Cyclodextrin-Based Peptide Self-Assemblies (Spds) That Enhance Peptide-Based Fluorescence Imaging and Antimicrobial Efficacy.

Abstract

As a result of their high specificity for their corresponding biological targets, peptides have shown significant potential in a range of diagnostic and therapeutic applications. However, their widespread use has been limited by their minimal cell permeability and stability in biological milieus. We describe here a hepta-dicyanomethylene-4-pyran appended β-cyclodextrin () that acts as a delivery enhancing "host" for 1-bromonaphthalene-modified peptides, as demonstrated with peptide probes . Interaction between the fluorescent peptides and results in the hierarchical formation of unique supramolecular architectures, which we term supramolecular-peptide-dots (). Each (, , and ) was found to facilitate the intracellular delivery of the constituent fluorescent probes (), thus allowing spatiotemporal imaging of an apoptosis biomarker (caspase-3) and mitosis. , incorporating the antimicrobial peptide , was found to provide an enhanced therapeutic benefit against both Gram-positive and Gram-negative bacteria relative to alone. In addition, a fluorescent was prepared, which revealed greater bacterial cellular uptake compared to the peptide alone () in . (ATCC 25922) and (ATCC 25923). This latter observation supports the suggestion that the platform reported here has the ability to facilitate the delivery of a therapeutic peptide and provides an easy-to-implement strategy for enhancing the antimicrobial efficacy of known therapeutic peptides. The present findings thus serve to highlight a new and effective supramolecular delivery approach that is potentially generalizable to overcome limitations associated with functional peptides.