BRIGE: Delivery of Silencing RNA and TGF-b1 from Biopolymer Hydrogels to Inhibit Osteogenesis and Promote Chondrogenesis in Growth Plate Injuries

项目描述：本研究旨在研究两种不同类型的生物活性因子的受控持续递送系统，这些生物活性因子可以帮助修复儿童受损的生长板。如果生长板中的软骨组织受伤，骨组织就会沉积在受伤部位，从而破坏生长板并导致异常的骨生长。将设计一种新的生物材料递送系统，该系统提供沉默RNA和TGF-1生长因子的局部持续递送，并且检查这些生物活性因子的共同递送对间充质干细胞的软骨形成分化的影响。短干扰RNA（siRNA）提供了一种强大的基因沉默机制，通过靶向破坏特定mRNA序列在翻译水平上抑制基因表达。由于这种沉默特定蛋白质表达的能力，并且由于siRNA直接在细胞的细胞质中发挥作用而不是掺入基因组DNA中并且其作用是短暂的，因此siRNA在临床应用中的影响可能是巨大的。不幸的是，siRNA的递送目前是其临床应用的主要障碍，因为siRNA容易降解并从体内清除。该提案中的工作将提供以持续、受控的方式将siRNA递送到局部位点的新方法。还将检查生长因子的共同递送以改善生长板损伤的软骨修复。因此，这里提出的工程解决方案是开发一种能够释放两种不同生物活性因子的递送系统，一种用于抑制损伤部位骨组织的形成，另一种用于促进该区域中存在的干细胞的软骨分化，从而形成软骨组织。更广泛的意义和重要性：最终，这项技术可以为儿童生长板损伤提供急需的治疗选择。随着儿童的成长，他们的骨骼通过生长板中骨软骨界面处的软骨矿化而延长。对生长板的损伤可导致骨组织沉积在软骨内，从而破坏生长板。这种破坏可能导致严重的后果，包括骨骼不能生长到其全长或异常生长，使得骨骼在生长时弯曲。除了解决明确的临床需求外，拟议工作的结果将为沉默RNA的局部和持续递送提供新的方法，这可能会在未来的其他应用中受益。更广泛的影响：该奖项将支持克雷布斯教授实验室的推广工作的增加和继续。它将直接支持一名研究生的培训2年，并至少有一名本科生和一名高中实习生参与该项目。PI和研究生将参加K-6阅读障碍学生的夏令营，设计科学模块，将在夏令营的5周中的2周内向学生展示。这将对夏令营的学生产生重大影响，唤醒他们的科学兴趣，也会对PI和研究生产生重大影响，使他们更多地了解阅读障碍以及个人克服阅读障碍和/或利用阅读障碍为自己谋利的方法。PI还将继续支持在学年期间通过当地高中的实习计划在实验室接待1-2名女高中实习生。这些学生将与研究生和PI一起在一个特定的项目上并肩工作，并在一年中看到它的发展。最后，该项目将通过提供一种新的生物材料输送系统产生广泛的社会影响，该系统可以改善生长板损伤的治疗，并在未来用于其他组织再生应用。这是工程教育和中心部工程项目的一部分。

Project Description: This research seeks to investigate a controlled, sustained delivery system for two different types of bioactive factors that could aid in the repair of injured growth plates in children. If the cartilage tissue in the growth plate is injured, bony tissue is deposited at the injured site, thus disrupting the growth plate and leading to abnormal bone growth. A new biomaterial delivery system that provides local, sustained delivery of silencing RNA and TGF-1 growth factor will be engineered, and the influence of the co-delivery of these bioactive factors on the chondrogenic differentiation of mesenchymal stem cells examined. Short interfering RNA (siRNA) provides a powerful gene silencing mechanism, inhibiting gene expression at the translational level by targeted destruction of specific mRNA sequences. Due to this ability to silence the expression of specific proteins, and since siRNA functions directly in the cytoplasm of the cell rather than being incorporated into the genomic DNA and its effect is transient, the impact of siRNA in clinical applications could be enormous. Unfortunately, the delivery of siRNA is currently a major hurdle to its clinical use, as siRNA is readily degraded and cleared from the body. The work in this proposal will provide new methods for delivering siRNA to a local site in a sustained, controlled manner. Co-delivery of growth factor to improve cartilage repair of growth plate injuries will also be examined. Thus, the engineering solution proposed here is the development of a delivery system capable of releasing two different bioactive factors, one to inhibit the formation of the bony tissue at the injury site and another to encourage the chondrogenic differentiation of stem cells that are present in the area so they form cartilage tissue. Broader Significance and Importance: Ultimately this technology could offer a much-needed therapeutic option for growth plate injuries in children. As children grow, their bones lengthen by mineralization of cartilage at the bone-cartilage interface in the growth plate. Injury to the growth plate can lead to the deposition of bony tissue within the cartilage, thus disrupting the growth plate. This disruption can result in serious consequences, including the bone not growing to its full length or the growth occurring abnormally such that the bone curves as it grows. In addition to addressing a clear clinical need, the results of the proposed work will provide new methods for localized and sustained delivery of silencing RNA, which could potentially benefit other applications in the future as well.Broader Impacts: This award will support both the increase and continuation of outreach efforts by Professor Krebs's lab. It will directly support the training of one graduate student for 2 years and the involvement of at least one undergraduate student and one high school intern in the project. The PI and graduate student will be participating in a summer camp for K-6 dyslexic students, designing science modules that will be presented to the students over the course of 2 of the 5 weeks of the summer camp. This will have a substantial impact on the students at the camp in awakening their scientific interest, and also on the PI and graduate student in learning more about dyslexia and ways that individuals can overcome it and/or use it to their benefit. The PI will also continue her support of hosting 1-2 female high school interns in the lab during the academic year through internship programs of local high schools. These students will work side-by-side with a graduate student and the PI on a specific project, and see it develop over the course of the year. Finally, the project would have broad societal impacts by providing a new biomaterial delivery system that could improve the treatment of growth plate injuries and also be used for other tissue regeneration applications in the future.This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.