NIR Absorbing Nanoparticles For Cancer Therapy

据统计，50多年来，癌症一直是美国第二大死因 造成超过25%的人口死亡。每年有超过一百万的病例被诊断出来， 导致超过500,000人死亡(美国癌症协会，2001年)。纳米技术可能提供新的选择 用于癌症的诊断和治疗。一种基于纳米颗粒的癌症治疗新方法已经问世 在我们实验室接受调查。近红外吸收纳米颗粒被静脉注射并 由于泄漏的血管系统和/或靶向，允许在肿瘤中积聚，随后照射 这种动物有近红外(NIR)光。近红外光不会被组织成分明显吸收， 可以在不损害正常组织的情况下进行深度穿透。利用一类近红外吸收纳米颗粒 名为金-二氧化硅纳米壳，我们已经证明了肿瘤的完全消融和长期存活。 没有肿瘤的动物会重新生长。我们最近开始了对另外两类近红外光谱的体外研究。 吸收纳米颗粒--金-金硫化物纳米壳和金纳米棒。在体外，我们已经能够 由于这两种新型纳米粒子具有更高的吸收率，因此可以实现更快的加热 和较低的散射(加热顺序、纳米棒、金-金硫化物纳米壳、金-二氧化硅纳米壳)，以及 因此相信，在癌症治疗中，它们在较低剂量下比黄金更有效- 二氧化硅纳米壳。然而，这三类纳米粒子的大小差别很大。金硅石 纳米壳层直径约100纳米，金-硫化金纳米壳层约50纳米，以及 金纳米棒的直径为20 nm。因此，这些颗粒的生物分布会有很大的不同，并可能对 治疗效果。我们建议评价其生物分布、生物相容性和肿瘤消融效果。 这些吸收近红外的纳米颗粒。我们将在以下模型中进一步研究最优粒子配方 髓母细胞瘤。

For over fifty years, cancer has remained the second leading cause of death in the United States, accounting for over 25% of the deaths in the population. More than one million cases are diagnosed eachyear, resulting in over 500,000 deaths (American Cancer Society, 2001). Nanotechnology may offer new options for both diagnosis and treatment of cancer. A new nanoparticle-based approach to cancer therapy has been under investigation in our laboratory. Near infrared-absorbing nanoparticles are injected intravenously and allowed to accumulate in the tumor, due to the leaky vasculature and/or targeting, followed by illumination of the animal with near infrared (NIR) light. NIR light is not appreciably absorbed by tissue components, allowing deep penetration without damage to normal tissues. Using a class of NIR-absorbing nanoparticles called gold-silica nanoshells, we have demonstrated complete tumor ablation and long term survival of animals without tumor regrowth. We have recently begun in vitro studies with two other classes of NIR- absorbing nanoparticles - gold-gold sulfide nanoshells and gold nanorods. In vitro, we have been able to achieve much more rapid heating with these two newer types of nanoparticles due to their higher absorption and lower scattering(order of heating, nanorods, gold-gold sulfide nanoshells, gold-silica nanoshells), and thus believe that they have the potential to be more effectiveat lower doses in cancer therapy than gold- silica nanoshells. However,the sizes of these three classes of nanoparticles varieswidely. Gold-silica nanoshells are approximately 100 nm in diameter, gold-gold sulfide nanoshells approximately 50 nm, and gold nanorods 20 nm. Thus, biodistribution of the particles will be quite different and may drastically affect therapeutic efficacy. We propose to evaluate biodistribution, biocompatibility and tumor ablation efficacy of these NIR-absorbing nanoparticles. The optimal particle formulation will be further examined in a modelof medulloblastoma.