转染碱性成纤维生长因子基因的骨髓间充质干细胞在珊瑚骨表面生长状况

背景:颌面骨缺损是临床上常遇到的问题,寻找理想的种子细胞同支架材料复合构建组织工程化人工骨成为该类疾病治疗的发展趋势.目的:将转染碱性成纤维生长因子基因的骨髓间充质干细胞与珊瑚骨的复合培养,观察转染碱性成纤维生长因子基凶的骨髓间充质干细胞在珊瑚支架材料上生长状况.设计、时间及单位:骨组织工程实验,于2006-0312008-06 在中山大学口腔医学研究所完成.材料:选用海南省浅海滩产石头状滨珊瑚为原料,将其制成8mm×8mm×2mm的珊瑚人工骨小块.方法:采用密度梯度离心法分离新西兰大白兔骨髓间充质干细胞,采用贴壁筛选法对分离出的骨髓间充质下细胞进行纯化,利用脂质体转染bFGF-pcDNA3到骨髓间充质干细胞.取生长良好的转染碱性成纤维生长因子基因骨髓间充质干细胞和未转染的骨髓间充质干细胞,分别接种于不同珊瑚表面.主要观察指标:MTT法观察细胞-支架联合培养骨髓间充质干细胞的增殖情况和利用扫描电镜观察珊瑚支架上细胞的生长状况.结果:MTT法检测显示细胞-支架联合培养转染组细胞与联合培养未转染组细胞增殖相比差异有显著性意义(P＜0.05),联合培养转染组细胞生长增殖强于未转染组细胞.而联合培养的转染组细胞同单纯培养转染组细胞增殖相比差异无显著性意义(P＞0.05).扫描电镜观察显示复合骨髓间充质干细胞细胞贴附在珊瑚上,并在材料上完全铺展,形态多样,细胞向孔内长入或跨越微孔表面,部分区域有细胞外基质形成.结论:转染碱性成纤维生长因子基因的骨髓间充质干细胞在珊瑚支架材料上生长状况较未转染组好,珊瑚人工骨不影响骨髓间充质干细胞的增殖,可以作为骨髓间充质干细胞支架材料构建组织工程骨.     

The osteogenicity of implanted engineered bone constructs is related to the density of clonogenic bone marrow stromal cells

Reproducible osteogenicity is a key requirement for the clinical use of bone substitutes based on bone marrow stromal cells (BMSCs) and three-dimensional (3D) scaffolds. In this study we addressed whether a minimal cell density is required for ectopic osteogenicity of constructs generated using a recently developed perfusion system for seeding and culturing human BMSCs on 3D scaffolds. Cells from human bone marrow aspirates were directly seeded and expanded for 3 weeks within the pores of ceramic-based scaffolds, using a perfusion bioreactor. The resulting constructs were either implanted subcutaneously in nude mice, to determine their capacity to generate bone tissue, or digested to retrieve the expanded cells and assess their number, phenotype and clonogenic capacity. The final number of BMSCs in the constructs was correlated neither to the initial number of seeded cells, nor to the subsequent bone formation. Instead, the final number of clonogenic BMSCs in the constructs was positively correlated to the initial number of BMSCs seeded, and was significantly higher in osteogenic than in non-osteogenic constructs. These results indicate that clonogenic cells play a crucial role in determining the osteogenicity of engineered bone substitutes. Possible ways to quantify the density of clonogenic cells as a quality control parameter to predict potency of BMSC-based constructs are discussed.     

