Stout David A, Raimondo Emilia, Marostica Giuliano, Webster Thomas J
Center for Biomedical Engineering, School of Engineering, Brown University, 184 Hope St., Box D, Providence RI 02906, USA Department of Mechanical and Aerospace Engineering, California State University, Long Beach, 1250 Bellflower Blvd., Long Beach CA 90840, USA.
Division of Biology and Medicine, Brown University, 91 Waterman Street Providence RI 02912, USA.
Biomed Mater Eng. 2014;24(6):2101-7. doi: 10.3233/BME-141020.
During a heart attack, the heart's oxygen supply is cut off, and cardiomyocytes perish. Unfortunately, once these tissues are lost, they cannot be replaced and results in cardiovascular disease-the leading cause of deaths worldwide. Advancements in medical research have been targeted to understand and combat the death of these cardiomyocytes. For example, new research (in vitro) has demonstrated that one can expand cardiomyocyte adhesion and proliferation using polylactic-co-glycolic acid (PLGA) (50:50 (weight percent)) supplemented with carbon nanofibers (CNFs) to create a cardiovascular patch. However, the examination of other cardiovascular cell types has not been investigated. Therefore, the purpose of this present in vitro study was to determine cell growth characteristics of three different important cardiovascular cell types (aortic endothelial, fibroblast and cardiomyocyte) onto the substrate. Cells were seeded onto different PLGA:CNF ratio composites to determine if CNF density has an effect on cell growth, both in static and electrically stimulated environments. During continuous electrical stimulation (rectangle, 2 nm, 5 V/cm, 1 Hz), cardiomyocyte cell density increased in comparison to its static counterparts after 24, 72 and 120 hours. A minor rise in Troponin I excretion in electrical stimulation compared to static conditions indicated nominal cardiomyocyte cell function during cell experiments. Endothelial and fibroblast cell growth experiments indicated the material hindered or stalled proliferation during both static and electrical stimulation experiments, thus supporting the growth of cardiomyocytes onto the dead tissue zone. Furthermore, the results specified that CNF density did have an effect on PLGA:CNF composite cytocompatibility properties with the best results coming from the 50:50 [PLGA:CNF (weight percent:weight percent)] composite. Therefore, this study provides further evidence that a conductive scaffold using nanotechnology should be further research for various cardiovascular applications.
在心脏病发作期间，心脏的氧气供应被切断，心肌细胞死亡。不幸的是，一旦这些组织受损，就无法被替换，从而导致心血管疾病——这是全球范围内死亡的主要原因。医学研究的进展一直致力于了解和对抗这些心肌细胞的死亡。例如，新的研究（体外研究）表明，使用聚乳酸-乙醇酸共聚物（PLGA）（50:50（重量百分比））并添加碳纳米纤维（CNF）来制造心血管贴片，可以促进心肌细胞的黏附与增殖。然而，尚未对其他心血管细胞类型进行研究。因此，本体外研究的目的是确定三种不同的重要心血管细胞类型（主动脉内皮细胞、成纤维细胞和心肌细胞）在该基质上的细胞生长特性。将细胞接种到不同PLGA:CNF比例的复合材料上，以确定CNF密度在静态和电刺激环境下是否对细胞生长有影响。在持续电刺激（矩形，2纳米，5伏/厘米，1赫兹）过程中，与静态条件下的对应细胞相比，心肌细胞密度在24、72和120小时后有所增加。与静态条件相比，电刺激过程中肌钙蛋白I排泄量略有上升，表明在细胞实验期间心肌细胞功能正常。内皮细胞和成纤维细胞生长实验表明，在静态和电刺激实验中，该材料都会阻碍或抑制增殖，从而支持心肌细胞在坏死组织区域的生长。此外，结果表明CNF密度确实对PLGA:CNF复合材料的细胞相容性有影响，其中50:50[PLGA:CNF（重量百分比:重量百分比）]复合材料的效果最佳。因此，本研究进一步证明，利用纳米技术的导电支架应针对各种心血管应用进行进一步研究。
