Characterization of activin A in the culture of primitive human umbilical cord blood hematopoietic cells

Transforming growth factor-β (TGF-β) superfamily controls many physiological processes such as cell proliferation and differentiation, immune responses, wound repair and various endocrine activities. As a member of TGF-β, activin A can maintain the pluripotency of embryonic stem cells. We report here that activin A exhibited cell type-dependent function of expanding the human primitive hematopoietic cells isolated from umbilical cord blood (UCB). However, the multipotency of the cells pretreated with activin A was exhausted in the sequential dilution culture. In conclusion, activin A may not be a key factor, but a regulator, in the multipotency maintenance of primitive hematopoietic cells and the application of activin A in the hematopoietic stem/progenitor cells (HS/PCs) culture expansion remains a significant challenge.     

原核表达重组人白介素-3及其对脐带血造血干细胞体外增殖的影响

目的研究原核表达重组人白介素-3(rhIL-3)及其对脐带血造血干细胞体外增殖的影响。方法构建pET-43.1-rhIL-3表达载体,克隆至BL21菌株,并进行中试发酵生产,所得包涵体经透析复性后,采用阳离子交换柱纯化,纯化产物送N-端测序。Ficoll密度梯度离心结合免疫磁珠法富集人脐带血中CD34+细胞,以不同浓度rhIL-3及干细胞因子(SCF)、Fms样酪氨酸激酶受体-3配体(FL)和促血小板生成素(TPO)因子组合培养1周,测定细胞总数,计算CD34+细胞增殖倍数。结果在SCF和FL存在下,rhIL-3可明显促进造血干祖细胞增殖,但较无rhIL-3时CD34+细胞占细胞总数的比例有所下降。与SCF、FL共同作用时的最佳浓度在15 ng/mL左右,与SCF、FL、TPO共同作用时的最佳浓度在50 ng/mL左右。结论高效表达及纯化的rhIL-3与SCF、FL和TPO细胞因子组合对脐带血造血干细胞具有良好的增殖作用。     

Quality-assessments of characteristics of placental/umbilical cord blood associated with maternal age- and parity-related factor

Umbilical cord blood (CB) has been widely used for unrelated allogeneic stem cell transplantation. It is important to determine the quality of CB units to avoid frequent problem of limited cell yields. However, no practical and/or optimum obstetric factors to predict them are yet available. This study analyzed the relationship between maternal/neonatal obstetric factors and the laboratory parameters of CB units to identify the optimum factors associated with a high yield of total nucleated cells (TNC). Primiparae in their early 30s may be one of the first selection criteria for CB donors to obtain higher yield of TNC.     

培养条件对体外诱导造血干/祖细胞向血小板定向增殖与分化的影响

目的观察3种不同培养基以及细胞接种密度对体外诱导造血干/祖细胞向血小板方向增殖和分化的影响。方法用添加干细胞因子(SCF)和促血小板生成素(TPO)等细胞因子的无血清培养基(StemSpan(SFEM和X-VIVO10)或IMDM/10%FBS来扩增脐血CD34+细胞向血小板定向分化,比较不同培养基的培养效果;CD34+细胞接种浓度为5×103/ml、104/ml和105/ml,比较不同接种浓度对扩增效果的影响。结果培养d 14、d 24和d 29时,StemSpan(SFEM培养基体系中细胞分别扩增了(11 000±577.35)、(196 666.67±14 529.66)和(176 666.67±8 819.17)倍,显著高于X-VIVO10和IMDM/10%FBS组,其中在d 24和d 29时,巨核系细胞所占比例分别是(54.57±2.32)%和(69.4±2.02)%,显著高于X-VIVO10和IMDM/10%FBS组。培养14 d后初始接种浓度为104/ml的CD34+细胞在StemSpan(SFEM培养基体系中扩增(11 000±577.35)倍,显著高于初始接种浓度为5×103/ml和105/ml组。结论和X-VIVO10和IMDM/10%FBS相比,StemSpan(SPEM培养基最有利于脐血CD34+细胞体外向血小板定向扩增和分化;104/ml的CD34+细胞接种密度最有利于细胞扩增和分化。     

