胎儿毛乳头细胞的培养和鉴定及其体外诱导分化

目的探讨胎儿毛乳头细胞（dermal papilla cells，DPCs）生物学特性和体外诱导分化潜能，论证作为组织工程种子细胞的可行性。方法Ⅰ型胶原酶消化法分离毛乳头，Eagle动物细胞培养基（DMEM）／F12（3：1）中培养细胞，通过免疫荧光检测α平滑肌动蛋白（smooth muscle actin-α，SMA—α）、Ⅰ型胶原、Ⅱ型胶原、层粘连蛋白，对细胞的生物学特性进行鉴定。取第3、7代细胞以成脂诱导液、成骨诱导液体外定向诱导7～10d，油红染色和Von Kossa染色、骨桥蛋白免疫荧光检测鉴定细胞的成脂和成骨特性。结果体外培养的DPCs表达SMA—α、Ⅰ型胶原、Ⅳ型胶原和层粘连蛋白，成脂诱导10d后油红染色可见细胞胞浆内红色脂滴形成，成骨诱导7d后Von Kossa染色细胞间有黑色钙结节形成，细胞表达骨桥蛋白。结论体外培养DPCs具有干细胞特性，可作为皮肤组织工程和骨组织工程一种新的种子细胞。     

人间充质干细胞在骨组织工程中的应用

目的从数量与功能两方面探讨人间充质干细胞(humanmesenchymalstemcells,hMSCs)作为骨组织工程种子细胞的可行性。方法髂骨穿刺,梯度离心分离获得hMSCs,体外扩增培养;对第3代细胞用地塞米松、β-甘油磷酸、维生素C等成骨诱导培养,检测细胞碱性磷酸酶、骨钙素的表达和钙结节形成情况;诱导细胞与可吸收性复合支架材料体外构建复合体,植入裸小鼠皮下,对照组仅植入支架材料,术后3周取材检测骨钙素、Ⅰ型胶原表达。结果4ml骨髓含3.2×107～6.0×107个单个核细胞,培养3周收获hMSCs2.5×107～4.3×107;成骨诱导后,表达碱性磷酸酶、骨钙素阳性细胞数>50%,对照组<10%;诱导细胞与材料复合后植入体内仍然高表达骨钙素、Ⅰ型胶原。结论hMSCs能够满足体外构建组织工程化骨,对种子细胞数量和功能的要求。     

兔脂肪干细胞体外成骨诱导培养及成骨活性鉴定的实验研究

目的体外分离培养兔脂肪干细胞（adipose-derived stem cells,ADSCs）,在成骨诱导条件下鉴定其成骨活性。方法取4月龄新西兰大白兔腹股沟区脂肪,Ⅰ型胶原酶消化,分离、培养及传代原细胞,将第3代ADSCs消化后,加入成骨培养液中诱导分化,分别行碱性磷酸酶染色、茜素红染色、VonKoss（a钙结节）染色,以鉴定分化结果。结果体外分离培养的细胞增殖活跃,成骨诱导后碱性磷酸酶染色、茜素红染色及Von Kossa染色均呈阳性表达。结论脂肪干细胞具有成骨分化能力,是一种理想的骨组织工程种子细胞。     

人羊膜间充质细胞向成骨细胞诱导分化的实验研究

目的 观察人羊膜间充质细胞(human amnion mesenchymal cells,hAMCs)体外诱导向成骨细胞分化,为骨组织工程提供种子细胞。方法 从剖宫产后废弃的人羊膜组织分离培养hAMCs,经成骨细胞诱导条件培养基诱导后,对细胞形态特征、碱性磷酸酶、骨桥素、骨钙素表达以及I型胶原分泌进行观察和检测。结果 原代培养的hAMCs形态呈长梭形或不规则形,呈均匀分布生长,传代后细胞体积略变大,约5～7d传代1次。经成骨细胞诱导培养15d后,hAMCs碱性磷酸酶、骨钙素、骨桥素的表达呈阳性,并且检测有I型胶原分泌。结论 hAMCs易于体外分离培养及扩增,体外成骨细胞定向诱导的hAMCs具有典型的成骨细胞的形态和功能性特征,是良好的骨组织工程种子细胞。     

