Seyedeh Sabereh Samavati - Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
Mahnaz Hadizadeh - Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
Mohammad Abedi - Department of Chemical Technologies, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
Morteza Rabiei - Nanobiotechnology Department, Faculty of Innovative Science and Technology, Razi University, Kermanshah, Iran
Hossein Derakhshankhah - Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran

Objective(s): Encapsulation of essential oil in polymeric nanoparticles (NPs) increases their retention and improves their efficacy. Here, eucalyptus essential oil (EEO) encapsulate in the chitosan (CS) NPs increases its retention, and enhances the anticancer effect of EEO.Materials and Methods: The effects of pH, chitosan sodium tripolyphosphate ratio, and chitosan concentration on the size and charge NPs were evaluated. The success of EEO encapsulation was confirmed by FT-IR, UV–Vis spectroscopy, and GC techniques. The toxic effect of free EEO and CS-EEO NPs was investigated in MDA-MB-۲۳۱ breast cancer cells and fibroblast normal cells. Results: The optimized obtained EEO -loaded chitosan nanoparticles (CS-EEO NPs) were spherical with an average diameter of ۸۶ nm, a polydispersity index below ۰.۴, and positive zeta potential (+۱۴.۲۵ mV) as confirmed. Increasing the concentration and pH of the chitosan solution and decreasing the chitosan/sodium tripolyphosphate ratio, the size of NPs decreased. Loading capacity (LC) and encapsulation efficiency (EE) of EEO in the NPs were about ۴۵% and ۳۲–۷۶%, respectively. The chitosan nanoparticles exhibited a biphasic release profile with the release of ۸۷% of the EEO in the first ۵ h, followed by a sustained release for the next ۴۳ h. Conclusion: The free EEO was more toxic for MDA-MB-۲۳۱ cells than fibroblast cells; however, CS-EEO NPs were non-toxic for fibroblast cells and more toxic for MDA-MB-۲۳۱ cells compared to free EEO. Therefore, the CS-EEO NPs illustrate smart behavior in killing cancerous cells and will be suggested for breast cancer drug delivery.

Chitosan nanoparticles, Eucalyptus essential oil, Encapsulation, MDA-MB-۲۳۱ cells