Song Yan, Wennink Jos W H, Poot Andre A, Vermes Istvan, Feijen Jan, Grijpma Dirk W
Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, Institute for Biomedical Technology, University of Twente, Enschede, The Netherlands.
Int J Artif Organs. 2011 Feb;34(2):161-71. doi: 10.5301/ijao.2011.6396.
Tubular scaffolds (internal diameter approximately 3 mm and wall thickness approximately 0.8 mm) with a porosity of approximately 83% and an average pore size of 116 µm were prepared from flexible poly(trimethylene carbonate) (PTMC) polymer by dip-coating and particulate leaching methods. PTMC is a flexible and biocompatible polymer that crosslinks upon irradiation; porous network structures were obtained by irradiating the specimens in vacuum at 25 kGy before leaching soluble salt particles. To assess the suitability of these scaffolds in dynamic cell culturing for cardiovascular tissue engineering, the scaffolds were coated with a thin (0.1 to 0.2 mm) non-porous PTMC layer and its performance was evaluated in a closed pulsatile flow system (PFS). For this, the PFS was operated at physiological conditions at liquid flows of 1.56 ml/s with pressures varying from 80-120 mmHg at a frequency of 70 pulsations per minute. The mechanical properties of these coated porous PTMC scaffolds were not significantly different than non-coated scaffolds. Typical tensile strengths in the radial direction were 0.15 MPa, initial stiffness values were close to 1.4 MPa. Their creep resistance in cyclic deformation experiments was excellent. In the pulsatile flow setup, the distention rates of these flexible and elastic scaffolds were approximately 0.10% per mmHg, which is comparable to that of a porcine carotid artery (0.11% per mmHg). The compliance and stiffness index values were close to those of natural arteries.?In long-term deformation studies, where the scaffolds were subjected to physiological pulsatile pressures for one week, the morphology and mechanical properties of the PTMC scaffolds did not change. This suggests their suitability for application in a dynamic cell culture bioreactor.
采用浸涂法和颗粒沥滤法，由柔性聚碳酸三亚甲基酯（PTMC）聚合物制备了内径约3mm、壁厚约0.8mm、孔隙率约83%、平均孔径116µm的管状支架。PTMC是一种柔性且生物相容的聚合物，在辐照时会交联；在沥滤可溶性盐颗粒之前，通过在真空中以25kGy的剂量辐照样品获得多孔网络结构。为了评估这些支架在心血管组织工程动态细胞培养中的适用性，在支架上涂覆了一层薄的（0.1至0.2mm）无孔PTMC层，并在封闭脉动流系统（PFS）中评估其性能。为此，PFS在生理条件下运行，液体流速为1.56ml/s，压力在80 - 120mmHg之间变化，频率为每分钟70次脉动。这些涂覆的多孔PTMC支架的力学性能与未涂覆的支架没有显著差异。径向的典型拉伸强度为0.15MPa，初始刚度值接近1.4MPa。它们在循环变形实验中的抗蠕变性极佳。在脉动流装置中，这些柔性和弹性支架的扩张率约为每mmHg 0.10%，与猪颈动脉的扩张率（每mmHg 0.11%）相当。顺应性和刚度指数值与天然动脉接近。在长期变形研究中，支架在生理脉动压力下作用一周，PTMC支架的形态和力学性能没有变化。这表明它们适用于动态细胞培养生物反应器。
