Thermal, structural and in vitro dissolution of antimicrobial copper-doped and slow resorbable iron-doped phosphate glasses

This paper focuses on investigating and comparing the effects of CuO and Fe₂O₃ addition on the bioactive response of glass having composition [xCuO or Fe₂O₃ + (100 − x) (0.2CaO + 0.2SrO + 0.1Na₂O + 0.5P₂O₅)] (in mol%), where x is ranging from 0 up to 5. The addition of CuO was found to increase the hot processing window and the dissolution rate leading to a fast surface layer precipitation. Using IR and Raman spectroscopies, we related this change in the bioactive response of this glass to the progressive depolymerization of the glass network induced by the addition of CuO. On the other hand, the addition of Fe₂O₃ was found to reduce the hot processing window and the dissolution rate as no depolymerization of the network occurs due to the formation of P–O–Fe bonds at the expense of P–O–P bonds. All the glasses were found to dissolve congruently and in a controlled manner. Finally, the antimicrobial properties of the copper-doped glasses were examined and compared to bioactive glasses which are known to exhibit good antimicrobial properties. The CuO addition leads to higher antimicrobial properties than the commercial bioactive glass S53P4 and total bacterial elimination could be obtained.