De Aza P N studied Chemistry-Ceramics at the Santiago de Compostela University, where she received her Doctoral Degree in 1995. She did a Postdoctoral stage at the IRC in Biomaterials at the Queen Mary & Wetsfield College, University of London (UK) working on in vitro and in vivo behavior of Bioceramics. At this moment, she is the Chair of the Materials Science, Optic and Electronic Technology Department, Professor of Materials Science and Metallurgical Engineering and Researcher at the Bioengineering Institute at the Miguel Hernandez de Elche University.
In the present study, a new single phase Si-Ca-P based ceramic (called Nurse´s Ass) was obtained and it´s in vitro behaviour for potential bone tissue regeneration was explored. Porous Si-Ca-P (Nurse´s Ass) single phase ceramic was obtained from high temperature sintering of γ-dicalcium silicate and β-tricalcium phosphate previously synthetized. The apatite-mineralization ability and dissolution rate have been systematically studied by immersion of the material in simulated body fluid (SBF) for several periods of time. A massive formation of a new dense calcium deficient hydroxyapatite (CDHA) layer was observed at the SBF-sample interface. Adjacent to the dense CDHA layer a porous structure has been developed parallel to the interface which is formed by pseudomorphic transformation of the Si-Ca-P (Nurse´s Ass) into CDHA. In addition, cell attachment test showed that the new material supported the adult human bone marrow-derived mesenchymal stem cells (hMSCs) adhesion and spreading; the cells established close contact with the ceramic surface in an extended culture of 28 days (Figure 1). In view of the results, Nurse´s Ass ceramic should be an effective substrate promoter of bone tissue regeneration suitable for bone tissue bioengineering. Future performance should be led using standard biomaterials, such as Si-HA or Si-TCP. The Nurse´s Ass biological performance should be investigated as proposed in International Standard ISO-10993-5.
Jesús Ma Rincon is a Senior Research Professor (Profesor de Investigación) at the Instituto E Torroja de Ciencias de la Construcción, CSIC, Madrid, where he is the Founder and Head of the Glass-Ceramics Laboratory. He was General Secretary of the Spanish Glass and Ceramic Society and Editor-in-Chief of Bol. Soc. Esp. Ceram. Vidrio. He has conducted electron microscopy on ceramics, glasses and glass-ceramics and their raw materials, being author of seven monograph books and more than 170 papers in glass-ceramics and advanced ceramics. He was invited Professor at the Department of Materials Science and National Electron Microscopy Lab, University California, Berkeley, during 1984-85 working in zirconial/mullite composites. Since last 15 years, he is active in the vitrification and recycling of a wide range of residues, up to simulated radioactive industrial wastes. Recently, he was the past President of the Spanish Society of Scientists.
Some glasses and glass-ceramics obtained from Canary Islands basalt rocks (La Gomera Fuerteventura, Tenerife and El Hierro) have been obtained by controlled melting and recrystallization. The electrical measurements have been carried out under complex impedance at temperatures in the 250°C-700°C range. From these electrical determinations, it was possible to follow the evolution of original glasses with respect the nucleation and crystal growth process. The main crystalline phases were pyroxenes, feldspar (anorthite) and magnetite. The magnetite decorates the dendritic crystallization of pyroxenes and it is the responsible phase of the electrical conduction properties. The ratio between Fe2+-Fe3+ was related to the Fe2+/Fe total content in the final materials allowing to propose an electronic conduction model.