REGULATED OSTEOINDUCTIVE PLASMID GENE TRANSFER VIA GENE

通过基因调控骨诱导质粒基因转移

• 批准号: 6379884
• 负责人: KEVIN G RICE
• 金额: $ 8.5万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6379884
• 关键词: biomaterial development /preparation; bone transplantation; fibroblasts; gene therapy; implant; laboratory rat; medical implant science; oral facial restoration material; osteogenesis; tissue /cell culture; tissue engineering; tissue support frame

The need for a safe and effective bone substitute still exists in dentistry and orthopedics: bone graft materials are difficult to work with and allografts may be unsafe; the rate of new bone growth associated with bone grafts is unacceptably slow; the long-term stability of bone graft substitutes is doubtful and osteoconduction is unacceptably slow; and the promise of a graft material (or graft substitute) augmented with a biological substance (e.g., osteogenic cytokine) has yet to be realized. A delivery system (GAM) has been developed in which osteoinductive plasmid genes are delivered from a moldable, biodegradable structural matrix. Successful feasibility studies have been conducted in rat and canine models, and this work has shown for the first time that new bone will form rapidly in vivo following direct osteoinductive plasmid gene transfer to fibroblasts involved in skeletal repair. The feasibility studies support an overall hypothesis that rapid new bone formation can be induced via GAM osteoinductive plasmid gene transfer. However, a consistent finding has been that the center of a large osseous defect is the last and most difficult region to regenerate. Because full-thickness regeneration is crucial to clinical success, this grant application proposes a series of interdisciplinary experiments that are designed to understand the mechanism of GAM gene transfer. In essence, we believe that full- thickness regeneration of large osteotomy defects will only be realized through an increased understanding of the basic mechanisms associated with plasmid gene transfer. The specific hypothesis to be explored in this application is that GAM constructs can be pre-designed so as to increase the percentage of genetically modified fibroblasts and, therefore, the rate and amount of new bone that forms in vivo. In this regard, a series of rational modifications to the GAM plasmid DNA and the GAM structural matrix are proposed (Specific Aims 1-2). By studying these modifications, important new insights into the mechanism of GAM gene transfer will be gained. How these modifications affect the behavior of osteogenic cells following gene transfer will be measured in a cell culture model system in vitro (Specific Aim 3). From these measures we should gain new insight into the biological process of new bone formation. While likely beyond the scope of the present application, a long term goal will be to measure the efficacy of rationally pre-designed GAM constructs in vivo using established bone defect animal models.

对安全有效的骨替代品的需求仍然存在于 牙科和整形外科：骨移植材料很难使用 同种异体骨移植可能不安全；新骨生长的速度 与骨移植相关的速度慢得令人无法接受；长期 骨移植替代物的稳定性令人怀疑，骨传导也受到影响 慢得令人无法接受；以及嫁接材料(或嫁接)的前景 替代)用生物物质(例如，成骨物质)增强的 细胞因子)尚未被认识到。一个交付系统(GAM)已经被 骨诱导质粒基因是从一种 可注塑、可生物降解的结构基质。成功的可行性 已经在大鼠和狗的模型上进行了研究，这项工作已经 首次表明新骨在体内会迅速形成 直接将骨诱导基因转移至成纤维细胞后 参与骨骼修复的。 可行性研究支持了一个总体假设，即快速新的 GAM成骨诱导基因可诱导成骨 调职。然而，一个一致的发现是，一个 巨大的骨缺损是最后一个也是最难修复的区域。 重生。因为全层再生对临床来说至关重要 成功，这项拨款申请提出了一系列跨学科的 旨在了解GAM基因机制的实验 调职。从本质上讲，我们认为全厚度再生 大的截骨术缺陷只有通过增加 了解与质粒基因相关的基本机制 调职。 在此应用程序中要探索的特定假设是GAM 可以预先设计构造，以增加 因此，转基因成纤维细胞的比率和数量 在体内形成的新骨。对此，一系列理性的 对GAM质粒DNA和GAM结构基质的修饰是 建议(具体目标1-2)。通过研究这些修改， 对GAM基因转移机制的重要新见解将是 收获了。这些修饰如何影响成骨细胞的行为 随后的基因转移将在细胞培养模型系统中进行测量 体外实验(特异靶3)。从这些措施中，我们应该获得新的 洞察新骨形成的生物学过程。虽然很有可能 在本申请的范围之外，长期目标将是 为了衡量合理预先设计的GAM结构在 体内采用已建立的骨缺损动物模型。