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This research uses alginate and hyaluronic acid as the main component to prepare support, then explores the possibilities as a tissue engineering scaffold. Firstly, prepare HA with various average molecular weight and alginate with different viscosity, mix them up at a certain proportion and make it into a AlgCa 2+-HA composite scaffold with a film-forming method. This article discusses the feasibility of this scaffold used in tissue engineering field according to the consequence of moisture content testing, mechanical analysis, and scanning electron microscopy analysis. The structure and properties of AlgCa2+-HA composite scaffold are closely related to some factors such as average molecular weight of hyaluronic acid, hyaluronic acid concentration, alginate viscosity, cross-linking agents and processing technology. The AlgCa 2+-HA composite material, which is at different proportions and adding different cross-linking agent,has some certain characteristics:moisture content ranging from 50%to 95%, tensile strength between 2.69 N/mm2 and 4.299 N/mm2, and elongation at break is about 58%to 160%. The prepared AlgCa2+-HA composite scaffolds can be used as tissue engineering scaffolds resulting from its high moisture content, good mechanical properties and ideal pore structure.
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干细胞与心肌组织工程学研究
虽然干细胞移植在世界各地进行得如火如荼,部分单位已经进入临床实验,取得了很好的结果[1-2].但是对于大面积心肌梗死,细胞移植很难逆转心功能的进一步恶化;对于先天性心脏病患者,单纯的细胞移植不可能替代或修补心脏缺损.而且,目前所用的修复重建材料都缺乏收缩性和生长潜能,并有钙化和血栓生成的危险.寻找能避免上述不足的理想材料一直是心血管领域基础研究的热点之一[3].
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半月板组织工程研究进展
半月板损伤是关节外科中常见的损伤之一,半月板的组织工程学修复成为了研究重点。笔者就半月板组织工程涉及的种子细胞、支架材料、细胞因子、机械刺激等新研究进展作一概述。
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开拓进取学术至上产学研结合患者第一戴戎院士介绍
戴戎,中国工程院院士,上海交通大学医学院附属第九人民医院终身教授。1955年毕业于上海第一医学院。1983~1984年在美国 Mayo医学中心研修。先后担任原上海第二医科大学附属第九人民医院骨科主任、院长、临床医学院院长。现任上海交通大学医学院骨与关节研究所主任、上海市关节外科临床医学中心主任、数字医学临床转化教育部工程研究中心主任、上海交通大学转化医学研究院干细胞与再生医学转化基地主任,以及医用生物力学和临床骨科杂志主编,《中华创伤外科杂志英文版》副主编。
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椎间盘组织工程学种子细胞来源的研究进展
椎间盘退变(intervertebral disc degeneraton,IDD)所致腰腿痛是骨科的常见疾病,目前对IDD所致腰腿痛的治疗手段都属对症治疗,不能阻止或逆转椎间盘退变,因此不能从根本上解决椎间盘退变所致腰腿痛.椎间盘组织工程学旨在通过恢复或者重建椎间盘原有的生理结构及生物学功能,有望成为一种治疗IDD的有效手段[1],但组织工程研究和治疗需要大量的种子细胞,现有种子细胞来源有限,探索相对理想的种子细胞成为研究的热门.作者就种子细胞来源的研究进展综述如下.
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3D打印技术在心血管组织工程中的研究进展
近年来,3 D打印技术已成为心血管组织工程领域的研究热点,并取得了一些进展。但是将来如何应用到临床上仍需进一步的研究。本文回顾近年来3D打印技术在心肌组织、心脏瓣膜、冠状动脉应用的研究进展,并对未来的研究进行展望。
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组织工程化皮肤研究新进展
组织工程化皮肤是指运用工程及生命科学的原理和方法构建出的用于修复、维持和改善损伤皮肤组织功能的替代物;其核心是建立由细胞和生物材料构成的三维空间复合体。理论上,组织工程化皮肤应具有如下功能:①作为损伤皮肤的替代物;②作为基质植入宿主体内并生长;③或作为含药理成分的化学刺激物,促进创面愈合[1]。但现阶段,还不能作为永久性的皮肤替代物。本文对以胶原为细胞外基质材料所形成的组织工程化皮肤的研究进展作一简要综述。 一、胶原作为细胞外基质材料及特点 胶原蛋白是真皮结缔组织的主要成分,占皮肤干重的70 %,具有天然的抗拉性、抗张力性、低抗原性、良好的生物相容性及完全的生物可降解性,还在细胞(尤其是成纤维细胞)表面黏附、趋化、生长、分化及介导免疫反应等方面起重要作用,是良好的皮肤组织工程的支架材料[2,3]。胶原类材料包括动物胶原和同种胶原。前者主要来自牛真皮、牛的跟腱、牛眼水晶体、大鼠尾腱、豚鼠真皮等;后者由尸体真皮提供胶原材料。现已知胶原作为细胞外支架材料特点如下:①黏附性好,利于细胞的生长和基质的沉积,血管再生及上皮细胞附着;②胶原取材于动物或人尸体皮,作为异物,仍存在排斥反应,导致严重的后果;③胶原类材料降解情况受局部因素影响很大,降解速度可控制性不如人工聚合物。胶原主要是被组织中的酶类降解,胶原酶为机体的主要溶解酶类,创面愈合过程中,胶原酶活性往往增加;④胶原材料具有适宜的孔径,保持了天然的渗透性,适合营养物质、生物因子等的扩散和血管长入;⑤具有创面止血和缓解疼痛的作用;⑥存在微生物如HIV病毒等的污染危险性。
