BioArchive自动液氮储存系统保存的胎盘脐血的冷冻生物学特征

为了解在特定降温和复温过程中于BioArchive自动液氮储存系统保存的胎盘脐血 (PCB)的冷冻生物学特征 ,采用Procount方法流式细胞术测定CD34+ 细胞含量 ,细胞集落形成单位 (CFU)检测CD34+ 细胞的增殖能力 ,台盼蓝拒染法和白细胞分类测定有核细胞活存率和白细胞分类变化。结果显示 ,冻存复温后PCB有核细胞平均活存率为 (73.3± 12 .5 ) % ;PCBCD34+ 细胞的含量在冻存前为 (0 .3± 0 .2 1) % ,冻存复温后为 (0 .4 5± 0 .36 ) %。冻存复温后PCBCFU GM / G/ GEMM形成能力为冻存前的 (97.9± 39.9) %。比较大、小冷冻袋冻存复温后PCB细胞活存率和CFU GM/ G/ GEMM的形成能力无显著差异。另外 ,冻存复温后PCB的白细胞分类明显改变 ,粒细胞百分比明显降低 ,淋巴细胞和单核细胞百分比明显升高。结论 :在本研究中所采用的降温与复温程序不适于保存粒细胞 ,但是能够很好地保存淋巴细胞和单核细胞 ,尤其是CD34+ 的幼稚造血细胞。

Cryobiological Characteristics of Placental Cord Blood Preserved in BioArchive Auto-Preserved Liquid Nitrogen System

The aim of this study was to investigate the cryobiological characteristics of placental cord blood (PCB) cryopereserved by using BioArchive auto-preserved liquid nitrogen system (BioArchive system). After Hespan depletion of red blood cells, 5 ml mixture of DMSO and 10% Dextran 40 were added into 20 ml of enriched leukocyte. 53 PCB units were cryopreserved as following protocol: pre-freeze rate 10 degrees C/min, start freeze temperature -3 degrees C, end freeze temperature -10 degrees C to -15 degrees C, post freeze rate 2 degrees C/min, and end temperature -50 degrees C. After rapid thawing at 38 degrees C, the PCB were washed with 5% human serum albumin -10% Dextran 40 and centrifuged at 400 x g, 10 degrees C for 20 minutes. The results showed that the viability of nucleated cells post-thaw was (73.3 +/- 12.5)%, the CD34(+) cell content was (0.3 +/- 0.21)% for pre-freeze PCB and (0.45 +/- 0.36)% for post-t haw PCB. No significant difference for CFU-GM/-G/-GEMM counts was found between pre-freeze and post-thaw PCB. Thawed PCB contained in two compartments (20 ml and 5 ml) of a freezing bag showed similar viability and clonogenic capacity. Differential count of white blood cell was significantly changed. For post-thaw PCB, it was dramatically decreased for the percentage of granulocytes, and highly increased for the percentage of lymphocytes and monocytes. It was concluded that the condition for cryopreservation and thawing of PCB may be harmful to mature cells, and cells with large size, such as granulocyte, but suitable to lymphocyte and monocyte, especially for the cells with small size, such as CD34(+) cells.