Cupuaçu (Theobroma grandiflorum) butter nanoparticles associated with oligosaccharides as cosmetic carriers for prebiotic effect: development, physicochemical characterization, and preclinical evaluation.

The skin microbiota is essential for cutaneous homeostasis, and prebiotics may support it. Nanostructured systems, such as cupuaçu-derived nanoparticles, enhance the delivery and stability of cosmetic active substances, but their role in modulating the skin microbiota remains unclear and requires targeted evaluation. In this study, lipid-polymeric hybrid nanoparticles based on cupuaçu (Theobroma grandiflorum) butter were developed as potential carriers for oligosaccharides. Three formulations were developed: cupuaçu butter (CB-NP), α-glucan oligosaccharide (AGO-CB-NP), and polydextrose nanoparticles (PD-CB-NP). They showed mean diameters of approximately 110 nm, low polydispersity index (PdI < 0.30), and moderately negative zeta potentials (around -16 mV). Rheology demonstrated pseudoplastic behavior. Structural characterization by X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS) indicated reduced crystallinity, chemical compatibility among the ingredients, and a hybrid core-shell organization, with a lipid-rich inner region and an outer layer likely associated with oligosaccharides. The formulations exhibited neither eye irritation nor phototoxicity potential in toxicological screening, conducted in accordance with OECD TG 491 and TG 432. In vitro prebiotic potential showed species-dependent responses: AGO-CB-NP stimulated the mutualist Staphylococcus epidermidis while inhibiting Malassezia furfur, whereas CB-NP inhibited Candida albicans growth. Moderate antioxidant activity (around 20% DPPH scavenging) was observed, and cupuaçu butter contained low levels of phenolic compounds (around 0.12 mg GAE g-1) and intermediate protection against UVA-induced reactive oxygen species. Among the tested formulations, AGO-CB-NP showed the most favorable profile. Overall, the results suggest a promising strategy for developing carriers for microbiome-oriented cosmetic formulations, encouraging further investigation in more complex biological systems, such as in clinical trials.