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Tissue engineering technologies offer new treatment strategies for the repair of peripheral nerve injury, but cell loss between seeding and adhesion to the scaffold remains inevitable. A thermo-sensitive collagen hydrogel was used as an extracellular matrix in this study and combined with bone marrow mesenchymal stem cells to construct tissue-engineered peripheral nerve compos-ites in vitro. Dynamic culture was performed at an oscillating frequency of 0.5 Hz and 35° swing angle above and below the horizontal plane. The results demonstrated that bone marrow mesen-chymal stem cells formed membrane-like structures around the poly-L-lactic acid scaffolds and exhibited regular alignment on the composite surface. Collagen was used to ifll in the pores, and seeded cells adhered onto the poly-L-lactic acid ifbers. The DNA content of the bone marrow mesenchymal stem cells was higher in the composites constructed with a thermosensitive colla-gen hydrogel compared with that in collagen I scaffold controls. The cellular DNA content was also higher in the thermosensitive collagen hydrogel composites constructed with the thermo-sensitive collagen hydrogel in dynamic culture than that in static culture. These results indicate that tissue-engineered composites formed with thermosensitive collagen hydrogel in dynamic culture can maintain larger numbers of seeded cells by avoiding cell loss during the initial adhe-sion stage. Moreover, seeded cells were distributed throughout the material.
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关键词: tissue engineering
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Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as wel as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa-line groups than in the nerve growth factor-microspheres and autologous nerve groups. Electro-physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation il ustrated that the di-ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits com-bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits.
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In this study, we constructed tissue-engineered nerves with acel ular nerve al ografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cel s of Wistar rats cultured in vitro, to repair 15 mm sciatic bone defects in Wistar rats. At postoperative 12 weeks, electrophysiological detection results showed that the conduction velocity of regenerated nerve after repair with tis-sue-engineered nerves was similar to that after autologous nerve grafting, and was higher than that after repair with acel ular nerve al ografts. Immunohistochemical staining revealed that motor endplates with acetylcholinesterase-positive nerve fibers were orderly arranged in the middle and superior parts of the gastrocnemius muscle;regenerated nerve tracts and sprouted branches were connected with motor endplates, as shown by acetylcholinesterase histochemistry combined with silver staining. The wet weight ratio of the tibialis anterior muscle at the affected contralateral hind limb was similar to the sciatic nerve after repair with autologous nerve grafts, and higher than that after repair with acel ular nerve al ografts. The hind limb motor function at the affected side was significantly improved, indicating that acel ular nerve al ografts combined with bone marrow me-senchymal stem cel bridging could promote functional recovery of rats with sciatic nerve defects.
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软骨组织工程基础及临床应用研究
软骨组织工程是组织工程研究领域开展早、发展快的研究内容之一,目前主要经历了两个阶段的发展,第一阶段主要是应用组织工程技术在免疫功能缺陷的裸鼠体内构建软骨组织,探讨软骨组织工程构建的可行性;第二阶段是在全面进行软骨组织工程研究的基础上,重点解决制约软骨组织工程发展的关键性问题,同时应用组织工程技术,在具有完全免疫功能的高等大型哺乳动物体内构建软骨组织并修复组织缺损,为组织工程化软骨的临床应用奠定基础.目前阻碍组织工程发展的瓶颈性问题主要包括以下几个方面:①软骨种子细胞来源有限:软骨细胞体外培养扩增困难且极易老化,难以获得大量的细胞满足软骨组织构建的需要,严重制约了临床应用;②针对众多应用于软骨组织工程的生物材料,尚缺乏系统的对照研究与统一标准,寻找适用于软骨组织构建的生物材料已经成为软骨组织工程生物材料研究的重中之重;③应用组织工程技术,在具有完全免疫功能的高等大型哺乳动物体内构建软骨组织并修复组织缺损,是组织工程技术向临床应用过渡的关键步骤与必要技术准备,而国际上相关工作尚未开展;④应用组织工程技术在人体内形成组织工程化软骨是组织工程研究的近期科学目标,也是组织工程技术临床修复软骨组织缺损的关键所在,相关研究尚未见报道.
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组织工程技术系列专题(二)——种子细胞与组织工程的研究
组织工程研究成功与否主要取决于以下三个基本要素:种子细胞、支架材料以及有助于细胞生长、分化的外在环境.其中获得足够数量、不引起免疫排斥反应且具有再生活力的种子细胞是开展组织工程研究的前提和基础.组织工程研究需要的种子细胞有多种来源,如自体细胞、同种异体细胞、异种细胞以及自体或同种异体干细胞,每一种细胞来源都有其优缺点.近年来,干细胞的研究取得了显著性进展,展现出广阔的应用前景[1-3].