人脐血单个核细胞和脐带间充质干细胞移植用于大鼠脊髓损伤的实验研究

目的:探讨人脐血单个核细胞和脐带间充质干细胞(MSCs)移植对脊髓损伤功能恢复的影响,寻找一种更适合治疗脊髓损伤的细胞源。方法:采集新鲜人脐带血和脐带,分离培养单个核细胞和MSCs。将脊髓损伤模型随机分成3组:单个核细胞移植组、MSCs移植组和低糖必需培养基(L-DMEM)培养组。采用免疫组化和免疫荧光检测细胞移植后1—4周细胞在脊髓内的存活情况和迁移情况,使用BBB行为学评分评估大鼠脊髓功能恢复情况。结果:L-DMEM培养液组在术后各时间点观察评分无明显差异,而细胞移植组脊髓功能处于逐渐恢复过程,与L-DMEM培养液比较,差异有显著性意义。单个核细胞移植组对损伤脊髓功能的修复作用较MSCs移植组显著,且差异有显著性意义。结论:与MSCs相比较,人脐血单个核细胞更适合作为治疗脊髓损伤的细胞源。     

Mesenchymal stem cells from CD34− human umbilical cord blood

Umbilical cord blood (UCB) is well known to be a rich source of stem cells especially for haematopoietic stem cells (HSCs). Recently, mesenchymal stem cells (MSCs) have also been shown to exist in cord blood. Although MSCs have been described by a subset of surface antigens after expansion, little is known about the cell surface phenotype of undifferentiated MSCs. The aim of this study therefore was to clarify whether undifferentiated MSCs are resident among CD34^? UCB cells. CD34⁺ cells were separated from UCB mononuclear cells (MNCs) by magnetic sorting and the CD34^? cell fractions were cultured in Dulbecco's modified Eagle's medium (DMEM) with 10% foetal calf serum (FCS) and basic‐fibroblast growth factor. Isolated CD34⁺ cells were also cultured in the same medium. Adherent fibroblast‐like cells at passage 3–4 were analyzed by fluorescence‐activated cell sorting (FACS) for MSC marker expression , and standard adipogenic, osteogenic and chondrogenic assays were used to investigate their differentiation potentials. After 4–5 weeks in culture, the cells from the CD34^? fraction became confluent with flat and fibroblast‐like morphology. These cells were positively stained for the mesenchymal cell markers CD29, CD73 and CD105. In adipogenic differentiation, the cells showed oil red O positive and expressed FABP4, adipsin and proliferation‐activated receptor γ‐2 (PPARγ2 genes) associated with adipogenesis. In osteogenic differentiation, calcium accumulation and osteocalcin were detected. The cells grown in chondrogenic conditions were positively stained for human aggrecan and expressed collagen type II and Sox‐9 genes. In contrast, cells from the CD34⁺ fraction failed to generate any cells with MSC morphology under the same culture conditions. Our results showed that UCB contained MSCs which are only resident in the CD34^? fraction. The MSCs could be induced to differentiate into at least three lineage cell types, adipocytes, osteoblasts and chondrocytes.     

