Department of Materials Science and Engineering, University of Delaware , Newark, Delaware, USA.
Tissue Eng Part A. 2010 Apr;16(4):1247-61. doi: 10.1089/ten.tea.2009.0344.
Vocal fold diseases and disorders are difficult to treat surgically or therapeutically. Tissue engineering offers an alternative strategy for the restoration of functional vocal folds. As a first step toward vocal fold tissue engineering, we investigated the responses of primary vocal fold fibroblasts (PVFFs) to two types of collagen and hyaluronic acid (HA)-based hydrogels that are compositionally similar, but structurally variable and mechanically different. Type A hydrogels were composed of mature collagen fibers reinforced by oxidized HA, whereas type B hydrogels contained immature collagen fibrils interpenetrated in an amorphous, covalently cross-linked HA matrix. PVFFs encapsulated in either matrix adopted a fibroblastic morphology and expressed genes related to important extracellular matrix proteins. DNA analysis indicated a linear growth profile for cells encapsulated in type B gels from day 0 to 21, in contrast to an initial dormant, nonproliferative period from day 0 to 3 experienced by cells in type A gels. At the end of the culture, similar DNA content was detected in both types of constructs. A reduction in collagen content was observed for both types of constructs after 28 days of culture, with type A constructs generally retaining higher amounts of collagen than type B constructs. The HA content in the constructs decreased steadily throughout the culture, with type A constructs consistently exhibiting less HA than type B constructs. Using the torsional wave analysis, we found that the elastic moduli for type A constructs decreased sharply during the first week of culture, followed by 2 weeks of matrix stabilization without significant changes in matrix stiffness. Conversely, the elastic modulus for type B constructs increased moderately over time. It is postulated that PVFFs residing in gels alter the matrix organization, chemical compositions, and viscoelasticity through cell-mediated remodeling processes.
声带疾病和障碍很难通过手术或治疗来治疗。组织工程为恢复功能性声带提供了一种替代策略。作为声带组织工程的第一步，我们研究了两种类型的胶原蛋白和透明质酸（HA）基水凝胶对原代声带成纤维细胞（PVFF）的反应，这两种水凝胶在组成上相似，但结构不同，力学性能也不同。A型水凝胶由氧化 HA 增强的成熟胶原纤维组成，而 B 型水凝胶则包含相互渗透的不成熟胶原原纤维，位于无定形的、共价交联的 HA 基质中。包埋在任何基质中的 PVFF 都采用成纤维细胞形态，并表达与重要细胞外基质蛋白相关的基因。DNA 分析表明，与包埋在 A 型凝胶中的细胞在第 0 天至第 3 天经历的初始休眠、非增殖期相反，B 型凝胶中的细胞在第 0 天至第 21 天呈线性生长趋势。在培养结束时，两种类型的构建体中都检测到相似的 DNA 含量。培养 28 天后，两种类型的构建体中的胶原蛋白含量均减少，而 A 型构建体通常保留的胶原蛋白比 B 型构建体多。在整个培养过程中，构建体中的 HA 含量持续下降，而 A 型构建体中的 HA 含量始终低于 B 型构建体。通过扭转波分析，我们发现 A 型构建体的弹性模量在培养的第一周急剧下降，随后基质稳定 2 周，基质硬度没有明显变化。相反，B 型构建体的弹性模量随时间适度增加。据推测，PVFF 存在于凝胶中，通过细胞介导的重塑过程改变基质的组织、化学组成和粘弹性。
