Gold nanoparticles with triggerable biorecognition for enhanced tumour specificity.

In latest years colloidal gold systems decorated with biological molecules and polymers have been developed as a platform for drug and gene delivery, for diagnostic and other biomedical applications. Gold nanopaprticles are particularly interesting because of the Surface Plasmon Absorption (SPA) properties, which allows for localized heating by laser irradiation. They are devoid of targeting properties that must be conferred by surface functionalization. Indeed, gold nanoparticles can be coated with a variety of functional modifiers: polymers, environmentally-sensitive and targeting agents which allow obtaining versatile systems. Previous studies showed that decoration of gold nanoparticles with thermosensitive polymers allow for temperature controlled cellular penetration [1]. Here we report the preparation of a “smart” system by decorating gold nanoparticles with thermo-responsive polymers and folic acid to achieve temperature triggered biorecognition of folate receptor overexpressing tumor cells. This is aimed to improve site selectivity in the tumor compartment where a physiopathologic temperature increase is found [2].