增强型绿色荧光蛋白(EGFP)转染对人骨髓基质细胞体外成骨诱导的影响

目的 研究增强型绿色荧光蛋白(EGFP)转染人骨髓基质细胞(MSC)，对其体外诱导后表达成骨表型的影响，探讨EGFP作为骨组织工程种子细胞示踪剂的可行性。方法 构建携带增强型绿色荧光蛋白(EGFP)重组逆转录病毒载体，并转染骨髓基质细胞，G418进行筛选。将转染后稳定表达绿色荧光蛋白的骨髓基质细胞(MSC-EGFP)进行成骨诱导扩增，以未转染的MSC为对照组，分别检测成骨诱导后碱性磷酸酶(AKP)活性，骨钙蛋白(OCN)含量和成骨细胞转录因子(Cbfal)的表达。结果 构建携带增强型绿色荧光蛋白(EGFP)重组逆转录病毒载体，转染后获得稳定表达绿色荧光蛋白的MSC-GFP，其体外经成骨诱导后，同样能表达成骨特征性表型，AKP，OCN，Cbfal表达和未转染组无明显差别。结论 MSC转染EGFP后，不影响其体外成骨诱导后成骨表型的表达，EGFP可作为骨组织工程种子细胞(MSC)良好的示踪剂。     

成骨诱导的人骨髓基质干细胞生物安全性评价

目的分析人骨髓基质干细胞在体外成骨诱导培养条件下，其染色体核型及端粒酶活性是否发生异常的改变，细胞是否产生致肿瘤性，为验证人骨髓基质干细胞作为骨组织工程种子细胞的安全性提供实验依据。方法采用常规细胞染色体G显带处理方法对3例成骨诱导培养的人骨髓基质干细胞样本进行核型分析，采用端粒酶活性PCRELISA检测法分析细胞的端粒酶活性，并通过裸鼠皮下致肿瘤试验对细胞的致肿瘤性进行研究。结果人骨髓基质于细胞体外成骨诱导培养至第7代，未发现染色体核型异常改变，相应的端粒酶活性也未出现异常增高。致肿瘤试验，在观察期内均未见结节形成或可疑病灶产生，符合围家医疗产品生物学评价标准的要求。结论人骨髓基质干细胞在体外长期成骨诱导培养条件下，染色体核型及端粒酶活性均未出现异常改变，且无致肿瘤性，符合作为骨组织工程种子细胞的生物安全性应用要求。     

皮肤源祖细胞的培养、鉴定和体外诱导分化

目的探讨皮肤源祖细胞的体外培养、鉴定及定向诱导成脂、成骨的方法，为组织工程提供较理想的种子细胞。方法出生1～3d的sD大鼠幼鼠皮肤，以含表皮生长因子和成纤维细胞生长因子的培养基进行培养。观察细胞生长情况，描绘生长曲线；免疫荧光鉴定细胞表达Nestin和Fibronectin情况；将第3代细胞，分别用成脂和成骨诱导液培养14d，以油红O染色、茜素红染色和免疫荧光检测皮肤源祖细胞诱导成脂、成骨情况。结果细胞呈悬浮生长，迅速增殖形成克隆球团；细胞免疫荧光表达Nestin和Fibronectin；成脂诱导14d后，细胞内大量致密颗粒形成，油红O染色可见红色脂滴；成骨诱导14d后，茜素红染色可见暗红色钙盐沉积，骨桥蛋白表达阳性显示成骨细胞形成。结论皮肤源祖细胞具有干细胞的特性，能分化为成骨细胞和脂肪细胞。     

兔脂肪干细胞的分离培养鉴定及成骨诱导分化研究

[目的]探讨在成骨诱导条件下兔脂肪干细胞的体外诱导分化情况：[方法]取3个月龄日本大耳白兔颈背部皮下脂肪，用Ⅰ型胶原酶消化获得细胞。Stro-1免疫细胞化学染色鉴定细胞性质；加入成骨诱导液后依次进行形态学、Ⅰ型胶原、碱性磷酸酶及钙盐沉积相关检测。[结果]（1）原代所获细胞Stro—1表达阳性？（2）在诱导条件下，Ⅰ型胶原、碱性磷酸酶及钙盐沉积均呈阳性表达。[结论]脂肪干细胞来源广、易获取、对机体创伤小，与骨髓间充质干细胞类似，经体外诱导后可实现成骨分化，为骨组织工程提供了一种新的种子细胞：     

兔骨髓基质细胞的分离培养

目的 为骨组织工程寻找一种理想的种子细胞。方法 采取兔骨髓组织，应用梯度离心获取骨髓基质细胞，体外培养传代，通过光镜、透射电镜及成骨特性的鉴定，观察细胞的形态、生长特点及成骨特性。结果 培养的骨髓基质细胞形态多为三角形或梭形，生长增殖迅速，具有成骨能力，易于定向分化为成骨细胞。结论 自骨髓获得的骨髓基质细胞具有明显的增殖能力和成骨活性，可以做为骨组织工程中比较理想的种子细胞。     

