Nanopartículas poliméricas para entrega controlada de luteína: desenvolvimento, caracterização, atividade antioxidante e citotoxicidade

Abstract

Lutein is a natural carotenoid known for its high antioxidant capacity, thus potentially useful in anti-aging products. However, its instability to light, heat, and oxygen, as well as low water solubility, limit its bioavailability in the skin. The development of nanostructured drug delivery systems containing lutein presents an interesting approach to optimize its characteristics and enhance skin penetration. Thus, efforts were made to develop, characterize, and evaluate the antioxidant activity and cytotoxicity of polymeric nanocapsules containing lutein, employing poly(ε-caprolactone) polymer. The systems were obtained by the pre-formed polymer interfacial deposition method and characterized through physicochemical studies using dynamic light scattering (DLS), electrophoretic mobility, and pH measurements in a calibrated potentiometer; morphological analysis by FEG-SEM and structural analysis by XRD and FTIR. Antioxidant activity was evaluated using FRAP, DPPH• and ABTS•+ methods and cytotoxicity was evaluated in vitro on fibroblasts-3T3. Polymeric nanocapsules containing lutein were successfully obtained using the chosen method. Morphologically, the nanocapsules exhibited a spherical shape with smooth, regular surfaces, nanometric and homogeneous size, consistent with DLS results, showing nanocapsules of approximately 300 nm, a polydispersity index of 0.2, and a zeta potential near to - 30 mV. The samples exhibited pH levels ranging from 5,02 ± 0,023 to 5,94 ± 0,037. The X-ray diffraction confirmed that the encapsulation method was efficient, and the drug is primarily in molecular dispersion within the oily core of the nanocapsules. The FTIR confirmed that there were no chemical bonds between lutein and PCL. Ambient and 4 °C temperatures preserved the characteristics of the nanosystems for 30 days. Lutein encapsulation in nanocapsules ensured high efficacy of antioxidant activity in the evaluated methods. Cell viability assays confirmed that lutein did not present toxicity in fibroblast cells at concentrations lower than 6.25% (v/v) compared to the control. Thus, the results provide an experimental basis supporting the use of PCL-coated lutein nanocapsules as a viable and innovative alternative for cutaneous administration of lutein.