Drug delivery systems: hydrophilic gold nanoparticles for controlled drug loading and release

Drug delivery systems based on gold nanoparticles (AuNPs) are being widely applied, due to their unique chemical and physical properties, biocompatibility, and well-established strategies for surface modification. In this framework we report studies about drug delivery systems based on gold nanoparticles stabilized by sodium 3-mercapto-1-propane sulfonate (Au-3MPS NPs) used as carrier for different drugs: the dexamethasone, DXM and copper complexes, Cu(I)R, based drugs. The drug loading and release were optimized for each delivery system and the bioconjugates were characterized by means of several technique, (Uv-visible, FTIR, XPS, DLS, FESEM, AFM). After optimization studies the best loading for Au-3MPS NPs @DXM have efficiency 80% , for Au-3MPS NPs @Cu(PTA)4 have efficiency 78%. Studies regarding the release were performed in the range 1-14 days, showing at the end a drug release around 85% for each systems. The stability (see Fig.1) and citotoxicity studies on AuNPs confirm the biocompatibility of the drug delivery systems and open new exciting perspectives in the field in vitro and in vivo studies.