Mineralization and bone regeneration using a bioactive elastin-like recombinamer membrane

The search for alternative therapies to improve bone regeneration continues to be a major challenge for the medical community. Here we report on the enhanced mineralization, osteogenesis, and in vivo bone regeneration properties of a bioactive elastin-like recombinamer (ELR) membrane. Three bioactive ELRs exhibiting epitopes designed to promote mesenchymal stem cell adhesion (RGDS), mineralization (DDDEEKFLRRIGRFG), and both cell adhesion and mineralization were synthesized using standard recombinant protein techniques. The ELR materials were then used to fabricate membranes comprising either a smooth surface (Smooth) or channel microtopographies (Channels). Mineralization and osteoblastic differentiation of primary rat mesenchymal stem cells (rMSCs) were analyzed in both static and dynamic (uniaxial strain of 8% at 1 Hz frequency) conditions. Smooth mineralization membranes in static condition exhibited the highest quantity of calcium phosphate (Ca/P of 1.78) deposition with and without the presence of cells, the highest Young's modulus, and the highest production of alkaline phosphatase on day 10 in the presence of cells growing in non-osteogenic differentiation medium. These membranes were tested in a 5 mm-diameter critical-size rat calvarial defect model and analyzed for bone formation on day 36 after implantation. Animals treated with the mineralization membranes exhibited the highest bone volume within the defect as measured by micro-computed tomography and histology with no significant increase in inflammation. This study demonstrates the possibility of using bioactive ELR membranes for bone regeneration applications.     

Bioactive ceramics: the effect of surface reactivity on bone formation and bone cell function

Surface reactivity is one of the common characteristics of bone bioactive ceramics. It contributes to their bone bonding ability and their enhancing effect on bone tissue formation. During implantation, reactions occur at the material-tissue interface that lead to time-dependent changes in the surface characteristics of the implant material and the tissues at the interface. This review describes some of the current concepts regarding the surface reactivity of bone bioactive materials and its effect on attachment, proliferation, differentiation and mineralization of bone cells.     

Umbilical cord and bone marrow mesenchymal stem cell seeding on macroporous calcium phosphate for bone regeneration in rat cranial defects

Human umbilical cord mesenchymal stem cells (hUCMSCs) are inexhaustible and can be harvested at a low cost without an invasive procedure. However, there has been no report on comparing hUCMSCs with human bone marrow MSCs (hBMSCs) for bone regeneration in vivo. The aim of this study was to investigate hUCMSC and hBMSC seeding on macroporous calcium phosphate cement (CPC), and to compare their bone regeneration in critical-sized cranial defects in rats. Cell attachment, osteogenic differentiation and mineral synthesis on RGD-modified macroporous CPC were investigated in vitro. Scaffolds with cells were implanted in 8-mm defects of athymic rats. Bone regeneration was investigated via micro-CT and histological analysis at 4, 12, and 24 weeks. Three groups were tested: CPC with hUCMSCs, CPC with hBMSCs, and CPC control without cells. Percentage of live cells and cell density on CPC in vitro were similarly good for hUCMSCs and hBMSCs. Both cells had high osteogenic expressions of alkaline phosphatase, osteocalcin, collagen I, and Runx2. Bone mineral density and trabecular thickness in hUCMSC and hBMSC groups in vivo were greater than those of CPC control group. New bone amount for hUCMSC-CPC and hBMSC-CPC constructs was increased by 57% and 88%, respectively, while blood vessel density was increased by 15% and 20%, than CPC control group at 24 weeks. hUCMSC-CPC and hBMSC-CPC groups generally had statistically similar bone mineral density, new bone amount and vessel density. In conclusion, hUCMSCs seeded on CPC were shown to match the bone regeneration efficacy of hBMSCs in vivo for the first time. Both hUCMSC-CPC and hBMSC-CPC constructs generated much more new bone and blood vessels than CPC without cells. Macroporous RGD-grafted CPC with stem cell seeding is promising for craniofacial and orthopedic repairs.     

