title: [Experimental study of tissue-engineered heart tissue using type I collagen as scaffold].
abstract: OBJECTIVE
  To construct tissue-engineered heart tissue (EHT) using liquid collagen as scaffold.
  
  
  METHODS
  Neonatal rat cardiac myocytes were isolated, cultured, and mixed with liquid collagen type I and matrix factors and then cast in circular molds to construct circular cardiac myocytes/collagen strand. After a 7-day culture in circular molds, the strands were removed, and subjected to 10% static stretch for another 7 days. Microscopy and transmission electron microscopy, routine HE staining and immunohistochemical staining were used to analyze the engineered heart tissue.
  
  
  RESULTS
  Beating areas could be seen on the surface of the EHTs at the second day after stretching; more beating areas could be seen thereafter. These areas beat stronger and stronger, and finally came to synchronzation. Histological and immunohistochemical analyses showed that the cardiac myocytes in the EHTs distributed evenly in the whole strand and the majority of the cells, with elongated nuclei, stretched along the stretching direction. The morphology of EHTs resembled that of the native adult cardiac tissue. Transmission electron microscopy revealed that the cardiac myocytes in EHTs contained arranged myofibrils oriented parallel to the longitudinal cell axis. Clearly defined sarcomeres and Z lines were observed.
  
  
  CONCLUSIONS
  Liquid type I collagen is a good scaffold for generation of EHTs similar to the native heart tissue.
authors.affiliation: Tissue Engineering Research Centre, Institute of Basic Medical Sciences, Academy of Military Medical Sciences, Beijing 100850, China.
authors.forename: Yun-shan
authors.initials: YS
authors.lastname: Zhao
authors.forename: Chang-yong
authors.initials: CY
authors.lastname: Wang
authors.forename: Xi-min
authors.initials: XM
authors.lastname: Guo
authors.forename: Xi-zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Xiu-li
authors.initials: XL
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Qiao
authors.forename: Cui-mi
authors.initials: CM
authors.lastname: Duan
authors.forename: Ling-zhi
authors.initials: LZ
authors.lastname: Dong
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D024042:Collagen Type I / Q000378:metabolism*; D008854:Microscopy, Electron; D009206:Myocardium / Q000166:cytology* / Q000648:ultrastructure; D032383:Myocytes, Cardiac / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D012518:Sarcomeres / Q000648:ultrastructure; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D024042:Collagen Type I