TY - JOUR A1 - Barheine, Sabrina A1 - Hayakawa, S. A1 - Osaka, A. A1 - Jäger, Christian T1 - A NMR investigation of borate incorporation in apatitic biomaterials N2 - The incorporation of ions in the lattice of hydroxyapatite alters significantly its structure. Particularly, if anions such as trigonal borate units are accommodated in the lattice severe distortions must occur around the substitution site because of different geometric shape, electric charge and anion size. Solid-state NMR has been used to investigate this problem in detail for a hydroxyapatite sample synthesized by high temperature solid state reaction. The results clearly verify the existence of network distortions. Indeed, only about 1/3 of the total phosphate content forms crystalline hydroxyapatite (also found in XRD) whereas the residual amount is contained in two different phosphate sites with 31P chemical shifts of 5.5 ppm and 2.3 ppm, but broad resonances lines suggesting disorder. