血管内皮细胞对骨髓基质细胞促成骨作用的研究

在骨组织工程研究中 ,因营养血管长入材料非常缓慢而影响材料深部的成骨作用一直是困扰科研人员的难题之一。骨髓基质细胞能分泌血管内皮生长因子 (VEGF) ,内皮细胞可以产生骨形态发生蛋白 (BMP) ,因此我们设想将骨髓基质细胞和内皮细胞联合种植在生物材料上构建组织工程化骨 ,则可能在促进成骨的同时 ,又促进局部血管生成 ,满足成骨过程的营养需要。在本实验中我们比较了内皮细胞培养液作用下的骨髓基质细胞、经诱导的骨髓基质细胞和未处理的骨髓基质细胞之间碱性磷酸酶 (AL P)活性和骨钙素 (OCN)分泌量的差别 ,结果表明内皮细胞培养液作用下的骨髓基质细胞和经诱导的骨髓基质细胞之间碱性磷酸酶活性和骨钙素分泌量无统计学差异 ,但均明显高于未处理的骨髓基质细胞 (P<0 .0 1) ,说明内皮细胞培养液中的分泌因子对骨髓基质细胞具有促成骨作用 ,可以达到和成骨诱导液相同的效果。     

体外构建血管化组织工程心肌

目的:探讨体外构建血管化组织工程心肌的可行性。方法:大鼠骨髓间充质干细胞以浓度为10μmol/L的5-氮胞苷诱导为心肌细胞并用DAPI标记、骨髓源内皮祖细胞以内皮细胞培养基EGM2-MV定向诱导为内皮细胞并用CM-dil标记。标记后的心肌细胞与内皮祖细胞按2:1比例,以4×10~6个/ml的密度种植于Matrigel基质胶支架上。同种密度心肌细胞种植为对照组。对复合体形态、细胞分布等进行观察。结果:H-E染色及荧光显微镜观察可见两组复合体的细胞分布均匀,生长状态良好;单纯心肌细胞种植组可见细胞黏附聚集生长,并未出现网状结构,而2:1混合培养组24 h后可见内皮细胞相互连接成网状结构,出现典型的"成血管现象",且形成的血管样结构明显多于对照组;心肌细胞凋亡数较对照组少。结论:骨髓源性心肌细胞与骨髓源性内皮细胞联合种植于Matrigel基质胶共培养,可于体外成功构建血管化组织工程心肌。     

初级组织工程小口径血管的制备

目的 探讨利用组织工程技术构建小口径组织工程化血管的可行性.方法 将犬骨髓细胞诱导为平滑肌细胞和内皮细胞后,用Brdu标记平滑肌细胞,DAPI标记内皮样细胞,观察细胞标记的成功率;血管平滑肌样细胞和血管内皮样细胞分层种植于胶原包埋PGA的复合支架表面:将细胞和支架的复合体种植于犬皮下,并设立对照组,分别于植入后的第4、6、8周取出植入皮下的组织工程化血管,进行相关检查分析.结果 免疫荧光提示Brdu、DAPI标记种子细胞效果良好;核呈蓝色荧光的内皮样细胞均匀排列在支架表面:组织工程化血管材料植入动物皮下取出后观察,实验组管壁结构比较清晰,细胞数量也已减少、胶原成分增多,管壁分层明显,可见内膜、中膜和外膜结构,对照组无此特点;免疫荧光观察,8周实验组组织工程血管壁内有Brdu标记的种子细胞存在.结论 以动物的皮下为生物反应器,采用静态培养的方式可强化组织工程血管壁,该组织的结构与天然血管相似,种子细胞同时参与初级组织工程小口径血管的构建.     