CD137 enhances cytotoxicity of CD3CD56 cells and their capacities to induce CD4 Th1 responses

CD137 (4-1BB) is a TNFR superfamily member that mediates the costimulatory signal resulting in T cells and NK cells proliferation and cytokines production, but the effects of CD137 signaling on CD3⁺CD56⁺ cell subpopulation have not been well-documented. The aim of this study was to investigate the effects of CD137 signaling on regulation of CD3⁺CD56⁺ cell function. Anti-CD137 mAb or mouse IgG1 isotype control was added to CIK cell culture to determine the effects of proliferation and anti-tumor effects on CD3⁺CD56⁺ cells. We observed that anti-CD137 mAb could dramatically promote proliferation of CIK cells. And CD137–CIK cells and CD3⁺CD56⁺ cell subpopulation within them possessed higher ability to kill tumor cell line A549. The SCID mice engrafted with A549 cells and treated with CD137–CIK cells have prolonged survival. Further studies revealed that the percentages of CD3⁺CD56⁺ cells were elevated significantly in CD137–CIK cells. The expression of NKG2D was up-regulated on CD3⁺CD56⁺ cells from CD137–CIK cells. The expression of IFN-γ, IL-2 and TNF-α increased significantly whereas the production of TGF-β₁, IL-4 and IL-10 decreased in CD3⁺CD56⁺ cells from CD137–CIK cells. In addition, anti-CD137 mAb can elevate the capacity of CD3⁺CD56⁺ cells to induce CD4⁺ Th1 responses. We further showed that the anti-CD137 mAb also had the same effects on CD3⁺CD56⁺ cells expanded from the PBMCs of patients with NSCLC. We concluded that CD137 signaling could enhance the abilities of CIK cells to kill tumor cells in vitro and in vivo via increasing the proportion of CD3⁺CD56⁺ cells and their cytotoxicity. Furthermore, CD137 signaling can elevate the capacity of CD3⁺CD56⁺ cells to induce CD4⁺ Th1 responses which may enhance their anti-tumor activity indirectly. Taken together, our studies could be considered as valuable in CIK cells-based cancer immunotherapy.     

人脐带和骨髓源间充质干细胞对脐血单个核细胞增殖能力的影响

目的：探讨人脐带间充质干细胞（UCMSCs）与骨髓间充质干细胞（BMMSCs）在体外对造血干细胞的支持作用。方法分别从人脐带和骨髓中分离、培养间充质干细胞,通过免疫细胞化学染色等方法对其进行表型鉴定;采用流式细胞仪测定脐血单个核细胞的周期分布,采用甲基纤维素法测定脐血单个核细胞混合集落形成单位（CFU-Mix）,比较 UCMSCs和BMMSCs对脐血单个核细胞细胞周期、CFU-Mix形成能力的影响。结果成功培养获得 UCMSCs和BMMSCs,鉴定结果符合预期;与非共培养组细胞相比,UCMSCs和 BMMSCs共培养均能促进脐血单个核细胞进入增殖周期,并增加其形成CFU-Mix的能力（P＜0．05）,但UCMSCs和BMMSCs共培养组之间比较差异无统计学意义（P＞0．05）。结论成功从人脐带和骨髓组织中培养获得间充质干细胞,两种来源的间充质干细胞均能提高脐血单个核细胞的体外增殖能力及 CFU-Mix形成能力,均具有造血支持作用。     

不同培养体系培养人脐血源基质细胞的探索性研究

目的 探索不同培养体系对人脐血源基质细胞原代培养的影响，并观察人脐血源基质细胞的生物学特性。方法 取产科胎儿脐带血，采用经典和改良Dexter培养体系培养人脐血源基质细胞。倒置显微镜动态观察细胞生长情况，瑞氏染色观察细胞形态特征，采用细胞化学和免疫细胞化学进行鉴定。结果 改良Dexter培养体系在48 h细胞贴壁数、细胞开始伸展时间及原代培养时间明显优于经典Dexter培养体系。原代培养9-14天(平均12.1天)时贴壁细胞集落开始形成，15-21天(平均19.4天)时集落数量最多，培养28天贴壁细胞铺满培养皿底，细胞类型以成纤维样细胞、巨噬样细胞、“小圆”类细胞为主。细胞化学染色显示：非特异性酯酶染色法(NSE)显示阳性，阳性率100％；过氧化物酶染色法(POX)显示阴性；糖原染色(PAS)显示阳性，阳性率为100％；碱性磷酸酶(ALP)染色显示部分阳性，阳性率26％。免疫细胞化学染色显示：CD31显示阳性率为96％，CD68显示阳性率为95％，CD45阴性，Fn显示阳性率94％。结论 改良Dexter培养体系是一种理想人脐血源基质细胞培养体系，人脐血源基质细胞在体外的成功培养为从一新的角度进一步研究其在临床的早日应用提供理论基础。     

