The effects of dynamic compression on the development of cartilage grafts engineered using bone marrow and infrapatellar fat pad derived stem cells
The effects of dynamic compression on the development of cartilage grafts engineered using bone marrow and infrapatellar fat pad derived stem cells
复制标题
DOI：
10.1088/1748-6041/10/5/055011
复制
发表时间：
2015-09-01
影响因子：
4
通讯作者：
Kelly, Daniel J.
中科院分区：
文献类型：
--
作者：
Luo, Lu;Thorpe, Stephen D.;Kelly, Daniel J.
使细胞接种的支架或水凝胶经受生物物理刺激的生物反应器已被用于改善组织工程化软骨的功能性，并探索此类构建体如何响应关节特异性机械负荷的应用。一种特定的细胞类型是否适当地响应生理水平的生物物理刺激可以被认为是其适用于软骨组织工程应用的关键决定因素。本研究的目的是确定动态压缩对从不同组织来源分离的干细胞的软骨形成的影响。将猪骨髓（BM）和髌下脂肪垫（FP）衍生的干细胞包封在琼脂糖水凝胶中，并在自由膨胀（FS）条件下在软骨形成培养基中培养21 d，之后使样品经受10%应变（1 Hz，1 h d（-1））的动态压缩（DC）另外21 d。骨髓来源的干细胞（BMSC）和FP来源的干细胞（FPSC）都能够产生具有接近天然水平的硫酸化糖胺聚糖（sGAG）含量的软骨组织，尽管工程化移植物的空间发育强烈依赖于干细胞来源。从两种干细胞来源产生的软骨移植物的机械性能也接近在脊椎未成熟动物中观察到的机械性能。根据干细胞来源和供体，DC的应用增强或对使用BMSC或FPSC工程化的软骨移植物的功能发育没有显著影响。BMSC接种的构建体经受DC染色，I型胶原蛋白染色强度较低。此外，组织学和显微计算机断层扫描分析表明，骨髓间充质干细胞接种的结构内的矿物质沉积受到抑制的应用程序的DC。因此，虽然DC在体外的应用可能只会导致软骨移植物的机械功能的适度改善，但它可能在表型稳定的构建体的开发中发挥重要作用。
Bioreactors that subject cell seeded scaffolds or hydrogels to biophysical stimulation have been used to improve the functionality of tissue engineered cartilage and to explore how such constructs might respond to the application of joint specific mechanical loading. Whether a particular cell type responds appropriately to physiological levels of biophysical stimulation could be considered a key determinant of its suitability for cartilage tissue engineering applications. The objective of this study was to determine the effects of dynamic compression on chondrogenesis of stem cells isolated from different tissue sources. Porcine bone marrow (BM) and infrapatellar fat pad (FP) derived stem cells were encapsulated in agarose hydrogels and cultured in a chondrogenic medium in free swelling (FS) conditions for 21 d, after which samples were subjected to dynamic compression (DC) of 10% strain (1 Hz, 1 h d(-1)) for a further 21 d. Both BM derived stem cells (BMSCs) and FP derived stem cells (FPSCs) were capable of generating cartilaginous tissues with near native levels of sulfated glycosaminoglycan (sGAG) content, although the spatial development of the engineered grafts strongly depended on the stem cell source. The mechanical properties of cartilage grafts generated from both stem cell sources also approached that observed in skeletally immature animals. Depending on the stem cell source and the donor, the application of DC either enhanced or had no significant effect on the functional development of cartilaginous grafts engineered using either BMSCs or FPSCs. BMSC seeded constructs subjected to DC stained less intensely for collagen type I. Furthermore, histological and micro-computed tomography analysis showed mineral deposition within BMSC seeded constructs was suppressed by the application of DC. Therefore, while the application of DC in vitro may only lead to modest improvements in the mechanical functionality of cartilaginous grafts, it may play an important role in the development of phenotypically stable constructs.