转碱性成纤维细胞生长因子基因组织工程骨修复兔骨缺损

背景:生物活性玻璃是一类具有良好生物活性及骨修复特性的生物医用材料,将其与血、脱钙骨基质或与骨形态发生蛋白等混合来促进成骨形成,增加强度,骨愈合更接近于天然骨结构。目的:观察生物活性玻璃结合转碱性成纤维细胞生长因子基因骨髓间充质干细胞构建组织工程骨修复兔骨缺损的效果。方法:以生物活性玻璃作为转碱性成纤维细胞生长因子基因骨髓间充质干细胞的可吸附载体,体外构建组织工程骨,将其植入兔桡骨中段 10 mm 骨缺损处,以自体骨移植组、生物活性玻璃/骨髓间充质干细胞组和空白组作为对照,术后 2,4,8,12 周进行影像学、病理组织切片、生物力学测试,观察各组骨缺损修复效果。结果与结论:以生物活性玻璃作为转碱性成纤维细胞生长因子基因骨髓间充质干细胞的可吸附载体,体外构建的组织工程骨植入兔桡骨骨缺损的成骨效应、骨愈合后的抗扭转强度明显优于其他各组(P < 0.01)。说明生物活性玻璃结合转碱性成纤维细胞生长因子基因骨髓间充质干细胞构建的组织工程骨可用于骨缺损修复,优于自体骨移植。     

转碱性成纤维细胞生长因子基因组织工程骨修复兔骨缺损

背景：生物活性玻璃是一类具有良好生物活性及骨修复特性的生物医用材料,将其与血、脱钙骨基质或与骨形态发生蛋白等混合来促进成骨形成,增加强度,骨愈合更接近于天然骨结构。目的：观察生物活性玻璃结合转碱性成纤维细胞生长因子基因骨髓间充质干细胞构建组织工程骨修复兔骨缺损的效果。方法：以生物活性玻璃作为转碱性成纤维细胞生长因子基因骨髓间充质干细胞的可吸附载体,体外构建组织工程骨,将其植入兔桡骨中段 10 mm 骨缺损处,以自体骨移植组、生物活性玻璃/骨髓间充质干细胞组和空白组作为对照,术后 2,4,8,12 周进行影像学、病理组织切片、生物力学测试,观察各组骨缺损修复效果。结果与结论：以生物活性玻璃作为转碱性成纤维细胞生长因子基因骨髓间充质干细胞的可吸附载体,体外构建的组织工程骨植入兔桡骨骨缺损的成骨效应、骨愈合后的抗扭转强度明显优于其他各组（P 〈 0.01）。说明生物活性玻璃结合转碱性成纤维细胞生长因子基因骨髓间充质干细胞构建的组织工程骨可用于骨缺损修复,优于自体骨移植。     

聚碳酸亚丙酯/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞修复兔骨缺损

背景：骨组织工程细胞移植技术是近年来的研究热点,支架材料是其重要组成部分,同时也是三大要素中最有望取得突破性进展的环节,随着组织工程材料工艺的革新,有望为更好地修复骨缺损带来新的希望。目的：评价聚碳酸亚丙酯/壳聚糖纳米纤维（propylene carbonate/chitosan nanofibers,PPC/CSNF）三维多孔支架复合骨髓间充质干细胞（bone marrow mesenchymal stem cell,BMSCs）修复兔股骨髁部骨缺损的能力。方法：二次相分离法制作PPC/CSNF复合三维多孔支架,将第3代的BMSCs种植到复合材料上。36只新西兰大白兔右侧股骨髁制作直径6mm深10mm骨缺损,于缺损处实验组植入复合BMSCs的PPC/CSNF多孔支架,对照组植入单纯PPC/CSNF多孔支架,标准组于兔髂后上棘取自体松质骨移植于缺损部位,空白组不做处理。术后第4,8,12周取材,通过大体观察、放射学检查和组织学检查等方法评价其修复缺损情况。结果与结论：实验组放射学评价与标准组无显著差异,两组结果均优于对照组（P〈0.05）;实验组大体标本与标准组基本一致;实验组组织学检查新骨生成速度、生成量优于对照组（P〈0.05）;空白组不能自行修复骨缺损,最后缺损由纤维组织充填。结果显示PPC/CSNF多孔支架具有较好的细胞和组织相容性,复合兔BMSCs能加速新骨形成,可用于修复兔股骨髁部骨缺损。     

