A Fluorescent Pillarplex Rotaxane as a Modular Supramolecular Organometallic Platform for Nanoassemblies
Year: 2026
Type: preprint
Abstract: Mechanically interlocked molecules (MIMs) offer attractive opportunities to modularly integrate bioactivity, molecular recognition, and optical readout within a single supramolecular architecture. Here, we report a fluorescent [2]rotaxane platform based on a cationic organometallic pillarplex ring and fluorescein stoppers as intrinsic imaging labels. The pillarplex ring promotes interactions with biorelevant polyanions such as nucleic acids, while the fluorescein stoppers ensure optical traceability by confocal microscopy. Cellular uptake by A549 cancer cells is demonstrated, showing that the fluorescent rotaxane remains predominantly localized in the cytoplasm. The rotaxane can furthermore be integrated into multicomponent nanoassemblies, such as coacervates and biopharmaceutical-relevant polyplexes. For the latter, in the presence of siRNA and cationic polymers, the rotaxane forms assemblies that even enhance cellular uptake and imaging. Collectively, these findings demonstrate that dye incorporation provides a powerful strategy for modulating pillarplex rotaxanes, thereby enabling controlled uptake, localization within the cell by fluorescence labeling and co-assembly.
Source: ChemRxiv
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204773346