骨髓间充质干细胞移植对老年性痴呆行为学的影响

BACKGROUND:Drug treatment for senile dementia has unsatisfactory outcomes although to a certain extent it can reduce and delay the progression of Alzheimer’s disease. Stem cell transplantation is a new attempt for the treatment of senile dementia. OBJECTIVE:To observe the effect of bone marrow mesenchymal stem cell transplantation on the behavior of senile dementia rats. METHODS:Rat models of senile dementia were made in 20 Sprague-Dawley rats that were given continuous 60-day gavage of aluminium chloride solution. Then, model rats were randomized into model group treated with normal saline injection and experimental group treated with hippocampal injection of bone marrow mesenchymal stem cells, respectively. Another 10 rats undergoing normal feeding served as control group. Learning and memory ability of rats were tested by Morris water maze, and superoxide dismutase activity and malondialdehyde content in brain tissues of rats were measured by colorimetric method at 4 weeks after cell transplantation. RESULTS AND CONCLUSION:Compared with the model group, the escape latency was shortened and the cross-platform frequency was increased in the experimental group (P < 0.05), and moreover, significantly elevated superoxide dismutase activity and reduced malondialdehyde content in the brain tissues of rats were found in the experimental group (P < 0.05). These findings indicate that bone marrow mesenchymal stem cell transplantation contributes to behavior improvement in senile dementia rats by improving the learning and memory ability.     

细胞传代对骨髓间充质干细胞向神经干细胞分化的影响

BACKGROUND:It is unclear whether serial cell passage in vitro influences the differentiation of bone marrow mesenchymal stem cells into neural stem cells. OBJECTIVE:To investigate the effect of cell passage on the differentiation of bone marrow mesenchymal stem cells into neural stem cells. METHODS:Rat bone marrow mesenchymal stem cells were isolated and cultured by the whole bone marrow adherence method. Bone marrow mesenchymal stem cells at passages 3, 6, 9, 12 were incubated in serum-free medium. After culture for 7 and 14 days, cell biological characterization was observed and differenitaiton ability into neural stem cells was observed by detecting Nestin expression in cells using flow cytometry. Then, the cells were further induced to differentiate and cell multipotential differentiation capacity was detected by measurement of nerve enolase and glial acidic protein expression. RESULTS AND CONCLUSION:Under induction, bone marrow mesenchymal stem cells at different passages were all differentiated into Nestin-positive neural stem cells. However, there was a significant difference in differentiation proportion of cells at different passages (P < 0.05). Strongest differentiation ability was found in the passage 6 cells, with the Nestin expression up to (93.7±2.3)% at 7 days of induction and (96.2±1.8)% at 14 days of induction. The proportion of differentiated cells at passages 6 and 9 was signfiicantly higher than that at passages 3 and 12. Moreover, adherent cells were positive for nerve enolase and glial acidic protein. All these findings indicate that the differentiation of bone marrow mesenchymal stem cells into neural stem cells is correlated with cell passage. Cells at lower or higher passages are both detrimental to cell differentiation.     

bFGF与骨髓间充质干细胞联合移植对脑损伤后神经再生的影响

探讨碱性成纤维细胞生长因子(bFGF)和骨髓间充质干细胞(BMSCs)联合移植对脑损伤后神经再生的影响。利用血清培养技术获得小鼠BMSCs,行Hoechst33342标记。40只小鼠随机分为4组:正常组、损伤组、BMSCs移植组、bFGF+BMSCs移植组,每组各10只。采用自由落体撞击脑损伤模型,然后经尾静脉注射移植液,2d后行caspase-3免疫荧光染色检测BMSCs的凋亡情况;2w后行HE染色结合形态学图像分析软件计算脑切片的缺损面积、免疫组织化学检测星形胶质细胞及神经元数目变化、Y迷宫测试检测小鼠学习记忆能力。结果显示:bFGF+BMSCs移植组骨髓间充质干细胞的caspase-3表达量是BMSCs移植组的0.5倍;BMSCs移植组和bFGF+BMSCs移植组的学习记忆能力及缺损面积较损伤组有改善(P<0.05),且bFGF+BMSCs移植组与BMSCs移植组比较有显著性差异(P<0.05);GFAP和MAP-2在损伤组表达极少,在BMSCs移植组只有少量表达,而bFGF+BMSCs移植组呈高表达,MAP-2表达水平增高更显著。以上结果提示bFGF+BMSCs移植较BMSCs移植可更好地促进脑损伤后的神经再生。     

