微载体cytodex 3大量扩增成人骨髓间充质干细胞的初步研究

目的建立一种体外分离、大量扩增培养成人骨髓间充质干细胞(hMSCs)的方法。方法用Percoll梯度离心结合贴壁法分离hMSCs,用微载体cytodex 3培养hMSCs,以普通单层聚苯乙烯(TCPS)培养作对照,用流式细胞仪(FCM)和MTT法对其细胞表型和增殖活性检测。结果①梯度离心结合早期换液是分离hMSCs的较好方法,FCM检测表明hMSCs表面表达CD29、CD44和CD105,而不表达CD14、CD34、CD45、VLA-1和HLA-DR。hMSCs细胞周期分布显示:G0/G1期(86.4±3.8)%,S G2 M期(13.6±4.2)%;②hMSCs与cytodex 3有良好的相容性,MTT法表明hMSCs在cytodex 3表面悬浮生长时具有比普通单层TCPS培养时更高的数量和增殖活性,FCM分析表明两者的细胞表型和细胞周期分布相同,无显著性差异(P>0.05)。结论微载体cytodex 3培养方法是扩增组织工程种子细胞hMSCs的有效方法。     

成骨细胞在旋转壁式生物反应器内的大规模扩增

目的 进行SD大鼠成骨细胞在旋转壁式生物反应器内大规模扩增培养的研究。方法利用微载体悬浮培养法在旋转壁式生物反应器内大规模扩增成骨细胞，检测其组织形态和生物功能后。作为接种到支架材料上并于反应器内三维环境中培养组织工程骨的种子细胞。结果成骨细胞在生物反应器中每代可以扩增十倍以上，同时经过倒置相差显微镜、SEM(扫描电镜)以及ALP(碱性磷酸酶)和MTT等生物学性能检测后，发现在旋转壁式生物反应器中三维培养的成骨细胞各种生物指标性能良好。结论新型旋转壁式生物反应器可以提供低剪切力的培养环境，而且细胞之间有三维联系的机会，成骨细胞表现出良好的体外扩增能力，适于建立一种理想的成骨细胞体外扩增的三维培养体系。     

体外刺激肾移植受者外周血淋巴细胞进行免疫监测的临床研究

目的探讨应用体外刺激外周血淋巴细胞的方法进行免疫监测来预测肾移植术后急性排斥反应的价值。方法选取40例肾移植受者,将其分为急性排斥反应组(20例)和肾功能正常组(20例);选取10名健康供者作为正常对照组。抽取所有研究对象的外周静脉血,分离出外周血淋巴细胞,并经佛波酯(phorbol myfismte acetate,PMA)和离子霉素(ionomycin,Ion)体外刺激8h。应用流式细胞术检测细胞培养上清液白介素(IL)-2、IL-6的表达强度及CD3+CD69+、CD3+CD71+淋巴细胞比例;应用受试者工作特征(ROC)曲线评价IL-2联合IL-6、CD3+CD69+联合CD3+CD71+预测肾移植术后急性排斥反应的敏感度和特异度。结果急性排斥反应组的IL-2、IL-6的荧光强度和CD3+CD69+、CD3+CD71+淋巴细胞比例均显著高于肾功能正常组(P≤0.01);IL-2联合IL-6预测肾移植受者急性排斥反应的敏感度为0.90,特异度为0.95。CD3+CD69+联合CD3+CD71+预测急性排斥反应的敏感度为0.95,特异度为0.90。结论监测肾移植受者外周血淋巴细胞体外刺激上清液中的IL-2、IL-6及CD3+CD69+、CD3+CD71+的表达强度,可以预测急性排斥反应。此法简便,敏感度和特异度高。     

鸡胚细胞的培养

研究了鸡胚细胞的生长规律，葡萄糖的利用和乳酸、氨等代谢产物的积累规律，比较了培养基对细胞生长的促进作用，筛选了合适的微载体，初步探讨了用微载体培养鸡胚细胞的方法。实验结果表明，鸡胚细胞在DMEM培养基中生长良好，最适合的微载体为胶原型微载体，如GT-2，Gytodex-3。     

用大孔明胶微载体培养Vero细胞

以明胶为原料，用悬浮成球、甲苯制孔的方法制备大孔明胶微载体。考察了表面活性剂及其配比、油水比、明胶浓度、制备方式和表面修饰等对载体性能的影响。优化了制备大孔明胶微载体的条件，制得了直径为１００－３００μｍ，孔径为１０－３０μｍ的大孔明胶微载体。     

永生化软骨细胞体外快速扩增的实验研究

目的　探讨获取大量软骨组织工程种子细胞的方法和技术。方法　通过真核表达载体 ,把人端粒酶逆转录酶基因 (hTERT)转入兔髁状突软骨细胞 ,筛选、挑选阳性克隆在微载体 RCCS内快速扩增永生化软骨细胞。观测RCCS中微载体培养永生化软骨细胞的生长情况和检测细胞代谢率 ,进行Ⅱ型胶原免疫组化染色 ,并与常规培养方法进行比较。结果　永生化软骨细胞在微载体 RCCS中生长迅速、细胞代谢率高、倍增时间缩短 (P <0 0 1)。在培养第 8天 ,细胞数量可达最初接种的 95倍 (P <0 0 1)。结论　联合应用微载体和RCCS培养技术 ,能够在体外快速、大量扩增永生化软骨细胞     