聚碳酸亚丙酯/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞修复兔骨缺损

背景:骨组织工程细胞移植技术是近年来的研究热点,支架材料是其重要组成部分,同时也是三大要素中最有望取得突破性进展的环节,随着组织工程材料工艺的革新,有望为更好地修复骨缺损带来新的希望。目的:评价聚碳酸亚丙酯/壳聚糖纳米纤维(propylene carbonate/chitosan nanofibers,PPC/CSNF)三维多孔支架复合骨髓间充质干细胞(bone marrow mesenchymal stem cell,BMSCs)修复兔股骨髁部骨缺损的能力。方法:二次相分离法制作PPC/CSNF复合三维多孔支架,将第3代的BMSCs种植到复合材料上。36只新西兰大白兔右侧股骨髁制作直径6mm深10mm骨缺损,于缺损处实验组植入复合BMSCs的PPC/CSNF多孔支架,对照组植入单纯PPC/CSNF多孔支架,标准组于兔髂后上棘取自体松质骨移植于缺损部位,空白组不做处理。术后第4,8,12周取材,通过大体观察、放射学检查和组织学检查等方法评价其修复缺损情况。结果与结论:实验组放射学评价与标准组无显著差异,两组结果均优于对照组(P<0.05);实验组大体标本与标准组基本一致;实验组组织学检查新骨生成速度、生成量优于对照组(P<0.05);空白组不能自行修复骨缺损,最后缺损由纤维组织充填。结果显示PPC/CSNF多孔支架具有较好的细胞和组织相容性,复合兔BMSCs能加速新骨形成,可用于修复兔股骨髁部骨缺损。     

聚左旋乳酸/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞修复兔骨缺损

背景：骨髓间充质干细胞具有向多种间质细胞谱系分化的能力,且支架材料的性能对骨缺损的修复有重要影响。目的：观察聚左旋乳酸/壳聚糖纳米纤维三维多孔支架复合骨髓间充质干细胞治疗骨缺损。方法：对骨缺损模型兔分别采用空白植入、髂后上棘自体松质骨移植、聚左旋乳酸/壳聚糖纳米纤维多孔支架移植和复合了骨髓间充质干细胞的聚左旋乳酸/壳聚糖纳米纤维多孔支架移植修复缺损部位。结果与结论：至移植12周,移植复合了骨髓间充质干细胞的聚左旋乳酸/壳聚糖纳米纤维多孔支架的实验兔的缺损处有骨组织生成,支架材料降解,已完成缺损修复,其修复情况接近松质骨组;髂后上棘自体松质骨移植的实验兔的缺损修复完好,新形成的骨组织较规则;只植入聚左旋乳酸/壳聚糖纳米纤维多孔支架的实验兔有少量骨组织形成,材料部分降解;空白植入的实验兔缺损处无新生骨组织生成,主要由纤维结缔组织填充。说明新型的生物支架材料聚左旋乳酸/壳聚糖纳米纤维三维多孔支架与来源于新西兰大白兔的骨髓间充质干细胞复合培养后,植入同种异体兔股骨髁缺损处,使骨缺损的修复速度加快,表现为较好的体内诱导成骨的作用。     