Toward biomimetic materials in bone regeneration: functional behavior of mesenchymal stem cells on a broad spectrum of extracellular matrix components

Bone defect treatments can be augmented by mesenchymal stem cell (MSC) based therapies. MSC interaction with the extracellular matrix (ECM) of the surrounding tissue regulates their functional behavior. Understanding of these specific regulatory mechanisms is essential for the therapeutic stimulation of MSC in vivo. However, these interactions are presently only partially understood. This study examined in parallel, for the first time, the effects on the functional behavior of MSCs of 13 ECM components from bone, cartilage and hematoma compared to a control protein, and hence draws conclusions for rational biomaterial design. ECM components specifically modulated MSC adhesion, migration, proliferation, and osteogenic differentiation, for example, fibronectin facilitated migration, adhesion, and proliferation, but not osteogenic differentiation, whereas fibrinogen enhanced adhesion and proliferation, but not migration. Subsequently, the integrin expression pattern of MSCs was determined and related to the cell behavior on specific ECM components. Finally, on this basis, peptide sequences are reported for the potential stimulation of MSC functions. Based on the results of this study, ECM component coatings could be designed to specifically guide cell functions.     

骨髓间充质干细胞促进胰岛再生的作用与研究现状

背景：研究发现,骨髓间充质干细胞移植入糖尿病大鼠后能够降低其血糖。 目的：综述骨髓间充质干细胞在促进胰岛再生方面的作用与研究现状。 方法：应用计算机检索2003年7月至2011年12月PubMed数据库相关文章,检索词为“bone marrow derive mesenchymal stem cell,islet cells”,并限定文章语言种类为English。同时计算机检索2003年7月至2011年12月万方数据库相关文章,检索词为“骨髓间充质干细胞,胰岛细胞”,并限定文章语言种类为中文。最终纳入符合标准的文献25篇。 结果与结论：目前,移植胰岛治疗糖尿病已取得良好疗效,但由于胰岛来源匮乏和异种或异体来源的胰岛引起免疫排斥反应而难以使众多糖尿患者受益。骨髓间充质干细胞取材方便,容易进行体外分离、培养和纯化,且具有多向分化潜能。若将骨髓间充质干细胞诱导分化为胰岛细胞,可望解决胰岛细胞来源和免疫排斥问题。文章对骨髓间充质干细胞分化为胰岛细胞治疗糖尿病的研究进展进行综述,并指出了存在问题和今后的研究方向。     

骨髓间充质干细胞定向趋化及骨修复中基质细胞衍生因子1的作用

背景：骨折愈合与聚集在骨折端的骨髓间充质干细胞的数量及功能密切相关,基质细胞衍生因子1可增强骨髓间充质干细胞的趋化功能。 目的：采用携带绿色荧光蛋白转基因骨髓间充质干细胞的骨髓嵌合体小鼠,制作左胫骨骨折模型,观察基质细胞衍生因子1对骨髓间充质细胞定向迁移的影响及其骨折修复中的作用,并初步探讨其作用机制。 方法：利用密度梯度离心法从携带绿色荧光蛋白转基因小鼠C57BL的骨髓内分离培养出携带绿色荧光蛋白的骨髓间充质干细胞;将经X射线照射后携带绿色荧光蛋白转基因的骨髓间充质干细胞与雄性小鼠的骨髓非贴壁细胞联合移植,最后建立起稳定的骨髓嵌合型小鼠模型,再建立左胫骨骨折模型。建模后分别用基质细胞衍生因子1和基质细胞衍生因子1抗体干预,并设置对照组。 结果与结论：建模后第1,3,7,14天各相应时相点骨折端的骨髓间充质干细胞数量,建模后第14,21天各相应时相点的骨痂量,建模后第28天抗折力,均为基质细胞衍生因子1组>对照组>基质细胞衍生因子1抗体组(P < 0.05);在建模后第28天基质细胞衍生因子1组骨痂量减少(P < 0.05),骨小梁融合成片,部分骨髓腔再通,对照组和基质细胞衍生因子1抗体组髓腔未通。证实,基质细胞衍生因子1 可促进骨髓间充质干细胞向骨折端迁移,具有促进骨折愈合的作用。     

