骨髓间充质干细胞向成骨细胞诱导分化的实验研究

目的:采用地塞米松、β-磷酸甘油和维生素C3种物质作为诱导骨髓间充质干细胞(bone marrow stromal stem cells,BMSCs)向成骨细胞分化的基本辅剂,定向诱导犬第2代BMSCs,探讨BMSCs向成骨细胞分化的潜能和成骨细胞的特征性鉴定方法.方法:无菌条件下行犬髂骨穿刺,采集骨髓15～ 20 mL,全骨髓10％ FBS DMEM培养液进行原代培养.将第2代纯化的BMSCs细胞悬液(调整细胞密度为1×105/mL)接种于含地塞米松、β-磷酸甘油和维生素C的DMEM/FI2培养液的培养瓶(皿)中,体外扩增培养、传代.对细胞形态特征进行观察;行碱性磷酸酶(ALP)染色,骨桥素以及Ⅰ型胶原相关蛋白免疫荧光化学检测鉴定细胞性质.结果:原代培养的BMSCs形态呈长梭形或不规则形,呈均匀分布生长.诱导分化后的细胞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;BMSCs成骨诱导增殖后电镜下细胞呈多边形,可见ALP染色阳性;经成骨细胞诱导培养14 d后,细胞骨桥素以及Ⅰ型胶原相关蛋白表达阳性.结论:BMSCs易于体外分离培养及扩增,地塞米松、β-磷酸甘油和维生素C体外定向诱导能够在短时间内获得大量成骨细胞,且所培养的细胞具有典型的成骨细胞形态和功能.     

兔骨髓基质细胞的体外分离培养及诱导成骨的实验研究

目的 探讨兔骨髓基质细胞（BMSCs）的体外分离培养及定向诱导成骨的方法。方法 选择10周龄新西兰兔，抽取其股骨大转子部骨髓，体外分离纯化得到BMSCs，再利用条件培养液将其向成骨方向定向诱导培养。采用碱性磷酸酶（ALP）和冯库萨（Von Kossa）染色方法，鉴定其成骨性能。结果 BMSCs在培养皿中贴壁生长、增殖，经ALP和Yon Kossa染色证实其有成骨潜能。结论 兔BMSCs的体外培养增殖能力强，能诱导分化为成骨细胞，可以作为骨组织工程的种子细胞。     

Beta‐tricalcium phosphate ceramic triggers fast and robust bone formation by human mesenchymal stem cells

Due to their osteoconductive and inductive properties, a variety of calcium phosphate (CaP) scaffolds are commonly used in orthopaedics as graft material to heal bone defects. In this study, we have used two CaP scaffolds with different hydroxyapatite (HA) and β‐tricalcium phosphate (β‐TCP) ratios (MBCP®; 60/40 and MBCP⁺®; 20/80) to investigate their intrinsic capacity to favour human bone marrow stem cells (hBMSCs) osteogenic differentiation capacity. We report that MBCP⁺® showed in in vitro culture model a higher rate of calcium ion release in comparison with MBCP®. In two defined coculture systems, the hBMSC seeded onto MBCP⁺® presented an increased amount of VEGF secretion, resulting in an enhanced endothelial cell proliferation and capillary formation compared with hBMSC seeded onto MBCP®. When both ceramics combined with hBMSC were implanted in a nude mouse model, we observed a faster osteogenic differentiation and enhancement mature bone deposition sustained by the presence of a vast host vasculature within the MBCP⁺® ceramics. Bone formation was observed in samples highly positive to the activation of calcium sensing receptor protein (CaSr) on the surface of seeded hBMSC that also shown higher BMP‐2 protein expression. With these data we provide valuable insights in the possible mechanisms of ossification and angiogenesis by hBMSC that we believe to be primed by calcium ions released from CaP scaffolds. Evidences could lead to an optimization of ceramic scaffolds to prime bone repair.     

