Testing the therapeutic potential of carbon nanodots in bone mineralization diseases

项目摘要 传统方法将药物输送到骨骼以治疗矿化疾病，如骨质疏松症，可以 也会破坏其他组织的动态平衡。为了克服这一重要问题，开发新的药物输送方式至关重要。 精确地将药物专门输送到骨骼的方法。一种新的药物输送方法是使用碳纳米点 (C-DOTS)是一种新型的纳米粒子，具有高度的稳定性和良好的生物相容性。我们在斑马鱼上的研究已经 鉴定了一类特定的C-点，它与幼虫和成虫的骨骼具有高亲和力和特异性，而不结合 转移到其他组织。基于这一点和更多的初步证据，我们在这里寻求开发C-DOTS作为一种新的方法 专门针对骨骼的精确药物输送。通过系统地定义C-点的化学性质 对于骨结合和药物传递是必不可少的，我们将确定C-Dot的结合特异性和亲和力的机制 同时开发一套新颖和多功能的载体，用于精确地将药物输送到骨骼。 作为C-DOTS可用作新型治疗药物给药系统的原理证据，我们将目标对准了维甲酸 酸信号通路参与骨矿化的动态平衡调节。人类罕见的突变有 确定维甲酸是骨矿化的关键调节剂。这些突变，可以忠实地概括出来 在斑马鱼中，会导致维甲酸过度蓄积，促进骨细胞过度分化，并引发 骨融合手术。因此，招募维甲酸信号通路来调节骨细胞的产生代表了一种新的 以及很大程度上未被探索的调节骨矿化用于疾病治疗的方法。我们正在结合我们的专业知识 在碳基材料化学和维甲酸信号转导中确定斑马鱼中C-点的机制 与骨骼结合，并提高其作为骨骼特异性给药系统的效率。 该项目的目标是：1)确定C-DOTS作为骨特异性药物递送剂的功能范围； 多种维甲酸激活剂和阻滞剂负载C-DOTS并检测骨细胞的变化 在发育、成熟和再生骨骼中的分化和骨矿化；2)增加 C-点可输送到骨骼的药物；通过化学改变C-点表面的连接物和官能团 并测试它们在我们的骨细胞分化和骨矿化范例中的活性。 发展C-dots作为研究和精确治疗骨矿化疾病的工具将有助于 增加我们对细胞信号在促进和阻止骨细胞分化中的作用的理解。通过 扩大C-DOTS可以携带的药物种类，这个新的药物传递平台还将在未来的工作中允许， 以改变骨骼动态平衡的其他过程为靶点，包括癌症。因此，细胞和分子数据从 基于C-Dot的试剂的使用将带来新的生物学见解和创新的骨疗法的发展。

Project Summary Traditional methods to deliver drugs to bones for the treatment of mineralization diseases, such as Osteoporosis, can also disrupt homeostasis in other tissues. To overcome this important problem it is critical to develop novel drug delivery methods that precisely deliver drugs exclusively to the bones. One novel method of drug delivery uses Carbon nanodots (C-dots), an emerging class of nanoparticles with high stability and excellent biocompatibility. Our work in zebrafish has identified a particular class of C-dots that bind with high affinity and specificity to larval and adult bones, without binding to other tissues. Based on this and additional preliminary evidence, here we seek to develop C-dots as a novel method for the precise delivery of drugs exclusively to bones. By systematically defining the chemical properties of C-dots that are essential for bone binding and drug delivery, we will determine the mechanism of C-dot's binding specificity and affinity to bones, while developing a novel and versatile set of carriers for delivering drugs precisely to bones. As proof of principle that C-dots can be used as novel therapeutic drug delivery system, we are targeting the Retinoic Acid signaling pathway involved in the homeostatic regulation of bone mineralization. Rare mutations in humans have identified Retinoic Acid as a key regulator of bone mineralization. These mutations, which can be faithfully recapitulated in the zebrafish, cause excessive Retinoic Acid accumulation, promote excessive osteocyte cell differentiation, and trigger bone fusions. Thus, recruiting the Retinoic Acid signaling pathway to regulate osteocyte production represents a novel and largely unexplored approach to regulating bone mineralization for disease treatment. We are combining our expertise in carbon-based material chemistry and Retinoic Acid signaling in zebrafish to determine the mechanisms of C-dots binding to bones, and improve their efficiency as a bone-specific drug delivery system. The aims of this project are: 1) to determine C-dots' range of function as bone-specific, drug delivery agents; by loading C-dots with a variety of Retinoic Acid activator and inhibitor drugs and measuring changes in osteocyte cell differentiation and bone mineralization in developing, mature, and regenerating bones; 2) to increase the repertoire of drugs that C-dots can deliver to bones; by chemically changing the linkers and functional groups on the C-dots surface and testing their activity in our osteocyte cell differentiation and bone mineralization paradigm. The development of C-dots as tools for the study and precise treatment of bone mineralization diseases will help increase our understanding of the function of cell signaling in promoting and preventing osteocyte differentiation. By expanding the repertoire of drugs that C-dots can carry, this novel drug-delivery platform will also allow, in future work, to target other processes altering bone homeostasis, including cancer. Thus, cellular and molecular data emerging from the use of C-dot-based reagents will lead to new biological insights and the development of innovative bone therapies.