成骨诱导的兔骨髓基质干细胞成骨活性的表达及维持

目的观察成骨诱导的兔骨髓基质干细胞(BMSCs)体内、外环境下成骨活性的表达及维持。方法观察BMSCs在体外成骨诱导培养条件下的成骨分化特性;构建兔BMSCs与活骨组织共培养模型模拟体内“成骨环境”,将成骨诱导的MSCs置于共培养及普通传代培养条件下进行传代培养,观察经成骨诱导的BMSCs在体外及模拟体内的培养条件下细胞的表型维持情况。结果药物成骨诱导培养的BMSCs,其ALP活性及骨钙素均显著高于普通培养组(P<0.05);经过诱导培养的BMSCs,其Ⅰ型胶原、骨钙素免疫组化阳性。RT-PCR法半定量测定Ⅰ型胶原mRNA,成骨诱导培养的Ⅰ型胶原mRNA表达量明显高于普通传代培养对照组。药物成骨诱导后的细胞在体外普通传代培养传5代后,细胞碱性磷酸酶(ALP)活性、骨钙素水平及Ⅰ型胶原表达稳定维持在较高水平,保持其成骨细胞的表型;在共培养条件下,ALP活性、骨钙素水平Ⅰ型胶原表达保持在高水平,且ALP活性、骨钙素水平在大部分时间点均高于普通传代培养。结论药物成骨诱导培养呈现促BMSCs向成骨方向转化的特点,能使ALP、骨钙素及Ⅰ型胶原表达短期内达到高水平;经成骨诱导的BMSCs在体外或模拟的体内传代培养条件下,均能维持成骨表型,保持成骨活力。     

人毛乳头细胞生长相关蛋白作用下细胞VEGF的表达

目的研究人毛乳头生长相关蛋白作用下不同代人毛乳头细胞VEGF的表达。方法通过体外培养低传代的人毛乳头细胞,收集其上清配制成条件培养基,用此条件培养基培养高传代人毛乳头细胞,通过RT-PCR观察各代毛乳头细胞的VEGF变化。结果用低传代人毛乳头细胞的上清液培养过的9代人毛乳头细胞的VEGF表达不仅明显好于对照组(P<0.01),而且明显好于基础培养基作用下的7代人毛乳头细胞的VEGF表达(P<0.01)。结论低传代人毛乳头细胞的培养液在体外能明显地促进VEGF的表达。     

In Vivo Osteogenic Capability of Human Mesenchymal Cells Cultured on Hydroxyapatite and on β-Tricalcium Phosphate

The aim of the current study was to examine in vitro osteogenic capability and in vivo bone formation of mesenchymal stromal cells (MSCs) on two kinds of calcium phosphate ceramics. MSCs derived from human bone marrow were seeded on either hydroxyapatite (HA) ceramic or β-tricalcium phosphate (β-TCP) ceramic and then cultured in a medium supplemented with a donor's serum, vitamin C, β-glycerophosphate, and dexamethasone. The culture revealed the expression of alkaline phosphatase activity, indicating the osteogenic differentiation of the MSCs on the ceramics (fabrication of tissue-engineered construct). The constructs were then implanted subcutaneously into nude rats for 8 weeks. New bone formation was observed in both types of ceramics, and human-specific Alu sequence was detected by in situ hybridization analysis. Quantitative microcomputed tomography showed that the volume of the new bone in the HA ceramic was greater than that in the β-TCP ceramic in six of seven cases. These results suggest that human MSCs cultured on ceramics could retain their osteogenic capability even after ectopic implantation and provide a rationale for the use of tissue-engineered constructs derived from a patient's MSCs and calcium phosphate ceramics in bone tissue regeneration.     

Bone formation by osteoblast-like cells in a three-dimensional cell culture

Summary Cells of the clonal osteogenic cell line MC3T3-E1 were seeded onto a three-dimensional matrix of denatured collagen type 1 and cultured for a period of up to 8 weeks. Specimens were analyzed by histological, enzyme histochemical, immunocytochemical, and ultrastructural methods and byin situ hybridization between day 7 and day 56 after seeding. In 56-day cultures, the MC3T3-E1 cells were arranged in a three-dimensional network and formation of bone-like tissue was indicated by calcification of a newly synthesized collagen type I matrix resembling osteoid and surrounding osteocyte-like cells. The differentiating culture showed high expression of osteocalcin and alkaline phosphatase activity. NIH3T3 fibroblasts used as control cells passed through the network of the substrate forming a confluent monolayer underneath. This culture system offers a potentially powerful model for bone formationin vitro and for investigating the osteogenic potential of bone-derived cells.     

