Tensile properties of engineered cartilage formed from chondrocyte- and MSC-laden hydrogels
Tensile properties of engineered cartilage formed from chondrocyte- and MSC-laden hydrogels
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DOI：
10.1016/j.joca.2008.02.005
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发表时间：
2008-09-01
影响因子：
7
通讯作者：
Mauck, R. L.
中科院分区：
文献类型：
--
作者：
Huang, A. H.;Yeger-McKeever, M.;Mauck, R. L.
目的：本研究的目的是确定装载软骨细胞和间充质干细胞（MSC）的水凝胶构建物在添加转化生长因子- β 3 （tgf - β 3）的化学定义培养基中培养时获得天然组织拉伸性能的能力。设计：细胞负载琼脂糖水凝胶结构（用牛软骨细胞或MSCs种子）形成柱状条，在化学定义的无血清培养基中培养，存在或不存在tgf - β 3。在56天的时间内评估播种密度（10 vs 30万个细胞/mL）和细胞类型（软骨细胞vs间充质干细胞）的影响。每两周评估生化含量、胶原基质沉积和定位以及拉伸性能（斜坡模量、极限应变和韧性）。结果：细胞种子琼脂糖构建物的拉伸性能随培养时间的延长而增加。然而，第56天获得的拉伸性能（模量、极限应变和韧性）与初始播种密度或所采用的细胞类型无关。当在添加tgf - β 3的培养基中培养时，每种细胞类型和起始细胞浓度的拉伸模量均在300- 400kpa水平上增加并趋于稳定。极限应变和韧性也相对于初始值有所增加。在两种细胞类型和两种播种密度的构建体中，胶原沉积增加，暴露于tgf - β 3导致明显向II型胶原沉积转变，这是由免疫组织化学染色确定的。结论：这些研究结果表明，在工程水凝胶基软骨结构中，拉伸性能（一个重要但经常被忽视的软骨发育指标）随着培养时间的增加而增加。在本研究中采用的自由膨胀条件下，拉伸模量和韧性与天然组织不匹配，尽管在tgf - β 3的加入下观察到明显的时间依赖性增加。值得注意的是，msc种子构建物获得了与软骨细胞种子构建物相当的拉伸性能，证实了这种替代细胞来源在软骨组织工程中的实用性。进一步的工作，包括化学和机械培养环境的调节，需要优化胶原蛋白的沉积及其重塑，以实现与天然组织相匹配的工程结构的拉伸性能。(C) 2008国际骨关节炎研究学会。Elsevier Ltd.出版。版权所有。
Objective: The objective of this study was to determine the capacity of chondrocyte- and mesenchymal stem cell (MSC)-laden hydrogel constructs to achieve native tissue tensile properties when cultured in a chemically defined medium supplemented with transforming growth factor-beta3 (TGF-beta 3).Design: Cell-laden agarose hydrogel constructs (seeded with bovine chondrocytes or MSCs) were formed as prismatic strips and cultured in a chemically defined serum-free medium in the presence or absence of TGF-beta 3. The effects of seeding density (10 vs 30 million cells/mL) and cell type (chondrocyte vs MSC) were evaluated over a 56-day period. Biochemical content, collagenous matrix deposition and localization, and tensile properties (ramp modulus, ultimate strain, and toughness) were assessed biweekly.Results: Results show that the tensile properties of cell-seeded agarose constructs increase with time in culture. However, tensile properties (modulus, ultimate strain, and toughness) achieved on day 56 were not dependent on either the initial seeding density or the cell type employed. When cultured in medium supplemented with TGF-beta 3, tensile modulus increased and plateaued at a level of 300-400 kPa for each cell type and starting cell concentration. Ultimate strain and toughness also increased relative to starting values. Collagen deposition increased in constructs seeded with both cell types and at both seeding densities, with exposure to TGF-beta 3 resulting in a clear shift toward type II collagen deposition as determined by immunohistochemical staining.Conclusions: These findings demonstrate that the tensile properties, an important and often overlooked metric of cartilage development, increase with time in culture in engineered hydrogel-based cartilage constructs. Under the free-swelling conditions employed in the present study, tensile moduli and toughness did not match that of the native tissue, though significant time-dependent increases were observed with the inclusion of TGF-beta 3. Of note, MSC-seeded constructs achieved tensile properties that were comparable to chondrocyte-seeded constructs, confirming the utility of this alternative cell source in cartilage tissue engineering. Further work, including both modulation of the chemical and mechanical culture environment, is required to optimize the deposition of collagen and its remodeling to achieve tensile properties in engineered constructs matching the native tissue. (C) 2008 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.