Cobalt Ferrite Nanoparticles Conjugated with Methylene Blue: A Promising Approach for Photodynamic Therapy in Breast Cancer

Abstract Breast cancer, as the most frequently diagnosed malignancy, is the main cause of cancer mortality due to cancer all around the world among women. Therefore, developing effective breast cancer treatment approaches is crucial. Photodynamic therapy (PDT) is a novel and rapidly developing therapeutic approach that has been studied extensively in treating various cancer types. PDT depending on light-activated photosensitizers eliminate cancer cells selectively. Moreover, its effectiveness is highly improved by nanoparticle incorporation. In this study, cobalt ferrite nanoparticles (CFNPs) were prepared by the co-precipitation method, coated with mesoporous silica, and loaded with methylene blue (MB) as a photosensitizer. XRD, SEM, and FT-IR were used in carrying out structural analysis of the synthesized nanoparticles. First of all, XRD patterns demonstrated the spinel phase crystalline structure of the nanoparticles. The average size of crystallite was calculated 38 nm for Fe3O4 nanoparticles. This size decreased up to 15.8 nm for Co1.5Fe1.5O4 nanoparticles together with depending on Co ratio. Afterwards, it increased, and it was calculated 37.8 nm for Co3O4 nanoparticles. Secondly, SEM analysis also showed that increasing cobalt content leads to a decrease in particle size and the formation of a more homogeneous spherical particle distribution, and this is consistent with XRD results. However, agglomeration was observed at higher cobalt ratios (x = 2 and x = 3), and particle size increased considerably. Finally, FTIR results clarified the functional groups of the nanoparticles according to the increasing Co ratio in CoxFe3–xO4 formulated samples. The photodynamic activity of the MB-loaded silica-coated CFNPs was investigated on MDA-MB-231 breast cancer cells after irradiation at 635 nm for 30 min. The MB-loaded CFNPs induced cell death in breast cancer cells following irradiation, indicating considerable photodynamic activity against breast cancer. This study highlights the potential of CFNPs as efficient photosensitizer delivery systems in PDT, presenting them as a promising therapeutic strategy for treating breast cancer.