New Chemistry of Making Porphyrin-based Nanostructures

卟啉是自然界中的内源性发色团，如红细胞中的血红素和绿色植物中的叶绿素。卟啉和卟啉类分子因其在能源（染料敏化太阳能电池）和医学（光动力治疗剂和荧光探针）中的应用而闻名，但迄今为止很少对其纳米级性质的潜力进行研究。在先前的NSERC发现资助的支持下，我的实验室发现了“卟啉”，这是第一种具有固有多模态光子特性的全有机纳米颗粒（Nature Materials 2011），被誉为“一种粒子统治一切”（Nature Methods 2011），并被加拿大癌症协会命名为“2011年十大癌症突破”之一。* 卟啉体的发现不仅将自然界最迷人的分子之一卟啉转变为光子纳米材料，而且还将脂质在超分子结构中的简单纳米支架支撑作用转变为内在多峰平台，随后为基于内在多峰卟啉构建块的不同卟啉纳米结构的大探索打开了大门。自成立以来，这一概念已经扩展到其他治疗诊断平台，包括卟啉聚合物，胶束，脂质体，神经酰胺酶体和其他混合纳米颗粒。* 我的研究计划的长期目标是通过学习卟啉如何形成超分子结构以及它们在自然界中如何发挥作用来研究和开发新的卟啉纳米化学（例如，光捕获细菌），并将这些自然的教训用于构建具有不同尺寸，形状和功能的新卟啉纳米材料，这可能在能源和医学方面具有广泛的应用。短期目标是探索可能导致全新卟啉脂质纳米结构的三个方向。这些措施是：1）通过创建卟啉中不同的卟啉-脂质结构单元的库来理解卟啉超分子组装的基本化学（例如，膨胀的卟啉、卟啉类似物、它们的金属螯合等），脂质（例如，阳离子、具有不同的侧链长度、w/o间隔基等）和卟啉/脂质比率; 2）通过学习自然界的有序染料聚集体，使用新型相变卟啉纳米结构来创建“刺激驱动的光传输”的新机制; 3）通过使用超声波触发的卟啉壳微泡到卟啉纳米颗粒的转变来研究微纳米转换的化学。* 我相信，拟议的基础研究将导致卟啉纳米材料的指数增长，具有多方面的用途，也将有助于保持这一新的令人兴奋的纳米技术领域的世界领导地位，我们开创了这一领域。

Porphyrins are the endogenous chromophores of nature such as hemes in red blood cells and chlorophylls in green plants. Porphyrins and porphyrin-like molecules are well known for their applications in energy (as dye-sensitized solar cells) and in medicine (as photodynamic therapy agents and fluorescent probes) but rarely investigated for its potential for its nanoscale properties until now. Supported by the previous NSERC discovery grant, my lab discovered `porphysomes', the first all-organic nanoparticles with intrinsic multimodal photonic properties (Nature Materials 2011), hailed as "one particle to rule them all" (Nature Methods 2011) and named as one of the "Top Ten Cancer Breakthroughs in 2011" by the Canadian Cancer Society. ***The discovery of porphysome not only turned one of nature's most fascinating molecules, porphyrins, into photonic nanomaterials but also shifted the simple nanoscaffold support role of lipids in supramolecular structures to an intrinsic multimodal platform, which subsequently opened the door for the grand exploration of different porphyrin nanostructures based on the intrinsic multimodal porphyrin building blocks. Since its inception, this concept has already been extended to other theranostic platforms including porphyrin polymers, micelles, liposomes, cerasome, and other hybrid nanoparticle. ***The long term goal of my research program is to study and develop new porphyrin nanochemistry by learning how porphyrins form supramolecular structures and how they function in nature (e.g., light harvesting bacteria) and adapting these nature's lesson into building new porphyrin nanomaterials with different sizes, shapes and functions, which could have broad applications in both energy and medicine. The short term goals are to explore three directions that could lead to entirely new porphyrin-lipid nanostructures. These are: 1) to understand the fundamental chemistry of porphyrin supramolecular assembly by creating a library of porphyrin-lipid building blocks varying in porphyrins (e.g., expanded porphyrins, porphyrin analogs, their metal-chelation, etc.), lipids (e.g., cationic, with different side chain length, w/o spacers, etc.) and porphyrin/lipid ratios; 2) to create a new mechanism of `stimuli-driven light transmission' using novel phase change porphyrin nanostructures by learning from nature's ordered dye aggregates; 3) to study the chemistry of micro-to-nano conversion by using ultrasound-triggered transformation of porphyrin shell microbubbles into porphyrin nanoparticles. ***I believe the proposed fundamental studies will lead to exponential growth of porphyrin nanomaterials with versatile utilities and will also help to maintain the world leadership position of this new exciting nanotechnology field, for which we pioneered.**