Protein triggered fluorescence switching of near-infrared emitting nanoparticles for contrast-enhanced imaging
作者:Ragini Jetty、Yuriy P. Bandera、Michael A. Daniele、David Hanor、Hsin-I. Hung、Venkat Ramshesh、Megan F. Duperreault、Anna-Liisa Nieminen、John J. Lemasters、Stephen H. Foulger
DOI:10.1039/c3tb20681e
日期:——
Sub-100 nm colloidal particles which are surface-functionalized with multiple environmentally-sensitive moieties have the potential to combine imaging, early detection, and the treatment of cancer with a single type of long-circulating “nanodevice”. Deep tissue imaging is achievable through the development of particles which are surface-modified with fluorophores that operate in the near-infrared (NIR) spectrum and where the fluorophore's signal can be maximized by “turning-on” the fluorescence only in the targeted tissue. We present a general approach for the synthesis of NIR emitting nanoparticles that exhibit a protein triggered activation/deactivation of the emission. Dispersing the particles into an aqueous solution, such as phosphate buffered saline (PBS), resulted in an aggregation of the hydrophobic fluorophores and a cessation of emission. The emission can be reinstated, or activated, by the conversion of the surface-attached fluorophores from an aggregate to a monomeric species with the addition of an albumin. This activated probe can be deactivated and returned to a quenched state by a simple tryptic digestion of the albumin. The methodology for emission switching offers a path to maximize the signal from the typically weak quantum yield inherent in NIR fluorophores.
表面功能化具有多种环境敏感基团的亚100纳米胶体粒子,具有将成像、早期检测与治疗癌症结合在一种长循环"纳米装置"中的潜力。通过开发表面修饰有近红外(NIR)光谱范围内工作的荧光团的粒子,并仅在目标组织中"开启"荧光,可以实现深层组织的成像。我们提出了一种合成NIR发射纳米粒子的通用方法,这些纳米粒子表现出由蛋白质触发的激发/失活。将这些粒子分散在磷酸盐缓冲盐水(PBS)等水溶液中,会导致疏水性荧光团的聚集和发射停止。通过添加白蛋白,将表面附着的荧光团从聚集态转变为单体,可以恢复或激活发射。通过简单的胰蛋白酶消化白蛋白,可以使这种激活的探针失活并返回到淬灭状态。发射开关的方法提供了一条途径,以最大化来自NIR荧光团固有的通常较弱的量子产量的信号。