NIR Light-Activated Nanoparticles for Drug and Gene Delivery

描述（由申请人提供）：我们的目标是开发稳健的siRNA和micro-RNA方法来调节基因用于基础研究，允许在细胞培养物和C. elegans通过使用中空金纳米壳（HGN）的独特化学和物理性质。HGN是30 - 40 nm直径，3-5 nm厚的金壳，设计用于强烈吸收生理友好的NIR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容易地缀合到小分子、靶向配体、聚合物、siRNA和DNA，或者并入或栓系到脂质体中。水、蛋白质、脂质等不吸收近红外光，因此培养物中的细胞基本上是透明的，这消除了暴露期间的损伤。飞秒NIR光脉冲通过破坏硫醇键而不损坏siRNA来触发硫醇缀合的siRNA或其他分子从HGN的释放。对于开发有效的寡核苷酸和小分子递送甚至更重要的是，通过将HGN吸收的生理上友好的NIR光能转化为热量，可以绕过众所周知的内体逃逸的瓶颈，从而产生不稳定的微泡，该微泡在几秒钟内机械地破裂内体并将siRNA释放到胞质溶胶中。这允许使用低得多的浓度的HGN-siRNA缀合物，大大增加转染效率，并提供空间和时间控制的转染，其可用于使培养的细胞图案化并寻址C.优雅HGN转染与Lipofectamine一样有效，但无毒，并且可用于活生物体。在这项提案中，我们将使用HGN-siRNA平台开发掩蔽和解蔽技术，用于通过远程控制激活或灭活生物过程，以设计真实的实时培养细胞的光刻图案化的简单且可扩展的方法。我们将使用NIR光触发来控制释放，从而使基本的细胞生物学研究，包括人类干细胞分化，癌症生物学和信号转导途径以及在化疗和药物递送中应用的途径和路线。我们将开发使用硫醇和二硫醇锚定物的组合从单个HGN多重释放的方法，所述硫醇和二硫醇锚定物在不同能量下解吸以释放多种化学物质。将合成新的银纳米壳和金和银纳米棒，以探测NIR光谱的其他区域，并提供同时传递和成像的机会。这些新的结构可以通过使用不同波长的NIR照射独立地寻址。该项目充分利用HGN与生理友好型近红外光的独特相互作用，以毫秒级的速率在活细胞和生物体中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.