Bio-Gide胶原膜对兔骨髓间充质干细胞增殖和成骨分化的影响

背景：相关实验表明Bio-Gide胶原膜与细胞有良好的生物相容性,但有关与其复合培养干细胞成骨分化能力的报道少见。 目的：观察Bio-Gide胶原膜对骨髓间充质干细胞增殖及成骨分化的影响。 方法：全骨髓贴壁法体外分离培养兔骨髓间充质干细胞,将第3代兔骨髓间充质干细胞分别接种于覆盖Bio-Gide胶原膜的培养板(实验组)与单纯培养板(对照组)培养。于培养1,4,7,14 d利用CCK-8试剂盒检测细胞增殖;成骨分化诱导培养1,4,7,14 d收集细胞培养液上清,检测细胞碱性磷酸酶活性。 结果与结论：两组细胞数量均随着培养时间的增加而不断增加,对照组培养7 d细胞数量明显多于实验组(P < 0.05),其他时间点组间比较差异无显著性意义。两组细胞碱性磷酸酶活性均随着培养时间的增加而不断增加,实验组成骨诱导14 d细胞碱性磷酸酶活性高于对照组(P < 0.05),其他时间点组间比较差异无显著性意义。表明Bio-Gide胶原膜可促进兔骨髓间充质干细胞的增殖及成骨分化。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：     

果糖和二硫苏糖醇对骨髓间充质干细胞冻存后活性及多能性的影响

背景:冻存是保证干细胞临床应用的关键步骤之一,但现有冻存技术常导致细胞活性降低、多能性丧失及分化能力下降。目的:探究果糖及二硫苏糖醇是否有助于维持冻存后骨髓间充质干细胞多能性及成骨分化潜能。方法:分离培养SD大鼠骨髓间充质干细胞,在细胞冻存前分别用果糖(200μmol/L),二硫苏糖醇(500μmol/L)μmol/L)及果糖(200μmol/L)+二硫苏糖醇(500预处理1 h。冻存6个月后,复苏细胞并用倒置显微镜观察细胞形态,MTT实验检测细胞活性,定量PCR检测相关干性基因(Nanog,Oct4及Sox2)的表达,碱性磷酸酶活性测试及茜素红染色检测复苏骨髓间充质干细胞成骨分化能力。结果与结论:(1)复苏后各组细胞在形态上无明显差别;(2)果糖预处理及联合预处理有助于骨髓间充质干细胞活性维持;(3)二硫苏糖醇预处理可显著促进骨髓间充质干细胞多能性相关基因Nanog及Sox2的表达;(4)果糖、二硫苏糖醇及联合预处理皆有助于维持骨髓间充质干细胞成骨分化潜能,但以二硫苏糖醇及联合预处理组效果最佳;(5)结果表明,果糖预处理有助于维持冻存骨髓间充质干细胞活性,二硫苏糖醇有助于维持冻存骨髓间充质干细胞多能性及成骨分化能力。     