颞下颌关节继发性强直与幼年期髁状突纵行骨折的关系

背景髁状突骨折作为一种较严重的颞下颌关节(temporomandibular joint,TMJ)损伤受到学者们关注.但是,受诊断方法限制,学者们一直对髁状突横断骨折研究较多,而对髁状突纵行骨折研究较少,对儿童髁状突纵行骨折了解更少.目的探讨幼年期髁状突纵行骨折对TMJ继发性强直的影响.设计随机对照的实验研究.单位解放军总医院口腔科.材料实验在解放军总医院实验动物中心完成.选择北京农业大学实验动物研究所培育的中国实验用小型猪12头,两三个月龄,体质量5～5.5kg,混合饲料喂养,随机分为3组.方法小型猪于术前12 h禁食水,以5.0～15.0 mg/kg噻胺酮腹腔麻醉.麻醉成功后取右侧卧位,常规消毒,左耳前切口,横行切开关节囊,暴露髁状突,牵拉髁状突向下,用宽5 mm小骨凿沿内侧1/3处纵行劈骨,造成前后矢状骨折.于术后3个月与6个月分批处死动物,取其髁状突标本进行观察.主要观察指标①肉眼观察3组动物髁状突标本的形态学变化.②光镜观察3组动物髁状突标本的组织学改变.结果术后3个月组可见关节盘与髁状突明显粘连(下称盘突粘连),其中1例可见关节窝、关节盘、髁状突之间均出现粘连,2只动物形成双髁状突畸形,未见关节盘穿孔.术后6个月组见盘突粘连紧密,3只动物形成双髁状突畸形,关节盘则明显增厚.光镜检查骨折后3个月见盘突粘连明显,粘连部位与周围组织的界限不清,粘连区由纤维结缔组织组成,内含大量的软骨细胞,部分粘连区纤维结缔组织与骨小梁紧密结合,关节盘纤维排列紊乱,出现血管及脂肪细胞.骨折后6个月粘连组织内可见血管、大量的成纤维细胞及散在的软骨细胞.关节盘胶原纤维排列呈旋窝状内含大量脂肪细胞并可见血管.在未粘连部位可见髁状突表面纤维软骨增厚,表面纤维排列紊乱.关节盘表面呈增生改变.结论幼年期髁突纵行骨折对TMJ造成严重继发性损伤,髁突纵行骨折与关节强直关系密切.     

以裸鼠为活体生物反应器构建可移植组织工程骨的可行性研究

目的研究以裸鼠为活体生物反应器构建组织工程骨进行自体移植的可行性。方法常规培养兔骨髓间充质干细胞后，选取第4代细胞向成骨细胞诱导分化。与珊瑚复合后，植入裸鼠体内，8局后取出形成之骨组织，放人自体家兔背部肌肉组织间隙中，分别于14、28、56d后测量血清中兔抗裸鼠抗体滴度，2、7、14、28、56d后检测白细胞介素(IL)-2水平，8周标本行免疫组化染色，判定局部免疫反应水平。结果整个实验过程中均未能测出血清IL-2活性，兔抗裸鼠抗体滴度阳性，免疫组化染色阴性。结论本实验中裸鼠体内长成的组织工程骨未表现出明显的免疫原性，提示裸鼠作为活体生物反应器构建组织工程骨有一定的可行性。     

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.     

在多孔胶原支架上构建三维工程的心肌组织

背景目前已有转化的SV40细胞系、C2C12成肌细胞、心肌细胞、骨骼肌细胞以及胚胎干细胞用于修复哺乳动物心脏的细胞移植治疗,然而细胞移植治疗对严重缺失或损伤心肌结构的治疗的作用却不大.组织工程技术为此类心肌疾病的研究及治疗提供了新的可能性,目前已有可替代和改善骨、软骨、肾、肝、神经及皮肤等组织和器官的生物合成结构物.目的探索多孔胶原作为构建三维工程心肌组织支架材料的可行性.设计非随机、对照的实验研究.地点和对象实验地点军事医学科学院生物工程研究所.动物清洁级1日龄Wistar大鼠400～500只,雌雄不限,体质量8～10 g;成年Wistar大鼠五六只,雌雄不限,体质量250 g,由军事医学科学院实验动物中心提供,饲养温度22～26℃,湿度40%～60%.干预在无菌条件下,将经胰蛋白酶消化获得的新生鼠心肌细胞分别接种于三维多孔胶原支架和培养板上,比较心肌细胞在两种培养模式的代谢差异.主要观察指标检测葡萄糖比消耗率、乳酸比产率、乳酸转化率、肌酸激酶及乳酸脱氢酶活力变化.结果培养于多孔胶原支架上的心肌细胞的代谢特性近似于心肌细胞在培养板上培养的二维生长模式.结论心肌细胞与多孔胶原支架形成了具有自律性同步收缩的三维工程心肌组织,多孔胶原作为心肌组织工程的支架材料有良好的应用前景.     

