| OBJECTIVE: In vascular graft field, many studies have been reported that the significant biological differences were present due to different selections of biological materials and methods of material stabilization. To future understand the technology of dye-mediated photooxidation, we described the biological property of rabbit's thoracic aorta cross-linked by dye-mediated photooxidation and evaluated the allogenic arteries' biocompatibility, cytotoxicity, biological stability and anti-calcification property in the blood flow.METHODS: Eighteen rabbits were divided randomly into three groups. The rabbits whose allogenic thoracic aorta were cross-linked by dye-mediated photooxidation treatment (DMP, N=6) were divided into group DMP. The rabbits whose allogenic thoracic aorta were cross-linked by glutaraldehyde (GA, N=6) were divided into group GA. The remaining rabbits whose homogenic abdominal aortam were orthotopic transplanted (OT, N=6) were divided into group OT. The biocompatibility of free artery seqments were tested by hemolytic test, then the donor arteries were transplanted experimentaly in the posion of abdominal arteries of rabbits. Postoperative animals were feeded in 1 month, and then each grafted artery was taken off for observation. The condition of coverage of endothelial cell (ES) inside the grafts was observed by scanning-electron microscopy in order to evaluate cytotoxicity. Biological stability was evaluated by histological analysis using microscopy. Anti-calcification property was evaluated by measuring calcium content in transplanting vessels. RESULTS(1)MortalityThe mortality of the rabbit with abdominal aorta transplant was 14.3%.(2) Biocompatibility testThe hemolytic index of DMP group and GA group were 0.69% and 3.76%, respectively. Both of them were lower than American ASTM standard and national standard (5%). Absorbency in group DMP was obviously lower comparing it in group GA(P<0.05).(3)Cytotoxicity testThe ratio of ES fraction coverage in DMP group and GA group were 86.2±3.3% and 47.2±4.2%, respectively. There was a significant statistically difference between two groups (P<0.01). The ratio in DMP group was more higher than it in GA group.(4)The biological stability testBiological stability index in DMP group, GA group and OT group were 91.3±3, 79.7±5.7 and 92.9±4.3. There was no statistically difference between group DMP and group OT(P>0.05). However, it revealed a significant statistically difference between group DMP and group GA(P<0.01). The stability index in DMP group was much higher than it in GA group.(5)Anti-calcification property testThe results of calcium content in DMP group, GA group and OT group were 3.58±0.22μg/mg, 22.5±0.53μg/mg and 2.99±0.33μg/mg. There was no statistically difference between group DMP and group OT(P>0.05). However, it revealed a significant statistically difference between group DMP and group GA(P<0.01). The calcium content in group DMP was much lower than it in group GA.CONCLUSIONS(1)The rabbit abdominal aorta transplant model was suitable for estimating the changes of the bioprosthetic vessel in blood flow. (2)In hemolysis test, both of hemolysis experimental indexes of rabbit thoracic aorta treated by DMP or GA were lower than ASTM and national standards. The index in group DMP was lower than that in group GA.(3)Cytotoxicity test indicated that the graft arteries treated by DMP had no obvious cytotoxicity. Comparing the arteries treated by GA, it more suitable for endothelial cell adhesively growth.(4) The biological stability maintained in graft arteries treated by DMP was similar with it in autologous arteries. It was more stable than the group treated by GA.(5)The Anti-calcification property in group DMP, which was similar with it autologous arteries, was better than it in group GA.(6)The results of this study demonstrated that DMP could be used to modify the arteries with diameter less than 6 mm wildly. And graft arties treated by DMP would be a new method for modifying allogenic artery transplant.
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