骨髓间充质干细胞构建组织工程化小口径血管

目的采用在动物体外构建初级组织工程化血管、体内强化的方法,探讨构建小口径组织工程化血管的可能性.方法体外培养骨髓间充质干细胞(BMSC),用含全反式维甲酸(AT-RA)、双丁酰环磷酸腺苷(db-cAMP)的DMEM-LG培养液和含血管内皮细胞生长因子(VEGF)的培养液诱导BMSC分别向血管平滑肌样细胞和血管内皮样细胞分化.免疫荧光观察平滑肌样细胞β肌动蛋白的表达和内皮样细胞vWF的表达.电镜观察超微结构的改变.诱导的血管平滑肌样细胞和血管内皮样细胞,分层种植于胶原包埋聚乙醇酸(PGA)的复合支架表面,将细胞和支架复合体种植于动物皮下,于植入后第4、8周再次麻醉动物,取出植入皮下的组织工程化血管,行组织学检查、压力实验及免疫荧光检查.结果诱导14 d后,BMSC能够分化为血管平滑肌样细胞和血管内皮样细胞:β肌动蛋白和vWF呈阳性表达,电镜证实细胞出现了相应的形态学改变.人工血管组织学观察见管壁结构清晰.单纯支架组可承受100～150 mm Hg(1mm Hg=0.133 kPa)的血管腔内压力,实验组则均可承受200mm Hg的血管腔内压力不破裂.实验组皮下培养8周Brdu标记细胞的免疫荧光结果显示部分细胞核呈现明亮的黄绿色荧光.结论以动物皮下为生物反应器可构建出组织工程化血管,其大体结构和天然血管相似.     

骨髓间充质干细胞-聚乙醇酸支架复合体种植动物皮下构建组织工程化小口径血管

背景：课题组的前期工作已证实骨髓间充质干细胞可以诱导分化为血管内皮细胞和血管平滑肌细胞,并证实所诱导的细胞和胶原包埋的聚乙醇酸支架具有良好的组织相容性。 目的：探讨利用动物皮下作为生物反应器构建小口径组织工程化血管的可行性。 方法：骨髓间充质干细胞诱导分化为血管平滑肌样细胞和血管内皮样细胞,分层种植于胶原包埋聚乙醇酸支架表面,然后将细胞-支架复合体种植于动物皮下,构建小口径组织工程化血管。 结果与结论：人工血管组织学观察见管壁结构清晰,其大体结构和天然血管相似,可承受26.6 kPa的血管腔内压力不破裂。皮下培养8周免疫荧光观察Brdu标记的部分细胞核呈现明亮的黄绿色荧光。结果说明利用动物的皮下作为生物反应器,采用静态培养的方式构建小口径组织工程化血管是可行的。     

骨髓间充质干细胞复合鸡蛋膜构建组织工程化骨的实验研究

目的探讨鸡蛋膜作为组织工程支架材料同大鼠骨髓间充质干细胞（bone marrow mesenchy-cmal stem cells,BMSCs）复合培养构建组织工程化骨的可行性。方法采用梯度离心法分离大鼠骨髓间充质干细胞;将第2代BMSCs同鸡蛋膜支架材料复合,利用含0.1μmol/L地塞米松、10mmol/Lβ-甘油酸钠、50μg/ml维生素C的条件培养液诱导培养2周后,分别将复合材料植入Wistar大鼠右侧背部皮下,左侧植入无细胞复合的鸡蛋膜作为对照。28d后处死大鼠收集标本,利用扫描电镜技术、HE染色、免疫组织化学（Ⅰ型胶原、碱性磷酸酶）和茜素红染色进行相应检测。结果细胞同鸡蛋膜复合培养后,细胞在鸡蛋膜上容易贴附生长,7d后鸡蛋膜表面有大量的细胞生长,14d后细胞连接成片且鸡蛋膜网状孔隙中有大量的细胞生长。复合材料植入大鼠28d后,实验组鸡蛋膜内部有大量细胞存在,植入区可见有组织形成,对照组鸡蛋膜内部无细胞,植入区未见组织形成;实验组BMSCs向成骨细胞分化并分泌矿化基质,表达Ⅰ型胶原,碱性磷酸酶,对照组均为阴性。结论鸡蛋膜具有良好的组织生物相容性,以BMSCs作为种子细胞、鸡蛋膜作为支架材料构建组织工程化骨具备一定的可行性。     