GMP-compliant culture of human hair follicle cells for encapsulation and transplantation

Human hair follicle cells, both bulge and dermal papilla cells, were isolated and cultured in a GMP cell factory, in order to obtain an in vitro hair follicle source for encapsulation end transplantation in alopecia regenerative cell therapy. An in vitro model, constituted by organotypic cultures of human skin sample, was set up to simulate the dermal-epidermal interaction between bulge cells and dermal papilla cells, evaluating the possible new follicles formation and the regenerative potentiality of these hair follicle cells. Both the bulge and dermal papilla cells show an excellent cellular proliferation as well as an abundant extracellular matrix production. The immunofluorescence investigation revealed the positivity of both cell lines to CK15 and CD200, whereas both cell lines were negative to CD71 and Oct-4. The pool of cultured bulge and dermal papilla cells was injected into the deep dermis; at day 28 of culture, some organized areas with a higher cell density can be observed: the cells self-organize into papilla-like lengthened aggregates. In samples in which the follicular cells have been seeded on the dermis surface, an epidermis-like homogeneous monolayer on the dermis surface can be seen, therefore showing a potentiality of these cells for epidermis regeneration. These data show the efficacy of a cellular isolation and amplification approach to obtain an in vitro human hair follicle regenerative source on industrial scale in a GMP cell factory. The results also proved an intrinsic potentiality of follicular cells to in vitro recreate the epidermis for tissue engineering purposes. Thus, it is feasible to produce bioengineered hair follicles in a GMP cell factory, for encapsulation and transplantation in alopecic patients.     

Role of hair papilla cells on induction and regeneration processes of hair follicles

Hair dermal papilla cells are specialized mesenchymal cells that exist in the dermal papilla located at the bottom of hair follicles. These cells play pivotal roles in hair formation, growth, and cycling. Hair follicle formation is usually directed by an aggregation of dermal mesenchymal cells, the origin of dermal papilla cells, in the embryonic skin. We noticed that cultured dermal papilla cells also have hair-forming activity and do not lose the activity even after long-term cultivation, if they are cultured with conditioned medium from keratinocytes obtained from the sole or with a medium containing fibroblast growth factor. The secreted factors from keratinocytes and fibroblast growth factor are, therefore, important for maintaining the cellular properties of dermal papilla cells. Even if the hair bulb, including the hair matrix and the dermal papilla, has been removed from vibrissal follicles in vivo, the new hair matrix and papilla can regenerate from the rest of the follicle, and eventually a hair shaft regrows. It has been reported that hair bulb regeneration does not occur when the lower half of a hair follicle is removed. However, new hair bulbs were formed in the remaining upper halves of vibrissal follicles if the amputated follicles had been implanted under the kidney capsule. The formed bulbs were small and pelage-type, not large vibrissa-type. Histological studies showed that the new dermal papillae were derived from dermal sheath cells surrounding upper follicular epidermis, and the new hair matrices were produced from the follicular epidermis. Moreover, the upper halves of vibrissal follicles reformed large vibrissa-type bulbs when they were associated with dermal papillae or cultured papilla cells and implanted in the kidney. Thus, dermal papilla cells and probably dermal sheath cells have the ability to induce and form hair bulbs under preferred environmental conditions. Attempts to identify the genes and proteins associated with hair-forming activity of dermal papilla cells have been carried out. We and other groups successfully isolated the molecules that were specifically expressed in dermal papilla cells. The nature of the hair-producing factors could be understood through the studies of these molecules.     

同种异体脂肪干细胞复合脱钙骨修复大鼠尺骨缺损

目的探讨同种异体脂肪干细胞修复管状骨缺损的可行性。方法获取SD大鼠的腹股沟处脂肪,分离培养脂肪干细胞（Adipose-Derived Stem Cells,ADSCs）;鼠第3代ADSCs与脱钙骨复合,24 h后进行成骨诱导培养。检测细胞在材料表面的生长及成骨分化能力。建立鼠两侧尺骨缺损模型,分别植入鼠ADSCs-脱钙骨复合物（实验侧）和单纯脱钙骨材料（对照侧）;8周、24周后取样,行DR和组织学检测,观察成骨情况。结果 ADSCs能在脱钙骨上很好地黏附和生长,并维持成骨分化能力。细胞-材料复合物植入24周后,DR显示实验侧有新生骨基质长成,对照侧未见骨组织生成。组织学检测显示,实验侧缺损区被典型的骨组织取代,可见新生骨小梁附着于脱钙骨表面;对照侧只有少量的骨组织和纤维组织充填。结论 ADSCs-脱钙骨材料复合物植入,能成功修复临界大小的管状骨缺损。     

