多孔陶瓷板固定床生物反应器设计及模拟

设计了一种结构新型的多孔陶瓷固定床生物反应器，与传统的固定床相比，该反应器具有氧传递性能好，能够均匀接种等优点，通过模拟，考察了反应器内的流体流动和气液传递性质，计算证明反应器的供氧能力能够满足链霉菌发酵过程对氧的需求。     

人脂肪干细胞结合微载体在生物反应器中向软骨细胞分化

[目的]探索在旋转生物反应器内,应用微载体技术快速扩增并向软骨分化人脂肪干细胞。[方法]将人脂肪干细胞结合Cytodex3微载体在旋转的生物反应器(RCSS)内进行动态培养,应用倒置显微镜和扫描电镜对微载体表面的脂肪干细胞进行动态观察,并对收获的脂肪干细胞进行Safran in-O、tolu id ine b lue染色等组织化学染色及Ⅱ型胶原的免疫化学染色分析。[结果]脂肪干细胞于24 h内贴附于Cytodex3微载体表面,细胞形态为短梭形,随时间的延长,贴附于微载体的细胞逐渐增多,到培养后期,细胞密度可达最初接种的19倍左右,在微载体上收获的细胞进行番红花O、阿利新蓝染色呈阳性,Ⅱ型胶原染色阳性,均强于对照组。[结论]利用微载体细胞培养技术可简便快速地在体外扩增脂肪干细胞,并成功实现向软骨细胞分化。     

Production and release of infectious hepatitis C virus from human liver cell cultures in the three-dimensional radial-flow bioreactor

Lack of efficient culture systems for hepatitis C virus (HCV) has been a major obstacle in HCV research. Human liver cells grown in a three-dimensional radial-flow bioreactor were successfully infected following inoculation with plasma from an HCV carrier. Subsequent detection of increased HCV RNA suggested viral replication. Furthermore, transfection of HCV RNA transcribed from full-length cDNA also resulted in the production and release of HCV virions into supernatant. Infectivity was shown by successful secondary passage to a new culture. Introduction of mutations in RNA helicase and polymerase regions of HCV cDNA abolished virus replication, indicating that reverse genetics of this system is possible. The ability to replicate and detect the extracellular release of HCV might provide clues with regard to the persistent nature of HCV infection. It will also accelerate research into the pathogenicity of HCV, as well as the development of prophylactic agents and new therapy.     

静态与动态下脱细胞猪主动脉瓣种植人成纤维细胞初步研究

目的 探索在脱细胞猪主动脉瓣膜材料上种植人成纤维细胞的方法与效果；材料和方法 采用在脱细胞猪主动脉瓣膜材料上静态与动态种植人成纤维细胞，并对其结果进行比较研究。结果 静态种植不能在猪主动脉瓣叶的两侧形成完整的单层人成纤维细胞融合层；而经过动态种植，在一定条件下可以在猪主动脉瓣叶两侧形成完整的单层人成纤维细胞融合层；结论 动态种植较之静态种植易达到形成完整均匀的细胞种植效果。     

软骨组织工程中力学因素的影响及应用

力学因素是软骨组织工程中的重要影响因素之一。近年来的研究表明，力学作用可以刺激细胞因子及激素的分泌，改变三维支架上培养的软骨细胞的新陈代谢，从而促进软骨组织的生长与重建。目前已经有诸多关于体外构建软骨组织的报道，但对于其中的力学因素的影响（包括力学因素对软骨细胞增殖的促进及力学刺激的传导机制等）还没有完全认识。就以上几方面做一综述，并简单介绍生物反应器在软骨组织工程中的应用。     

Development of a novel pulsatile bioreactor for tissue culture

The construction of tissue-engineered parts such as heart valves and arteries requires more than just the seeding of cells onto a biocompatible/biodegradable polymeric scaffold. It is essential that the functionality and mechanical integrity of the cell-seeded scaffold be investigated in vitro prior to in vivo implantation. The correct hemodynamic conditioning would lead to the development of tissues with enhanced mechanical strength and cell viability. Therefore, a bioreactor that can simulate physiological conditions would play an important role in the preparation of tissue-engineered constructs. In this article, we present and discuss the design concepts and criteria, as well as the development, of a multifunctional bioreactor for tissue culture in vitro. The system developed is compact and easily housed in an incubator to maintain sterility of the construct. Moreover, the proposed bioreactor, in addition to mimicking in vivo conditions, is highly flexible, allowing different types of constructs to be exposed to various physiological flow conditions. Initial verification of the hemodynamic parameters using Laser doppler anemometry indicated that the bioreactor performed well and produced the correct physiological conditions.     

