ANTIOXIDANT NATURAL COMPOUNDS ADSORBED ON SILICA NANOPARTICLES

GIORGI, EXEQUIEL; GENOVÉS, SOFIA; CONTI, FLORENCIA; BAUDOU, FEDERICO G.; DIAZ, SOFIA; DE MARZI, MAURICIO C.; DIAZ, MARIA EUGENIA

Mar del Plata

Congreso; ANNUAL MEETING OF BIOSCIENCE SOCIETIES 2021; 2021

Therapeutic nanotechnology involves the use of nanoparticles (NPs) as vectorization, protection and controlled release systems for molecules of therapeutic interest like antioxidants. These vectors make possible to improve the biodistribution of fragile or complex molecules and favor their interaction with specific tissues. Antioxidant compounds are of great interest since uncontrolled production of free radicals has been related to several diseases. The aim of this work was to obtain fungal enriched protein extracts with antioxidant activity and to adsorb them on silica NPs in order to evaluate their antioxidant potential. To achieve this goal, P. ostreatus and A.bisporus fruiting bodies were homogenized, centrifuged and the supernatants were treated with ice cold ethanol to precipitate soluble proteins. The precipitates were resuspended in buffer and enriched proteins extracts were obtained. Silica nanoparticles (SiNPs) were synthesized by the Stöber method and a portion of these were grafted with APTES to add amino groups to their surface, obtaining modified SiNPs (SiNPsNH2). Both variants of NPs were characterized by TEM, DLS and Z potential. These NPs of spherical form were a homogeneous population of diameter 110 ± 10 nm. Fungal extracts were incubated with NPs at 40 rpm and 4°C overnight to allow the proteins adsorption on the NPs. Antioxidant activity was evaluated using ABTS radicals generated by the reaction of ABTS and potassium persulfate overnight at room temperature in the dark. For the assay, samples were incubated with the radical ABTS for 30 min in the dark and the absorbance was measured at 734 nm. The results showed that a high amount of the proteins of A. bisporus extracts were adsorbed on both SiNPs and SiNPsNH 2, while P. ostreatus proteins were not adsorbed. But only A. bisporus proteins-SiNPs complex presented significant antioxidant activity. Therefore, this complex is of interest to be studied as a possible therapeutical tool.