In Vitro Studies Demonstrate Antitumor Activity of Vanadium Ions from a CaO-P 2 O 5 -CaF 2 :V 2 O 5 Glass System in Human Cancer Cell Lines A375, A2780, and Caco-2.

In this research, we investigated the structural and biological properties of phosphate glasses (PGs) after the addition of VO. A xVO∙(100 - x)[CaF∙3PO∙CaO] glass system with 0 ≤ x ≤ 16 mol% was synthesized via a conventional melt-quenching technique. Several analysis techniques (dissolution tests, pH, SEM-EDS, FT-IR, and EPR) were used to obtain new experimental data regarding the structural behavior of the system. In vitro tests were conducted to assess the antitumor character of VO-doped glass (x = 16 mol%) compared to the matrix (x = 0 mol%) and control (CTRL-) using several tumoral cell lines (A375, A2780, and Caco-2). The characterization of PGs showed an overall dissolution rate of over 90% for all vitreous samples (M and V1-V7) and the high reactivity of this system. EPR revealed a well-resolved hyperfine structure (hfs) typical of vanadyl ions in a C symmetry. FT-IR spectra showed the presence of all structural units expected for PO, as well as very clear depolymerization of the vitreous network induced by VO. The MTT assay indicated that the viability of tumor cells treated with V7-glass extract was reduced to 50% when the highest concentration was used (10 µg/mL) compared to the matrix treatment (which showed no cytotoxic effect at any concentration). Moreover, the matrix treatment (without VO) provided an optimal environment for tumor cell attachment and proliferation. In conclusion, the two types of treatment investigated herein were proven to be very different from a statistical point of view ( < 0.01), and the in vitro studies clearly underline the cytotoxic potential of vanadium ions from phosphate glass (V7) as an antitumor agent.