Inorganic & Coordination Chemistry, Short Talk
IC-017

Polyoxometalate-Loaded Carboxymethyl Chitosan Nanoparticles with Anticancer Activity

J. M. Parris1, G. Wiprächitger1*, R. Hooshmandabbasi2*, G. R. Patzke1*, C. Maake2*
1Department of Chemistry, University of Zurich, 2Institute of Anatomy, University of Zurich

Polyoxometalates (POMs) have emerged over the last half a century as promising biomedicinal agents ([1], [2], [3]), due to their ability to interact with biomolecules and the tunability of their properties ([1], [2], [4], [5], [6]) In this study, a small series of polyoxometalates and carboxymethyl chitosan nanoparticles are explored for their anticancer activity through extended viability assays, in which the cell viability is investigated for one or two days post 24 h of treatment. Cytotoxicity based on tungsten nuclearity and structure-type is investigated. Among the tested species, [NaP5W30O110]14-   exhibited significantly higher cytotoxicity towards the PC-3 prostate cancer cells, with an IC50 value ca. 5 times lower (per mole of tungsten) than smaller tungstates ([WO4]2-, [PW9O34]9-, and [PW12O40]3-). [Co4(H2O)2(PW9O34)2]10- showed generally reduced cytotoxicity, suggesting that the heteroatom influences the activity.

Encapsulation of POMs in 100-250 nm carboxymethyl chitosan nanoparticles ([7], [8]),  characterized by cryo-TEM, DLS, and other spectroscopic techniques, typically enhances cytotoxicity compared to the pristine POM. Interestingly, a simple CMC/POM mixture was also found to enhance the activity. Additionally, a CMC-[Co4(H2O)2(PW9O34)2]10- nanoparticle formulation showed selective toxicity towards HeLa cervical cancer cells over non-malignant MRC-5 cells in the extended viability assay. These findings highlight the potential of POM/CMC nanosystems for targeted anticancer therapies.

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