脐血混合培养纯化人间充质干细胞及生物学特性研究

目的探讨体外分离、混合培养纯化人脐血间充质干细胞的适宜体系,观察该人脐血间充质干细胞生物学特性。方法收集孕足月新生儿脐血,每3份脐血[(70—100)ml/份]混合;采用1.077 g/ml的淋巴细胞分离液(Ficoll)以1 500 r/min密度梯度离心法分离脐血中的单个核细胞,在Mesencult培养基中贴壁培养筛选人脐血间充质干细胞,显微镜下观察细胞生长形态变化,细胞计数并绘制细胞生长曲线,流式细胞仪检测细胞抗原表达,分析细胞周期;体外诱导脐血间充质干细胞成脂、成骨分化。结果密度梯度离心法所获得的单个核细胞,在培养基中培养约3—5 h开始出现贴壁生长,24 h后贴壁细胞增多,呈明显纺锤状,10 d后开始出现细胞克隆,3周后呈漩涡状生长。原代培养时间为15 d,P1代倍增时间为26 h。流式细胞仪鉴定:贴壁生长的细胞表达CD29、CD44和CD105,不表达CD34、CD45。分化潜能鉴定体外培养细胞可以成脂、成骨分化。结论所贴壁培养出的细胞的生长形态、流式表形、分化潜能具有人脐血间充质干细胞生物学特征,混合培养可以提高间充质干细胞培养成功率,实验中采用的培养体系适宜人脐血间充质干细胞的分离培养。     

Albumin-based solution is the ideal post-thawing suspension medium for cord blood hematopoietic stem cells: A stability and proliferative evaluation

Background

Cryopreservation and thawing protocols represent key factors for the efficacy of cellular therapy products, such as hematopoietic stem cells (HSCs). While the HSC cryopreservation has already been standardized, the thawing procedures have been poorly studied. This study aimed to evaluate the thawing and washing protocol of cord blood (CB) derived HSCs or the HPC(CB), by selecting the optimal thawing solution and determining CD34+ cells' stability over time.

Study Design and Methods

Seven cryopreserved CB products were thawed, washed, and resuspended in three different solutions (10% Dextran40 in NaCl equally prepared with 5% human albumin; 5% human albumin in PBS/EDTA; and normal saline) and stored at 4°C (±2°C). Mononuclear cell (MNC) count, CD45+/CD34+ cell enumeration, and cell viability were tested at 0, 1, 2, 4, 6, 8, 12, 24, 36, and 48 h. The protocol with the selected solution was further validated on additional 10 CB samples. The above parameters and the colony-forming unit (CFU) assay were analyzed at time points 0, 2, 4, 6, and 8 h.

Results and Discussion

The results showed that the 5% human albumin was the most suitable thawing solution. MNCs were stable up to 4 h (p = 0.009), viable CD45+ cells were unstable even at 2 h (p = 0.013), and viable CD34+ cells were stable until 6 h (p = 0.019). The CFU assay proved the proliferative potential up to 8 h, although significantly decreased after 4 h (p = 0.013), and correlated with the viable CD34+ cell counts. We demonstrated that the post-thawed and washed HPC(CB) using 5% human albumin is stable for up to 4 h.     

