理和生物特性类似于实际组织的细胞基质。在组织工程构建体中，成骨细胞和内皮细胞（ECs）之间的复杂对话将直接调节血管生成和骨再生。本研究旨在探讨成骨细胞和血管生成细胞是否可以通过骨髓间充质干细胞（MSCs）共培养来影响细胞活性和新骨形成。
将间充质干细胞双重诱导分化为成骨细胞（OMSCs）和 ECs；将两种细胞类型以不同比例共培养，通过 ELISA、RT-qPCR 和 MTT 检测来研究它们的作用和潜在机制。选择的细胞混合物被移植到纳米羟基磷灰石/聚氨酯（n-HA/PU）支架上，形成细胞-支架构建体，然后植入大鼠股骨髁。通过组织学和 micro-CT 进行进一步验证。
ELISA 和基因表达研究表明，共培养的 OMSCs/ECs（0.5/1.5）显著提高了碱性磷酸酶（ALP）、Col-I 和 OCN 等成骨基因以及 Msx2、Runx2 和 Osterix 等转录因子的转录水平；与单独培养或其他比例培养的细胞相比，它还上调了血管内皮生长因子（VEGF）和 CD31 等血管生成因子。优化的 OMSCs/ECs 组具有更丰富的钙磷晶体沉积，进一步促进了其体内成骨作用。
最佳细胞比例（0.5/1.5）的 OMSCs/ECs-支架构建体实现了增强的成骨和血管生成因子表达和生物矿化，从而更有效地促进了骨形成。
