Doped calcium phosphate bone cements and real-time monitoring of their hardening mechanism

Nowadays, considerable efforts have been focused on various calcium phosphate based cement compositions (CPC), developed to restore the damaged human hard tissues, like vertebras and osteoporotic bone. Furthermore, CPC materials are widely used as synthetic substitutes for non-load bearing fractures, bone defects and teeth reconstruction, due to their chemical similarity to the mineral component of the natural hard tissue. However, the proposed up to now cement formulations can be improved by endowing cements with additional properties, requested for a certain application field. For example, the bone graft associated infections can be prevented by doping the synthetic materials with Ag+ ions at low (non cytotoxic) concentrations. This way seems to be more appropriate, because the antimicrobial agents could be provided directly at the implantation site. Another interesting functionalization option are Zn2+ ions - an essential trace element participating in a variety of cellular processes, including DNA synthesis, behavioural responses, bone formation and growth and wound healing. Moreover, zinc plays an important role in gene expression and in the regulation of cellular growth and differentiation. To this end, Zn2+ is known to possess antibacterial, osteo- and angiogenetic properties, enhancing the proliferation of osteoblastic cells. The aim of this research is to develope functionalized cements for several bone grafting applications, among them those mentioned above. In order to monitor in real time all these processes, the Energy Dispersive X-Ray Diffraction (EDXRD) technique is applied, being very suitable for this task.