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组织工程技术的发展现状及趋势(三)——组织工程用生物材料的研究
1 组织工程用生物材料的概述生物材料又称生物医用材料,是指用于对生物体进行诊断、治疗和置换损伤组织、器官或增进其功能的材料[1].按发展阶段分为生物惰性材料、生物活性可降解材料以及细胞和基因活化的材料3大类.
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膝关节韧带和肌腱的生物力学研究(中)
五、增强愈合韧带和肌腱性能的功能性组织工程学方法功能性组织工程学(functional tissue engineering,FTE)是一个为了寻求更新的治疗方法而出现的联合了分子生物学、生物化学以及生物力学的新型领域.过去十年,我们探索了一些新的方法来改善韧带和肌腱的愈合与调节.
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基因强化组织工程在牙髓牙本质复合体和牙周组织再生中的应用研究进展
基因强化组织工程(gene-enhanced tissue engineering)是利用基因转染技术将编码蛋白因子的目的基因转染种子细胞或生物活性基质材料,使转染的细胞或基质表达目的基因,终在体内促进靶细胞的增殖、分化及发挥正常的生理功能,从而促进组织的修复和重建的一种方法.
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周围神经损伤与组织工程修复的研究进展
近年来,周围神经损伤组织工程修复的研究取得了很大的进展.动物实验与临床研究主要聚焦于寻找理想的人工神经移植替代物、神经导管和种子细胞.神经导管有非降解或可降解两种,神经移植物有自体神经、同种异体神经及异种神经移植物,作为桥接神经缺损的支架有各自的优点与缺点.同时,培养、种植一定数量与高纯化度的具有分泌多种神经营养因子活性的施万细胞也是提高修复神经损伤效果的关键.
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人骨髓间充质干细胞的获取与体外培养的研究 : 作为喉、气管软骨组织工程重建种子细胞的可能性
Objective To observe the feasibility of using bone marrow-derived mesenchymal stem cells (MSCs) as seed cells for tissue-engineering in Otolaryngology. Method MSCs were isolated from bone marrow of human rib and purified by centrifuge and cultured in vitro. The proliferation and growth characteristics of MSCs were observed in primary and passage culture. Result Human bone marrow-derived MSCs showed active proliferation capacity in vitro in primary and passage cultures. Conclusion Human bone marrow-derived MSCs have relatively young biologic age and they can be used as the seed cells for tissue engineering.
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精选目次:组织工程
Multilineage cells from human adipose tissue: implications for cell- based therapies. 2001 Apr;7(2):211- 28. 人类脂肪组织的多线性细胞:在细胞疗法中的意义 Evaluation of nanostructured composite collagen- chitosan matrices for tissue engineering. 2001 Apr;7(2):203- 10. 评估纳米结构复合物胶原-壳聚糖基质在组织工程中的应用 Two- photon laser scanning microscopy of epithelial cell- modulated collagen density in engineered human lung tissue. 2001 Apr;7(2):191- 202. 人类工程肺组织的上皮细胞调节的胶原密度的双光子激光扫描显微学 Aggregation enhances catecholamine secretion in cultured cells. 2001 Apr;7(2):179- 90. 多聚化增加培养细胞儿茶酚胺的的分泌
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注射性软组织填充材料及组织工程研究的进展
注射性医用生物材料,尤其是注射性软组织填充材料,对整形、美容外科医师来说,尤其是面部整形外科医师来说,一直是一个挑战性的问题。整形、美容外科医师试图寻找一种长期、安全、有效的生物相容性好的材料已有百余年的历史,至今仍然是一个挑战性问题,未能很好解决。国内程宁新[1]、周智、鲁开化[2]、张晨[3]、沙镝[4]、高景恒[5]等人曾在这方面的作了综述,笔者加以补充文献复习。1 人工合成类软组织填充材料 1.1 Bioplastique(硅胶+PVP) Bioplastique是荷兰的Uroplasty BV报道的,它是由固体硅胶微粒(直径100~400μm)混合在聚乙烯吡咯烷酮(polyvivylpyrrolidone-PVP)或称聚烯吡酮(Povidone)液体中,此材料一旦注入人体引起局部低度炎性反应,并通过肾脏排泄到体外。但动物试验未发现异物迁移的证据。局部胶原沉积包裹硅胶代替聚烯吡酮,其成分比硅胶稍高于1∶1。因此不提倡过多纠正,为防止可能触到的硬结主张在皮下注射,未见严重并发症报道,Romano JJ报道在内窥镜下在输尿管周围注射Teflon和液态硅胶可成功减少膀胱输尿管返流有效率达80%。澳大利亚的Rudolph CM等人1999年报道利用Bioplestique(2例)和Artecoll(3例)注射引起因异物肉芽肿而切除的病例[6]。