Curcumin-Loaded Iron Oxide Nanoparticles Coated with Sodium Alginate and Hydroxyapatite and Their Cytotoxic Effects Against the HT-29 and MCF-7 Cancer Cell Lines

Background: Curcumin, a bioactive component of Curcuma langa, has been investigated for its anti-proliferative effects against various cancer cell lines. Although results are very promising, the poor water solubility and low bioavailability of curcumin are its main limitations for clinical application. Objectives: The purpose of this study was to develop a drug delivery system, consisting of hydroxyapatite (HAp) polymer and sodium alginate (NaAlg), covering the magnetic core of iron oxide nanoparticles (IONPs), and loaded with curcumin in order to enhance its bioavailability and therapeutic efficacy. Methods: In this study, IONPs were prepared by the co-precipitation method and coated with HAp and NaAlg. The nanoparticles (NPs) were characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR), and electron microscopy (TEM and SEM). Encapsulation efficiency and curcumin loading rate were examined. Drug release rate was also measured in vitro at pH = 7.5 and 5.5. The toxicity of curcumin-loaded NPs and free curcumin was evaluated against HT-29 and MCF-7 cancer cells. Results: The assessment of physicochemical characteristics showed the synthesis of spherical particles with nanometer sizes (5 - 7 nm) and a high encapsulation efficiency (84.16 ± 3.51 %) and drug loading capacity (21.03 ± 0.87%). Maximum drug release was obtained at pH = 5.5. Iron oxide nanoparticles showed no significant cytotoxic effects. Curcumin-loaded coated IONPs showed a higher toxicity against HT-29 and MCF-7 cancer cells compared to free curcumin. Conclusions: This in vitro study showed that the encapsulation of curcumin, as a potent herbal drug, into IONPs enhanced its bioavailability, suggesting the NPs as an efficient vehicle for targeted drug delivery in cancer treatment.