摘要
目的为软骨组织工程学中力学因素的引入提供相应的技术参数。方法新西兰兔8只,左膝关节采用 HE 染色方法进行组织学观察,右膝关节采用0.4%链霉蛋白酶和0.025%Ⅱ型胶原酶消化分离关节软骨细胞,台盼蓝排除法检测细胞存活率,分别测量组织切片上及完全消化后软骨细胞的直径。采用微管吸吮技术结合半无限体模型分析软骨细胞的力学特性(杨氏模量、粘弹性)。结果 HE 染色示正常软骨分4层:浅表层、过渡层、辐射层、钙化层。完全消化后细胞存活率平均为98.2%。切片上与消化后软骨细胞的平均直径分别为(14.2±2.9)、(14.9±2.2)μm,二者差异无统计学意义(t=1.31,P=0.19)。正常软骨细胞在一定负压下首先发生瞬时弹性响应,随后是变形率单调减少的蠕变过程,最终达到稳定态,软骨细胞被吸入长度通常达到微管半径的3倍,而细胞不能被完全吸人微管,卸载后软骨细胞完全恢复变形。正常软骨细胞的杨氏模量为(0.57±0.43)kPa,其黏弹性参数 k_1、k_2、和μ分别为(0.37±0.07)、(0.29±0.04)、(6.36±1.12)kPa-s。直线相关性分析表明仅 k_1与软骨细胞直径有微弱相关性但有统计学意义(r=0.4,P=0.031)。结论正常软骨细胞表现为典型的黏弹性固体蠕变特征;微管吸吮技术可以作为测量关节软骨细胞力学特性的可靠方法。
Objective To measure the mechanical properties of chondrocytes of articular cartilage of knee in order to provide relevant technical parameters into the development of cartilage tissue engineering. Methods Eight NZW rabbits were killed, and their bilateral knee joints were taken out. The articular cartilage of the left knees were used for histological study, and articular cartilage of the right knees was digested with 0. 4% pronase and 0.025% collagenase type Ⅱ so as to make isolation of chondroeytes. The viability rate of the isolated chondrocytes was detected by trypan blue staining. The diameters of the chondrocytes in the histological sections and single cell suspension were measured respectively. The mechanical properties of the chondrocytes were determined using micropipette aspiration technique coupled with half-space model. Results In the normal articular cartilage 4 structural zones were differentiated： tangential, transitional, radial, and calcified zones. The viability rate of chondrocytes was 98. 2% on average after isolation. The mean diameter of the chondrocytes in the histological sections was （ 14.2 ± 2.9 ） p,m, not significantly different from that in the single cell suspension [ （ 14.9 ± 2.2） μm, t = 1.31, P = 0. 19]. In response to a prescribed pressure, the chondrocytes exhibited viscoelastic solid creep behavior characterized initially by a jump in displacement followed by a monotonically decreasing rate of deformation that generally reached an equilibrium displacement. The cells were observed to deform to a length of as much as three times the radius of the micropipette without completely entering the micropipette. The cells were then extruded from the micropipette and completely recovered. The Young＇s modulus of the normal chondrocytes was（0.57±0.43） kPa, and the k1, k2, and μ of the viscoelastic parameters were（0. 37 ± 0. 07） kPa, （0.29 ± 0. 04） kPa, and （6.36 ± 1.12 ） kPa-s respectively. The k1 is positively correlated to the cell diameter （ r = 0.4, P = 0. 031 ）. Conclusion Chondrocytes from normal articular cartilage behave as a viscoelastic solid. Micropipette aspiration technique is an efficient method for the study of chondrocyte biomechanics.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2007年第13期916-920,共5页
National Medical Journal of China
基金
国家自然科学基金重点资助项目(10332060)
山西省归国留学人员重点科研基金
关键词
软骨
关节
软骨细胞
Cartilage, articular
Chondrocytes