Synergistic effect of scaffold composition and dynamic culturing environment in multilayered systems for bone tissue engineering

Bone extracellular matrix (ECM) is composed of mineralized collagen fibrils which support biological apatite nucleation that participates in bone outstanding properties. Understanding and mimicking bone morphological and physiological parameters at a biological scale is a major challenge in tissue engineering scaffolding. Using emergent (nano)technologies scaffold designing may be critically improved, enabling highly functional tissue substitutes for bone applications. This study aims to develop novel biodegradable composite scaffolds of tricalcium phosphate (TCPs) and electrospun nanofibers of poly(?‐caprolactone) (PCL), combining TCPs osteoconductivity with PCL biocompatibility and elasticity, mimicking bone structure and composition. We hypothesized that scaffolds with such structure/composition would stimulate the proliferation and differentiation of bone marrow stromal cells (BMSCs) towards the osteogenic phenotype. Composite scaffolds, developed by electrospining using consecutive stacked layers of PCL and TCPs, were characterized by FTIR spectroscopy, X‐Ray diffraction and scanning electronic microscopy. Cellular behavior was assessed in goat BMSCs seeded onto composite scaffolds and cultured in static or dynamic conditions, using basal or osteogenic media during 7, 14 or 21 days. Cellular proliferation was quantified and osteogenic differentiation confirmed by alkaline phosphatase activity, alizarin red staining and immunocytochemistry for osteocalcin and collagen I. Results suggest that PCL‐TCP scaffolds provide a 3D support for gBMSCs proliferation and osteogenic differentiation with production of ECM. TCPs positively stimulate the osteogenic process, especially under dynamic conditions, where PCL‐TCP scaffolds are sufficient to promote osteogenic differentiation even in basal medium conditions. The enhancement of the osteogenic potential in dynamic conditions evidences the synergistic effect of scaffold composition and dynamic stimulation in gBMSCs osteogenic differentiation. Copyright © 2012 John Wiley & Sons, Ltd.     

改良法培养骨髓基质干细胞向成骨细胞分化的实验研究

目的:研究大鼠骨髓基质干细胞的生长特点和在诱导条件下的成骨能力。方法:通过改良的骨髓培养法分离成年大鼠骨髓基质干细胞,应用含地塞米松、β-甘油磷酸钠和维生素C的诱导分化培养液定向诱导传代细胞向成骨细胞分化,并检测骨钙素的分泌、碱性磷酸酶的活性和细胞矿化作用。结果:原代培养基质干细胞首先形成细胞集落,12d时集落间接近融合;传代细胞体积变大,约5～7d传代一次。诱导条件下,细胞碱性磷酸酶活性明显增高,并出现了矿化结节。结论:骨髓基质干细胞易于分离培养及体外扩增,成骨能力肯定,可作为骨组织工程的种子细胞     

大鼠骨髓基质干细胞的成骨诱导及鉴定

目的：研究大鼠骨髓基质干细胞（BMSCs）在体外培养、诱导后的形态学改变及生物活性．探讨BMSCs作为骨组织工程种子细胞的可能性和可行性。方法：通过改良的骨髓培养法分离成年大鼠BMSCs，经条件培养液诱导培养后，进行形态学观察和碱性磷酸酶（ALP）、骨钙素（OCN）的测定。结果：经过体外成骨诱导的BMSCs表现出增殖、聚集、结节和矿化期的阶段性形态特征，同时在诱导2周后表达ALP活性，在结节期和矿化期OCN表达呈阳性。结论：体外成骨定向诱导的BMSCs具有典型的成骨细胞的形态和功能性特征，可以作为骨组织工程的种子细胞。     

多孔碳酸钙陶瓷与干细胞源性成骨细胞的相容性

背景：国内外的研究证实普通碳酸钙陶瓷作为骨替代材料时具有细胞支架作用。目的：观察多孔碳酸钙陶瓷与成骨细胞的相容性,及作为骨组织工程支架的可能性。方法：SD大鼠骨髓基质干细胞经矿化诱导培养、扩增并检测证实其已具成骨细胞表型后,分别与多孔碳酸钙陶瓷支架、普通羟基磷灰石陶瓷支架体外复合培养。结果与结论：骨髓基质干细胞经体外诱导形成成骨细胞,钙结节、Ⅰ型胶原和碱性磷酸酶免疫染色结果阳性。多孔碳酸钙陶瓷支架材料与羟基磷灰石陶瓷材料皆有细胞附着生长,但多孔碳酸钙陶瓷支架材料细胞的黏附能力、增殖活力及成骨活性均强于羟基磷灰石陶瓷材料。提示多孔碳酸钙陶瓷支架材料与SD大鼠骨髓基质干细胞源性成骨细胞有良好相容性。     