碱性成纤维细胞生长因子基因真核表达载体转染骨髓间充质干细胞移植治疗糖尿病

BACKGROUND:Existing studies have shown that bone marrow mesenchymal stem cells can significantly improve islet function in diabetic rats to decrease excessively high blood glucose level, which may be related to the enhancement of differentiation ability of autologou pancreatic stem cells. OBJECTIVE:To observe the therapeutic efficacy of basic fibroblast growth factor gene eukaryotic expression vector (PEGFP-C3-BFGF) transfection of bone marrow mesenchymal stem cells in diabetic rats. METHODS:Recombinant adenovirus (Ad.aFGF) mediated PEGFP-C3-BFGF was transfected into bone marrow mesenchymal stem cells, and PEGFP-C3-BFGF expression was observed using fluorescence microscopy. Eighty Sprague-Dawley rats were randomly divided into normal control group, diabetes group, transplantation group, gene transfection group, with 20 rats in each group. After modeling, rats in different groups were given portal vein injection of normal saline, PBS, 1 mL of bone marrow mesenchymal stem cell suspension, and 1 mL of PEGFP-C3-BFGF-transfected bone marrow mesenchymal stem cell suspension. RT-PCR method was used to detect mRNA expression of matrix metalloproteinases in pancreatic tissue of rats in each group. Blood glucose levels of rats were detected at 24 hours, 3, 7, 14, 21 days after transplantation. ELISA method was used to detect plasma insulin levels in rats. Pathological changes of the pancreas were observed using hematoxylin-eosin staining. RESULTS AND CONCLUSION:Under the fluorescence microscope, PEGFP-C3-BFGF transfected into cells after 48 hours showed significant specific red fluorescence. Two weeks after transplantation, matrix metalloproteinases mRNA expression was significantly increased in the diabetes group compared with the control group (P < 0.05), while it was decreased in the transplantation and gene transfection groups compared with the diabetes group (P < 0.05). After transplantation, the blood glucose levels in rats were ranked as follows: control group < gene transfection group < transplantation group < diabetes group (P < 0.05), and the plasma insulin levels in rats ranked as follows: control group > gene transfection group > transplantation group > diabetes group (P < 0.05). Pathological findings of the pancreas showed that the transplantation group was superior to the diabetes group, but inferior to the gene transfection group that was similar to the control group. All these findings indicate that PEGFP-C3-BFGF-transfected bone marrow mesenchymal stem cell transplantation can improve blood glucose levels and stimulate insulin secretion in diabetic rats, which may improve the severity of diabetes mellitus by decreasing the mRNA expression of matrix metalloproteinases.     

Chemical interaction of polyphosphoric acid with titanium and its effect on human bone marrow derived mesenchymal stem cell behavior

The aim of this study was to evaluate the effect of treating titanium (Ti) with polyphosphoric acid on the attachment and proliferation of human bone marrow derived mesenchymal stem cells (hBMSCs). Cleaned Ti disks were immersed into three different concentrations of polyphosphoric acid solution (0.1, 1, and 10 wt %) and 10 wt % orthophosphoric acid solution for 24 h at 37 degrees C. Ti immersed in distilled water for 24 h at 37 degrees C served as control. The level of polyphosphoric acid that interacted with the Ti surface was determined by measuring the surface P/Ti ratio (atom%/atom%) using X-ray photoelectron spectroscopy. Degrees of cell attachment (1, 3, 5 h after cell seed) and proliferation (1, 3, 5, and 7 days after cell seed) on each treated Ti disk were evaluated by MTS assay. The mean surface P/Ti ratios increased in a polyphosphoric acid concentration dependent manner. A significantly higher cell attachment was found on Ti treated with polyphosphoric acid in contrast to untreated Ti (control) for all three culture periods. MTS assay also revealed that cell proliferation levels significantly increased following a polyphosphoric acid dose dependency. Ti surface treatment with orthophosphoric acid did not influence the cell attachment and proliferation. It was concluded that polyphosphoric acid treatment of Ti enhanced the attachment and proliferation of hBMSCs.     

异种骨材料浸提液对骨髓间充质干细胞生物学特性的影响

背景：如何在去抗原等处理基础上保留异种骨材料的生物学性能及成骨诱导活性成为研究热点之一。目的：探讨异种骨材料浸提液对骨髓间充质干细胞增殖迁移及成骨分化能力的影响。方法：SD大鼠骨髓间充质干细胞分别用异种骨材料浸提液(实验组)和含体积分数为10%胎牛血清的DMEM/F12培养基培养(对照组)。MTT法、Transwell小室法、流式细胞仪检测骨髓间充质干细胞增殖能力、迁移能力、细胞周期变化。取第3代SD大鼠骨髓间充质干细胞,实验组加入成骨诱导分化浸提液,对照组加入成骨诱导分化培养液,培养至第7,14天进行碱性磷酸酶染色,培养第21天进行茜素红染色,观察钙结节形成情况。结果与结论：实验组培养1,3,5,7 d的细胞增殖活性与对照组比较差异无显著性意义(P > 0.05),两组细胞周期差异无显著性意义(P > 0.05)。对照组迁移细胞数显著少于实验组(P < 0.05)。培养第7,14天时实验组碱性磷酸酶水平均显著高于对照组(P < 0.05),成骨诱导第21天进行茜素红染色可见两组均有钙结节形成,实验组钙结节面积更大。结果表明异种骨材料无细胞毒性,具有良好的细胞相容性,可以对骨髓间充质干细胞增殖迁移及定向分化成骨细胞产生有利的促进作用。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Transplantation of bone marrow mesenchymal stem cells on collagen scaffolds for the functional regeneration of injured rat uterus

