Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente, Enschede, The Netherlands.
Tissue Eng Part A. 2011 Feb;17(3-4):381-7. doi: 10.1089/ten.TEA.2009.0805. Epub 2010 Oct 12.
Porous, tubular, flexible, and elastic poly(trimethylene carbonate) (PTMC) scaffolds (length 8 cm and inner diameter 3 mm) for vascular tissue engineering were prepared by means of a dip-coating and particulate leaching procedure. Using NaCl as porogen, scaffolds with an average pore size of 110 μm and a porosity of 85% were obtained. Before leaching the salt, the structures were made creep-resistant by means of crosslinking at 25 kGy gamma irradiation. To increase the efficiency of cell seeding, the scaffolds were provided with a microporous outer layer of 0.2 mm with an average pore size of 28 μm and a porosity of 65% (total wall thickness 1 mm). Human smooth muscle cells (SMCs) were seeded in these scaffolds with an efficiency of 43%, as determined after 24 h cell adhesion. SMCs were cultured in the scaffolds up to 14 days under stationary conditions or under pulsatile flow conditions in a bioreactor (pressure 70-130 mmHg, 69 pulsations/min, and average wall shear rate 320 s(-1)). Although SMCs proliferated under both conditions, cell numbers were three to five times higher in case of dynamic culturing. This was qualitatively confirmed by means of histology. Also, in terms of mechanical properties, the dynamically cultured constructs performed better than the statically cultured constructs. After culturing for 14 days, the maximum tensile strengths of the constructs, determined in the radial direction, had increased from 0.16 MPa (unseeded scaffold) to 0.48 MPa (dynamic culturing) and 0.38 MPa (static culturing). The results of this study indicate that a potentially useful medial layer for tissue-engineered vascular grafts can be prepared by dynamic culturing of human SMCs seeded in porous tubular poly(trimethylene carbonate) scaffolds.
多孔、管状、柔性和弹性的聚（三亚甲基碳酸酯）（PTMC）支架（长 8cm，内径 3mm），用于血管组织工程，是通过浸涂和颗粒沥滤法制备的。使用 NaCl 作为成孔剂，可以得到平均孔径为 110μm 和孔隙率为 85%的支架。在沥滤盐之前，通过在 25kGyγ射线照射下交联使结构具有抗蠕变性。为了提高细胞接种效率，支架的外表面具有一层 0.2mm 的微孔层，平均孔径为 28μm，孔隙率为 65%（总壁厚 1mm）。将人平滑肌细胞（SMC）接种到这些支架中，24 小时后细胞黏附的效率为 43%。在静止条件下或在生物反应器中（压力 70-130mmHg，69 次/分钟，平均壁面剪切率 320s(-1))）进行脉动流条件下培养，SMC 可在支架中培养长达 14 天。尽管在这两种条件下SMC 都增殖，但在动态培养的情况下细胞数量是静态培养的三到五倍。这通过组织学定性地得到了证实。此外，就机械性能而言，动态培养的构建物优于静态培养的构建物。培养 14 天后，径向方向测定的构建物的最大拉伸强度从 0.16MPa（未接种支架）增加到 0.48MPa（动态培养）和 0.38MPa（静态培养）。这项研究的结果表明，通过动态培养接种人平滑肌细胞的多孔管状聚（三亚甲基碳酸酯）支架，可以制备出一种潜在有用的组织工程血管移植物中层。