高密度微载体培养人肝癌细胞

目的研究人肝癌细胞在高密度微载体培养时的生长条件与培养方式,建立实验室规模高效、简便培养人肝癌细胞的方法。方法应用微载体CuhiSpher-S和Cytodex-1在1 L SuperSpinner搅拌瓶中培养人肝癌细胞THCC-98,采用批式换液连续培养的方式,对细胞生长及营养物质葡萄糖利用、代谢产物乳酸生成进行分析。结果人肝癌细胞THCC-98在CultiSpher-S和Cytodex-1培养中葡萄糖13消耗量高达2mmol／10^6。细胞（2．17和2．3）,乳酸日生成率为0．75—1．08mmol／10^6。细胞,最高浓度为9mmol／L（9．2比9．5）。通过实施批式换液连续培养,换液0．3—0．9V／d,可使细胞最高密度达（1．04比0．89）×10^7cells／ml。就两种微载体培养比较,CultiSpher-S由于具有更大的表面积／体积比,提供给细胞更大的生长空间,其所能达到的细胞密度高且营养物质利用更为有效。结论用1 L SuperSpinner搅拌瓶Cultisphere微载体批式换液连续高密度培养人肝癌细胞,细胞密度可达10^7cells／ml,批式收获细胞〉10^10。     

Improved expansion of human bone marrow‐derived mesenchymal stem cells in microcarrier‐based suspension culture

Human bone marrow‐derived mesenchymal stem cells (hBM‐MSCs) have potential clinical utility in the treatment of a multitude of ailments and diseases, due to their relative ease of isolation from patients and their capacity to form many cell types. However, hBM‐MSCs are sparse, and can only be isolated in very small quantities, thereby hindering the development of clinical therapies. The use of microcarrier‐based stirred suspension bioreactors to expand stem cell populations offers an approach to overcome this problem. Starting with standard culture protocols commonly reported in the literature, we have successfully developed new protocols that allow for improved expansion of hBM‐MSCs in stirred suspension bioreactors using CultiSpher‐S microcarriers. Cell attachment was facilitated by using intermittent bioreactor agitation, removing fetal bovine serum, modifying the stirring speed and manipulating the medium pH. By manipulating these parameters, we enhanced the cell attachment efficiency in the first 8 h post‐inoculation from 18% (standard protocol) to 72% (improved protocol). Following microcarrier attachment, agitation rate was found to impact cell growth kinetics, whereas feeding had no significant effect. By serially subculturing hBM‐MSCs using the new suspension bioreactor protocols, we managed to obtain cell fold increases of 10³ within 30 days, which was superior to the 200‐fold increase obtained using the standard protocol. The cells were found to retain their defining characteristics after several passages in suspension. This new bioprocess represents a more efficient approach for generating large numbers of hBM‐MSCs in culture, which in turn should facilitate the development of new stem cell‐based therapies. Copyright © 2012 John Wiley & Sons, Ltd.     

Spontaneous osteogenesis of MSCs cultured on 3D microcarriers through alteration of cytoskeletal tension

3-dimensional microcarrier (3D-MC) cell culture systems are often used for expansion of stem cells including mesenchymal stem cells (MSCs) for high cell volumes required in clinical applications. However, compared to 2-dimensional (2D) cell culture, effects of 3D-MC systems on MSC differentiation have not been well studied. In this study, the behavior of various sources of MSCs from two species was observed and compared on 3D collagen I-coated-MCs (COL-MC) versus 2D culture. Proliferation of all MSCs cultured on 3D COL-MC was much decreased compared to 2D culture. Unexpectedly, COL-MC-cultured MSCs underwent spontaneous osteogenesis without exogenous addition of biochemical factors, as evidenced by increased osteogenic genes expression, ALP activity, calcium deposition, and collagen I secretion. Furthermore, MSCs cultured on 3D-MC alone without collagen I coating is sufficient to induce osteogenesis. The spontaneous lineage commitment induced by 3D-MC culture was mediated by increased cytoskeletal tension and actomyosin contraction of MSCs, which could be prevented by latrunculin B and blebbistatin, inhibitors of cytoskeletal tension and actomyosin contraction respectively. Our findings show that the combination of bioengineered MC and MSCs alone can induce specific lineage commitment very efficiently. These data have strong implications in simplifying tissue engineering strategies for therapeutic applications.     

纤维素与明胶微载体微重力培养肝细胞的比较

目的 探讨商品化的多孔微载体:cytopore 2和cultispher S何种更适合于微重力条件下培养CL-1细胞.方法 采用RCCS旋转培养系统.在50 ml水平微重力旋转培养CL-1细胞.分别对接种至cytopore 2和cultispher S的细胞进行动态形态学观察、细胞计数和功能学检测.结果 CL-1细胞在两种载体上均可粘附生长,并于第9天达到生长高峰.细胞计数结果提示cultispher S的细胞密度可达到4×10 6个/ml.在第10、11、12天,cytopore 2组的上清中自蛋白浓度明显高于cultispher S组.有显著差异(P<0.05),在第10、11天,cytopore 2组的上清中尿素浓度明显高于cultispher S组,有显著差异(P<0.05).结论 Cytopore 2培养的CL-1细胞计数低于Cultispher S组,但功能好于Cultispher S组.