Surface reactivity and silanization ability of borosilicate and Mg-Sr-based bioactive glasses

Borosilicate bioactive glasses are attracting an increasing interest due to their good hot forming ability, low crystallization tendency and high bioactivity. Surface functionalization of bioactive glasses is a versatile tool for modulation of their properties and consequently of their biological response and it is still an unexplored topic in the case of borosilicate glasses. The possibility to graft 3-aminopropyltriethoxysilane (APTES) to various borosilicate bioactive glasses have been investigated in the present research work. Glasses were produced by melting and completely characterized (SEM-EDS, density, FTIR-ATR, Raman, NMR, zeta potential and reactivity in SBF and TRIS/HCl). Then, APTES was grafted to the surface of the glasses and its presence was verified by means of XPS, contact angle and zeta potential measurements. This study has shown the possibility to silanize borosilicate bioactive glasses for the first time, however, this silanization protocol does not induce the formation of a continuous coating on the glass surface.