標題: Fibroblast-seeded collagen gels in response to dynamic equibiaxial mechanical stimuli: A biomechanical study
作者: Lee, Pei-Yuan
Liu, Yen-Ching
Wang, Mei-Xuan
Hu, Jin-Jia
機械工程學系
Department of Mechanical Engineering
關鍵字: Fibroblast-seeded collagen gels;3D cell culture;Cyclic stretching;Bioreactor;Mechanical properties;Mechanobiology
公開日期: 10-Sep-2018
摘要: The remodeling of fibroblast-seeded collagen gels in response to dynamic mechanical stimuli was investigated by using a newly developed biaxial culture system capable of cyclically stretching planar soft tissues. Fibroblast-seeded collagen gels were subjected to three distinct dynamic mechanical conditions for six days: Cyclic Equibiaxial Stretching at two constant strain magnitudes (CES-7% and CES-20%), and Cyclic Equibiaxial Stretching with incrementally Increasing stain magnitude (ICES, 7% 15% 20% each for two days). The frequency of cyclic stretching was set at 1 Hz. At the end of culture, mechanical properties of the gels were examined by biaxial mechanical testing and checked again upon the removal of seeded cells. Collagen microstructure within the gels was illustrated by multiphoton microscopy. The mRNA levels of collagen type I and type III and fibronectin in the cells were examined by reverse transcription PCR. The protein expression of alpha-smooth muscle actin was detected by immunohistochemistry. We found that the gels cultured under cyclic stretching were stiffer than those cultured under static stretching. Particularly, the stiffness appeared to be significantly enhanced when the ICES was employed. The enhancement of mechanical properties by cyclic stretching appeared to persist upon cell removal, suggesting an irreversible remodeling of extracellular matrix. Second harmonic generation images showed that collagen fibers became thicker and more compact in the gels cultured under cyclic stretching, which may explain the mechanical findings. The mRNA expression of collagen type I in the cells of the ICES was significantly greater than that of the other groups except for the CES-20%. This study suggests that when cyclic stretching is to be used in engineering soft tissues, incrementally increasing strain magnitude may prove useful in the development of the tissue. (C) 2018 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.jbiomech.2018.07.030
http://hdl.handle.net/11536/148217
ISSN: 0021-9290
DOI: 10.1016/j.jbiomech.2018.07.030
期刊: JOURNAL OF BIOMECHANICS
Volume: 78
起始頁: 134
結束頁: 142
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