The development and characterization of an andiroba oil-based nanoemulsion (Carapa guianensis, Aubl.): insights into its physico-chemical features and in vitro potential healing effects

Abstract

Background/Objectives: Andiroba oil, extracted from Carapa guianensis seeds, possesses therapeutic properties including anti-inflammatory and wound healing effects. This study aimed to develop and characterize a nanoemulsion formulation containing andiroba oil (NeAnd) and to evaluate its cytotoxicity and wound healing potential in vitro. Methods: The oil was evaluated for acidity, antioxidant activity, and fatty acid composition. NeAnd was produced by ultrasonication and characterized using FTIR (Fourier transform infrared spectroscopy), Raman spectroscopy, dynamic light scattering, and transmission electron microscopy. Results: NeAnd exhibited a spherical shape and stable physicochemical properties, with an average hydrodynamic diameter (HD) of 205.7 ± 3.9 nm, a polydispersity index (PdI) of 0.295 ± 0.05, a negative zeta potential of −4.16 ± 0.414 mV, and pH of approximately 6.5. These nanodroplets remained stable for 120 days when stored at 4 °C and maintained their parameters even under pH variations. FTIR and Raman analyses confirmed the presence of functional groups and the organization of fatty acid chains in NeAnd. Cell viability assays revealed no statistically significant differences in cytotoxicity at various concentrations (90–360 µg/mL) after 24 and 48 h. In scratch wound healing assays, NeAnd significantly enhanced wound closure (88.9%) compared to the PBS control (38%) and free andiroba oil (68.6%) in keratinocytes (p < 0.05). Conclusions: These promising findings indicate NeAnd as a potential nanophytomedicine for wound healing and tissue regeneration treatments.