人脐带血干细胞移植防治兔急性心肌缺血的实验研究

目的:利用人脐带血干细胞(humanumbilicalcordbloodstemcells,HUCBSC)移植治疗兔急性心肌缺血,探索防治缺血性心脏病的新方法。方法:新西兰白兔40只,雌雄不拘,随机等分为细胞移植组和对照组。两组均结扎冠状动脉左前降支中1/2,复制心肌梗死模型。缺血60min后将108/mlHUCBSC0.3ml注入细胞移植组兔的缺血区心肌组织;对照组兔缺血区心肌组织中注射等体积的人静脉血。3周后观察两组心功能、心肌梗死面积及缺血区心肌内血管计数。用Northern印迹和ELISA法观察缺血区心肌组织中血管内皮细胞生长因子(vascularendothelialgrowthfactor,VEGF)和碱性成纤维细胞生长因子(basicfibroblasticgrowthfactor,b-FGF)基因的转录和表达。结果:细胞移植组的左心室收缩压(leftventricularsystolicpressure,LVSP)和左心室最大变化速率(±LVdp/dtmax)均显著高于对照组(P<0.01);其左心室舒张末期压(leftventricularenddiastolicpressure,LVEDP)显著低于对照组(P<0.01);其心肌梗死面积显著小于对照组(P<0.01);缺血区心肌的血管计数显著多于对照组(P<0.01)。Northern印迹和ELISA试验显示,细胞移植组VEGF和b-FGF基因的转录和表达均显著强于对照组(P<0.01)。结论:HUCBSC移植能明显改善兔急性心肌缺血的心功能,促进缺血区心肌细胞和血管的再生,从而显著减小心肌梗死的面积,有望成为防治缺血性心脏病的一种新的治疗策略。     

脐血造血干/祖细胞体外定向诱导扩增的研究

目的　观察不同因子组合在体外对脐血 (CB)中的巨核系等造血祖细胞的诱导扩增作用。方法　用体外液体悬浮培养法 ,将白细胞介素 3(IL 3)、白细胞介素 6 (IL 6 )、血小板生成素 (TPO)、脐血血浆 (CBP)作为刺激因子 ,添加不同的细胞因子组合 ,对CB的单个核细胞 (MNC)短期培养 2 1d。在培养的 0、7、14、2 1d检测新鲜细胞和培养细胞中的有核细胞数 (NC)、巨核系祖细胞 (CFU Mk)、粒巨噬系祖细胞 (CFU GM)、混合系祖细胞 (CFU GEMM)增殖倍数。结果　在 2 1d内 ,3个实验组的NC数 ,CFU GM、CFU Mk、CFU GEMM都有不同程度的增加 ,其中NC、CFU GM在培养的 2 1d达到高峰。CFU Mk、CFU GEMM在培养的 14d达高峰。在含有TPO的实验组中 ,CFU Mk的增殖倍数高于不含TPO的实验组 ,CFU GM、CFU GEMM增殖的倍数也高于不含TPO的实验组。含有CBP的实验组对CFU GM、CFU Mk、CFU GEMM有明显的促增殖作用。结论　CB中的含有丰富的造血干 祖细胞 ,可以在不同细胞因子的刺激下进行定向扩增 ,TPO可以促进干 祖细胞向巨核系分化 ,对粒巨噬系祖细胞也有促进作用。脐血血浆可以作为协同刺激因子促进CB中干 祖细胞增殖。     

混合脐血血浆对脐血CD34^＋细胞体外扩增的作用

采用两步法分离出脐血CD34~ 细胞,比较研究了混合脐血血浆联合IL-3,IL-6,GM-CSF,Epo 4种中、晚期造血因子和单纯的4种造血因子情况下脐血CD34~ 细胞的体外扩增。结果表明,混合脐血血浆联合造血因子对粒-巨噬细胞集落形成单位(granulocyte-macrophage colony-forming unit,CFU-GM),红系爆式集落形成单位(burst-forming unit of erythriod,BFU-E),混合集落形成单位(minxed colony-forming unit,CFU-mix)3种集落的扩增效果明显优于单纯的4种造血因子联合组,差异具有统计学意义(P<0.01),但单纯混合脐血血浆扩增效果较差。脐血造血细胞扩增对子成人脐血移植有重要意义。上述结果提示,混合脐血血浆的扩增成功,可代替或弥补早期造血生长因子的作用,用于脐血造血细胞的体外扩增。     

