MECHANISMS & ENHANCEMENT OF INTEGRATIVE CARTILAGE REPAIR

机制

• 批准号: 6628105
• 负责人: Robert L Sah
• 金额: $ 30.24万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-10 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6628105
• 关键词: SDS polyacrylamide gel electrophoresis; animal tissue; articular cartilage; biomaterial interface interaction; biomechanics; blocking antibody; cell adhesion; cell cell interaction; cell membrane; cell transplantation; chondrocytes; cow; extracellular matrix; flow cytometry; growth media; high performance liquid chromatography; intermolecular interaction; protein biosynthesis; regeneration; tissue /cell culture; tissue /cell preparation; tissue engineering; tissue support frame; western blottings

Tissue engineering therapies for repair or regeneration of articular cartilage typically involve grafting cells alone, cells within engineered scaffolds, or tissues containing cells. A major unresolved problem is the inconsistent integration between the implant and the host articular cartilage. The long- term goal of this project is to develop a quantitative understanding of cellular and molecular processes leading to integrative cartilage repair and to apply this information to improve medical, surgical, and physical therapies for stimulating successful cartilage healing. Our working general hypothesis is: functional integrative repair can result from a local sequence of events at a cartilage surface that includes: (a) cellular biosynthesis of molecular components of collagen fibrils and molecules that regulate fibrillogenesis, (b) coordinated extracellular deposition of these molecules and associated remodeling of the fibrillar collagen meshwork. A corollary of this hypothesis is: transplanted chondrocytes can mediate and accelerate this process if these cells remain adherent at the defect site and contribute appropriate molecular products. Our recent studies (i) implicated collagen biosynthesis by endogenous chondrocytes, and subsequent deposition and crosslinking of collagen, as critical factors for the modest biomechanical integration that occurs between apposing surfaces of bovine cartilage in vitro, (2) developed a method to transplant chondrocytes quantitatively onto a cartilage surface and thereby provide metabolically active cells at a cartilage-cartilage interface, and (3) developed a system to characterize adhesiveness of chondrocytes to articular cartilage (e.g., the surrounding host tissue). We now propose to test two specific hypotheses. (i) The ability of transplanted chondrocytes to adhere to articular cartilage depends on the extent of interactions between the cartilage matrix substrate and the surface receptors or pre-formed pericellular matrix of the transplanted cells. (2) The ability of endogenous and transplanted chondrocytes to promote integrative repair of articular cartilage in vitro depends on their ability to locally deposit molecules that contribute to remodeling of the collagen meshwork. The approaches proposed include (a) relating biomechanical function to the metabolism of specific molecules, (b) making quantitative measurements to characterize collagen synthesis, diffusion, and crosslinking, and (c) investigating manipulations that are of potential clinical utility and provide insight into underlying molecular mechanisms.

修复或再生关节软骨的组织工程疗法通常涉及单独嫁接细胞，工程支架内的细胞或包含细胞的组织。一个尚未解决的主要问题是植入物与宿主关节软骨之间的不一致整合。该项目的长期目标是对细胞和分子过程进行定量理解，从而实现整合软骨修复，并将这些信息应用于改善医疗，外科和物理疗法，以刺激成功的软骨愈合。我们工作的一般假设是：功能整合修复可能是由软骨表面的局部事件序列引起的，该事件包括：（a）胶原原纤维和分子的分子成分的细胞生物合成，这些分子成分和分子调节纤维化的发生，（b）这些分子的纤维固定和相关的纤维膜的固定外层外膜的外层外层。该假设的推论是：如果这些细胞在缺陷部位保持粘附并贡献适当的分子产物，则移植软骨细胞可以介导和加速该过程。我们最近的研究（i）将内源软骨细胞的胶原蛋白生物合成以及随后的沉积和交联胶原蛋白作为适度生物力学整合的关键因素，这些因素发生在牛皮体系中，在牛内植物的综合体中，（2）开发了一种动作量化的方法，以将其量化为量化的量化量和量化的方法。软骨 - 卡托尔界面和（3）开发了一个系统，以表征软骨细胞对关节软骨的粘附性（例如，周围的宿主组织）。我们现在建议检验两个特定的假设。 （i）移植的软骨细胞粘附在关节软骨上的能力取决于软骨基质底物与表面受体或移植细胞的预先形成的细胞周围基质之间的相互作用程度。 （2）内源性和移植的软骨细胞在体外促进关节软骨综合修复的能力取决于它们在局部沉积分子的能力，从而有助于胶原蛋白网状的重塑。提出的方法包括（a）将生物力学功能与特定分子的代谢相关，（b）进行定量测量以表征胶原蛋白合成，扩散和交叉链接，以及（c）研究具有潜在临床效用的操纵，并将洞察力洞悉基础分子机制。