Supramolecular organic photochemistry: incorporating function through molecular design

超分子有机光化学研究光与有机分子组成的超分子组合的相互作用。经过光诱导过程的超分子组件不断被开发用于定制功能，例如药物输送，催化和光电子分子器件。超分子组件实现的功能是互补的分子间相互作用的结果，这种相互作用指导了它们的形成和分子组件的光化学性质。我们正在开发创新的，功能性脂质体，通过整合光致变色化合物与脂质互补和可逆光控制的元素。这些光致变色脂质体将经历可逆的膜通透性变化，这将在被封装化合物释放后恢复膜的完整性。我们将通过整合跨越整个脂质双分子层的光致色素来实现这一目标。到目前为止，光致变色系统缺乏这方面的组织，并且它们的光诱导释放的程度很小，除非脂质体的稳定性受到不可逆的损害。通过跨越双分子层，异构化将产生可渗透的通道，被捕获的分子将通过这些通道扩散，导致光色素结构的变化。带电荷的系链将破坏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，恢复局部脂质秩序。这种方法将通过脂质类似物与两个光致变色基团的整合来发展。这些二聚体不仅会比以前的系统产生更大的膜通透性增加，而且还能恢复膜的完整性。此外，我们将开发具有改进双光子吸收的类似光致色素，以增强这些脂质体在实际应用中的空间和时间选择性，例如光调节药物递送，其中递送剂量将被光精确和可逆地控制。这一战略将通过缩短住院时间、产生可获得专利的技术、并为加拿大卫生保健系统带来总体节省，从而使公共卫生受益。

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.