Detoxifying Antitumoral Drugs via Nanoconjugation: The Case of Gold Nanoparticles and Cisplatin
Figure 3
(a) UV-Vis spectroscopy of conjugates with increasing aquated cisplatin concentrations shows that this concentration should not exceed 0.39 mM to guarantee colloidal stability. (b) When an excess of drug was introduced, the MUA charge became progressively quenched, which lead to aggregation of AuNPs, as denoted by the red-shift and further intensity decrease of SPR intensity in less than one hour. (c) Red-shift of the SPR peak at the working conditions: the initial peak of citrate-capped AuNPs shifted from 515 nm to 521.5 nm after MUA conjugation and to 523 nm after cisplatin conjugation. (d) Time evolution of ζ-potential after addition of [Pt (H2O)2(NH3)2]2+ indicates the quenching of negative charge on the MUA by the formation of a coordination bond between the carboxylic acid group and aquated cisplatin. Conjugates remained stable at ζ-potential values more negative than –25 mV. (e) Scheme showing the functionalization steps followed to obtain the cisplatin delivery system.