Effect of size charge and concentration of sílica nanoparticles on the metabolic activity of Spodoptera frugiperda Sf9 cells

SANTO ORIHUELA, PABLO LUIS; FOGLIA, MARÍA LUCIA; TARGOVNIK, ALEXANDRA MARISA; DIAZ, LUIS EDUARDO; MIRANDA, MARÍA VICTORIA; DESIMONE, MARTÍN FEDERICO

Buenos Aires

Congreso; IV Congreso Argentino de la Sociedad de Toxicología y Química Ambiental SETAC Argentina; 2012

Sociedad de Toxicología y Química Ambiental Argentina SETAC

The application of silica nanoparticles (NPs) in the biomedical field has experienced great development. The driving forces behind these and future developments are the possibility to design NPs with homogeneous size and structure and amenable to specific grafting. Moreover, it is possible to tune the characteristics of the NPs to meet the requirements of each specific cell and desired application. Herein, we analyzed the effect of silica NPs of various size and surface charge on the metabolic activity of Spodoptera frugiperda cells (Sf9 cell line) with the aim of extending the knowledge of possible toxicity of NPs in the environment and development of new tools for insect control. Moreover, these results will also contribute to develop more effective systems for gene vectors delivery and recombinant proteins expression. Silica NPs of 14 nm, 380 nm and 1430 nm with a negative zeta potential, as well as 131 nm and 448 nm with positive zeta potential, were obtained by the Stöber method. The NPs were characterized by DLS, zeta potential measurements and TEM. The metabolic activity of the cells was assessed by the MTT test. It was observed that the 14 nm NPs possessed the highest toxicological effect. Indeed, after 24 h the metabolic activity of the cells exposed to the lower concentration of NPs (0.12 mg/ml) was about 40% of the value obtained for the control cells not exposed to NPs. Moreover, the exposure to other negative charged NPs also caused a lower activity when compared with the control. Lower concentrations of positive charged NPs (i.e.: 0.12 or 0.6 mg/ml) demonstrated to stimulate the proliferation of the cells and higher concentrations (i.e.: 7.2 mg/ml) did not present effects. In conclusion, we have demonstrated that the NPs possess an effect that is highly influenced by the size, charge and concentration. Although silica NPs are being used in the biomedical field, these results contribute to further understand the risk that would be associated with nanoparticles and how they can be modified in order to meet the requirements of each desired application.