CT灌注成像在组织工程骨材料修复缺损早期血液灌注及血管化检测的应用

Effects of CT perfusion imaging on the monitoring of hemoperfusion and vascularization in the early post-transplanted period of tissue engineered bone scaffold

[目的]探讨CT灌注成像在组织工程骨材料植入早期血液灌注及血管化监测中的应用。[方法]层层自组装方法制备肝素-壳聚糖涂层脱细胞骨基质材料并测定其体外释放肝素抗凝效果;取30只新西兰大白兔依据观察时间不同随机分为6组（1、3、7、14、21、28 d）,在桡骨中段（60侧）制作15 mm的骨膜与骨缺损模型;一侧植入复合肝素/壳聚糖脱细胞基质材料;另一侧植入单纯脱细胞骨基质材料进行自身对照。分别于术上述各时间点行CT灌注成像检查,并计算血容量（Blood volume BV）、血流量（Blood flow BF）;标本取材行常规切片,HE染色组织学观察,计数新生血管数。[结果]术后各时间点复合材料组的BV及BF值均显著高于单纯材料组（P〈0.05）;复合材料组术后3～7 d材料微孔间出现新生血管并呈逐渐增多趋势;而单纯材料组2周后见周围有少量血管,材料逐渐吸收并纤维包裹。材料植入3 d后,CT灌注成像BV变化与组织血管数成正相关（r=0.78）。[结论]CT灌注成像能够及时地反映组织工程骨植入后初期血液灌注及血管化情况,且具有无创、动态和可定量分析的优点。抗凝处理可显著改善材料植入后初始阶段的血液灌注及早期血管化。

[Objective]To investigate the effects of computerized tomographic perfusion imaging on the monitoring of hemoperfusion and vascularization in the early post-transplanted period of tissue engineered bone scaffold.[Method]A heparin-chitosan layer by layer coated acellularized bone matrix was prepared,and the effect on anticoagulation of released heparin from the scaffold was evaluated.Thirty rabbits were randomized into 6 time groups（1,3,7,14,21 and 28 days）,with 5 rabbits in each time group.The bone defect in the right radius was implanted with HC/ACBM and the left side with ACBM material.CT perfusion was done at the time point,blood volume and blood flow ware calculated from the data.At the same time,samples were prepared and stained with HE to assess neovascularization.[Result]BV and BF ware significantly higher in the HC/ACBM implanted side than that in the ACBM implanted side.New vessels developed in the micropore of HC/ACBM from 3 to 7 days and increased with time.In the ACBM scaffold,only a small quantity of new vessels developed in the wraped fabric tissue.There was a positive correlation between the BF and number of new vessels at 3 days of scaffolds implantation（r=0.78）.[Conclusion]CT perfusion as a non-invasive,quantitative analysis technology for detecting blood supply can be used in tissue engineering in the early post-transplanted period.Heparin released from the heparin chitosan coated ACBM scaffold can lengthen the APTT within one week.When implanted into the bone defect,the heparin-chitosan film can promote blood perfusion and angiopoiesis in scaffolds.