Cancer is one of the main causes of death across major mammalian orders, being the mammary gland tumor the most frequent in females. Surgery is the most widely used prescription for this condition; however, due to its side effects, new and less invasive treatments using bioactive compounds are being sought. Nanostructured systems, such as nanoemulsions (NEs), enable more efficient delivery and protection of these compounds, allowing it to reach its site of action more effectively. The present study aimed to develop oil-in-water (O/W) NEs with tea tree essential oil integrating quercetin, rosmarinic acid, or both and evaluate them as potential therapeutic agents in breast cancer cells. The NEs were characterized by particle size distribution and Z-potential for 4 weeks. Subsequently, their impact on cell viability was assessed in MDA-MB-231 cells, a triple-negative breast cancer cell line. The four NEs had an average size within the nanometer scale (10^–9 m), ideal to passive target the anticancer effect (< 200 nm) due to the retention effect and facilitate its permeability. These vehicles were kept stable at 4 °C for 4 weeks. Our findings demonstrate that with initial doses of 3.9 μg/mL of these NEs, significant antiproliferative activity is achieved in cancer cells (~ 80%, p < 0.001); furthermore, the induction of apoptosis through caspase activation was demonstrated in MDA-MB-231 cells. In summary, our preliminary results suggest that nanoemulsions (NEs) of tea tree oil incorporating the bioactive compounds uercetin and rosmarinic acid may have potential therapeutic applications as co-adjuvant treatment of human breast cancer.

Cataracts are the leading cause of reversible blindness worldwide; this condition results from the aggregation of lens proteins. Currently, surgery remains the only treatment; however, there is growing interest in non-surgical approaches, including the use of bioactive compounds incorporated into nanostructured systems designed to enhance solubility, enable controlled release, and improve bioavailability and bioactivity. Among the bioactive compounds investigated, curcumin has attracted considerable attention due to its antioxidant and anti-inflammatory properties, positioning it as a potential anticataractogenic agent. In the present study, curcumin-loaded nanoemulsion was developed via ultrasonication and characterized by average particle size, D90 percentile, ζ potential, and rheological behavior. In addition, its anti-cataract efficacy was evaluated both using an in vivo model in rats and an ex vivo model employing human cataract samples. The resulting curcumin-loaded nanoemulsion exhibited an average particle size of 152 ± 19.79 nm with a monomodal distribution, along with good physical stability over time. The nanoemulsion exhibited apparent viscosity between 30 and 25 mPa·s, at shear rate values (100 to 0 s⁻¹), indicating slight shear-thinning behavior. Regarding the effect on cataracts, in the in vivo model, cataract reversal was observed. Furthermore, ex vivo isothermal titration calorimetry (ITC) analyses indicated exothermic heat exchange between the curcumin nanoemulsions and cataract fragments, consistent with binding interactions occurring within lens components, likely involving crystallin proteins. These findings provide biophysical and in vivo evidence that intravitreally administered curcumin-loaded nanoemulsions not only prevent but actively reverse lens opacity, positioning them as a promising non-surgical therapeutic approach for cataract treatment.

Cataracts are the leading cause of reversible blindness worldwide, this condition results from the aggregation of lens proteins. Currently, surgery remains the only effective treatment; however, there is growing interest in non-surgical approaches, including the use of bioactive compounds incorporated into nanostructured delivery systems designed to enhance solubility, enable controlled release, and improve bioavailability and bioactivity. Among the bioactive compounds investigated, curcumin has attracted considerable attention due to its antioxidant and anti-inflammatory properties, positioning it as a potential anticataractogenic agent. In the present study, a curcumin-loaded nanoemulsion was developed via ultrasonication and characterized in terms of average particle size, D90 percentile, ζ potential, temporal stability, and rheological behaviour. In addition, its anti-cataract efficacy was evaluated both using an in vivo model in rats and an ex vivo model employing human cataract samples. The resulting curcumin-carrying nanoemulsion exhibited an average particle size of 152 ± 19.79 nm with a monomodal distribution, along with good physical stability over time. On the other hand, the nanoemulsion exhibited viscosity values of 31.36 ± 1.88 to 25.96 ± 0.81 mPa·s and a near Newtonian flow behavior. Regarding the effect on cataracts, in the in vivo model, cataract reversal of at least two grades was observed. Furthermore, ex vivo isothermal titration calorimetry analyses confirmed exothermic binding interactions between the curcumin nanoemulsions and cataract fragments, suggesting the involvement of multiple binding sites within lens components, most likely crystallin proteins. These findings support the potential of curcumin-based nanoemulsions as promising therapeutic candidates for the treatment of cataracts.