组织工程软骨生物反应器的设计

目的 根据流体力学原理优化反应器内腔结构,并设计一套组织工程软骨生物反应器.方法 采用计算机仿真的方法对反应器内腔流场进行仿真计算,通过流场分析确定内腔结构,最终构建一套完整的生物反应器系统.结果 确定了生物反应器的内腔结构,生物反应器由控制系统和细胞培养室两部分构成,能置于培养箱中对软骨细胞材料复合物进行动态培养.结论 反应器内腔的结构是合理的.整个生物反应器系统运行可靠.     

一种新型血管生物反应器的研究与开发

目的 根据流体力学的分析改进支撑PGA-细胞材料复合物的硅胶管,设计一种应用于体外培养组织工程血管的生物反应器.方法 利用计算机仿真分析的方法对硅胶管内腔的压力场进行仿真计算,通过计算分析确定硅胶管的结构,进而开发一种新型血管生物反应器.结果 确定了硅胶管的尺寸结构以及培养室内相应的辅助结构,使整个反应器系统能够对PGA-细胞材料复合物进行动态培养.结论 改进后的硅胶管结构合理,整个血管生物反应器系统运行稳定.     

组织工程软骨实验生物反应器的设计

目的:设计一套计算机控制的组织工程软骨实验用灌流型生物反应器。方法:通过计算机控制时间及流量,利用蠕动泵、密闭的硅胶管、玻璃管、储液瓶等串联设计一套无菌的灌流型软骨组织工程用生物反应器。结果:生物反应器由控制系统和培养系统组成,运行良好,能置于培养箱中对软骨细胞材料复合物进行动态培养。结论:反应器设计合理。整个生物反应器系统运行可靠。     

组织工程化肌腱体外构建的环境优化及系统设计

目的 设计一套构建具有一定功能和形态的肌腱组织的体外培养方法。方法 根据肌腱细胞体内的生物力学环境，在细胞的培养过程中，设计一套能够提供张力和参数测量系统的生物反应器，在肌腱的培养过程中对肌腱施加不同形式的张应力作用，以期在体外获得力学性能优化的自体肌腱。结果 细胞培养和张应力控制系统是由完全透明的有机材料制成的，整个系统由细胞培养室、测量系统和排换液系统等部分构成，在长期的肌腱细胞培养中，可提供肌腱一材料支架动态的培养方式。细胞培养室能很方便与气动肌腱连接，产生持续的脉冲张力作用。结论 用肌腱生物反应器可以使肌腱组织复合物在形成过程中始终处于力学环境中，促进肌腱组织中胶原纤维的平行排列，提高肌腱的力学性能，为组织工程化肌腱的产业化提供一种新的方法。     

新型编织型生物反应器内大量乳猪肝细胞的组织化培养

目的使反应器内培养的肝细胞能在较长时间保持肝细胞的特殊功能和活力,提高生物反应器的功效并为反应器内储存和运输肝细胞提供可能.方法将新生实验型小猪肝细胞与微载体共同培养,待肝细胞与微载体充分粘附形成微载体-球形聚集体后,将其置入新型编织型生物反应器的外腔,用培养液循环式人工毛细管培养系统进行培养,在培养液内加入氯化氨、醋胺酚检测生物反应器的转化功能,行无血清培养检测肝细胞的白蛋白的合成功能,观察肝细胞的酶漏出量.锥虫蓝染色观察肝细胞的活力,电镜观察其超微结构.结果生物反应器内培养的肝细胞在1周内能保持较高的活力,并保持着较高的氯化氨、醋胺酚的生物转化及白蛋白合成功能,酶的漏出量也少.肝细胞超微结构示内质网、线粒体等细胞器丰富,核内染色体分布均匀,肝细胞间的微绒毛形成胆小管样结构.结论肝细胞与微载体及肝细胞之间的聚集,形成直径大小不等的肝细胞-微载体球形聚集体,这种由肝细胞重新结合而成的聚集体类似于体内的肝组织结构,在新型编织型生物反应器内的中空纤维网架的支持下,肝细胞聚集体均匀地分散其中,为肝细胞的生长提供了一个类似体内内环境的三维空间,因而在无氧合器供氧的情况下,肝细胞也能在1周内保持较好的形态和功能.     

