Gold nanoparticles stabilized with beta cyclodextrin -2 - amino -4 -(4-chlorophenyl) thiazole complex: a novel system for drug transport

Abstract

While 2-amino-4-(4-chlorophenyl)thiazole (AT) drug and thiazole derivatives have several biological applications, these compounds present some drawbacks, such as low aqueous solubility and instability. A new complex of beta CD-AT has been synthesized to increase AT solubility and has been used as a substrate for the deposit of solid-state AuNPs via magnetron sputtering, thus forming the beta CD-AT-AuNPs ternary system, which is stable in solution. Complex formation has been confirmed through powder X-ray diffraction and 1D and 2D nuclear magnetic resonance. Importantly, the amine and sulfide groups of AT remained exposed and can interact with the surfaces of the AuNPs. The complex association constant (970 M-1) has been determined using phase solubility analysis. AuNPs formation (32 nm average diameter) has been studied by UV-Visible spectroscopy, transmission/scanning electron microscopy and energy-dispersive X-ray analysis. The in vitro permeability assays show that effective permeability of AT increased using beta CD. In contrast, the ternary system did not have the capacity to diffuse through the membrane. Nevertheless, the antibacterial assays have demonstrated that AT is transferred from beta CD-AT-AuNPs, being available to exert its antibacterial activity. In conclusion, this novel beta CD-AT-AuNPs ternary system is a promising alternative to improve the delivery of AT drugs in therapy.