重组人骨形态发生蛋白2与碱性成纤维细胞生长因子联合促进兔骨髓基质细胞血管内皮细胞生长因子表达及其成骨潜能

背景：了解在体外或体内环境下,应用重组人骨形态发生蛋白2和碱性成纤维细胞生长因子,能否达到既加强成骨又促进血管内皮细胞生长因子表达的双重作用。 目的：观察兔骨髓基质细胞经重组人骨形态发生蛋白2与碱性成纤维细胞生长因子刺激后,其血管内皮细胞生长因子表达及成骨潜能的变化。 方法：取兔双侧股骨骨髓基质细胞,采用骨髓基质细胞体外培养技术,单独或联合以重组人骨形态发生蛋白2、碱性成纤维细胞生长因子刺激细胞。细胞培养5 d后,进行细胞形态、增殖情况、碱性磷酸酶活性、成骨结节、血管内皮细胞生长因子阳性细胞率等项目的检测。 结果与结论：联合先后应用重组人骨形态发生蛋白2、碱性成纤维细胞生长因子在细胞计数、碱性磷酸酶活性、矿化面积百分率、血管内皮细胞生长因子阳性细胞率4个检测项目上优于同时应用重组人骨形态发生蛋白2或碱性成纤维细胞生长因子以及单独应用重组人骨形态发生蛋白2或碱性成纤维细胞生长因子。结果表明合理的联合使用重组人骨形态发生蛋白2和碱性成纤维细胞生长因子,不仅可促进骨髓基质细胞的快速增殖及向成骨细胞转化,还可促进促血管内皮细胞增生的重要介质血管内皮细胞生长因子的表达。     

骨髓基质干细胞复合煅烧骨的皮下成骨

背景：研究证明骨髓基质干细胞与煅烧骨支架材料结合后可形成组织工程化骨,但在动物体内的生物相容性及皮下诱导成骨的能力国内报道较少。 目的：观察骨髓基质细胞复合异种煅烧骨植入BALB/c裸鼠背部皮下的成骨性能及煅烧骨材料作为组织工程骨支架材料的可行性。 方法：选用经脱脂及脱蛋白处理后高温煅烧形成的骨支架材料与梯度密度离心法分离培养至第3代的羊骨髓基质干细胞构建细胞-煅烧骨复合物植入BALB/c裸鼠背部皮下,选同期对侧背部皮下植入单纯煅烧骨为对照组。 结果与结论：煅烧后的松质骨块为白垩色,表面呈蜂窝状多孔结构,保留了天然松质骨的多孔状空间结构。骨小梁结构完整,孔隙相互连通。骨髓基质干细胞接种到煅烧骨后24 h可见大量细胞黏附于支架上,7 d后细胞分泌大量细胞外基质,细胞与基质分界不清,细胞能在材料上良好地黏附、增殖与生长,细胞活性未受到支架材料的影响。植入4周后,两组均可见煅烧骨边缘出现少量残片,细胞-煅烧骨复合物组煅烧骨孔隙周边可发现骨细胞,对照组煅烧骨表面可见纤维结缔组织包绕。植入后8周,两组均可见到煅烧骨部分降解为片状类骨质,周围有成纤维细胞包绕,排列紧密,形态多样,细胞-煅烧骨复合物组煅烧骨孔隙内可见煅烧骨表面有排列成行的成骨细胞,孔隙间有散在淋巴细胞浸润。对照组标本可见孔隙内有大量结缔组织长入,未见明显成骨迹象。结果说明,经高温煅烧后的松质骨材料,具有良好的生物相容性和生物安全性,可作为骨髓基质干细胞的良好载体,复合后植入体内能够诱导新生骨组织形成,可作为骨缺损组织工程修复的支架材料。     

组织工程化血管移植实验研究

目的 通过体外构建、体内培养的方法 构建组织工程化血管,并将其植入动物的股动脉,探讨利用小口径组织工程化血管进行血管移植的可能性.方法 首先用Brdu标记所有种子细胞,将血管平滑肌样细胞和血管内皮样细胞分层种植于胶原包埋PGA的复合支架表面;然后将细胞和支架的复合体种植于动物皮下构建组织工程化血管,并移植到股动脉;最后行HE染色及免疫荧光等相关检查,了解移植后血管的特点及细胞来源.同时以移植物为单纯支架在皮下培养所形成的管状结构作为对照组.结果 移植后组织工程化血管通畅无血栓形成.HE染色见血管壁和正常生理性血管壁的结构相似.可分内膜、中膜和外膜三层.种植2周后Brdu标记细胞的免疫荧光观察证实血管壁细胞来源于所种植的种子细胞.结论 利用骨髓间充质干细胞分化而来的种子细胞和胶原包埋的PGA支架可以构建组织工程化小口径血管,而且可以移植入动物体内.     

