Approach to deliver antioxidants wih silica nanoparticles

MITAROTONDA R; DE MARZI MC; FRONTERA E; GUERRA LN

CABA

Jornada; Jornada de la Sociedad Argentina de Biología; 2018

Sociedad Argentina de Biología

We showed that antioxidant N-acetylcysteine (NAC) inhibits cellular lipid accumulation during adipocyte differentiation, we carried outin vitro assays in which 0,01 mM to 5 mM NAC doses were added to culture media of the preadipocyte cell line 3T3-L1 (Soto et al,2016). Here we evaluated Oil-Red-O stained lipid content in 5mM NAC treated adipocytes (ACN) compared to adipocytes (AC), whichis set to 100 (100+4 [AC] vs 80+2 [ACN] arbitrary units (AU), p< 0.05). NAC cellular uptake was 17.4% of total NAC added for 5mMtreatment; with lower doses treatments, 5% of total NAC was absorbed by the cells. We developed 5mM NAC encapsulated silicananoparticles (NPsSiO2-NAC) and evaluated their cellular toxicity on 3T3-L1, by colorimetric test using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. We prepared silica nanoparticles (NPsSiO2) using organic mold with tetraethylorthosilicate asprecursor. We obtained spherical porous NPsSiO2, size of 20 + 4.5 nm, with an inner hollow of 16 + 1.3nm. These NPsSiO2 were ahomogeneous population (dynamic light scattering analysis), potential Z negatively charged. We prepared NPsSiO2-NAC by 2procedures, percentage of loaded NAC: (1) 32.7 ± 2.3% (constant agitation at 500 rpm at 4 ° C) and, (2) 96.4 ± 3.1% (sonication pulsesat room temperature). NAC release was completed within 28 h. We evaluated NPsSiO2-NAC from procedure (2); samples of 0.25mg/mLof NPsSiO2-NAC showed cytotoxicity of 84% (OD: 0.11+0.01 [NPsSiO2-NAC-0.25] vs 0.71+0.04 [nontoxic control], p < 0.01).Samples of 0.05 mg/mL showed lower cytotoxicity such as 57.75%, but only with a cover of bovine sera albumin we obtained nontoxicNPsSiO2-NAC (OD: 0.91+0.09 [NPsSiO2-NAC-0.05] vs 0.90+0.08 [no