Moghadam M Zahedi, Hassanajili Sh, Esmaeilzadeh F, Ayatollahi M, Ahmadi M
Department of Chemical Engineering, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran.
Transplant Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
J Mech Behav Biomed Mater. 2017 May;69:115-127. doi: 10.1016/j.jmbbm.2016.12.014. Epub 2017 Jan 3.
Scaffold is a 3D porous structure that is made of different materials, such as synthetic and natural polymers. It plays the role of a synthetic extracellular matrix and permits adhesion, proliferation and differentiation of the cells. Porosity and pore size are the important factors for any 3D scaffold used in bone tissue engineering. In this study, porous scaffolds were prepared by adding hydroxyapatite (HA) nanoparticles as filler to the polymeric matrix of polycaprolactone (PCL) blends with two different molecular weight by using supercritical CO (ScCO) foaming method. The effect of different parameters such as CO pressure, ratios of the polymers and amount of the filler on the scaffold properties was investigated. The results showed that porosity increased with increment of pressure and decreased with increasing the ratio of the high molecular weight PCL to the low molecular weight PCL in the scaffolds and also HA content. Optimum condition for obtaining adequate porous scaffold of HPCL/LPCL/HA occurred at 140bar and 45°C. The physical and mechanical properties of the prepared scaffolds were characterized using DSC, XRD, FTIR, SEM, contact angle and compression test. By analyzing the results of these tests, optimum sample for cell culture was selected. The biocompatibility of the selected HPCL/LPCL/HA scaffold (HPCL/LPCL 60/40 containing 2.5% HA) was assessed in vitro by using human mesenchymal stem cells (hMSCs).
支架是一种由不同材料制成的三维多孔结构，如合成聚合物和天然聚合物。它起到合成细胞外基质的作用，允许细胞黏附、增殖和分化。孔隙率和孔径是骨组织工程中使用的任何三维支架的重要因素。在本研究中，通过使用超临界CO₂（ScCO₂）发泡法，将羟基磷灰石（HA）纳米颗粒作为填料添加到具有两种不同分子量的聚己内酯（PCL）共混物的聚合物基质中，制备了多孔支架。研究了不同参数如CO₂压力、聚合物比例和填料用量对支架性能的影响。结果表明，孔隙率随着压力的增加而增加，随着支架中高分子量PCL与低分子量PCL的比例增加以及HA含量的增加而降低。在140bar和45°C条件下可获得具有足够孔隙率的HPCL/LPCL/HA多孔支架的最佳条件。使用差示扫描量热法（DSC）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、接触角和压缩试验对制备的支架的物理和力学性能进行了表征。通过分析这些测试结果选择了用于细胞培养的最佳样品。使用人间充质干细胞（hMSCs）在体外评估了所选的HPCL/LPCL/HA支架（含有2.5%HA的HPCL/LPCL 60/40）的生物相容性。
