Brazilian red propolis extract free and encapsulated into polymeric nanoparticles against ovarian cancer: formulation, characterisation and biological assays in 2D and 3D models.

Cancer incidence worldwide is alarming and among the cancers that affect women ovarian cancer is the most fatal. Many side effects are associated with conventional therapies and none of them are completely effective, so the development of new treatments is necessary. Brazilian red propolis extract is a natural product with complex composition and great potential for cancer treatment. However, its clinical application is harmed due to unfavourable physicochemical characteristics. To enable its application encapsulation in nanoparticles can be used. OBJECTIVES: The aims of this work were to develop polymeric nanoparticles with Brazilian red propolis extract and compare their action with the free extract against ovarian cancer cells. METHODS: Box Behnken design was used and nanoparticles were characterised using the techniques dynamic light scattering, nanoparticle tracking analysis, transmission electron microscopy, differential scanning calorimetry and encapsulation efficiency. Activity against OVCAR-3 was also tested on 2D and 3D models. KEY FINDINGS: Nanoparticles' sizes were ~200 nm with monomodal size distribution, negative zeta potential, spherical shape and with extract molecularly dispersed. Encapsulation efficiency was above 97% for the biomarkers chosen. Nanoparticles had greater efficacy in comparison with free propolis in OVCAR-3. CONCLUSIONS: So far, the nanoparticles here described have the potential to be a chemotherapy treatment in the future.