Tissue Engineering of Cartilage Subtypes

描述(由申请人提供)： 人们普遍认为，细胞通过改变其基因表达来对可溶性因子和生物机械力作出反应。来自不同解剖位置的软骨细胞都表达一组共同的基质分子，但这些基质分子要么在不同的解剖位置表达，要么在软骨中以不同的方式组装。据推测，生物机械力和局部可溶因素共同作用于细胞外基质的差异性组装。进一步假设，通过将软骨细胞从一个解剖位置移动到另一个解剖位置，软骨细胞将采用植入位置的基质结构。建议研究的目的是使用从耳软骨、鼻软骨、关节软骨和气管软骨中分离出来的软骨细胞来验证这一假设，这些软骨细胞已经在培养中扩增，并与有利于软骨产生的基质结合。这些不同解剖起源的结构将被切换到不同的解剖位置，同时对照结构将被植入回它们的起源位置。随着时间的推移，样本将被采集，并将接受生物力学、生化和免疫组织化学分析，以确定植入的软骨细胞是否已调整其细胞外基质以匹配植入位置。在进行植入实验之前，将编制关于天然软骨的生化、生物力学和免疫组织化学特征的基线数据。最后，软骨细胞将在兔喉管重建的临床前模型中进行测试。这项研究既解决了复杂的基质组装如何受到调控的基本问题，又测试了容易获得的耳廓软骨细胞在喉气管重建的临床前模型中的实际应用，该模型将测试移植的工程化软骨是否具有足够的生物力学强度和长期稳定性，以开发用于人类的软骨。

DESCRIPTION (provided by applicant): It is well accepted that cells respond both to soluble factors and to biomechanical forces by altering their gene expression. Chondrocytes from different anatomic locations all express a set of common matrix molecules, but those matrix molecules are either expressed at different levels or are assembled differently in cartilage at different anatomic locations. It is postulated that biomechanical forces in combination with local soluble factors are responsible for the differential assembly of the extracellular matrix. It is further hypothesized that by moving chondrocytes from one anatomic location to another, the chondrocytes will adopt the matrix structure of the implantation site. The objective of the proposed studies is to test this hypothesis using chondrocytes isolated from auricular, nasal, articular, and tracheal cartilage that have been expanded in culture and combined with a matrix that is conducive to cartilage production. These constructs of different anatomic origin will be switched into different anatomic sites, along with control constructs implanted back to their site of origin. Over time, the samples will be harvested and will undergo biomechanical, biochemical and immunohistochemical analyses to determine if the implanted chondrocytes have modulated their extracellular matrix to match the implant site. Prior to conducting the implant experiments, baseline data on the biochemical, biomechanical and immunohistochemical characteristics of native cartilage will be complied. Finally, chondrocytes will be tested in a pre-clinical model of laryngeal tracheal reconstruction in rabbits. This study addresses both the fundamental question of how complex matrix assembly is regulated and tests the practical use of easily-obtained auricular chondrocytes in a preclinical model for laryngeal-tracheal reconstruction that will test whether transplanted engineered cartilage has sufficient biomechanical strength and long-term stability to be developed for use in humans.