新型高效废水厌氧生物处理反应器研究进展

近年来，废水的厌氧生物处理工艺以其独特的技术优势受到人们的广泛关注，并发展了以厌氧膨胀颗粒污泥床、内循环式厌氧反应器、厌氧上流污泥床-过滤器和厌氧序批式间歇反应器等为代表的第三代新型高效厌氧反应器.本文综述了这些厌氧反应器的形成、结构、工作原理以及典型应用，比较了这些系统的运行特点及存在的问题，最后展望了该研究领域的发展及这些系统的应用前景.     

生物反应器系统在软骨组织工程中的应用

关节软骨的退行性变是当今社会主要的健康问题之一。据文献报道关节软骨的再生能力有限,到现在为止还没有一种十持久而且有效的治疗方法来替代关节软骨。组织工程是一个非常有潜力的领域,虽然要建立一套常规治疗软骨缺损的组织工程理论还有很多障碍,但是为治疗软骨损伤为目的的组织工程已经能够快速可靠的培养出适合的软骨组织。生物反应器和一些相关的设备为组织工程提供了一个快速且有效的方法。事实上,在体内生理刺激影响着软骨的功能,所以我们要设计一些特别的生物反应器来对在体外培养的关节软骨施加模拟应力的传导,像流体剪切力,流体静压力,周期压力,和一些混合力。本篇综述总结了一些软骨细胞反应器系统在细胞刺激和培养中的应用。     

红细胞携氧促进多层平板型生物反应器中肝细胞氧供

目的 生物人工肝作为肝功能衰竭的一种有效支持手段,近年来得到不断的改进,如何解决反应器中的氧供问题成为目前人们研究的焦点.本研究拟通过在循环培养液中加入红细胞为这一问题提供可能的解决方案.方法 将新鲜分离的原代猪肝细胞接种于笔者自主构建的新型生物反应器内.实验分为两组,对照组在反应器内仅加入RPMI1640培养液直接循环;实验组在培养液中同时加入猪红细胞(2.5×1011/L)进行循环,两组循环液均经过膜肺进行氧合.采用血气分析仪检测反应器中氧耗情况,同时检测反应器中葡萄糖消耗及肝细胞的功能表达.结果 实验组反应器中肝细胞氧耗率为对照组的1.5倍,葡萄糖消耗为对照组的2倍.同时,实验组肝细胞的白蛋白分泌及尿素合成各项功能均明显高于对照组.结论 在培养液中加入红细胞能显著改善反应器中肝细胞的氧供,从而提高反应器中细胞的葡萄糖代谢及各种肝特异功能的表达.该方法简便易行,效果明显,有望成为解决反应器中氧供的有效手段.     

混合型生物人工肝治疗急性肝衰犬的研究

我们在成功构建生物反应器 ,完成体外灌流实验基础上[1 ] ,建立混合型生物人工肝支持系统 (ＨＢＬＳ) ,对急性肝衰犬模型进行实验性治疗 ,以测试其效能。一、材料与方法1.实验动物 :杂种犬 7条 ,体重 15～18ｋｇ ,行门腔静脉吻合 ,肝蒂预置套带后关腹 ;48ｈ后再阻断肝蒂 1ｈ做成肝衰模型。 4条用ＨＢＬＳ治疗 ,另 3条空舱转流作为对照。2 .生物反应器的构成 :宁波亚泰Ⅱ级血浆分离器 (分子量截留为 75 0 0 0Ｄａｌｔｏｎｓ ,双醋酸纤维 ) ,纤维外间隙容积为 15 0ｍｌ ,内置 1.2× 10 9的数量级微载体培养Ｌ 0 2人肝细胞[2 ] 。3 .ＨＢＬＳ构…     

层流装置的设计及其流场分析

目的设计一套切应力作用下细胞培养的实验装置。方法采用有限元方法对设计的不同的层流装置进行流场分析,根据层流的理论公式对层流进行判定,最后设计完成合理的层流装置。结果从流场分析的结果可知层流装置中流场是合理和稳定的,通过实验和理论计算说明层流装置证明达到细胞培养的要求。结论由层流装置构建的系统性能稳定可靠,可以用于不同细胞的动态培养。     

Rotating three‐dimensional dynamic culture of adult human bone marrow‐derived cells for tissue engineering of hyaline cartilage