Oxy133, a novel osteogenic agent,promotes bone regeneration in an intramembranous bone‐healing model

Current reconstructive techniques for complex craniofacial osseous defects are challenging and are associated with significant morbidity. Oxysterols are naturally occurring cholesterol oxidation products with osteogenic potential. In this study, we investigated the effects of a novel semi‐synthetic oxysterol, Oxy133, on in vitro osteogenesis and an in vivo intramembranous bone‐healing model. Rabbit bone marrow stromal cells (BMSCs) were treated with either Oxy133 or BMP‐2. Alkaline phosphatase (ALP) activity, expression of osteogenic gene markers and in vitro mineralization were all examined. Next, collagen sponges carrying either Oxy133 or BMP‐2 were used to reconstruct critical‐sized cranial defects in mature rabbits and bone regeneration was assessed. To determine the mechanism of action of Oxy133 both in vitro and in vivo, rabbit BMSCs cultures and collagen sponge/Oxy133 implants were treated with the Hedgehog signalling pathway inhibitor, cyclopamine, and similar outcomes were measured. ALP activity in rabbit BMSCs treated with 1 μm Oxy133 was induced and was significantly higher than in control cells. These results were mitigated in cultures treated with cyclopamine. Expression of osteogenic gene markers and mineralization in BMSCs treated with 1 μm Oxy133 was significantly higher than in control groups. Complete bone regeneration was noted in vivo when cranial defects were treated with Oxy133; healing was incomplete, however, when cyclopamine was added. Collectively, these results demonstrate that Oxy133 has the ability to induce osteogenic differentiation in vitro in rabbit BMSCs and to promote robust bone regeneration in vivo in an animal model of intramembranous bone healing. Copyright © 2015 John Wiley & Sons, Ltd.     

Simvastatin induces the osteogenic differentiation of human periodontal ligament stem cells

Periodontal ligament stem cells (PDLSCs) are considered as potential mesenchymal stem cell sources for future clinical applications in periodontal regeneration therapy. Simvastation, widely used for lowering serum cholesterol, is known to have a bone stimulatory effect. However, it is not clear whether simvastation affects the differentiation of PDLSCs. This study examined the effects of simvastatin on human PDLSCs in vitro and in vivo. Using the limiting dilution technique, human PDLSCs were isolated and expanded. PDLSCs were cultured with simvastatin (0.01–10 μm ), and the proliferation was measured. The osteogenic differentiation was characterized by alkaline phosphatase (ALP) activity and Alizarin Red‐S staining for calcium deposition. The gene expression levels of osteogenic markers were evaluated by RT‐PCR. In addition, PDLSCs were transplanted into nude mice with ceramic bovine bone powders as carriers to observe the capacity of mineralized tissue formation in vivo. Simvastatin at concentrations <1 μm did not suppress the proliferation of PDLSCs. After the administration of 0.1 μm simvastatin, the expression of ALP, bone sialoprotein, and bone morphogenetic protein‐2 genes were significantly upregulated, and the ALP activity and mineralized nodule formation were significantly higher in the simvastatin‐treated cells than the control cells. In addition, the in vivo transplantation results showed that simvastatin treatment promoted the degree of mineralized tissue formation. Collectively, simvastatin has positive effects on osteogenic differentiation of human PDLSCs in vitro and in vivo. This suggests that simvastatin might be a useful osteogenic induction agent for periodontal bone regeneration.     