纳米羟基磷灰石/月交原/聚乳酸复合物与骨髓间充质干细胞修复兔下颌骨缺损

背景:为颌骨缺损患者选择适宜的骨移植材料替代自体骨是当前研究的热点.目的:观察纳米羟基磷灰石/胶原/聚乳酸与兔骨髓间充质干细胞复合物用于修复兔下颌骨缺损的能力,比较其与自体骨修复及单纯纳米羟基磷灰石/胶原/聚乳酸修复的差异.设计、时间及地点:随机对照动物实验,于2007-03/10在锦州市中心医院动物实验室完成.材料:40只新西兰兔随机分成纳米羟基磷灰石/胶原/聚乳酸复合骨髓基质干细胞填充组(简称复合组)、自体骨填充组、单纯支架材料填充组及空白对照组,每组10只.方法:在兔下颌骨体部制造大小为15 mm×15 mm的全厚骨缺损模型.复合组于缺损处植入骨髓基质十细胞与纳米羟基磷灰石/胶原/聚乳酸体外联合培养14 d的复合物:自体骨填充组于缺损处植入自体髂骨;单纯支架材料充填组于缺损处植入纳米羟基磷灰石/胶原/聚乳酸:空白对照组不作任何植入.主要观察指标:分别于植入后1,3,6个月进行骨密度检测及组织学染色观察,根据检测结果评价骨修复效果.结果:复合组与自体骨填充组骨密度比较,差异无显著性(P＞0.05),且均高于单纯支架材料充填组及空白对照组(p＜0.01).复合组和自体骨填充组材料植入后6个月时见,新生骨组织渐成熟.呈大块状,桥接缺损断端,支架材料已所剩无几.单纯支架材料充填组植入后6个月时见,植入区骨小梁增多,但仍见较多纤维组织嵌于其中,易见未降解完全的支架材料.结论:纳米羟基磷灰石/胶原/聚乳酸与骨髓间充质干细胞复合物修复下颌骨缺损效果与自体骨修复相似,均优于单纯支架材料修复.     

体外构建腺病毒介导骨形态发生蛋白2基因转染骨髓间充质干细胞复合纳米羟基磷灰石的植骨材料

背景:随着组织工程和基因工程技术迅速发展,基因增强的组织工程骨为临床治疗骨缺损带来美好的前景.目的:观察经腺病毒介导的人骨形态发生蛋白2表达载体(Ad-BMP-2)转染后的兔骨髓间充质干细胞在纳米羟基磷灰石植骨材料上的黏附、增殖及骨形态发生蛋白2的表达情况.方法:用Ad-BMP-2转染兔骨髓间充质干细胞,免疫组化、蛋白印迹法检测转染后细胞内骨形态发生蛋白2的表达情况.将转染48 h的细胞均匀接种到纳米羟基磷灰石植骨材料上,扫描电镜观察细胞黏附状况,并采用MTT比色法测定骨髓间充质干细胞的增殖情况;消化收集黏附植骨材料上第3,5,7天的细胞,蛋白印迹检测黏附材料上细胞骨形态发生蛋白2的表达.结果与结论:转染后,骨髓间充质干细胞内骨形态发生蛋白2有高表达;扫描电镜见转染细胞在纳米羟基磷灰石材料孔隙周围及孔隙内黏附生长良好并大量增殖,MTT分析结果显示,纳米羟基磷灰石对骨髓间充质于细胞的体外增殖无抑制作用,复合后骨形态发生蛋白2有较高表达.结果表明经Ad-BMP-2转染后的骨髓间充质干细胞与纳米羟基磷灰石植骨材料生物相容性好,细胞在材料上能稳定长效地分泌骨形态发生蛋白2.     

