Gold Nanoparticles Associated with Neutral Red as potential drug delivery for photodynamic therapy

Abstract

Gold Nanoparticles (AuNP‐TG) have been synthesized with surface modification to improve the interaction to neutral red (NR). We used AuNp‐TG NR system to evaluate possible clinical application in drug delivery system in photodynamic therapy (PDT)using visible light irradiation producing lethal agents that inactivate tumor cells. AuNP‐TG was prepared by sodium citrate reduction method. The interaction of neutral red with AUNP‐TG was performed adding increased volumes of neutral red to AuNP‐TG solution. NanoZetasizer equipment (Malvern Instrument) was used for recording the zeta potential and size distribution measurement. The AuNP and AuNP‐TG loaded with NR were evaluated in term of toxicity in NIH‐3T3 fibroblast and 4T1 tumor cells line. The distribution analyses (DLS) show a uniform size with varying diameters of AuNP‐TG (60,3nm); AuNPTG‐NR (165nm) systems. Also was estimated the number of surface atoms, Ns2 of NR on a single AuNP and AuNP‐TGA. The compound NR and AuNP‐TG‐NR induced toxicity in 4T1 tumor cell rather than NIH‐3T3 fibroblast under visible light irradiation. The modification on the surface of AuNP with TGA prevent the nanoparticle aggregation. The ability of carry more NR can be an advantage as drug delivery systems for PDT.CNPq, FAPDF,DPPUnB, FINATEC