Zhang Xiaoqing, Battiston Kyle G, Simmons Craig A, Santerre J Paul
Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Institute of Biomaterials and Biomedical Engineering, University of Toronto, 661 University Avenue, 14th Floor, Toronto, Ontario M5G 1M1, Canada.
Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ontario M5G 1G6, Canada.
ACS Biomater Sci Eng. 2018 Nov 12;4(11):3768-3778. doi: 10.1021/acsbiomaterials.7b00389. Epub 2017 Nov 2.
Vascular tissue engineering strategies using cell-seeded scaffolds require uniformly distributed vascular cells and sufficient extracellular matrix (ECM) production. However, acquiring sufficient ECM deposition on synthetic biomaterial scaffolds during the in vitro culture period prior to tissue implantation still remains challenging for vascular constructs. Two forms of vitamin C derivatives, ascorbic acid (AA) and sodium ascorbate (SA), are commonly supplemented in cell culture to promote ECM accumulation. However, the literature often refers to AA and SA interchangeably, and their differential effects on cell growth and ECM molecule (glycosaminoglycan, collagen, elastin) accumulation have never been reported when used in monoculture or coculture systems developed with synthetic three-dimensional (3D) scaffolds. In this study, it was found that 200 μM AA stimulated an increase in cell number, whereas SA (50, 100, and 200 μM) supported more calponin expression (immunostaining) and higher ECM accumulation from vascular smooth muscle cells (VSMCs) after 1 week in the degradable polar hydrophobic ionic polyurethane scaffold. The influence of AA and SA on ECM deposition was also studied in VSMC-monocyte cocultures to replicate some aspects of a wound healing environment in vitro and compared to their effects in respective VSMC monocultures after 4 weeks. Although 100 μM SA promoted ECM deposition in coculture, the condition of 100 μM AA + 100 μM SA was more effective toward enhancing ECM accumulation in VSMC monoculture after 4 weeks. The results demonstrated that AA and SA are not interchangeable, and the different effects of AA and/or SA on ECM deposition were both culture system (co- vs monoculture) and culture period (1 vs 4 week) dependent. This study provides further insight into practical vascular tissue engineering strategies when using 3D synthetic biomaterial-based constructs.
使用接种细胞的支架的血管组织工程策略需要血管细胞均匀分布以及足够的细胞外基质（ECM）生成。然而，在组织植入前的体外培养期间，在合成生物材料支架上获得足够的ECM沉积对于血管构建物来说仍然具有挑战性。两种形式的维生素C衍生物，即抗坏血酸（AA）和抗坏血酸钠（SA），通常在细胞培养中添加以促进ECM积累。然而，文献中经常将AA和SA互换使用，并且当它们用于用合成三维（3D）支架开发的单培养或共培养系统时，它们对细胞生长和ECM分子（糖胺聚糖、胶原蛋白、弹性蛋白）积累的不同影响从未被报道过。在本研究中，发现200μM AA刺激细胞数量增加，而在可降解的极性疏水离子聚氨酯支架中培养1周后，SA（50、100和200μM）支持血管平滑肌细胞（VSMC）更多的钙调蛋白表达（免疫染色）和更高的ECM积累。还在VSMC-单核细胞共培养中研究了AA和SA对ECM沉积的影响，以在体外复制伤口愈合环境的某些方面，并与它们在各自的VSMC单培养中4周后的效果进行比较。尽管100μM SA促进了共培养中的ECM沉积，但100μM AA + 100μM SA的条件在4周后对增强VSMC单培养中的ECM积累更有效。结果表明，AA和SA不可互换，并且AA和/或SA对ECM沉积的不同影响既取决于培养系统（共培养与单培养），也取决于培养时间（1周与4周）。本研究为使用基于3D合成生物材料的构建物的实际血管组织工程策略提供了进一步的见解。
