Subcritical CO2 sintering of microspheres of different polymeric materials to fabricate scaffolds for tissue engineering.
Subcritical CO2 sintering of microspheres of different polymeric materials to fabricate scaffolds for tissue engineering.
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DOI：
10.1016/j.msec.2013.08.010
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发表时间：
2013-12-01
期刊：
影响因子：
--
通讯作者：
Detamore MS
中科院分区：
文献类型：
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作者：
Bhamidipati M;Sridharan B;Scurto AM;Detamore MS
本研究的目的是在亚临界压力下使用CO2作为工具来烧结用于骨和软骨组织工程的3D大孔微球支架。采用致密相CO2烧结法制备聚乳酸-羟基乙酸共聚物（PLGA）或聚己内酯（PCL），接种大鼠骨髓间充质干细胞（rBMSCs），并暴露于成骨（PLGA、PCL）或成软骨（PLGA）条件6周。在成骨条件下，PLGA构建体产生的钙比PCL构建体多一个数量级，而PCL构建体在第6周时具有远上级PLGA构建体的机械和结构完整性（比PLGA构建体硬125倍），沿着PLGA构建体的两倍的细胞含量。软骨细胞的性能是有限的PLGA结构，可能是由于聚合物降解速率太高。目前的研究代表了第一个长期培养的CO2烧结微球为基础的支架，并建立了重要的热力学差异之间的烧结所选配方的PLGA和PCL，前者只需要调整压力，后者需要调整压力和温度。基于更直接的烧结条件和更有利的电池性能，PLGA可以是CO2烧结应用中微球的选择材料，尽管在微球中包封生长因子、细胞外基质衍生的纳米颗粒和/或缓冲液的不同PLGA制剂可能有利于实现比这里观察到的更上级的电池性能。
The aim of this study was to use CO2 at sub-critical pressures as a tool to sinter 3D, macroporous, microsphere-based scaffolds for bone and cartilage Tissue Engineering Porous scaffolds composed of ~200 µm microspheres of either poly(lactic-co-glycolic acid) (PLGA) or polycaprolactone (PCL) were prepared using dense phase CO2 sintering, which were seeded with rat bone marrow mesenchymal stromal cells (rBMSCs), and exposed to either osteogenic (PLGA, PCL) or chondrogenic (PLGA) conditions for 6 weeks. Under osteogenic conditions, the PLGA constructs produced over an order of magnitude more calcium than the PCL constructs, whereas the PCL constructs had far superior mechanical and structural integrity (125 times stiffer than PLGA constructs) at week 6, along with twice the cell content of the PLGA constructs. Chondrogenic cell performance was limited in PLGA constructs, perhaps as a result of the polymer degradation rate being too high. The current study represents the first long-term culture of CO2-sintered microsphere-based scaffolds, and has established important thermodynamic differences in sintering between the selected formulations of PLGA and PCL, with the former requiring adjustment of pressure only, and the latter requiring the adjustment of both pressure and temperature. Based on more straightforward sintering conditions and more favorable cell performance, PLGA may be the material of choice for microspheres in a CO2 sintering application, although a different PLGA formulation with the encapsulation of growth factors, extracellular matrix-derived nanoparticles, and/or buffers in the microspheres may be advantageous for achieving a more superior cell performance than observed here.