Li Kelvin W, Klein Travis J, Chawla Kanika, Nugent Gayle E, Bae Won C, Sah Robert L
Department of Bioengineering and Whitaker Institute of Biomedical Engineering, University of California-San Diego, San Diego, CA, USA.
Methods Mol Med. 2004;100:325-52. doi: 10.1385/1-59259-810-2:325.
Because of the limited availability of donor cartilage for resurfacing defects in articular surfaces, there is tremendous interest in the in vitro bioengineering of cartilage replacements for clinical applications. However, attaining mechanical properties in engineered cartilaginous constructs that approach those of native cartilage has not been previously achieved when constructs are cultured under free-swelling conditions. One approach toward stimulating the development of constructs that are mechanically more robust is to expose them to physical environments that are similar, in certain ways, to those encountered by native cartilage. This is a strategy motivated by observations in numerous short-term experiments that certain mechanical signals are potent stimulators of cartilage metabolism. On the other hand, excess mechanical loading can have a deleterious effect on cartilage. Culture conditions that include a physical stimulation component are made possible by the use of specialized bioreactors. This chapter addresses some of the issues involved in using bioreactors as integral components of cartilage tissue engineering and in studying the physical regulation of cartilage. We first consider the generation of cartilaginous constructs in vitro. Next we describe the rationale and design of bioreactors that can impart either mechanical deformation or fluid-induced mechanical signals.
由于用于修复关节表面缺损的供体软骨来源有限，人们对用于临床应用的软骨替代物的体外生物工程产生了浓厚兴趣。然而，当构建体在自由膨胀条件下培养时，此前尚未实现使工程化软骨构建体的机械性能达到天然软骨的机械性能。一种促进构建体发展从而使其机械性能更强健的方法是，将它们置于在某些方面与天然软骨所经历的物理环境相似的环境中。这一策略的依据是在众多短期实验中观察到某些机械信号是软骨代谢的有效刺激因素。另一方面，过度的机械负荷会对软骨产生有害影响。使用专门的生物反应器使得包含物理刺激成分的培养条件成为可能。本章探讨了将生物反应器用作软骨组织工程的组成部分以及研究软骨的物理调节时涉及的一些问题。我们首先考虑体外软骨构建体的生成。接下来我们描述能够施加机械变形或流体诱导机械信号的生物反应器的原理和设计。
