Brushite (Ca,M)HPO<inf>4</inf>, 2H<inf>2</inf>O doping with bioactive ions (M = Mg²⁺, Sr²⁺, Zn²⁺, Cu²⁺, and Ag⁺): a new path to functional biomaterials?

© 2019 Elsevier Ltd Dicalcium phosphate dihydrate, DCPD (CaHPO4·2H2O), brushite, is an important calcium phosphate compound encountered in mineralized tissues and used in medicine, especially in bone cement formulations. However, the use of DCPD as direct implantable biomaterial has not received dedicated attention. In addition, the possibility to dope DCPD with biologically active ions to modulate its performances was not systematically explored. We have investigated in depth the doping of DCPD with Mg2+, Sr2+, Zn2+, Cu2+, and Ag+ ions. Clear modifications in terms of chemical composition, particle size, pore distribution, crystal morphology, and affinity for water were pointed out. Then, the samples were cultured with human adipose-derived stem cells to explore cytotoxicity and proliferation. Various behaviors were noticed dependent on the incorporated metal ions. Such DCPD compounds associated with bioactive metal ions, and particularly Ag+ and Zn2+, appear promising as a new family of reactive materials for use, as such or in combination, in bone-related applications