Hidrogel de Aloe vera contendo óleo de copaíba encapsulado em carreadores lipídicos nanoestruturados para tratamento da dermatite atópica

Abstract

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by barrier dysfunction, pruritus, and recurrent inflammation. Copaiba oil (CO) exhibits anti-inflammatory and wound-healing activity, while hydration and emollient replenishment are fundamental in AD management. In this study, copaiba oil-loaded nanostructured lipid carriers (NLCs) were developed and their in vitro performance was investigated, aiming at topical use through incorporation into Aloe vera-based hydrogels. Dialyzed NLCs were produced by hot emulsification followed by ultrasonication, containing 6% CO, and showed a size of 192.7 ± 2.2 nm, PdI 0.13 ± 0.04, and zeta potential −35.2 ± 1.0 mV. The cytotoxicity of the formulations was assessed by the MTT assay in HaCaT cells, with an IC50 of 73.59 ± 1.21 μg/mL. Aloe vera mucilage was extracted and structurally characterized, including the presence of aloin; a polysaccharide profile was confirmed, along with low-intensity peaks related to aloin. Hydrogels containing the mucilage were produced and demonstrated rheological and texture properties suitable for topical application, even after association with the NLCs. Oxidative stress was evaluated in RAW 264.7 cells using the formulations at a final concentration equivalent to 25 μg/mL of CO, in which the hydrogel containing NLCs (H-NLC) was the only one able to completely attenuate the oxidant state induced by PMA (200 ng/mL). Anti-inflammatory activity was investigated under stimulation with LPS (1 μg/mL). For NO2− quantification, NLC significantly reduced this marker compared with LPS. By ELISA, a reduction in IL-6 was observed for NLC (−43.9%) and CO (−34.0%), whereas for TNF-α, NLC showed a statistically significant reduction (−23.2%). Therefore, it is concluded that nanoencapsulation promoted superior antioxidant and anti-inflammatory effects compared with free copaiba oil, highlighting the potential of the developed system for the treatment of topical inflammation.