Serious injuries of endometrium in women of reproductive age are often followed by uterine scar formation and a lack of functional endometrium predisposing to infertility or miscarriage. Bone marrow-derived mesenchymal stem cells (BM-MSCs) have shown great promise in clinical applications. In the present study, BM-MSCs loaded onto degradable collagen membranes were constructed. Collagen membranes provided 3-dimmensional architecture for the attachment, growth and migration of rat BM-MSCs and did not impair the expression of the stemness genes. We then investigated the effect of collagen/BM-MSCs constructs in the healing of severe uterine injury in rats (partial full thickness uterine excision). At four weeks after the transplantation of collagen/BM-MSCs constructs, BM-MSCs were mainly located to the basal membrane of regenerative endometrium. The wounded tissue adjacent to collagen/BM-MSCs constructs expressed higher level of bFGF, IGF-1, TGFβ1 and VEGF than the corresponding tissue in rats receiving collagen construct alone or in spontaneous regeneration group. Moreover, the collagen/BM-MSCs system increased proliferative abilities of uterine endometrial and muscular cells, facilitated microvasculature regeneration, and restored the ability of endometrium to receive the embryo and support its development to a viable stage. Our findings indicate that BM-MSCs may support uterine tissue regeneration.     

不同时间骨髓间充质干细胞移植对大鼠矽肺纤维化形成的影响

目的:研究外源性骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)在不同时间窗的移植对大鼠矽肺纤维化的疗效。方法:体外分离、培养雄性3周龄SD大鼠BMSCs传至3代备用。将50只SD雌性大鼠随机分为5组:对照组,矽肺模型组,早期治疗组,中期治疗组,晚期治疗组(n=10)。采用非暴露式气管插管一次性灌注二氧化硅(SiO2)粉尘混悬液法建立大鼠矽肺模型(50μg/ml),并分别于造模后1、14、28 d BMSCs干预治疗(1×106ml-1),各组大鼠分别于治疗后14 d处死取材。流式细胞仪鉴定BMSCs;HE染色观察肺组织形态学变化;免疫组织化学法及Western blot法检测MMP-9,Ⅰ型胶原和Ⅲ型胶原的定位和定量表达。结果:矽肺模型组较对照组大鼠有明显炎症细胞浸润、矽结节形成、胶原沉积等病理改变。BMSCs在矽肺早期(1 d)和中期(14 d)移植治疗较矽肺模型组病理改变有明显缓解(P0.05);BMSCs在矽肺晚期(28 d)移植治疗无显著效果(P0.05)。结论:BMSCs的移植在矽肺纤维化早中期对大鼠的病理进程起到延缓作用,晚期治疗效果不明显。     

Bioactive functionalized polymer of malic acid for bone repair and muscle regeneration

A bioactive poly(β-hydroxyalkanoate) derived from malic acid was prepared and tested on bone repair and muscle regeneration. This functionalized and hydrolyzable polymer was obtained after several steps, the first one being the anionic copolymerization of three malolactonic acid esters. Chemical modifications were carried out on the terpolymer to turn benzyl-protecting groups into carboxyl groups and allyl groups into sulfonate groups. The resulting polymer bore carboxylate, sulfonate, and sec-butyl pendent groups in 65/25/10 molar proportions and were aimed at interacting with heparan binding growth factors. This polymer did not present any toxic effect in cell viability of HepG₂ cells, over a large range of concentrations (0.01-0.25 mg l^-1). Its ability to improve wound healing was tested in vivo and positive results are reported. Furthermore, the bioactivity of this polymer was evaluated using the regeneration model of Extensor digitorum longus (EDL) rat muscle. The study displayed a significant increase in the muscle regeneration and maturation.     