The method of constructing cartilage tissue from bone marrow‐derived cells in vitro is considered a valuable technique for hyaline cartilage regenerative medicine. Using a rotating wall vessel (RWV) bioreactor developed in a NASA space experiment, we attempted to efficiently construct hyaline cartilage tissue from human bone marrow‐derived cells without using a scaffold. Bone marrow aspirates were obtained from the iliac crest of nine patients during orthopedic operation. After their proliferation in monolayer culture, the adherent cells were cultured in the RWV bioreactor with chondrogenic medium for 2 weeks. Cells from the same source were cultured in pellet culture as controls. Histological and immunohistological evaluations (collagen type I and II) and quantification of glycosaminoglycan were performed on formed tissues and compared. The engineered constructs obtained using the RWV bioreactor showed strong features of hyaline cartilage in terms of their morphology as determined by histological and immunohistological evaluations. The glycosaminoglycan contents per µg DNA of the tissues were 10.01 ± 3.49 µg/µg DNA in the case of the RWV bioreactor and 6.27 ± 3.41 µg/µg DNA in the case of the pellet culture, and their difference was significant. The RWV bioreactor could provide an excellent environment for three‐dimensional cartilage tissue architecture that can promote the chondrogenic differentiation of adult human bone marrow‐derived cells. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 517–521, 2009     

Computational Fluid Dynamics‐Based Design Optimization Method for Archimedes Screw Blood Pumps

An optimization method suitable for improving the performance of Archimedes screw axial rotary blood pumps is described in the present article. In order to achieve a more robust design and to save computational resources, this method combines the advantages of the established pump design theory with modern computer‐aided, computational fluid dynamics (CFD)‐based design optimization (CFD‐O) relying on evolutionary algorithms and computational fluid dynamics. The main purposes of this project are to: (i) integrate pump design theory within the already existing CFD‐based optimization; (ii) demonstrate that the resulting procedure is suitable for optimizing an Archimedes screw blood pump in terms of efficiency. Results obtained in this study demonstrate that the developed tool is able to meet both objectives. Finally, the resulting level of hemolysis can be numerically assessed for the optimal design, as hemolysis is an issue of overwhelming importance for blood pumps.     

生物反应器在组织工程中的应用

目的 阐述生物反应器对组织工程学发展的重要性，并进一步探讨生物反应器研究的发展方向。方法 大量查阅国内外相关文献，分析近年来生物反应器在组织工程中应用所取得的最新成果，并在此基础上进行总结。结果 生物反应器极大地推动了组织工程学在理论和实践上的进步。成为组织工程中的四大关键环节之一。结论 生物反应器是组织工程中不可或缺的重要部分，其发展方向应是集成化、自动化和智能化，应用贯穿于整个组织工程过程的始终。     

Cardiovascular tissue engineering I. Perfusion bioreactors: a review

Tissue engineering is a fast-evolving field of biomedical science and technology with future promise to manufacture living tissues and organs for replacement, repair, and regeneration of diseased organs. Owing to the specific role of hemodynamics in the development, maintenance, and functioning of the cardiovascular system, bioreactors are a fundamental of cardiovascular tissue engineering. The development of perfusion bioreactor technology for cardiovascular tissue engineering is a direct sequence of previous historic successes in extracorporeal circulation techniques. Bioreactors provide a fluidic environment for tissue engineered tissue and organs, and guarantee their viability, maturation, biomonitoring, testing, storage, and transportation. There are different types of bioreactors and they vary greatly in their size, complexity, and functional capabilities. Although progress in design and functional properties of perfusion bioreactors for tissue engineered blood vessels, heart valves, and myocardial patches is obvious, there are some challenges and insufficiently addressed issues, and room for bioreactor design improvement and performance optimization. These challenges include creating a triple perfusion bioreactor for vascularized tubular tissue engineered cardiac construct; designing and manufacturing fluidics-based perfused minibioreactors; incorporation of systematic mathematical modeling and computer simulation based on computational fluid dynamics into the bioreactor designing process; and development of automatic systems of hydrodynamic regime control. Designing and engineering of built-in noninvasive biomonitoring systems is another important challenge. The optimal and most efficient perfusion and conditioning regime, which accelerates tissue maturation of tissue-engineered constructs also remains to be determined. This is a first article in a series of reviews on critical elements of cardiovascular tissue engineering technology describing the current status, unsolved problems, and challenges of bioreactor technology in cardiovascular tissue engineering and outlining future trends and developments.     

