NIR Light-Activated Nanoparticles for Drug and Gene Delivery

描述（由申请人提供）：我们的目标是开发强大的siRNA和微rna方法来调节基因用于基础研究，利用中空金纳米壳（HGN）独特的化学和物理性质，在细胞培养和秀丽隐杆线虫中高效地控制转染的时间和空间。HGNs的直径为30 - 40 nm，厚度为3-5 nm，外壳为金色，旨在强烈吸收生理上友好的近红外光，并将该光能转化为局部加热。HGN可以通过简单的硫醇化学很容易地偶联到小分子上，靶向配体、聚合物、siRNA和DNA，或者结合到脂质体中或拴在脂质体上。水、蛋白质、脂类等不吸收近红外光，因此培养的细胞基本上是透明的，这消除了暴露时的损伤。飞秒近红外光脉冲通过破坏硫醇键而不破坏siRNA，从而触发硫醇共轭siRNA或其他分子从HGN中释放出来。对于高效寡核苷酸和小分子递送的发展更重要的是，众所周知的内体逃逸瓶颈可以通过将HGN吸收的生理友好的近红外光能量转化为热量来绕过，产生不稳定的微泡，这些微泡可以在几秒钟内机械地破坏内体并将siRNA释放到胞质溶胶中。这允许使用更低浓度的HGN-siRNA偶联物，大大提高转染效率，并提供空间和时间控制的转染，可用于培养细胞和处理秀丽隐杆线虫内的特定结构。HGN转染与Lipofectamine一样有效，但无毒，可用于生物体。在本提案中，我们将使用HGN-siRNA平台开发掩膜和揭膜技术，用于远程控制激活或灭活生物过程，以设计简单且可扩展的方法，实时对培养细胞进行光刻图图化。我们将研究含HGN的脂质体的小分子控制释放，使用近红外光触发来控制释放，从而实现基本的细胞生物学研究，包括人类干细胞分化，癌症生物学，信号转导途径和化疗和药物输送的应用途径。我们将开发一种方法，利用硫醇和二硫醇锚点的组合，以不同的能量解吸以释放多种化学物质，从单个HGN中多重释放。新的银纳米壳和金、银纳米棒将被合成，以探测近红外光谱的其他区域，并提供同步传输和成像的机会。这些新的结构可以通过使用不同波长的近红外辐射来独立地处理。该项目充分利用独特的HGN与生理友好的近红外光相互作用，在活细胞和生物体中以毫秒级的精确空间控制启动和控制生物过程。

DESCRIPTION (provided by applicant): Our goal is to develop robust siRNA and micro-RNA methods to regulate genes for basic research, permitting both temporal and spatial control of transfection with high efficiency in both cell culture and C. elegans by using the unique chemical and physical properties of hollow gold nanoshells (HGN). HGNs are 30 - 40 nm diameter, 3-5 nm thick, gold shells designed to strongly absorb physiologically friendly NIR light and convert this light energy into local heating. HGN can be easily conjugated to small molecules, targeting ligands, polymers, siRNA and DNA by simple thiol chemistry, or incorporated into or tethered to liposomes. Water, proteins, lipids, etc. do not absorb NIR light, so cells in culture are essentially transparent, which eliminates damage during exposure. Femtosecond NIR light pulses trigger release of thiol-conjugated siRNA or other molecules from the HGN by breaking thiol bonds without damaging the siRNA. Even more important to the development of efficient oligonucleotide and small molecule delivery, the well-known bottleneck of endosomal escape can be bypassed by converting the physiologically friendly NIR light energy absorbed by the HGN to heat, creating unstable microbubbles that mechanically rupture endosomes and release siRNA to the cytosol within seconds. This allows much lower concentrations of HGN-siRNA conjugates to be used, greatly increases transfection efficiency, and provides spatially and temporally controlled transfection that can be used to pattern cultured cells and address specific structures within C. elegans. HGN transfection is as efficient as Lipofectamine, but is non-toxic, and can be used in living organisms. In this proposal, we will use the HGN-siRNA platform to develop masking and unmasking techniques for activating or inactivating biological processes with remote control to devise simple and scalable methods of lithographic patterning of cultured cells in real time. We will investigate controlled release of small molecules from liposomes incorporating HGN using NIR light triggering to control release, thereby enabling basic cell biological studies, including human stem cell differentiation, cancer biology, and signal transduction pathways and routes to applications in chemotherapy and drug delivery. We will develop methods to multiplex the release from a single HGN using a combination of thiol and dithiol anchors that desorbs at different energies to release of multiple chemical species. New silver nanoshells and gold and silver nanorods will be synthesized to probe other regions of the NIR spectrum and provide simultaneous delivery and imaging opportunities. These new constructs could be addressed independently by using different wavelength NIR irradiation. This project takes full advantage of the unique HGN interactions with physiologically friendly NIR light to initiate and control biological processes with precise spatial control at millisecond rates in living cells and organisms.