Effect of rosemary extract on the microstructure, phase evolution, and magnetic behavior of cobalt ferrite nanoparticles and its application on anti-cancer drug delivery

Cobalt ferrite nanoparticles (CFO NPs) were synthesized by a modified sol-gel method using Fe(NO₃)₃.9 H₂O and Co(NO₃)₂·6H₂O as the sources of Fe 3+ and Co 2+ in presence of different volumes of rosemary extract and sucrose as gel agent, chelating agent and non-magnetic elements such as calcium and magnesium ions. The prepared nanoparticles were characterized via X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). The X-ray diffraction results confirmed that the sample prepared with 5 mL rosemary extract has single-phase spinel cobalt ferrite nanoparticles with a cubic crystal structure at 750 °C for 3 h (S1 sample). The average crystallite size was calculated about 33 nm using the Debye–Scherrer equation. Scanning electron microscopy also exposed that the prepared nanoparticles have a cubic morphology. Besides, the magnetic properties of the as-synthesized nanoparticles (S1 sample) indicated the highest saturated magnetization of 64 emu.g⁻¹ as compared to other samples. The nanoparticles were then coated with tripolyphosphate (TPP) and chitosan polymer (Cs) to be applied as a carrier for drug delivery CoFe₂O₄-TPP-Cs (CFO-TPP-CS). The antioxidant doxorubicin (DOX) drug was then covered on the surface of the nanoparticles, and its drug release (CFO-TPP–CS–DOX) from the substrate of coated nanoparticles containing doxorubicin was evaluated at different pH levels. The coated CFO nanoparticles with tripolyphosphate (TPP) –Chitosan (Cs) sample indicated the biocompatibility and non-toxic nature of CFO-TPP- Cs NPs. Meanwhile, the CFO-TPP–CS–DOX nanosystem showed good death percentage of the breast cell cancer line (MCF-7 cell) in an acidic medium.