Immunoregulatory role of exosomes derived from differentiating mesenchymal stromal cells on inflammation and osteogenesis

Bone marrow‐derived mesenchymal stem/stromal cells (BMSCs) can differentiate into bone‐forming osteoblasts, playing a crucial role in bone regeneration. Exosomes are naturally cell‐secreted nanovesicles and are lately regraded as an emerging mediator of cellular communication in physiological and pathological conditions. The present study aimed at investigating the complex cellular communications, especially those among the differentiating BMSCs, immune cells (e.g., macrophages), and newly recruited BMSCs via exosome‐mediated pathways. Exosomes were first isolated from osteogenically differentiating BMSCs at various stages (Day 0, Day 3, Day 7, and Day 14, respectively). The cellular uptake of isolated exosomes was examined in macrophages and human BMSCs (hBMSCs). The exosomes collected at various osteogenic differentiation stages (0d‐exo, 3d‐exo, 7d‐exo, and 14d‐exo) had no effect on the viability of hBMSCs. The uptake of exosomes (0d‐exo, 3d‐exo, and 7d‐exo) significantly decreased proinflammatory‐gene expression and the level of an M1 phenotypic marker. Our results then revealed that 3d‐exo, 7d‐exo, and 14d‐exo led to a remarkable increase in mesenchymal stem/stromal cell migration. In addition, 0d‐exo significantly promoted the expression of early osteogenic markers, such as alkaline phosphatase and bone morphogenetic protein 2, indicating a pro‐osteogenic role of hBMSC‐derived exosomes. Collectively, these results suggest that exosomes derived from differentiating mesenchymal stem/stromal cells play a unique osteoimmunomodulatory role in the regulation of bone dynamics.     

Effect of biomimetic zinc‐containing tricalcium phosphate (Zn–TCP) on the growth and osteogenic differentiation of mesenchymal stem cells

Several studies have shown the effectiveness of zinc‐tricalcium phosphate (Zn–TCP) for bone tissue engineering. In this study, marine calcareous foraminifera possessing uniform pore size distribution were hydrothermally converted to Zn–TCP. The ability of a scaffold to combine effectively with mesenchymal stem cells (MSCs) is a key tissue‐engineering aim. In order to demonstrate the osteogenic ability of MSCs with Zn–TCP, the scaffolds were cultured in an osteogenic induction medium to elicit an osteoblastic response. The physicochemical properties of Zn–TCP were characterized by XRD, FT–IR and ICP–MS. MSCs were aspirated from rat femurs and cultured for 3 days before indirectly placing four samples into each respective well. After culture for 7, 10 and 14 days, osteoblastic differentiation was evaluated using alizarin red S stain, measurement of alkaline phosphatase (ALP) levels, cell numbers and cell viability. XRD and FT–IR patterns both showed the replacement of CO₃^2– with PO₄^3–. Chemical analysis showed zinc incorporation of 5 mol%. Significant increases in cell numbers were observed at 10 and 14 days in the Zn–TCP group, while maintaining high levels of cell viability (> 90%). ALP activity in the Zn–TCP group was statistically higher at 10 days. Alizarin red S staining also showed significantly higher levels of calcium mineralization in Zn–TCP compared with the control groups. This study showed that MSCs in the presence of biomimetically derived Zn–TCP can accelerate their differentiation to osteoblasts and could potentially be useful as a scaffold for bone tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.     

Cyclic acetal hydroxyapatite composites and endogenous osteogenic gene expression of rat marrow stromal cells

