Co-founder and R&D researcher Cognita Technology Campinas, Sao Paulo, Brazil
The cytotoxicity evaluation of nanostructured lipid carriers (NLCs) loaded with free phytosterols (FPs), as bioactive compound, is the purpose of this research. NLCs were developed using edible fats and oils (high oleic sunflower oil, HOSO, and fully hydrogenated crambe oil, CR). NLCs were obtained by high-pressure homogenization (3 cycles/ 800bar) following a general formulation of 10% of the lipid phase and 90% (w/w) of the aqueous phase. Two NLCs systems were developed according to the lipid phase: NLC1 (FP+HOSO, 3/7) and NLC2 (FP+CR+HOSO, 3/1/7), 2% of Tween®80 was used as emulsiﬁer for both systems. NLC 1 and 2 presented, approximately, 174 and 195 nm. The toxicity of NLCs in cell culture was studied using MTT assay, employing Caco-2 (human colon adenocarcinoma) cells. Caco-2 cells were exposed to five different NLCs concentrations, 0.1, 1.0,10, 25 and 50 µl/mL. The relative cell viability was expressed as a % of the control group (cells with no particle exposure). The NLC1 presented values of viability of 91.74±5.63 and 146.52±6.51% at lower and higher concentrations; while NLC2 showed 110.17±6.34 and 103.07±1.76% of cell viability at lower and higher concentrations. Whereas the MTT test considers a normal variation of 20% in responses, considering the metabolic activity variations of cells, at the evaluated concentrations, these NLCs presented safe for this kind of cells, under the test conditions. So, the NLCs loaded FPs can be considered a safe option to be applied as a bioactive delivery system into foods.