Human elastic cartilage engineering from cartilage progenitor cells using rotating wall vessel bioreactor

Transplantation of bioengineered elastic cartilage is considered to be a promising approach for patients with craniofacial defects. We have previously shown that human ear perichondrium harbors a population of cartilage progenitor cells (CPCs). The aim of this study was to examine the use of a rotating wall vessel (RWV) bioreactor for CPCs to engineer 3-D elastic cartilage in vitro. Human CPCs isolated from ear perichondrium were expanded and differentiated into chondrocytes under 2-D culture conditions. Fully differentiated CPCs were seeded into recently developed pC-HAp/ChS (porous material consisted of collagen, hydroxyapatite, and chondroitinsulfate) scaffolds and 3-D cultivated utilizing a RWV bioreactor. 3-D engineered constructs appeared shiny with a yellowish, cartilage-like morphology. The shape of the molded scaffold was maintained after RWV cultivation. Hematoxylin and eosin staining showed engraftment of CPCs inside pC-HAp/ChS. Alcian blue and Elastica Van Gieson staining showed of proteoglycan and elastic fibers, which are unique extracellular matrices of elastic cartilage. Thus, human CPCs formed elastic cartilage-like tissue after 3-D cultivation in a RWV bioreactor. These techniques may assist future efforts to reconstruct complicate structures composed of elastic cartilage in vitro.     

Computational flow visualization in vibrating flow pump type artificial heart by unstructured grid

Computational flow visualization in the casing of vibrating flow pump (VFP) was made for various conditions based on the novel techniques of fluid dynamics. VFP type artificial heart can generate the oscillated flow and can be applied to the left ventricular assist device. Flow pattern of blood in an artificial heart is closely connected to mechanical performance and serious biomechanical problems such as hemolysis and blood coagulation. To effectively design the VFP for a left ventricular assist device, the numerical codes for solving Navier-Stokes equations were developed for three-dimensional blood flow based on the finite volume method. Furthermore, the simulation techniques based on the artificial compressibility method and the unstructured grid were also developed here. The numerical calculations were based on the precise configurations and the flow conditions of the prototype device. From the viewpoint of computational fluid dynamics (CFD), the detailed discussion of flow patterns in the casing of VFP, which were closely connected with hemolysis and blood coagulation, was made and the computational results were visualized by the use of the recent technique of computational graphics. Some useful design data of VFP were presented.     

A peek into the possible future of management of articular cartilage injuries: gene therapy and scaffolds for cartilage repair

Two rapidly progressing areas of research will likely contribute to cartilage repair procedures in the foreseeable future: gene therapy and synthetic scaffolds. Gene therapy refers to the transfer of new genetic information to cells that contribute to the cartilage repair process. This approach allows for manipulation of cartilage repair at the cellular and molecular level. Scaffolds are the core technology for the next generation of autologous cartilage implantation procedures in which synthetic matrices are used in conjunction with chondrocytes. This approach can be improved further using bioreactor technologies to enhance the production of extracellular matrix proteins by chondrocytes seeded onto a scaffold. The resulting "neo-cartilage implant" matures within the bioreactor, and can then be used to fill cartilage defects.     

去分化关节软骨细胞生物反应器培养反分化的实验研究

目的 观察体外经传代培养去分化的成人关节软骨细胞，在生物反应器培养后生物学性状的变化，探索去分化软骨细胞反分化的手段，为软骨细胞移植修复关节软骨缺损建立合适的体外培养方法。方法 无菌条件下取成人关节软骨组织，Ⅱ型胶原酶消化法（0．2％，37C，3h）分离软骨细胞，分成两组：一组常规单层传代培养，另一组添加重组人的生长因子（1ng／ml转化生长因子β1＋5ng／ml成纤维细胞生长因子2）体外培养传代大量扩增后，无微载体生物反应器内培养3周。血小板计数器行细胞计数，计算各代细胞倍增时间；细胞爬片和石蜡、冰冻切片进行HE、蕃红O、阿利新蓝染色，Ⅰ、Ⅱ型胶原和aggrecan免疫组织化学检测，观察细胞表型变化。结果 成人关节软骨细胞体外培养3代后迅速去分化，增殖缓慢。添加生长因子培养细胞去分化速度减缓；传10代，细胞扩增2000倍以上，部分去分化，但细胞扩增增殖能力仍很强；传20代软骨细胞表型基本丢失，但仍有增殖能力；置于生物反应器继续培养3周，细胞番红O染色强阳性、aggrecan和Ⅱ型胶原阳性，Ⅰ型胶原阴性，表型恢复良好。结论 软骨细胞在体外大量扩增后，在生物反应器培养，可恢复其表型，可望用于在体外培养时去分化软骨细胞的再分化。