title: Functional restoration of endothelial cells of the cryopreserved heart valve.
abstract: OBJECTIVE
  Although several approaches have been tried to improve the durability of cryopreserved valves, cellular restoration after thawing remains to be investigated. The aim of our study was to assess the functional restoration of endothelial cells of cryopreserved heart valves by in vitro culture for an alternative step to improving longevity.
  
  
  METHODS
  Cryopreserved human umbilical vein endothelial cells (HUVECs) and porcine aortic cusps were cultivated for 14 days after thawing. Then the cellular activity of the enzymes cytosolic esterase and mitochondrial dehydrogenase was measured. The cellular viability of cryopreserved cusps was also assessed using confocal laser scanning microscopy.
  
  
  RESULTS
  The number of viable HUVECs decreased markedly after cryopreservation and thawing but recovered to pre-cryopreservation level after 14 days of culture. In contrast, the enzyme activity of the cryopreserved porcine aortic cusps showed recovery at 7 days of in vitro tissue culture after thawing. Confocal laser scanning microscopy findings showed that the cellular cytosolic esterase activity of cryopreserved cusps deteriorated after thawing but displayed considerable recovery by day 14 of culture.
  
  
  CONCLUSIONS
  The functional recovery of endothelial cells in cryopreserved heart valves seems to require tissue culture of at least 14 days. Ex vivo endothelial restoration of cryopreserved heart valves may add to heart valve durability.
authors: Department of Cardiovascular Surgery, The University of Tokushima Graduate School of Health Biosciences, 3-18-15 Kuramoto-cho, Tokushima 770-8503, Japan.
authors: Eiki
authors: E
authors: Fujimoto
authors: Masanori
authors: M
authors: Yoshizumi
authors: Tamotsu
authors: T
authors: Kanbara
authors: Hirotsugu
authors: H
authors: Kurobe
authors: Tatsuo
authors: T
authors: Motoki
authors: Mikio
authors: M
authors: Sugano
authors: Taisuke
authors: T
authors: Nakayama
authors: Takashi
authors: T
authors: Kitaichi
authors: Tetsuya
authors: T
authors: Kitagawa
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001021:Aortic Valve / Q000166:cytology* / Q000201:enzymology; D015415:Biomarkers / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D015925:Cryopreservation; D003600:Cytosol / Q000201:enzymology; D042783:Endothelial Cells / Q000201:enzymology / Q000502:physiology*; D004950:Esterases / Q000378:metabolism; D006801:Humans; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000201:enzymology; D010088:Oxidoreductases / Q000378:metabolism; D013552:Swine; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D015415:Biomarkers; D010088:Oxidoreductases; D004950:Esterases