Tomkoria S, Masuda K, Mao J
Boston Scientific, Cardiac Surgery Division, Santa Clara, California, USA.
Proc Inst Mech Eng H. 2007 Jul;221(5):467-73. doi: 10.1243/09544119JEIM205.
Tissue-engineered cartilage constructs designed for in-vivo applications intuitively should mimic the mechanical properties of native cartilage. The objective of the present work was to characterize the nanomechanical properties of alginate-recovered chondrocyte matrices as a function of ex-vivo incubation time. Chondrocytes isolated from the articular cartilage of the mature bovine metacarpophalangeal joints were cultured with alginate hydrogel to allow for the formation of extracellular matrices. The recovered chondral constructs after 2, 4, 8, and 12 weeks of ex-vivo incubation were analysed using nanoindentation with atomic force microscopy to determine their mechanical properties. Chondral constructs had average Young's moduli of 123 +/- 22 kPa, 174 +/- 31 kPa, 373 +/- 40 kPa, and 564 +/- 79 kPa after incubation for 2, 4, 8, and 12 weeks respectively, indicating the gradual attainment of mechanical stiffness. This escalating trend of micromechanical properties as a function of increasing ex-vivo incubation time suggests that chondral constructs via a tissue-engineering approach are capable of elaborating extracellular matrices and increase mechanical stiffness. The relationship between Young's modulus and incubation time of the chondral constructs is useful in the design and fabrication of tissue-engineered cartilage constructs.
为体内应用设计的组织工程软骨构建体直观上应模仿天然软骨的力学性能。本研究的目的是表征藻酸盐回收的软骨细胞基质的纳米力学性能与体外培养时间的关系。从成熟牛掌指关节的关节软骨中分离出的软骨细胞与藻酸盐水凝胶一起培养，以形成细胞外基质。使用原子力显微镜进行纳米压痕分析，以确定体外培养2、4、8和12周后回收的软骨构建体的力学性能。软骨构建体在分别培养2、4、8和12周后的平均杨氏模量分别为123±22 kPa、174±31 kPa、373±40 kPa和564±79 kPa，表明其机械刚度逐渐增加。这种微观力学性能随体外培养时间增加而上升的趋势表明，通过组织工程方法构建的软骨构建体能够形成细胞外基质并增加机械刚度。软骨构建体的杨氏模量与培养时间之间的关系在组织工程软骨构建体的设计和制造中具有重要意义。