In this study, bone marrow stromal cells (BMSCs) were differentiated on cyclic acetal composites containing hydroxyapatite (HA) particles (110 or 550 nm). These composites were evaluated for their role in influencing osteogenic signalling by encapsulated BMSCs. While a number of factors exert influence on osteogenic signalling during the production of an osteogenic matrix, we hypothesize that HA particles may upregulate bone growth factor expression due to enhanced BMSC adhesion. To this end, fluorescence‐activated cell sorting (FACS) analysis was performed for the evaluation of BMSC surface marker expression after culture on two‐dimensional (2D) cyclic acetal/HA composites. Three‐dimensional (3D) composites were then fabricated by incorporating 110 or 550 nm HA particles at 5, 10 and 50 ng/ml concentrations. Bone growth factor molecules (TGFβ1, FGF‐2 and PDGFa), bone biomarker molecules (ALP, OC, OPN and OCN) and extracellular matrix‐related molecules (FN, MMP‐13, Dmp1 and aggrecan) were selected for evaluation of osteogenic signalling mechanisms when in presence of these composites. FACS results at day 0 demonstrated that BMSCs were a heterogeneous population with a small percentage of cells staining positive for CD29, CD90 and CD51/61, while staining negative for CD34 and CD45. At day 3, a significant enrichment of cells staining strongly for CD29, CD90 and CD51/61 was achieved. Gene expression patterns for bone growth factors and extracellular matrix molecules were found to be largely dependent upon the size of HA particles. Bone marker molecules, except OCN, had unaltered expression patterns in response to the varied size of HA particles. Overall, the results indicate that larger‐sized HA particles upregulate PDGF and these groups were also associated with the most significant increase in osteodifferentiation markers, particularly ALP. Our results suggest that endogenous signalling is dependent upon material properties. Furthermore, we propose that studying gene expression patterns induced by the surrounding biomaterials environment is a fundamental step in the creation of engineered tissues. Copyright © 2010 John Wiley & Sons, Ltd.     

人骨形态发生蛋白7基因转染对骨髓间充质干细胞增殖及成骨分化性能的影响

背景骨组织工程中一个重要的研究内容就是如何保持并提高成骨细胞的体内外成骨能力,采用基因转移技术有可能为此问题的解决提供一种新的有效方法.目的探讨逆转录病毒介导的人骨形态发生蛋白7基因转染对兔骨髓间充质干细胞增殖和向成骨细胞分化的影响.设计以细胞为研究对象,分组对照,重复观察测量.对象实验2001-07/2003-07在南方医科大学附属南方医院创伤骨科实验室完成.新西兰大白兔4只由第一军医大学动物实验中心提供,雌雄不拘,体质量1.0～1.5 kg.方法构建人骨形态发生蛋白7逆转录病毒载体,使用含目的基因的病毒液感染骨髓间充质干细胞,免疫组织化学方法检测人骨形态发生蛋白7蛋白的表达.四甲基偶氮唑盐法检测细胞增殖能力,使用流式细胞仪检测细胞周期,NPP法检测碱性磷酸酶合成情况.主要观察指标主要结局①细胞增殖检测结果.②碱性磷酸酶检测结果.次要结局①转染骨髓间充质干细胞中人骨形态发生蛋白7蛋白的表达.②细胞周期检测结果.结果经骨形态发生蛋白7基因转染的兔骨髓间充质干细胞免疫组织化学检测显示有人骨形态发生蛋白7的阳性表达.经人骨形态发生蛋白7基因转染的兔骨髓间充质干细胞增殖能力无明显改变(P＞0.05).经转染的骨髓间充质干细胞碱性磷酸酶合成(294.592±86.567)nkat/L与转染空载体(155.231±86.567)nkat/L、未转染的骨髓间充质干细胞(160.866±91.585)nkat/L相比较差异有显著性意义(F=5.660,P＜0.05).结论经骨形态发生蛋白7基因转染的骨髓间充质干细胞能够合成表达外源骨形态发生蛋白7,人骨形态发生蛋白7基因转染能够促进体外培养的骨髓间充质干细胞向成骨细胞转化,可用于以骨髓间充质干细胞为种子细胞的组织工程化骨组织的构建和进一步应用.     

