Supramolecular hybrid nanomaterials composed of metal nanoparticles and cyclodextrins for health applications

Cyclodextrins (CDs) are widely exploited as components of supramolecular functional hybrid nanomaterials in virtue of their well known ability to complex a variety of chemical species within their cavity through host- guest interactions. In combination with inorganic nanomaterials, CDs provide biocompatibility and stability which are very important for biomedical applications [1, 2]. Hybrid nanoassemblies composed of CDs covering metallic nanoparticles (NPs) are here shown. Gold NPs decorated with monomeric or polymeric CDs have been synthesized, showing complexing properties towards drugs as dopamine [3] and 5- fluorouracil. Interestingly, polymeric CD acts also as reducing and stabilizing agent towards Ag and Au precursors, allowing to obtain stable metal NPs. In particular, Ag NPs show promising antibacterial properties against S. aureus. In order to achieve a photo-antibacterial effect, the interaction with organic chromophores as porphyrins has been also studied. The nanoassemblies have been characterized through a combination of spectroscopic techniques as UV/Vis absorption, steady- state and time-resolved fluorescence, DLS and ζ-potential measurements. The high versatility of CDs and of our synthetic approach based on supramolecular interactions allow to prepare functional nanomaterials for several applications, as drug delivery systems and for environmental sensing.