Local structure of nanosized bioglasses doped with yttrium and lanthanum by 29Si and 31P MAS NMR

29 Si and 31 P MAS NMR has been used in order to study the structure of nanosized samples of 45S5, 60S and 60S bioglasses doped with yttrium and lanthanum atoms. The 29 Si NMR spectra of 60S bioglass show a much larger contribution of the SiO 4 tetrahedra bound into Q 4 groups by four bridging oxygen atoms compared to the 45S5 sample. The addition of yttrium and lanthanum to the 60S bioglass leads to an increase in the number of Q 2 groups of SiO 4 tetrahedra at the expense of Q 4 species, accompanied by additional deformations of SiO 4 tetrahedra belonging to the Q 2 groups. 31 P NMR spectra obtained for the 60S samples doped with Y and La atoms indicate the formation of Q 1 phosphorus groups and the involvement of the PO 4 tetrahedra in the formation of the polymer network.