Site-specific molecular diffusion in articular cartilage measured using fluorescence recovery after photobleaching
Site-specific molecular diffusion in articular cartilage measured using fluorescence recovery after photobleaching
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DOI：
10.1114/1.1581879
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发表时间：
2003-07-01
影响因子：
3.8
通讯作者：
Guilak, F
中科院分区：
文献类型：
--
作者：
Leddy, HA;Guilak, F
溶质的扩散运输对关节软骨的正常功能至关重要。大分子通过软骨的扩散可能受到局部组成和结构的影响，其随着距离组织表面的深度而变化。我们假设不带电分子的扩散系数也随深度和分子大小而变化。我们使用光漂白后的荧光恢复（FRAP）来测量猪关节软骨中荧光葡聚糖分子（3，40，70和500 kDa）的位点特异性扩散系数。使用FRAP测得的扩散系数表现出相反的尺寸依赖性，并与使用其他技术测得的一般协议。所有分子的扩散系数随深度显著变化的方式，取决于扩散分子的大小。3和500 kDa葡聚糖的扩散系数分别为1.6和2.4倍，在表面区相比，中间和深区，而40和70 kDa葡聚糖的扩散系数分别为0.3和0.2倍，在表面区相比，中间和深区。这些差异可能反映了胶原蛋白、蛋白聚糖和其他大分子在结构和组成上的差异。(C)2003生物医学工程学会。
Diffusive transport of solutes is critical to the normal function of articular cartilage. The diffusion of macromolecules through cartilage may be affected by the local composition and structure, which vary with depth from the tissue surface. We hypothesized that the diffusion coefficient of uncharged molecules also varies with depth and molecular size. We used fluorescence recovery after photobleaching (FRAP) to measure site-specific diffusion coefficients of fluorescent dextran molecules (3, 40, 70, and 500 kDa) in porcine articular cartilage. The diffusion coefficients measured using FRAP exhibited an inverse size dependence and were in general agreement with those measured using other techniques. The diffusion coefficients for all molecules varied significantly with depth in a manner that depended upon the size of the diffusing molecule. The diffusion coefficients for the 3 and 500 kDa dextrans were 1.6 and 2.4 times greater, respectively, in the surface zone as compared to the middle and deep zones, whereas the diffusion coefficients of the 40 and 70 kDa dextrans were 0.3 and 0.2 times lower in the surface zone as compared to the middle and deep zones. These differences may reflect variations in the structure and composition of collagen, proteoglycans, and other macromolecules among the zones. (C) 2003 Biomedical Engineering Society.