Biological Actions and Cellular Targeting of Nanoparticles for Medical Applicatio

描述（由申请人提供）：纳米技术是一个多学科领域，涉及原子、分子和大分子水平的工程装置的发展，在纳米范围内（通常为1-100纳米）。纳米技术的最新进展为纳米材料在生物医学成像和药物靶向递送方面的应用提供了令人兴奋的可能性。我们最近开发了一种新型纳米颗粒配方，对成骨细胞（负责骨形成的细胞）的形成具有强大的刺激作用，同时对破骨细胞（负责骨分解（再吸收）的细胞）的形成具有抑制作用。这种纳米颗粒可能有潜力发展成为一种强大的双重抗代谢和促代谢剂，用于治疗许多骨质疏松性疾病。然而，在任何试剂可以开发成用于人类的药物之前，必须了解其调节细胞代谢的分子和细胞机制，以评估其在体内的可能安全性，并了解对骨骼和非骨骼细胞的潜在毒性或非特异性副作用。我们的初步研究表明，这种纳米颗粒配方通过抑制核因子κ B （NF-kB）转录因子的机制来实现其对成骨细胞的刺激作用和对破骨细胞的抑制作用。NF-kB信号转导通路是体外和体内骨吸收破骨细胞产生的关键。相比之下，我们和其他人最近报道了NF-kB途径在体外有效抑制成骨细胞分化和矿化。基于我们的初步数据，我们假设这种新型纳米颗粒配方通过抑制NF-kB信号转导途径抑制破骨细胞活性并刺激成骨细胞活性。在具体目标1中，我们建议研究该纳米颗粒在分化破骨细胞和成骨细胞前体中对NF-kB信号转导通路的作用。在Specific Aim 2中，我们将生成具有不同物理和化学性质的野生型纳米颗粒的变体，包括表面电荷、表面装饰和大小的改变，以确定哪些特定属性负责内化进入细胞，以及NF-kB途径的生物作用。最后，在具体目标3中，我们将评估这种纳米颗粒配方在小鼠体内通过刺激成骨细胞骨形成和抑制破骨细胞骨吸收来增强骨矿物质密度和骨结构的潜力。

DESCRIPTION (provided by applicant): Nanotechnology is a multidisciplinary field involving the development of engineered devices at the atomic, molecular and macromolecular level, in the nanometer range (typically 1-100 nm). Recent advances in nanotechnology have raised exciting possibilities for the application of nanomaterials to biomedical imaging and the targeted delivery of drugs. We have recently developed a novel nanoparticle formulation with potent stimulatory effects on the formation of osteoblasts, the cells responsible for bone formation, and concomitant inhibitory effects on the formation of osteoclasts, the cells responsible for bone breakdown (resorption). This nanoparticle may have the potential to be developed into a powerful dual anticatabolic and proanabolic agent for the treatment of numerous osteoporotic diseases. However, before any reagent can be developed into a drug for use in humans it is imperative to understand the molecular and cellular mechanisms by which it regulates cell metabolism in order to assess its likely safety profile in vivo, and to understand potential toxic or non-specific side-effects on skeletal and non-skeletal cells. Our preliminary studies suggest that that this nanoparticle formulation achieves its stimulatory effects on osteoblasts, and inhibitory effects on osteoclasts, by a mechanism involving the suppression of the Nuclear Factor Kappa B (NF-kB) transcription factor. The NF-kB signal transduction pathway is established to be critical for production of bone resorbing osteoclasts in vitro and in vivo. By contrast, we and others have recently reported that the NF-kB pathway is potently inhibitory to osteoblastic differentiation and mineralization in vitro. Based on our preliminary data we hypothesize that this novel nanoparticle formulation inhibits osteoclast activity and stimulates osteoblast activity by suppressing the NF-kB signal transduction pathway. In Specific Aim 1 we propose to investigate the action of this nanoparticle on the NF-kB signal transduction pathway in differentiating osteoclast and osteoblast precursors. In Specific Aim 2 we will generate variants of the wild type nanoparticle possessing different physical and chemical properties including alterations to surface charge, surface decoration, and size, to determine which specific attributes are responsible for internalization entry into the cell, and biological action on the NF-kB pathway. Finally, in Specific Aim 3 we will evaluate the potential for this nanoparticle formulation to enhance bone mineral density and bone structure by stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption in mice in vivo. PUBLIC HEALTH RELEVANCE: Nanotechnology has the power to revolutionize medicine. We recently developed a nanoparticle capable of inhibiting bone breakdown, while simultaneously stimulating new bone formation. We now seek to fully investigate the action of this particle on bone cells, and test its capacity to enhance bone mass in vivo.