抑制EGFR信号通路对骨折愈合早期骨内、外膜来源干细胞增殖、分化能力影响的研究*

目的 探索抑制表皮生长因子受体（EGFR）信号通路对骨折愈合早期骨内、外膜来源SCs增殖、分化能力的影响。方法 将建立右股骨骨折模型成功的42只SD大鼠按随机数字表分为实验组与对照组,实验组给予Gefitinib 100 mg/（kg· d）（溶于0.5%甲基纤维素）灌胃,对照组给予等量0.5%甲基纤维素灌胃。术后1周提取右股骨骨内、外膜区域的SCs并进行体外培养。通过流式细胞术鉴定第3代干细胞表面标志物FITC-CD29、FITC-CD34、FITC-CD45、FITC-CD90; BrdU法检测各组干细胞增殖能力; 成骨诱导及成软骨诱导分化后行von Kossa染色及阿尔新蓝染色,检测干细胞的分化能力。结果 各组SCs表面标志物FITC-CD29、FITC-CD90呈高表达,FITC-CD34、FITC-CD45呈低表达; BrdU法检测发现实验组骨内、外膜SCs增殖能力较对照组显著降低（P<0.01）; 成骨诱导分化并染色后,实验组骨内、外膜SCs的矿化结节较对照组更多,成软骨诱导分化并染色后,实验组SCs的淡蓝色颗粒较对照组更多。结论 在骨折愈合早期,抑制EGFR信号通路能抑制骨内、外膜来源SCs的增殖,促进其成骨、成软骨的分化。     

On the physical properties of red cell ghost membranes in the affective disorders and psychoses A fluorescence polarization study

Membrane order was measured in the erythrocyte ghost membranes of DSM-III schizophreniform disorder (SF), DSM-III schizophrenic (SCZ) and DSM-III manic (bipolar) (M) patients and a group of age- and sex-matched controls. Fluorescence polarization with the probe 1,6-diphenyl1-1,3,5-hexatriene was used to determine the steady-state fluorescence anisotropy (r_s). The SF group showed a significant increase in r_s (Δr_s = 0.037) from the control group. Although the means were not significantly different, 3 of 8 Ms and 5 of 8 SCZs also had r_s values > the highest control value. Thermotropic behavior of the membranes was evaluated over the range of 40 to 20°C. No difference among groups in membrane enthalpy was detected. Thus, the differences in r_s appear to be associated with differences in entropy. Phosphatidylcholine (PC) levels, which were known to be abnormal in these patients, were compared with the r_s values. A significant (P < 0.001, R= -0.63) linear correlation between r_s and membrane PC levels was observed. Overall these data further support the view that unusual membrane biophysical factors may occur with high frequency in the psychoses and affective disorders.     

Effect of rhBMP-7 combined with two bone grafts on human periodontal ligament cell differentiation

The purpose of this study was to evaluate the in vitro effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) combined with demineralised freeze-dried bone allograft (DFDBA) and an inorganic bovine material with a synthetic peptide (PepGen P-15) on human periodontal ligament (hPDL) cell differentiation, in a time-dependent manner. hPDL cells were cultured and treated with: (1) 500 ng/ml of rhBMP-7, (2) 10 mg of DFDBA or PepGen P-15 and (3) their combination. Cell differentiation was estimated after 48 and 72 h by measuring alkaline phosphatase (ALPase) activity and osteocalcin (OC) secretion. The presence of rhBMP-7, DFDBA, PepGen P-15, rhBMP-7 + DFDBA and rhBMP-7+ PepGen P-15 promoted a significant increase of ALPase activity after 48 and 72 h. The combination of rhBMP-7 with DFDBA or PepGen P-15 did not lead to significant OC secretion. The results of this study imply that rhBMP-7 stimulates the early osteoblastic differentiation of hPDL cells and that DFDBA and PepGen P-15 could serve as carriers for rhBMP-7.