In vitro and biodistribution examinations of Tc-99m-labelled doxorubicin-loaded nanoparticles

BACKGROUND: Nanoparticles represent promising drug carrier systems. In the case of cytostatics such as doxorubicin, carrier colloid systems as human serum albumin (HSA) nanoparticles, may increase their therapeutic efficiency and decrease their side-effects (toxicity) and any potential multidrug resistance. In the present study, doxorubicin, as a widely used antineoplastic agent, was incorporated into the matrix of human serum albumin and three different particle-sized doxorubicin-loaded HSA nanoparticles were prepared, using a previously described desolvation method. Our objective was to find out if different particle sizes of colloid carriers can allow regarding the given cytostatic agent. MATERIAL AND METHODS: The three prepared nanoparticles were labelled using technetium (Tc-99m) and were tested for their physicochemical colloidal quality, fluctuations, and radiochemical stability. Biodistribution of different-sized radiolabelled colloids were determined by means of scintigraphic imaging studies in healthy male Wistar rats. Images were taken by gamma camera at several times and organ uptakes were estimated by quantitative ROI analysis. RESULTS: In vitro measurements showed that more than 95% of doxorubicin proportion was permanently adsorbed to human serum albumin. Radiolabelled doxorubicin-loaded particles had high-degree and durable labelling efficiency and particle size stability. Biodistribution results had a close correlation to earlier described results of radiocolloids in similar particle size ranges. In vivo examinations verified that colloid carriers have insignificant size fluctuations after an intravenous application and they show the proper distribution according to their particle size. CONCLUSIONS: Our investigations verified that different and stable particle sizes make drug carrier HSA nanoparticles possible to apply different drug targeting in a potential clinical use. Nuclear Med Rev 2011; 14, 2: 55–6