An Organoplatinum(II) Metallacycle-Based Supramolecular Amphiphile and Its Application in Enzyme-Responsive Controlled Release

Enzyme-responsive nanomaterials are emerging asimportant candidates for bioanalytical and biomedical applicationsdue to their good biocompatibilities and sensitivities. However, thelack of promising operation platforms compatible with enzymeresponsiveness greatly limits the scope and functionality of smartmaterials. Herein, we report the design and synthesis of anaphthalene-functionalized organoplatinum(II) metallacycle1bymeans of coordination-driven self-assembly, which is subsequentlyexploited as the organometallic platform to enable enzyme-responsive supramolecular materials. Specifically, a [2 + 2] self-assembled metallacycle1first self-assembles into nanosheets inaqueous solution, which can further transform into vesicles with the introduction of beta-cyclodextrin (beta-CD) because of the formationof a bola-type supramolecular amphiphile beta-CD-1. Interestingly, these vesicles show rare alpha-amylase responsiveness, as demonstratedby structurally transforming back into nanosheets after the addition of alpha-amylase to their solutions due to the enzyme-induceddegradation of cyclodextrins. We also demonstrate the potential application of the self-assembled vesicles in amylase-responsivecontrolled release

Automated summary

Enzyme-responsive nanomaterials have great potential for bioanalytical and biomedical applications, but the lack of compatible operation platforms limits their functionality. This study presents the design and synthesis of an organoplatinum(II) metallacycle that serves as a platform for enzyme-responsive supramolecular materials. The self-assembled nanosheets can transform into vesicles in the presence of beta-cyclodextrin, and demonstrate rare alpha-amylase responsiveness.