María Vallet-Regí was born in Las Palmas, Spain, in 1946. She studied Chemistry at the Universidad Complutense de Madrid (UCM) and received her PhD at the same University in 1974. She is full professor of Inorganic Chemistry and Head of the Department of Inorganic Chemistry and Bioinorganic at the Faculty of Pharmacy (UCM). Her current research field is solid state chemistry, covering aspects of synthesis, characterisation and reactivity in oxides and bioceramics. Daniel Arcos was born in Madrid, Spain, in 1971. He is holding a postdoctoral research position ('Ramón y Cajal' grant) at the Universidad Complutense de Madrid, Spain. Since completing his PhD in 2002 on the synthesis and evaluation of bioactive glasses and glass-ceramics, he has worked on the structural studies of silicon containing hydroxyapatites. Currently, his research is focused on mesoporous materials for biomedical applications