Self-Propelled Polymer-Based Multilayer Nanorockets for Transportation and Drug Release
Self-Propelled Polymer-Based Multilayer Nanorockets for Transportation and Drug Release
复制标题
用于运输和药物释放的自驱动聚合物基多层纳米火箭
DOI：
10.1002/anie.201301643
复制
发表时间：
2013-01-01
影响因子：
16.6
通讯作者：
He, Qiang
中科院分区：
文献类型：
--
作者：
Wu, Zhiguang;Wu, Yingjie;He, Qiang
科学界正在努力设计和制造由自生力驱动的多功能人工纳米马达，因为它们在定向药物输送、漫游传感器、目标隔离和检测、主动仿生系统和其他新兴应用领域具有潜力受到纳米级线性生物马达（例如，动力蛋白）的启发，它可以在水溶液中自主移动，并由生物能量单元的自发水解提供动力，在微纳米尺度上设计化学功能强大的合成马达的大量努力最近已经证明了将化学能转化为基于燃料溶液的自主运动的能力（例如，过氧化氢水溶液）。[2-4]为了解释这些化学动力系统的运动和能量传递过程，提出了几种机制，包括气泡推进、[5]界面张力梯度、[6]自电泳、[7]自扩散泳动、[8]渗透推进、[9]超声推进、[10]和聚合反应[11]。在各种合成微发动机中，与双金属纳米棒或Janus微球马达相比，采用卷取技术和模板电合成技术制备的化学动力管状微马达表现出高速和方向可控的运动特性。[12,13]这些像火箭一样的微型发动机能够接收、运输和释放各种货物，包括聚合物颗粒、核酸、癌细胞、细菌然而，它们仍然存在一些固有的局限性，如制备工艺复杂、表面改性困难、生物相容性或生物降解性差等。此外，在许多情况下，合成马达都需要能够以简单可控的方式自行封装、输送和释放目标物质，并具有良好的生物相容性和可生物降解性，特别是在生物医学和环境领域。因此，开发新的制造方法和扩大建筑构件的多样性仍然是一个挑战。在此，我们描述了通过纳米多孔模板辅助层层组装（LbL）成功构建了一个定义良好的聚合物多层管状纳米马达。指出所采用的纳米孔模板的孔道是不对称的，可以方便地实现运动方向的控制。将具有均匀大小和形状的铂纳米颗粒（PtNPs）组装在lb组装的纳米管的内表面，并催化过氧化氢（作为燃料）分解为水和氧。由此产生的氧气气泡（推进气体）向大开口移动，从这一端释放氧气气泡，反过来推动纳米管（小型化的火箭）。我们的方法的一个优点是，不仅可以在纳米尺度上控制所得到的纳米管的长度、壁厚、外径和内径，[18-20]而且可以通过组装相应的组件，如聚合物、[21]纳米颗粒、[22]蛋白质、[23]和无机或有机功能分子，方便地改变壁性质因此，lbl组装的纳米结构可以保留各种建筑单元的功能，并且通过组装相应的功能单元可以很容易地获得多功能纳米结构。[25,26]更有趣的是，研究表明，lb组装的多层膜对外部化学、物理或生物刺激有反应。到目前为止，大多数研究都……
There is a growing effort in the scientific community to design and fabricate versatile artificial nanomotors propelled by selfgenerated forces, because they have potential in the field of directed drug delivery, roving sensors, isolation and detection of targets, active biomimetic systems, and other emerging applications.[1] Inspired by the nanoscale linear biomotors (for example, kinesins), which can autonomously move in aqueous solution and are powered by spontaneous hydrolysis of biological energy units, substantial efforts towards the design of chemically powerful synthetic motors at the micro-and nanoscale have recently demonstrated the ability of converting chemical energy into autonomous motion based on a fuel solution (for example, aqueous hydrogen peroxide solution).[2–4] To explain the motion and energy transfer process in these chemically powered systems, several mechanisms, including bubble propulsion,[5] interfacial tension gradients,[6] self-electrophoresis,[7] self-diffusiophoresis,[8] osmotic propulsion,[9] ultrasound propulsion,[10] and polymerization reactions [11] were proposed. Among diverse synthetic microengines, chemically powered tubular micromotors prepared by the rolled-up technique and template electrosynthesis have displayed a high speed and the controllable directionality of the movement compared to bimetal nanorods or Janus microsphere motors.[12, 13] These rocket-like microengines are capable of the pick-up, transportation, and release of various cargoes, including polymer particles,[14] nucleic acids,[15] cancer cells,[16] and bacteria.[17] However, they still have some inherent limitations, such as complex preparation technology, difficulty of surface modification, and poor biocompatibility or biodegradability. Moreover, it is required in many cases that synthetic motors can encapsulate, transport, and release targeted substances by themselves in an easy and controllable way and have good biocompatibility and biodegradability, particularly in both biomedical and environmental fields. Therefore, it still remains a challenge to develop new fabrication methods and expand the diversity of the building components.Herein, we describe the successful construction of a welldefined polymer multilayer tubular nanomotor through the nanoporous template-assisted layer-by-layer (LbL) assembly. It is pointed out that the pore channels of the used nanoporous template are asymmetric so that the control of the movement directionality can be conveniently achieved. Platinum nanoparticles (PtNPs) with a uniform size and shape are assembled within the inner surface of LbL-assembled nanotubes and catalytically decompose hydrogen peroxide (as fuel) to water and oxygen. The resulting oxygen bubbles (propulsion gas) move towards the large opening, releasing oxygen bubbles from this end and in turn pushing the nanotube along (miniaturized rocket). One advantage of our approach is that not only can the length, wall thickness, and outside and inner diameters of the resulting nanotubes be controlled at the nanoscale,[18–20] but also the wall properties can be conveniently varied by assembling the corresponding components, such as polymers,[21] nanoparticles,[22] proteins,[23] and inorganic or organic functional molecules.[24] The LbL-assembled nanostructures can thus preserve the function of various building units, and multifunctional nanostructures can then easily be obtained by assembling the corresponding functional units.[25, 26] More interestingly, it has been demonstrated that the LbL-assembled multilayers are responsive to external chemical, physical, or biological stimuli. Until now, most of research has …