Unique and reliable rat model for the assessment of cell therapy: bone union in the rat mandibular symphysis using bone marrow stromal cells

Many kinds of bone graft materials have been developed and reported to repair various bone defects. The defects are usually created by surgical resection of pre‐existing bone tissue. However, spontaneous healing of bone defects without implantation of materials could be seen, because bone tissue possesses inherent repairing property. The central portion of the lower jaw bone in many animals consists of fibrous tissue and is called the mandibular symphysis. It persists even in old animals and thus can be interpreted as a physiological bone gap or a non‐healing bone defect. We implanted calcium phosphate porous ceramics alone or composites of the ceramics and bone marrow stromal cells (BMSCs) into the bone defect (mandibular symphysis) to examine whether it could be filled with new bone tissue, resulting in bone union. Eight weeks after implantation, micro‐computed tomography (micro‐CT) and histological and biomechanical analyses demonstrated that bone union of the mandibles occurred in all rats with composites but in none of those with ceramics alone. These results showed that the rat mandibular symphysis is a unique bone defect site for the evaluation of bone graft materials. These analyses demonstrated that ceramics alone could not contribute to bone healing in the defect; however, supplementation with BMSCs drastically changed the properties of the ceramics (turning them into osteogenic ceramics), which completely healed the defect. As BMSCs can be culture‐expanded using small amounts of bone marrow, the use of the composites might have clinical significance for the reconstruction of various bone tissues, including facial bone. Copyright © 2012 John Wiley & Sons, Ltd.     

Optimization of culture conditions for osteogenically‐induced mesenchymal stem cells in β‐tricalcium phosphate ceramics with large interconnected channels

The aim of this study was to optimize culture conditions for human mesenchymal stem cells (hMSCs) in β‐tricalcium phosphate ceramics with large interconnected channels. Fully interconnected macrochannels comprising pore diameters of 750 µm and 1400 µm were inserted into microporous β‐tricalcium phosphate (β‐TCP) scaffolds by milling. Human bone marrow‐derived MSCs were seeded into the scaffolds and cultivated for up to 3 weeks in both static and perfusion culture in the presence of osteogenic supplements (dexamethasone, β‐glycerophosphate, ascorbate). It was confirmed by scanning electron microscopic investigations and histological staining that the perfusion culture resulted in uniform distribution of cells inside the whole channel network, whereas the statically cultivated cells were primarily found at the surface of the ceramic samples. It was also determined that perfusion with standard medium containing 10% fetal calf serum (FCS) led to a strong increase (seven‐fold) of cell numbers compared with static cultivation observed after 3 weeks. Perfusion with low‐serum medium (2% FCS) resulted in moderate proliferation rates which were comparable to those achieved in static culture, although the specific alkaline phosphatase (ALP) activity increased by a factor of more than 3 compared to static cultivation. Gene expression analysis of the ALP gene also revealed higher levels of ALP mRNA in low‐serum perfused samples compared to statically cultivated constructs. In contrast, gene expression of the late osteogenic marker bone sialoprotein II (BSPII) was decreased for perfused samples compared to statically cultivated samples. Copyright © 2010 John Wiley & Sons, Ltd.     

Photopolymerizable chitosan–collagen hydrogels for bone tissue engineering

Photopolymerizable hydrogels derived from naturally occurring polymers have attracted significant interest in tissue‐engineering applications due to their excellent biocompatibility, hydrophilic nature favourable for cell ingrowth and ability to be cured in situ through a minimally invasive procedure. In this study, we developed a composite hydrogel consisting of photocrosslinkable methacrylated glycol chitosan (MeGC) and semi‐interpenetrating collagen (Col) with a riboflavin photoinitiator under blue light. The incorporation of Col in MeGC hydrogels enhanced the compressive modulus and slowed the degradation rate of the hydrogels. MeGC–Col composite hydrogels significantly enhanced cellular attachment, spreading, proliferation and osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) seeded on the hydrogels compared with pure MeGC hydrogels, as observed by upregulated alkaline phosphatase (ALP) activity as well as increased mineralization. Similarly, when cells were encapsulated within hydrogels, BMSCs exhibited greater proliferation, ALP activity and mineral deposits in the presence of Col. These findings demonstrate that MeGC–Col composite hydrogels may be useful in promoting bone regeneration. Copyright © 2014 John Wiley & Sons, Ltd.     