Enhancement of tibial regeneration in a rat model by adipose-derived stromal cells in a PLGA scaffold

IntroductionAutologous adipose-derived stromal cells (ASCs) are an obvious source of osteogenic cells and can be easily isolated from adipose tissue. We evaluated the potential of ASCs seeded onto a scaffold to heal tibial defects.MethodsAutologous ASCs were obtained from adipose tissue by collagenase digestion. The cells were seeded in three-dimensional poly(lactic)-glycolic acid (PLGA) scaffolds and cultured in osteogenic medium for four weeks. Evidence of osteogenesis was assessed by von Kossa staining in three-dimensional cultures following osteogenic induction. The critical size tibial defects (10 mm) were created using a rat model. Defects were either left empty (sham group), treated with a PLGA scaffold alone (PLGA group), or a PLGA/ASC composite (PLGA/ASC group). Using radiologic and histologic analyses, we assessed total bone volume and vascular density. Total RNA was prepared from regenerated bone and analyzed for osteogenic marker gene expression.ResultsIn three-dimensional cultures, the PLGA/ASC composite showed multiple calcified extracellular matrix nodules on von Kossa staining after four weeks of differentiation. Near complete healing was observed between the PLGA/ASC engrafted tibial defects on plain radiographs and micro-CT findings. Total bone volume and mechanical strength were significantly higher in the PLGA/ASC group compared to the sham and PLGA groups. Histologic analysis revealed increased new bone formation along capillaries in the PLGA/ASC group. Real-time RT-PCR analysis revealed a significant increase in the expression of osteogenic genes in the PLGA/ASC group.ConclusionsThe results showed that the repair of tibial defects was accelerated by implantation of autologous ASCs seeded onto a PLGA scaffold. Therefore, PLGA/ASC is a promising new cell-based therapy for healing critical size tibial defects.     

骨髓间充质干细胞复合组织工程化脱细胞真皮基质构建组织工程皮肤

目的：体外培养扩增SD大鼠骨髓间充质干细胞（bone marrow mesenchymal stem cells,BMSCs），复合组织工程化脱细胞真皮基质构建组织工程皮肤，为进一步临床应用奠定基础。方法：将SD大鼠骨髓间充质干细胞进行体外培养扩增后，以生长状态良好的骨髓间充质干细胞接种于制备好的组织工程化脱细胞真皮支架上，进行体外联合培养，构建组织工程皮肤。观察细胞生长情况及组织工程皮肤结构。结果：体外培养的SD大鼠骨髓间充质干细胞生长良好，传代扩增容易，组织工程化脱细胞真皮基质去细胞完全，骨髓间充质干细胞在脱细胞真皮基质中生长良好，可体外构建组织工程皮肤。结论：利用体外扩增培养的骨髓间充质干细胞及制备的组织工程化脱细胞真皮基质可以体外联合构建组织工程皮肤。     

The epitope characterisation and the osteogenic differentiation potential of human fat pad-derived stem cells is maintained with ageing in later life

Some clinical settings are deficient in osteogenic progenitors, e.g. atrophic nonunited fractures, large bone defects, and regions of scarring and osteonecrosis. These benefit from the additional use of bone marrow-derived mesenchymal stem cells, but these cells exhibit an age-related decline in lifespan, proliferation and osteogenic potential. Therapeutic approaches for the repair of bone could be optimised by the identification of a stem cell source that does not show age-related changes. Fat pad-derived stem cells are capable of osteogenesis, but a detailed study of the effect of ageing on their epitope profile and osteogenic potential has so far not been performed.Fat pad-derived cells were isolated from 2 groups of 5 patients with a mean age of 57 years (S.D. 3 years) and 86 years (S.D. 3 years). The proliferation, epitope profile and osteogenic differentiation potential of cells from the 2 groups were compared. Cells isolated from the fat pad of both groups showed similar proliferation rates and exhibited a cell surface epitope profile similar but not identical to that of bone marrow-derived stem cells. The cells from both groups cultured in osteogenic medium exhibited osteogenesis as shown by a significant upregulation of alkaline phosphatase and osteocalcin genes, and significantly greater alkaline phosphatase enzyme activity compared to cells cultured in the control medium. The cells cultured in the osteogenic medium also showed greater calcium phosphate deposition on alizarin red staining. There was no significant difference between the osteogenic potential of the two age groups for any of the parameters studied.The fat pad is a consistent and homogenous source of stem cells that exhibits osteogenic differentiation potential with no evidence of any decline with ageing in later life. This has many potential therapeutic tissue engineering applications for the repair of bone defects in an increasingly ageing population.