Platinum nanoparticles supported on functionalized hydroxyapatite: Anti-oxidant properties and bone cells response

Platinum ions and nanoparticles applications in the biomedical field include a number of pathologies. In particular, platinum ions are useful in the preparation of antitumoral drugs, whereas Pt nanoparticles (PtNPs) are known to reduce cellular oxidative stress. Herein, we developed composite materials using poly(ethylenimine) functionalized hydroxyapatite (HAPEI) as support for platinum. The presence of polyelectrolyte promotes interaction with platinum ion, which is loaded in greater amount than on pure hydroxyapatite. The dimensions of PtNPs are very small (about 1 nm), but increase up to about 20–30 nm on heat treatment. Loading Pt(II) ion on the apatitic supports provide a material with cytotoxic properties towards osteosarcoma derived cell lines (SaOS2 and MG63). On the contrary, PtNPs loaded apatitic supports display good anti-oxidant properties, in agreement with their quenching activity towards H2O2. Moreover, they promote differentiation of both primary osteoblast and osteoblast cell line, as shown by the increase of the levels of Alkaline Phosphatase and Collagen type 1, and reduce the level of reactive oxygen species with a consequent decrease of cellular oxidative stress.