大鼠骨髓间充质干细胞成骨诱导分化的超微结构变化

背景:目前对骨髓间充质干细胞成骨诱导分化的超微结构观察的报道甚少.目的:采用全骨髓贴壁法分离培养大鼠骨髓间充质干细胞,成骨诱导并染色鉴定,利用电镜观察诱导前后细胞超微结构变化特点.方法:全骨髓贴壁法体外分离、培养、纯化大鼠骨髓间充质干细胞,流式细胞仪检测细胞表面标记物,成骨染色鉴定向成骨方向诱导分化,扫描电镜及透射电镜观察成骨诱导前后细胞超微结构变化.结果与结论:培养的第3代骨髓间充质干细胞纯度高、活力强,成骨诱导后的碱性磷酸酶活性染色、钙化结节染色均呈阳性.扫描电镜及透射电镜观察显示,经向成骨细胞诱导分化后,细胞形态铺展,不规则,其线粒体、粗面内质网、空泡明显增多,表明细胞功能活跃.     

羌活鱼研粉物、水提及酸提物含药血清对骨髓间充质干细胞增殖及向成骨分化的影响

背景：羌活鱼经大量的临床观察和报道有促进骨折愈合的作用,其具体的作用机制及其有效成分的研究报道尚少。目的：分析羌活鱼研粉物、水提及酸提物含药血清对体外培养骨髓间充质干细胞增殖与成骨性分化的影响。方法：制备羌活鱼研粉、水提物、酸提物,分别采用高、中、低剂量灌服大鼠制得羌活鱼研粉物、水提及酸提物含药血清,以灌服等体积生理盐水制得对照血清;采用贴壁筛选法培养大鼠骨髓间充质干细胞,通过MTT法检测细胞增殖;于干预后的不同时间点分别测定细胞碱性磷酸酶活性、钙盐沉积量、成骨性分化基因表达以及钙化结节数、并比较各组间差异。结果与结论：羌活鱼研粉物及水提物含药血清具有刺激骨髓间充质干细胞增殖活性及促进其成骨性分化的能力,其中尤其以研粉物中剂量组最为明显,而酸提物含药血清并无此功效。主要表现在细胞增殖、碱性磷酸酶活性、钙盐沉积量、成骨性分化基因和钙化结节数显著高于空白对照组（P〈0.05）。     

Biofabrication of a PLGA–TCP‐based porous bioactive bone substitute with sustained release of icaritin

A phytomolecule, icaritin, has been identified and shown to be osteopromotive for the prevention of osteoporosis and osteonecrosis. This study aimed to produce a bioactive poly (l ‐lactide‐co‐glycolide)–tricalcium phosphate (PLGA–TCP)‐based porous scaffold incorporating the osteopromotive phytomolecule icaritin, using a fine spinning technology. Both the structure and the composition of icaritin‐releasing PLGA–TCP‐based scaffolds were evaluated by scanning electron microscopy (SEM). The porosity was quantified by both water absorption and micro‐computed tomography (micro‐CT). The mechanical properties were evaluated using a compression test. In vitro release of icaritin from the PLGA–TCP scaffold was quantified by high‐performance liquid chromatography (HPLC). The attachment, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on the composite scaffold were evaluated. Both an in vitro cytotoxicity test and an in vivo test via muscular implantation were conducted to confirm the scaffold's biocompatibility. The results showed that the PLGA–TCP–icaritin composite scaffold was porous, with interconnected macro‐ (about 480 µm) and micropores (2–15 µm). The mechanical properties of the PLGA–TCP–icaritin scaffold were comparable with those of the pure PLGA–TCP scaffold, yet was spinning direction‐dependent. Icaritin content was detected in the medium and increased with time. The PLGA–TCP–icaritin scaffold facilitated the attachment, proliferation and osteogenic differentiation of BMSCs. In vitro cytotoxicity test and in vivo intramuscular implantation showed that the composite scaffold had no toxicity with good biocompatibility. In conclusion, an osteopromotive phytomolecule, icaritin, was successfully incorporated into PLGA–TCP to form an innovative porous composite scaffold with sustained release of osteopromotive icaritin, and this scaffold had good biocompatibility and osteopromotion, suggesting its potential for orthopaedic applications. Copyright © 2012 John Wiley & Sons, Ltd.