聚己内酯和β-磷酸三钙复合支架经血小板衍生生长因子BB修饰后的促血管生成作用

背景：组织工程技术的发展为骨缺损的修复重建提供了新的思路,但是血管化问题使组织工程骨应用于临床受到了制约。血小板衍生生长因子在促进骨细胞形成的同时也可促进骨组织中血管的形成。目的：观察聚己内酯/β-磷酸三钙/血小板衍生生长因子BB支架对骨髓间充质干细胞成骨分化及人脐静脉内皮细胞增殖、黏附的影响,以及修复骨缺损的效果。方法：(1)利用3D快速成形机制备聚己内酯/β-磷酸三钙支架(记为PCL/β-TCP支架),将支架浸渍于血小板衍生生长因子BB溶液中制备聚己内酯/β-磷酸三钙/血小板衍生生长因子BB支架(记为PCL/β-TCP/PDGF BB支架)。(2)体外实验：将骨髓间充质干细胞、人脐静脉内皮细胞分别接种于两种支架上,检测骨髓间充质干细胞的成骨分化情况,检测人脐静脉内皮细胞的增殖、黏附与成血管基因表达。(3)体内实验：取21只成年大鼠,建立双侧胫骨缺损模型,实验组植入PCL/β-TCP/PDGF BB支架,对照组植入PCL/β-TCP支架,空白组不植入支架,每组7只。术后12周,进行Micro-CT扫描、骨组织形态学观察及成骨与成血管基因检测。结果与结论：(1)体外实验：与PCL/β-...     

多孔磷酸钙骨水泥与转染骨形态发生蛋白2基因的骨髓间充质干细胞复合修复股骨髁骨缺损

BACKGROUND: Bone morphogenetic protein (BMP) can improve the osteogenesis capacity of tissue-engineered bone. However, how to prolong BMP release is a key for constructing tissue-engineered bone. OBJECTIVE: To study the repair effect of porous calcium phosphate cement (CPC) with bone marrow mesenchymal stem cells transfected with BMP-2 gene on bone defects. METHODS: After modeling of bilateral femoral condyle bone defects, 12 model rabbits were given implantation of porous CPC with bone marrow mesenchymal stem cells transfected with BMP-2 on the left (experimental group) and given implantation of porous CPC with bone marrow mesenchymal stem cells on the right (control group). Bilateral femoral condyles were taken and analyzed histologically at 4 and 12 weeks after implantation. RESULTS AND CONCLUSION: Better osteogenesis including more newly formed bone tissues and faster scaffold absorption was observed in the experimental group compared with the control group at 4 and 12 weeks after implantation. The area of newly formed bone tissues at different time and rate of bone formation at 12 weeks were significantly higher in the experimental group than in the control group (P < 0.001, P < 0.05). These findings indicate that transfer of BMP-2 into bone marrow mesenchymal stem cells combined with porous CPC could increase repair of bone defects.     

瓦楞状组织工程骨支架对种子细胞接种和成骨的影响

背景：不同形状工程骨支架负载种子细胞修复骨缺损的研究效果评价不一,而负载细胞数量的多少是影响疗效的重要因素之一,目前该方面研究证据不多。 目的：自制瓦楞状组织工程骨支架和其他3种形状的支架,比较4种不同形状支架负载种子细胞的数量,以及瓦楞状组织工程骨支架体内成骨时凹槽的优势及特点。 方法：①体外实验：将体积和样本数相同的4组支架分为单纯瓦楞状支架组、无瓦楞支架组、圆柱状支架组和带中空管柱状支架组,分别以相同密度、相同容积的成骨诱导兔骨髓间充质干细胞悬液接种于支架表面,孵育、培养、消化、收集,进行细胞计数、吸光度值检测以及碱性磷酸酶和茜素红染色。②体内实验：将兔随机分为重组人骨形态发生蛋白2/瓦楞状自固化磷酸钙人工骨组,瓦楞状自固化磷酸钙人工骨组和松质骨组,将体积相同的3组支架植入兔L5-6两侧横突间,植入后4,8,12周行大体、组织学观察。 结果与结论：体外实验显示,瓦楞状工程骨支架上滴注的细胞液能充分停留在表面,由于表面瓦楞状凹槽和液体的表面张力以及支架本身的无孔隙性使得细胞液不向培养皿流失,每个样本平均消化下来的正常形态的细胞数量高于其他3组(P < 0.05),吸光度值差异无显著性意义(P > 0.05)。体内实验显示,各时间点重组人骨形态发生蛋白2/瓦楞状自固化磷酸钙人工骨组的成骨量比瓦楞状自固化磷酸钙人工骨组明显多(P < 0.05),与松质骨组之间比较差异无显著性意义(P > 0.05)。结果证实,实验自制的瓦楞状工程骨支架的形状特点有利于种子细胞负载,从数量上保证了接种种子细胞的有效性,可促进支架大量成骨和段状骨缺损的愈合。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接：     