Multidetector computed tomography of temporomandibular joint: A road less travelled

This article reviews the imaging anatomy of temporomandibular joint(TMJ), describes the technique of multi-detector computed tomography(MDCT) of the TMJ, and describes in detail various osseous pathologic afflictions affecting the joint. Traumatic injuries affecting the mandibular condyle are most common, followed by joint ankylosis as a sequel to arthritis. The congenital anomalies are less frequent, hemifacial microsomia being the most commonly encountered anomaly involving the TMJ. Neoplastic afflictions of TMJ are distinctly uncommon, osteochondroma being one of the most common lesions. MDCT enables comprehensive evaluation of osseous afflictions of TMJ, and is a valuable tool for surgical planning. Sagittal, coronal and 3D reformatted images well depict osseous TMJ lesions, and their relationship to adjacent structures.     

Comparing the osteogenic potential of bone marrow and tendon‐derived stromal cells to repair a critical‐sized defect in the rat femur

Despite significant advancements in bone tissue‐engineering applications, the clinical impact of bone marrow stromal cells (BMSCs) for the treatment of large osseous defects remains limited. Therefore, other cell sources are under investigation for their osteogenic potential to repair bone. In this study, tendon‐derived stromal cells (TDSCs) were evaluated in comparison to BMSCs to support the functional repair of a 5 mm critical‐sized, segmental defect in the rat femur. Analysis of the trilineage differentiation capacity of TDSCs and BMSCs cultured on collagen sponges revealed impaired osteogenic differentiation and mineral deposition of TDSCs in vitro, whereas chondrogenic and adipogenic differentiation was evident for both cell types. Radiographic assessment demonstrated that neither cell type significantly improved the healing rate of a challenging 5 mm segmental femoral defect. Transplanted TDSCs and BMSCs both led to the formation of only small amounts of bone in the defect area, and histological evaluation revealed non‐mineralized, collagen‐rich scar tissue to be present within the defect area. Newly formed lamellar bone was restricted to the defect margins, resulting in closure of the medullary cavity. Interestingly, in comparison to BMSCs, significantly more TDSC‐derived cells were present at the osteotomy gap up to 8 weeks after transplantation and were also found to be located within newly formed lamellar bone, suggesting their capacity to directly contribute to de novo bone formation. To our knowledge, this is the first study investigating the in vivo capacity of TDSCs to regenerate a critical‐sized defect in the rat femur. Copyright © 2015 John Wiley & Sons, Ltd.     

Asymmetrical seeding of MSCs into fibrin–poly(ester‐urethane) scaffolds and its effect on mechanically induced chondrogenesis

Mesenchymal stem cells (MSCs) are currently being investigated as candidate cells for regenerative medicine approaches for the repair of damaged articular cartilage. For these cells to be used clinically, it is important to understand how they will react to the complex loading environment of a joint in vivo. In addition to investigating alternative cell sources, it is also important for the structure of tissue‐engineered constructs and the organization of cells within them to be developed and, if possible, improved. A custom built bioreactor was used to expose human MSCs to a combination of shear and compression loading. The MSCs were either evenly distributed throughout fibrin‐poly(ester‐urethane) scaffolds or asymmetrically seeded with a small proportion seeded on the surface of the scaffold. The effect of cell distribution on the production and deposition of cartilage‐like matrix in response to mechanical load mimicking in vivo joint loading was then investigated. The results show that asymmetrically seeding the scaffold led to markedly improved tissue development based on histologically detectable matrix deposition. Consideration of cell location, therefore, is an important aspect in the development of regenerative medicine approaches for cartilage repair. This is particularly relevant when considering the natural biomechanical environment of the joint in vivo and patient rehabilitation protocols. © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons Ltd.     

