Comparison of morphology and mechanical properties between vitrified rabbit femoral arteries and cryopreserved rabbit femoral arteries / 中国组织工程研究

ABSTRACT

BACKGROUND: An effective preservation method must preserve the integrity of tissue structure. OBJECTIVE: To compare the effects of vitrification and cryopreservation method on the artery morphology and mechanical properties. DESIGN, TIME AND SETTING: The randomized controlled animal experiment was done at the Department of Orthopedics, General Hospital of Chinese PLA, between September 2001 and August 2004. MATERIALS Eighteen New Zealand rabbits were randomly divided into vitrified artery group, cryopreserved artery group and fresh artery group, with 6 rabbits in each group. METHODS: Femoral arteries were removed from rabbits and put in balanced solution. Arteries in the vitrified artery group were immersed in the 25%, 50% and 100% gradient vitrified solution at 4 ℃ and then were put in liquid nitrogen. Arteries in the cryopreserved artery group were cooled from normal temperature to 0, -20, -70 ℃, and balanced for 60 minutes, then were put in liquid nitrogen. Samples were preserved in liquid nitrogen for more than 14 days. MAIN OUTCOME MEASURES: The morphology changes of preserved arteries observed through naked eye and microscope; hysteresis loop; stress relaxation; breaking strength. RESULTS: Artery structures were all preserved well in the three groups, the integrity rate of vitrified artery group was 91.67%, which was significantly better than 54.17% of cryopreserved artery group (P 0.05). CONCLUSION: There influences of vitrification and cryoprsesrvation on the artery morphology and mechanical properties were not significant, while arteries preserved by vitrification had less tissue ruptures, so vitrification is suitable for preserving long vessels.