Research teams from ITMO University in Saint Petersburg and ETH Zurich have created biosafe luminescent nanoparticles for visualizing cancer tumors and damaged blood vessels in heart and brain.
This development will provide an alternative to the use of semiconductor nanoparticles called quantum dots which are very toxic. These new particles are made up of hafnium oxide and doped with rare earth metals, particularly europium and terbium. Hafnium oxide has been included in the list of oxides approved for invasive use.
These new nanoparticles can emit a visible light under the ultraviolet and blue excitation that will allow one to use them as a contrast agent when taking images of internal tissues.
The rare earth metals charge the surfaces of these particles for maintaining stability in biological fluids. The luminescence spectrum can also be shifted using these rare earth metals.
These biosafe luminescent nanoparticles can not only be used for imaging, but also for tumour therapy. Atoms of hafnium and rare earth metals like all heavy elements ionize water molecules in the presence of X-rays leading to production of free radicals. These free radicals, in turn, start killing the neighbouring cells. This method of cancer treatment is supposed to be more harmless.