NOVEL PHOTOSENSITISERS BASED ON CYCLODEXTRIN NANOSPONGES AND CATIONIC PORPHYRINS

The Antimicrobial Photodynamic Therapy (aPDT) is a well-known alternative to treat local infection caused by different microorganisms, such as Gram-positive and Gram-negative bacteria, viruses, fungi and protozoa. Nowadays, photo-antimicrobial systems based on cyclodextrin (CD) and photosensitizer (PS), both as PS eluting fabrics [1] or in aqueous dispersion [2] have been proposed as drug delivery platforms with high potential in aPDT. Over the last decade, CD nanosponges (CDNS) research have been boosted the interest of CD scientists thanks to the low preparation costs and high versatility of their use in various field such as drug delivery and driven-green chemistry processes [3-4]. Here we report on novel nano photosensitizer based on the anionic ?-CDNS (?NS-PYRO) and a cationic porphyrin 5,10,15,20-tetrakis (N-methyl-4-pyridyl)- 21H,23H-porphyrin (TMPyP), which currently is utilized in aPDT to photo inactivate Gram (-) bacterial cells. Complex was prepared in water by simple addition of ?NS-PYRO to TMPyP solution at 25:1 mass ratio and purified from free PS by ultracentrifugation and washing the dispersed powder, thus determining a PS loading of 1,3% (wt TMPyP /wt ?NS-PYRO). Complementary spectroscopic techniques such as UV-Vis, steady-state and time resolved fluorescence and anisotropy as well DLS and z-potential pointed out the complexation between ?-CDNS and PS with the formation of CD Nanoconstructs with photodynamic features. In this respect, in vitro photo-antibactericidal studies are in due course to elucidate the aPDT efficacy of these spongly photosensitizers.