贯叶连翘不定根反应器培养的初步研究

目的:对贯叶连翘不定根进行反应器培养,寻找适合不定根生长的适宜条件,为大量生产贯叶连翘不定根提供理论依据.方法:利用5L气升式生物反应器研究了IBA浓度、糖种类和浓度、不定根的接种量和通气量等影响因子对贯叶连翘不定根培养的影响.结果:在MS培养基中培养贯叶连翘不定根,随着IBA浓度的增加,贯叶连翘不定根增殖系数呈增长趋势,当IBA质量浓度在1.25～1.75 mg·L-1时不定根生长良好;在糖种类和浓度试验中,发现以蔗糖为碳源培养的不定根生长最好,增殖系数达最大值22.15,当蔗糖质量浓度为30g·L-1时鲜物重、干物重和增殖系数均达最大值;在接种量试验中,结果表明当反应器的接种量为20 g时有利于不定根的生长;在通气量试验中,当反应器的通气量为0.075(空气体积/培养体/min)时,不定根的生长最旺盛,不定根的增殖系数显著增加;在不同大小反应器中培养不定根,发现不定根在5L反应器中的培养条件完全适用于10,20 L的反应器.结论:IBA浓度、糖种类和浓度、不定根的接种量和通气量对贯叶连翘不定根的生物反应器培养有显著影响.     

药用植物发酵培养的工业化探讨

药用植物发酵培养的工业化 ,对我国有着特殊的意义。因为我国是世界上使用和出口药用植物最多的国家。国际上红豆杉、长春花、人参等“热门”药用植物的培养方兴未艾 ,药用植物的器官培养异军突起 ,药用植物发酵培养的研究逐渐深化。我国药用植物的培养在细胞、器官和毛状根等各方面均有所涉足 ,对长春花、三七、三分三、紫草、红豆杉等进行了大规模培养的探索。但总的看来 ,反应器的规模还很小 ,放大后培养的技术尚不成熟。我们应从发展的角度认识到药用植物发酵培养的巨大应用潜力 ;从中药现代化的高度开发药用植物发酵技术 ;特别要加强不同领域科研人员之间的合作 ,在世界上敢为人先 ,搞出我们拥有自主知识产权的技术来。     

Strategies for long-term gene expression in the skin to treat metabolic disorders

Due to its accessibility, size and contact with the blood circulation, the skin is an attractive target for somatic gene therapy. Permanent cutaneous expression can be achieved by genetic manipulation of epidermal keratinocytes ex vivo followed by transplantation or by local injection of viral vectors. Furthermore, progress is being made to develop topical gene transfer methods leading to permanent gene expression. There is experimental evidence showing that genetically engineered skin can produce and secrete medically relevant proteins to the circulation and also produce enzymes that can clear metabolites accumulating in various diseases. Thus, cutaneous gene transfer approaches may be relevant not only for local skin diseases, but also for certain systemic disorders.     

Deformation strain is the main physical driver for skeletal precursors to undergo osteogenesis in earlier stages of osteogenic cell maturation

Mesenchymal stem cells play a major role during bone remodelling and are thus of high interest for tissue engineering and regenerative medicine applications. Mechanical stimuli, that is, deformation strain and interstitial fluid‐flow‐induced shear stress, promote osteogenic lineage commitment. However, the predominant physical stimulus that drives early osteogenic cell maturation is not clearly identified. The evaluation of each stimulus is challenging, as deformation and fluid‐flow‐induced shear stress interdepend. In this study, we developed a bioreactor that was used to culture mesenchymal stem cells harbouring a strain‐responsive AP‐1 luciferase reporter construct, on porous scaffolds. In addition to the reporter, mineralization and vitality of the cells was investigated by alizarin red staining and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide. Quantification of the expression of genes associated to bone regeneration and bone remodelling was used to confirm alizarin red measurements. Controlled perfusion and deformation of the 3‐dimensional scaffold facilitated the alteration of the expression of osteogenic markers, luciferase activity, and calcification. To isolate the specific impact of scaffold deformation, a computational model was developed to derive a perfusion flow profile that results in dynamic shear stress conditions present in periodically loaded scaffolds. In comparison to actually deformed scaffolds, a lower expression of all measured readout parameters indicated that deformation strain is the predominant stimulus for skeletal precursors to undergo osteogenesis in earlier stages of osteogenic cell maturation.