组织工程是生物医学工程领域中一个快速发展的分支，它融合了细胞生物学和工程学的原理，目的在开发具生物活性的组织替代物，期能修复受损组织或是再生。由于组织工程对象是人体组织，细胞和组织块之体外培养条件必须仿生地接近人体内环境，因此生物反应器即为良好的应用工具，除在种子细胞增殖、组织块建构培养扮演重要角色外，生物反应器尚能控制pH、溶氧、机械应力、营养供给及代谢物移除等条件，为细胞的生长、分化和发育分化提供最适宜的环境。

软骨组织工程是将软骨种子种植于可生物降解、组织相容性好的生物材料形成复合物，然后再把该复合物植入软骨缺损处，生物材料自行降解的过程中，种植的细胞形成新的软骨来填充缺损^[1]。

组织工程软骨的构建需要具备三个主要条件

（1）足够数量、功能正常的种子细胞;

（2）合适的细胞支架;

（3）调节细胞增殖、保持细胞表型特征的细胞因子。

软骨组织工程研究展望

（1）种子细胞研究

（2）支架材料研究

（3）组织工程软骨体外构建的研究

（4）动物移植实验研究

（5）临床实验研究

（6）器官组织工程

利用生物反应器培养组织块

人体细胞仿生性地生长在三维支架（载体）中，除了比二维培养大幅增加细胞贴附的表面积外，也增加了生长因子供给效率和细胞外基质（ECM, extra cellular matrix）的合成量，有利于细胞朝多方向迁移、分化和大量增殖（5,6）。

另外，三维多孔结构也有利于氧气和营养物质的传输、代谢产物的排出，以及保持载体内部细胞旺盛的代谢活性（7）。单层细胞平盘培养之营养来源一般不受限制，这是因为依赖营养液的扩散，足以通过单层细胞10μm左右的厚度，但是当组织块的厚度超过100~200μm时，氧气和营养的扩散就会受到明显限制。实际上患者的组织或器官缺损的体积，往往远超过这个门坎，平盘培养既然无法有效率提供足量的种子细胞，便突显出生物反应器的重要性。它提供的动态培养环境使其内部培养液流动，并使支架内的氧及营养质传更充分，更利于代谢废物排出，并能使细胞分布更均匀，细胞基质分泌更多，细胞表型表达更充分（8,9）。

Freed等（10）利用生物反应器，在直径6.7mm、厚5mm的支架材料上培养出软骨组织块，II型胶原蛋白的含量占总胶原蛋白量的9%以上。

施加机械力刺激软骨生物反应器（bioreactors with mechanical force）

体内三维组织结构中的细胞在生长时受多种力学刺激，其中应力的作用对组织的结构、形态和功能产生明显的影响。关节软骨在体内正常生理状态下承受着间歇性自重直接压力，EBERS公司设计的TC-3软骨骨生物反应器，采用直接的压缩间歇性应力刺激软骨骨，在体外组织工程构建软骨，在压缩间歇性应力刺激条件下，成骨细胞的胶原蛋白用荧光染色后与常规静态的成骨细胞的胶原蛋白相比，胶原蛋白在培养后的7天内，明显提高。对于软骨的在人体关键部位起到缓冲作用，明显得到提高。同时TC-3软骨生物反应器还可以在平躺状态下实现对于细胞牵拉应变刺激，其诱导细胞排列沿张应力方向；较大的应力（12~24%），则诱导细胞排列延垂直于张应力方向。施加机械力的反应器，可设计周期性地对组织块施加应力，施力的大小可以控制，如为肌腱或韧带组织设计，可提供张力条件的反应器。

Mechancial Stimulation for cell culture made easy The TC-3 is a simple ａnd multipurpose cell culture bioreactor designed to provide mechanical stimulation to a variety of samples ａnd tissues. It permits to work with: Horizontally ａnd vertically arranged multiple samples Immersed ａnd air-liquid interface setups Sheet-shaped, rod-shaped ａnd cynlinder-shaped substrates Tension ａnd compression axial loading

Mechancial Stimulation for cell culture made easy

The TC-3 is a simple ａnd multipurpose cell culture bioreactor designed to provide mechanical stimulation to a variety of samples ａnd tissues. It permits to work with:

·Horizontally ａnd vertically arranged multiple samples

·Immersed ａnd air-liquid interface setups

·Sheet-shaped, rod-shaped ａnd cynlinder-shaped substrates

·Tension ａnd compression axial loading

Intelligent design

The TC-3 bioreactor allows subjecting culture substrates to tension ａnd compression mechanical stimuli. It has been designed taking into account the needs of cell culture researchers, so only the features of tension machines which are basical for the culture of cells have be included in the TC-3.

Among them, the possibility of inspecting the culture by microscopy techniques is of vital importance for the evaluation of culture status. A simple connection system between the culture chambers ａnd the rest of the system has been designed. Thereby, the chamber CAN be easily removed from the system maintaining a desired deformation state while it is taken to the microscope for visual inspection of the culture.

The TC-3 is compatible with most of the incubators, it is lightweight ａnd all the parts in contact with the culture mediumcan sterilized by autoclaving.

Main Features

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Versatile chambers allow culture inspection by microscopy techniques

Culture chambers are made of autoclavable materials ａnd can be easily assembled ａnd disassebled. Furthermore, visual inspection of the chambers by microscopy techniques is allowed by a optical grade window glass at the bottom of the chamber.

Three grips models adapting to your sample type

Three different models of interchangeable grips can be used with the TC-3 chambers. They have been designed to adapt to the most different types of samples ａnd loading conditions, so the optimal grip conditions are obtained for plane sheet-shaped, rod-shaped or cylinder-shaped substrates.

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Multiple parallel experiments

Up to three chambers can be actuated simultaneously in the TC-3 bioreactor. The loading conditions will be shared by all the chambers, whereas different culture conditions regarding the culture media may be established for each chamber.

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Horizontal ａnd vertical configurations

The TC-3 can be configured both in horizontal ａnd vertical configurations depending of the type of experiment you want to carry out. Air-liquid interfaces can be obtained with the horizontal configuration for cultures on sheet-like substrates, whereas the vertical configuration is more suitable for tests in which the sample is subjected to compression like, e.g., cultures on cylinder-shaped scaffolds.

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Control Software

The TC-3 is computer operated by a simple control software that allows the user to create complex loading profiles to be applied on the culture samples. All the accessory configuration parameters have been removed from the interface, leaving only those which are of interest to be manipulated by the user.

A graphical interface allows the user to easyly control ａnd check the status of the system without the need of learning complex control softwares with a multitude of configuration parameters.