供者特征对脐带血造血功能的影响

目的 分析可能影响脐带血造血功能的供者特征.方法 对广州脐带血库1998年6月至2008年12月保存的4 358份脐带血的供者特征(包括母亲年龄、分娩方式、妊娠期、婴儿体重、婴儿性别)和脐带血采集量及造血功能的指标(包括总有核细胞数、CD34+细胞、干细胞集落等)进行相关性分析.结果 婴儿体重、分娩方式及婴儿性别是影响脐带血采集量、总有核细胞数、CD34+细胞数、CFUs及CFU-GM的主要因素.随着婴儿体重的增加,脐带血采集量、总有核细胞数、CD34+细胞数、CFUs、CFU-GM均呈上升趋势(P=0.000).阴道分娩时脐带血的采集量虽然低于刮宫产(P=0.000),但总有核细胞数、CD34+细胞数、CFUs,CFU-GM均高于剖宫产(P=0.000).女婴脐带血中总有核细胞数含量高于男婴(P=0.000),但脐带血采集量(P=0.000)、CD34+细胞数(P=0.002)均低于男婴.随着妊娠期的延长,脐带血中总有核细胞数增加(P=0.000),但CD34+细胞数减少(P=0.001).结论 某些脐带血供者特征对脐带血造血功能指标有积极影响.     

脐血血浆替代胎牛血清培养脐带间充质干细胞及冷冻保存

背景：采用胎牛血清扩增培养及冷冻保存的间充质干细胞,在临床应用中存在一定的风险。目的：探讨以脐血血浆替代胎牛血清体外分离培养、扩增及冷冻保存脐带间充质干细胞的可行性。方法：选择符合广州脐血库供者合格性筛选标准的脐血,收集脐血干细胞制备过程中去除的血浆,经病原学及微生物检测合格,多份混合用于细胞培养。采用酶消化法从健康足月分娩新生儿的脐带组织分离获得脐带间充质干细胞,分为两组,分别以DMEM/F12为基础培养基,添加胎牛血清或混合脐血血浆,经培养扩增后,采用流式细胞仪检测细胞免疫表型,并进行间充质干细胞成骨、成脂分化鉴定。在含有10%二甲基亚砜的DMEM/F12培养基中,分别添加体积分数为20%的胎牛血清或混合脐血血浆作为冷冻保存液,对扩增至第3代的细胞冷冻保存至6个月以上,观察复苏后细胞的活率、贴壁情况、增殖、免疫表型及向成骨细胞分化的能力。结果与结论：两种培养体系下的脐带间充质干细胞均呈现典型的梭形漩涡状生长,间充质干细胞免疫表型的表达谱系基本无差异,均具有成骨、成脂分化的能力,但脐血血浆培养条件下细胞的增殖速度显著高于胎牛血清。冻存复苏后的细胞可正常贴壁,且具有向成骨细胞分化的能力,采用脐血血浆冻存的细胞具有更高的贴壁效率及扩增能力。上述结果表明,脐血血浆可以替代胎牛血清用于脐带间充质干细胞的扩增培养及冷冻保存,并维持了间充质干细胞的基本生物学特性,是大量扩增间充质干细胞用于临床治疗较为安全的选择。     