Construction of tissue-engineered homograft bioprosthetic heart valves in vitro

Human mesenchymal stem cells (MSCs) differentiate into multiple cell-lineages and may serve as an alternative source of seed cells for tissue engineering. We investigated whether MSCs could be induced to differentiate into endothelial cells (ECs) and function as seed cells for the in vitro construction of tissue-engineered heart valves (TEHVs). Aortic or pulmonary valve homografts were decellularized with 0.1% sodium dodecylsulphate and used as scaffolds for TEHVs. The MSCs were isolated from human bone marrow by Percoll gradient centrifugation (1.073 g/ml), differentiated into ECs with vascular endothelial growth factor (10 ng/ml), and seeded onto a decellularized scaffold (high-density seeding, >10(5) cells/cm2) and grown in static culture for 14 days. Over 90% of the differentiated cells from MSCs stained positively for von Willebrand factor and Tie-2-related antigen. Additionally, Weibel-Palade corpuscle was observed in the cytoplasm of these cells. Levels of reendothelialization in static culture on days 7, 14, and 20, were 73%, 85%, and 95%, respectively. These results show that MSCs from human bone marrow can differentiate, in vitro, into ECs that can then be used to construct TEHVs. Reendothelialization in static culture can be used to provide the basic material for pulsatile-flow cultivation.     

利用人骨髓基质干细胞构建组织工程心脏瓣膜的体外实验

BACKGROUND:Nowadays, mechanical or biological valve recipients used in the clinic are still at the risk of infection, hemorrhage, thrombosis and reoperation owing to valve stenosis. Tissue-engineered heart valve with biological activity can overcome the disadvantages above. While, the optimal choice of scaffolds and seeding cells remains disputable. OBJECTIVE:To explore the feasibility to construct tissue-engineered heart valve with acellularized porcine aortic valve scaffold and human bone marrow stromal stem cells in vitro. METHODS:The porcine aortic valves were decellularized with the detergent and enzymatic extraction process to remove the cellular components. Human bone marrow stromal stem cells were aspirated from sternum of the patients with simple congenital heart malformation, and then the cells were seeded on the acellularized porcine aortic valve scaffold and cultured for 5 days. RESULTS AND CONCLUSION:Flow cytometry identified that the characteristics of surface antigen of the inoculated seed cells were in line with those of human bone marrow stromal stem cells. Light microscopy and electron microscopy confirmed that the cellular components in the porcine aortic valves could be removed to obtain the complete acellular fiber mesh stent. There was no significant difference in biomechanical property between before and after acellularization. The human bone marrow stromal stem cells implanted on the acellularized porcine aortic valve scaffold could form a continuous cell layer on the surfaces of the scaffold. The inoculated bone marrow stromal stem cells could be differentiated into fibroblasts. The implantation of human bone marrow stromal stem cells on the acellularized porcine aortic valve scaffold can construct the tissue-engineered heart valve.     

胶原海绵上诱导骨髓间充质干细胞向软骨细胞分化的体外实验研究

研究在胶原海绵上间充质干细胞(M SC s)向软骨细胞的定向诱导,以及其对M SC s细胞增殖力、细胞周期的影响,为临床应用胶原海绵作为M SC s支架、修复软骨缺损奠定基础。取大鼠股骨骨髓,经梯度离心法和贴壁法分离M SC s,用加有转化生长因子1β10 ng/m l、地塞米松1-0 7m o l/L、转铁蛋白3 m g/m l、胰岛素2 m g/m l的诱导因子培养基分别在胶原海绵、培养板中进行诱导,14 d后免疫组化检测II型胶原分泌情况,四甲基偶氮唑蓝(M TT)法比较两者之间细胞增殖情况,流式细胞仪(FCM)检测各组细胞周期。14 d后,胶原海绵上及培养板中均诱导出表达II型胶原的软骨细胞,M TT法检测胶原海绵诱导组,和培养板诱导组细胞增殖值分别为0.9213±0.0312和0.5875±0.0258,两者间有显著性差异(P<0.05),FCM检测胶原海绵各组S期 G2/M期百分率,发现其与培养板中同期细胞相比有显著性差异(P<0.05),各组均未发现异倍体。结果表明在胶原海绵上,M SC s能定向诱导为软骨细胞,细胞增值能力更强,M SC s细胞DNA合成、细胞分裂增加,无异倍体产生,可作为一种较为理想的组织工程学支架。     

