Supramolecular organic photochemistry: incorporating function through molecular design

超分子有机光化学研究光与由有机分子组成的超分子组件之间的相互作用。经过光诱导过程的超分子组装体正在不断地被开发，以在药物输送、催化和光电分子器件等领域中定制功能。超分子组装所实现的功能是分子间互补相互作用的结果，分子间相互作用指导着超分子组装的形成和分子组成的光化学性质。我们正在通过将光致变色化合物与脂质互补和可逆光控制元素相结合来开发创新的、功能性的脂质体。这些光致变色脂质体将在膜通透性方面经历可逆的变化，从而在微囊化合物释放后恢复膜的完整性。我们将通过加入跨越整个脂质双层的光致变色剂来实现这一目标。到目前为止，光致变色系统缺乏这方面的组织，其光诱导释放的程度一直很小，除非脂质体的稳定性受到不可逆转的损害。通过跨越双层，异构化将产生可渗透的通道，由于光致变色结构的变化，被捕获的分子将通过这些通道扩散。带电的系链将把破坏性的光致变色单元固定在适当的位置，直到异构化回到它们更互补的形式恢复局部的脂质秩序。这种方法将通过将脂类类似物与两个光致变色部分相结合来开发。与以前的体系相比，这些二聚体不仅能提高膜的通透性，还能恢复膜的完整性。此外，我们将开发具有改进的双光子吸收的类似光致变色材料，以提高这些脂质体在实际应用中的空间和时间选择性，例如光调控药物传递，其中传递的剂量将通过光精确和可逆地控制。这一战略将通过减少住院时间使公共健康受益，带来可申请专利的技术，并为加拿大的医疗保健系统带来整体节省。

Supramolecular organic photochemistry examines the interaction of light with supramolecular assemblies composed of organic molecules. Supramolecular assemblies that undergo light-induced processes are continually being developed to custom-tailor functions in areas such as drug delivery, catalysis, and optoelectronic molecular devices. The functionality achieved by supramolecular assemblies is a consequence of complementary intermolecular interactions that direct their formation and the photochemical properties of the molecular components. We are developing innovative, functional liposomes through the integration of photochromic compounds with elements of lipid complementarity and reversible photocontrols. These photochromic liposomes will undergo reversible changes in membrane permeability that will restore membrane integrity following the release of encapsulated compounds. We will achieve this objective by incorporating photochromes that span the entire lipid bilayer. Thus far, photochromic systems have lacked this aspect of organization, and the extent of their photoinduced release has been small, except when liposome stability is irreversibly compromised. By spanning the bilayer, isomerization will produce permeable channels through which entrapped molecules will diffuse, resulting from changes in photochrome structure. Charged tethers will anchor the disruptive, photochromic units in place until isomerization back to their more complementary form restores the local lipid order. This approach will be developed through the integration of lipid analogues with two photochromic moieties. These dimers will not only produce larger increases in membrane permeability than previous systems, but also restore membrane integrity. In addition, we will develop similar photochromes with improved two-photon absorption to enhance the spatial and temporal selectivity of these liposomes in practical applications such as photoregulated drug delivery where the delivered dosage will be precisely and reversibly controlled with light. This strategy will benefit public health through a reduction in hospitalization time, lead to patentable technologies, and generate an overall savings to Canada's health care system.