Targeting Tumors with Resealable Nanovesicles Permeabilized by NIR Light

描述(申请人提供)：目前，很少有合成系统能够实现对生物环境中微或纳米微囊渗透的稳健的、按需的空间和时间控制。我们建议在原理验证实验的基础上建立这种膜渗透系统的可行性，并将这项技术应用于：1)触发肿瘤中的药物释放；2)通过远程加载和检索方法捕获肿瘤微血管内容物。已经提出了几种由外部刺激驱动的货物释放方法；但据我们所知，利用纳米胶囊中触发的渗透性来远程捕获和检索微血管内容物的概念尚未被探索。到目前为止，基本上所有从纳米载体体外触发的膜通透性的生物兼容方法都包括这样的系统，即当周围温度通过直接或间接加热高于体温几度时释放其内容物。然而，这样的机制不服从触发侧释放调制，并且窄的热操作窗口排除了在生理温度下载流子的稳定性。此外，生理条件缺乏稳定性，阻碍了这些材料更苛刻的应用，例如在以后的时间点触发释放以及远程加载和恢复。在这里，我们提出了一种全新的控释系统，它基于近红外光直接瞬时渗透的卟啉-磷脂掺杂(PoPD)脂质体，这是一种临床适用的刺激，在关闭状态下几乎不起作用，对生物组织的干扰最小。通过精确的空间和时间控制打开和关闭体内纳米囊泡的能力可能会带来治疗和理解癌症的全新方法。我们合成了一种新型的光吸收单体，它由临床批准的成分酯化而成，产生了高度稳定的卟啉双层。值得注意的是，使用最佳的卟啉-磷脂(而不是游离的卟啉)掺杂，在温和的近红外照射下短暂暴露后，可以快速和完全地释放货物。与前面描述的体系不同，释放发生在没有整体溶液光热加热或化学反应的情况下。在体外生理条件下，近红外辐射诱导活性负载阿霉素的释放速率增加25,000倍，比先前描述的触发释放方法大几个数量级。诱导渗透率既可用于卸货，也可用于卸货，并可通过改变卟啉掺杂、照射强度和照射时间来调节，以实现高度可调的操作 渗透作用。这个项目有三个具体目标。目标1：开发响应近红外光按需打开和关闭的微囊和纳米囊；目标2：使用近红外光向肿瘤输送癌症治疗药物；目标3：使用捕获和检索策略对肿瘤微血管内容物进行采样。

DESCRIPTION (provided by applicant): At present, few synthetic systems can achieve robust, on-demand spatial and temporal control of micro or nanovesicle permeabilization in biological environments. We propose to build upon proof-of-principle experiments establishing the feasibility of such a membrane permeabilization system and to apply this technology towards: 1) triggering drug release in tumors and 2) capturing tumor microvasculature contents via a remote loading and retrieval approach. Several methods for cargo release driven by external stimuli driven have been proposed; whereas to our knowledge the concept of remote capture and retrieval of microvessel contents using triggered permeability in nanovesicles has not yet been explored. So far, essentially all biocompatible approaches for externally triggered membrane permeabilization from nanocarriers comprise systems that release their contents when the surrounding temperatures are raised by a few degrees above body temperature via direct or indirect heating. However, such mechanisms are not amenable to trigger-side release modulation and the narrow thermal operating window precludes carrier stability at physiological temperatures. Furthermore, the lack of stability in physiological conditions prevents more demanding applications of these materials such as triggered release at later time points as well as remote loading and recovery. Here, we propose a fundamentally new controlled release system based on porphyrin- phospholipid doped (PoPD) liposomes transiently permeabilized directly by near infrared (NIR) light, a clinically-applicable stimulus that has negligible actuatin in the "off state" and minimal interference with biological tissues. The ability to open and close nanovesicles in the body with precise spatial and temporal control could lead to entirely new approaches to treating and understanding cancer. We synthesized a novel light-absorbing monomer esterified from clinically approved components that gave rise to highly stable porphyrin bilayer. Remarkably, rapid and complete cargo release was induced upon brief exposure to mild NIR irradiation using an optimal porphyrin-phospholipid (but not free porphyrin) doping. Unlike previously described systems, release occurred in the absence of bulk solution photothermal heating or chemical reactions. In physiological conditions in vitro, NIR irradiation induced a 25,000 fold increase in the release rate of actively loaded doxorubicin, orders of magnitude greater than previously described triggered release methods. Induced permeability could be used for both unloading and loading cargo, and could be modulated by varying porphyrin doping, irradiation intensity and irradiation duration for highly tunable manipulation of permeabilization. This project has three specific aims. Aim 1: Develop micro and nanovesicles that open and close on demand in response to NIR light; Aim 2: Use near infrared light to deliver cancer therapeutics to tumors; Aim 3: Sample tumor microvasculature contents using a capture and retrieve strategy.