NOD/SCID小鼠脐血单个核细胞骨髓腔内移植的实验研究

目的观察骨髓腔内移植(iBM)人脐血单个核细胞(MNC)对小鼠造血重建和免疫功能恢复的作用。方法NOD/SCID小鼠经137Cs全身照射后,在4h内无菌条件下局部麻醉后从尾静脉或骨髓腔内输注分离脐血MNC。受体小鼠随机分为5组:①对照组:骨髓腔内输注培养液;②阳性对照组(iTV):尾静脉输注脐血MNC3×107/只;③实验Ⅰ组(iBM1):骨髓腔内输注脐血MNC3×106/只;④实验Ⅱ组(iBM2):骨髓腔内输注脐血MNC1×107/只;⑤实验Ⅲ组(iBM3):骨髓腔内输注脐血MNC3×107/只。对照组4只小鼠,实验Ⅱ组7只小鼠,其余每组5只。24h后观察iBM22只小鼠未移植侧胫骨骨髓腔脐血细胞的迁移分布,动态观察移植后小鼠的存活和造血重建情况,7～8周后处死各组小鼠,检测骨髓细胞表面CD分子表达、碳青花(DilCM)染料示踪研究和脐血βactin的DNA标记。结果①照射后骨髓腔内输注脐血MNC,24h后在未输注脐血MNC的一侧胫骨骨髓细胞膜有DilCM标记;②7～8周后小鼠存活14只,其中对照组存活1只,iTV组、iBM1组各存活2只,iBM2组存活4只,iBM3组存活5只;③外周血常规检查结果显示iBM组白细胞的恢复速度比iTV组和对照组快而且稳定;④移植后存活小鼠骨髓细胞表面CD45标记、DilCM染料示踪研究和βactin均显示人源的标记。结论经iBM途径移植脐血MNC至NOD/SCID小鼠骨髓可以重     

1例神经母细胞瘤患儿脐带血造血干细胞移植术后的护理

研究发现,脐带血中含有可以重建人体造血和免疫系统的造血干／祖细胞,可用于造血干细胞移植,治疗多种疾病。造血干细胞移植整个过程是给予患者大剂量化、放疗等预处理后,将保存在-196摄氏度的液氮中经37～40摄氏度的温水解冻后快速输入患者体内,可以有效杀灭肿瘤细胞并重建造血系统,它的临床应用为恶性肿瘤患者提供了先进有效的治疗方法。本院于2009年10月收治了1例神经母细胞瘤的患儿,经采用造血干细胞移植后,取得较好的效果,现报道如下。     

人脐血中分离骨髓间充质干细胞成骨诱导前后的生物学特性

目的观察诱导因素对骨髓间充质干细胞向成骨方向分化的影响,探索骨组织工程的种子细胞来源。方法使用密度梯度离心法分离来源于人脐血的骨髓间充质干细胞进行培养,保留已贴壁细胞传代,观察在加有地塞米松、维生素C、β-甘油磷酸钠的培养液中骨髓间充质干细胞的生长及分化情况。结果分离得到的骨髓间充质干细胞呈成纤维样表现,诱导条件下第2代细胞碱性磷酸酶活性增高,12d达到最高,为(33.10±0.54)U/ml,P<0.001,t=-48.32,且出现矿化结节。结论人脐血来源的骨髓间充质干细胞在诱导培养液作用下具有一定的成骨能力,可作为骨组织工程种子细胞。     

不同冻存保护剂对脐血造血细胞生物学特性的影响

目的 探索有效低温保存脐血造血细胞的冻存保护剂。方法 对比４种不同的联合低温保护地脐血有核细胞（ＴＮＣ）的保护作用,并在冻存后１,２,３及４个月分别检测其复苏后脐血ＣＤＥ３４＾＋细胞及集落形成细胞（ＣＦＣ）数。结果 ４种不同联合的低温保护剂对脐血ＴＮＣ,ＣＤ３４＾＋细胞及ＣＦＣ的保护作用判别显,依次为右旋糖酐－４０（Ｄｅｘｔｒａｎ－４０）＋二甲基亚砜（ＤＭＳＯ）〉生理盐水＋ＤＭＳＯ〉ＤＭＳＯ＋自