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。     

Chondrogenic differentiation of human bone marrow mesenchymal stem cells in chitosan-based scaffolds using a flow-perfusion bioreactor

Native articular cartilage is subjected to synovial fluid flow during normal joint function. Thus, it is believed that the morphogenesis of articular cartilage may be positively regulated by the application of similar stimulation in vitro. In the present study, the effect of fluid flow over the chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) was investigated. We intended to find out whether the shear stress caused by perfusion of the medium through the constructs was capable of augmenting the differentiation process. Human BMSCs were isolated from bone marrow aspirates and were characterized by flow cytometry. After expansion, hBM-MSCs were seeded statically onto fibre mesh scaffolds, consisting of a blend of 50:50 chitosan:poly(butylene terephthalate adipate) (CPBTA). Constructs were cultured in a flow-perfusion bioreactor for 28 days, using complete medium for chondrogenesis supplemented by TGFβ3. An enhanced ECM deposition and collagen type II production was observed in the bioreactor samples when compared to the static controls. Moreover, it was observed that hBM-MSCs, in static cultures, take longer to differentiate. ECM accumulation in these samples is lower than in the bioreactor sections, and there is a significant difference in the expression of collagen type I. We found that the flow-induced shear stress has a beneficial effect on the chondrogenic differentiation of hMSCs.     

Rat bone marrow stromal cells‐seeded porous gelatin/tricalcium phosphate/oligomeric proanthocyanidins composite scaffold for bone repair

Repair of bone defects remains a major challenge in orthopaedic surgery. Bone tissue engineering is an attractive approach for treating bone loss in various shapes and amounts. The aim of this study was to prepare and evaluate the feasibility of a porous scaffold, which was composed of oligomeric proanthocyanidin crosslinked gelatin mixed with β‐tricalcium phosphate (GTP) and was seeded with bone marrow stromal cells (BMSCs) as a bone substitute. GTP scaffolds were made porous using a salt‐leaching method. The physicochemical properties of the scaffold were evaluated to determine the optimal salt:composite weight ratio. The results indicated that the GTP scaffold had a favourable macroporous structure and higher porosity when the salt:composite weight ratio was 4:1. Cytotoxic tests demonstrated that extracts from the GTP scaffolds promoted the proliferation of BMSCs. Rat BMSCs were seeded on a GTP scaffold and cultured in a spinner flask. After 2 weeks of culture, scanning electron microscopy observation showed that the cells adhered well to the surfaces of the pores in the scaffold. Moreover, this study explored the biological response of rat calvarial bone to the scaffold to evaluate its potential in bone tissue engineering. Bone defects were filled with BMSC‐seeded GTP scaffold and acellular GTP scaffold. After 8 weeks, the scaffold induced new bone formation at a bone defect, as was confirmed by X‐ray microradiography and histology. The BMSC‐seeded scaffold induced more new bone formation than did an acellular scaffold. These observations suggest that the BMSCs‐seeded GTP scaffold can promote the regeneration of defective bone tissue. Copyright © 2012 John Wiley & Sons, Ltd.     

三维支架中骨髓间充质干细胞及软骨细胞和脂肪源性成熟基质细胞的成软骨效应

背景：软骨修复的关键是种子细胞在三维支架中的定向分化,但细胞放入三维支架中很难有透明软骨表现。目的：考察3种种子骨髓间充质干细胞,软骨细胞和脂肪源性成熟基质细胞在支架中的成软骨特性。方法：抽取羊骨髓,胰酶消化后获得原代骨髓间充质干细胞细胞、软骨细胞和脂肪源性成熟基质细胞,单层培养扩增。取P1骨髓间充质干细胞,P3软骨细胞和P3脂肪源性成熟基质细胞种植入不同比例（10%,20%,50%,80%,100%）的胶原/透明质酸支架中,在无血清培养液中三维培养。2周后,用SO染色和免疫组织化学染色分析,观察硫酸软骨素和Ⅱ型胶原合成情况。结果与结论：种子细胞在三维支架中特定条件下有成软骨效应,骨髓间充质干细胞在含20%透明质酸的胶原/透明质酸支架扩增少于3代有成软骨效应,软骨细胞传代数更高仍然有成软骨效应,但脂肪源性成熟基质细胞成软骨效应能力较弱。结果提示,在同样条件下骨髓间充质干细胞、软骨细胞较脂肪源性成熟基质细胞有更好的成软骨性能。