Synthesis, Characterization and Biological Profile of Pentamidine-based Nano-antimicrobials

The development of gold/silver bimetallic nanoparticles (Au@Ag BMNPs) has gained growing interest over the last few years in view of their remarkable therapeutic potential, in particular as antimicrobial and anticancer agents.[1] Recently, their activity against tropical neglected infectious diseases has been also reported. Specifically, the antileishmanial activity against both promastigote and amastigoste forms of L. donovani has been described.[2,3] Nano-antimicrobials originated from the combination of noble metal nanoparticles with classical antimicrobial drugs are considered the next-generation antimicrobials as they enable to overcome the drawbacks of conventional ones [4], although their development is confined to the lab arena till now, due to the colloidal instability [5]. Taking advantage of the ability of cationic β-cyclodextrin to produce Au@Ag BMNPs with core-shell architecture and to accommodate low-molecular-weight lipophilic guests, we prepared a nano-sized supramolecular complex based on Au@Ag BMNPs and the antileishmanial drug Pentamidine (Pent).[4] The morphology, size and colloidal stability of Au@Ag@Pent BMNPs were investigated by UV-vis spectroscopy, transmission electron microscopy, zeta potential, and dynamic light scattering measurements.