Effects of oxygen on engineered cardiac muscle
Effects of oxygen on engineered cardiac muscle
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DOI：
10.1002/bit.10245
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发表时间：
2002-06-20
影响因子：
3.8
通讯作者：
Vunjak-Novakovic, G
中科院分区：
文献类型：
--
作者：
Carrier, RL;Rupnick, M;Vunjak-Novakovic, G
与体内血管化的工程化组织的体外培养相关的浓度梯度导致仅形成薄的外周组织样区域（例如，类似于工程化心肌的100 μ m）。我们以前证明，工程心脏结构内的扩散梯度可以通过直接灌注培养基通过该结构来最小化。本研究探讨了中等灌注速率和局部氧浓度（p（O2））对体外构建工程化心肌的影响。将新生大鼠心肌细胞接种到可生物降解的聚合物支架上（纤维盘，直径1.1 cm x 2 mm厚，由聚乙醇酸制成，每个支架24 x 10（6）个细胞）。将得到的细胞-聚合物构建体在串联连接的盒（n = 1-8）中培养总共12天，每个盒含有一个以0.2-3.0 mL/min的流速直接灌注培养基的构建体。在所有组中，氧浓度由于细胞呼吸而降低，并且取决于构建体在系列中的位置和培养基流速。较高的灌注率和较高的p（O2）与更多的需氧细胞代谢相关。DNA和蛋白质含量较高。与在p（O2）为60 mm Hg下培养的构建体相比，在p（O2）为160 mm Hg下培养的构建体具有高50%的DNA和蛋白质含量、显著更高的肌节α-肌动蛋白表达、更好组织的肌节和细胞连接以及高4.5倍的细胞呼吸速率。p（O2）为160时，相应心肌细胞单层的收缩率比60 mm Hg时高40%。因此，控制细胞微环境中的氧浓度可以改善工程化心肌的结构和功能。这类实验可以为氧对工程组织体外发育的影响的受控研究奠定基础。(C)2002 Wiley Periodicals，Inc.
Concentration gradients associated with the in vitro cultivation of engineered tissues that are vascularized in vivo result in the formation of only a thin peripheral tissue-like region (e.g., similar to100 pm for engineered cardiac muscle) around a relatively cell-free interior. We previously demonstrated that diffusional gradients within engineered cardiac constructs can be minimized by direct perfusion of culture medium through the construct. In the present study, we measured the effects of medium perfusion rate and local oxygen concentration (p(O2)) on the in vitro reconstruction of engineered cardiac muscle. Neonatal rat cardiomyocytes were seeded onto biodegradable polymer scaffolds (fibrous discs, 1.1 cm diameter x 2 mm thick, made of polyglycolic acid, 24 x 10(6) cells per scaffold). The resulting cell-polymer constructs were cultured for a total of 12 days in serially connected cartridges (n = 1-8), each containing one construct directly perfused with culture medium at a flow rate of 0.2-3.0 mL/min. In all groups, oxygen concentration decreased due to cell respiration, and depended on construct position in the series and medium flow rate. Higher perfusion rates and higher p(O2) correlated with more aerobic cell metabolism., and higher DNA and protein contents. Constructs cultured at p(O2) of 160 mm Hg had 50% higher DNA and protein contents, markedly higher expression of sarcomeric a-actin, better organized sarcomeres and cell junctions, and 4.5-fold higher rate of cell respiration as compared to constructs cultured at p(O2) of 60 mm Hg. Contraction rates of the corresponding cardiac cell monolayers were 40% higher at p(O2) of 160 than 60 mm Hg. The control of oxygen concentration in cell microenvironment can thus improve the structure and function of engineered cardiac muscle. Experiments of this kind can form a basis for controlled studies of the effects of oxygen on the in vitro development of engineered tissues. (C) 2002 Wiley Periodicals, Inc.