The effect of mesenchymal populations and vascular endothelial growth factor delivered from biodegradable polymer scaffolds on bone formation

The capacity to deliver, temporally, bioactive growth factors in combination with appropriate progenitor and stem cells to sites of tissue regeneration promoting angiogenesis and osteogenesis offers therapeutic opportunities in regenerative medicine. We have examined the bone regenerative potential of encapsulated vascular endothelial growth factor (VEGF(165)) biodegradable poly(DL-lactic acid) (PLA) scaffolds created using supercritical CO(2) fluid technology to encapsulate and release solvent-sensitive and thermolabile growth factors in combination with human bone marrow stromal cells (HBMSC) implanted in a mouse femur segmental defect (5 mm) for 4 weeks. HBMSC seeded on VEGF encapsulated PLA scaffolds showed significant bone regeneration in the femur segmental defect compared to the scaffold alone and scaffold seeded with HBMSC as analysed by indices of increased bone volume (BV mm(3)), trabecular number (Tb.N/mm) and reduced trabecular separation (Tb.Sp.mm) in the defect region using micro-computed tomography. Histological examination confirmed significant new bone matrix in the HBMSC seeded VEGF encapsulated scaffold group as evidenced by Sirius red/alcian blue and Goldner's trichrome staining and type I collagen immunocytochemistry expression in comparison to the other groups. These studies demonstrate the ability to deliver, temporally, a combination of VEGF released from scaffolds with seeded HBMSC to sites of bone defects, results in enhanced regeneration of a bone defect.     

Constructing a tissue-engineered ureter using a decellularized matrix with cultured uroepithelial cells and bone marrow-derived mononuclear cells

This study investigated the efficacy of the ureteral decellularized matrix (UDM) as a scaffold material for a tissue-engineered ureter, and the effect of bone marrow-derived mononuclear cells (BM-MNC) on the neovascularization of the scaffold. Canine ureters were treated with deoxycholic acid to remove all cells. Uroepithelial cells (UEC) were obtained from canine bladders, cultured, and then seeded onto the inner surface of the UDM before transplantation into the subcutaneous space of nude mice or the omentum of nude rats. The cultured UECs began showing vacuolar degeneration 3 days after transplantation and gradually disappeared thereafter. To facilitate neovascularization in the implant, BM-MNCs were seeded around the UDM before transplantation. This facilitated the survival of the UECs, which formed three to five cellular layers after 14 days. The mean microvessel density was significantly increased in tissues seeded with BM-MNCs. However, cell-tracking experiments revealed that the increased number of capillaries in the experimental group was not due to the direct differentiation of transplanted endothelial progenitor cells. Our results demonstrate that the UDM is a useful scaffold for a tissue-engineered ureter, especially when seeded with BM-MNCs to enhance angiogenesis.     

rhBMP-2／PLGA缓释支架的制备及对MSCs细胞成骨活性的体外研究

目的探讨骨形态发生蛋白（rhBMP-2）的聚乳酸聚乙醇酸共聚物（PLGA）体外缓释生物支架对人骨髓间充质干细胞（MSCs）细胞的影响。方法采用粒子沥滤-冷冻干燥复合工艺制备了附载rhBMP-2的PLGA生物支架,并检测了在PLGA的降解过程中rhBMP-2的释药规律;同时分离培养人骨髓间充质干细胞,体外培养后分别接种于附载和未附载rhBMP-2的PLGA支架上。扫描电镜观察不同时间段MSC在支架上的生长情况;MTT法测定细胞增殖情况。结果rhBMP-2能被包裹进PLGA支架中,而且可以在PLGA支架降解过程中持续释放出来并诱导骨发生。结论骨形态发生蛋白的PLGA复合载体是一种较为理想的新型生物支架。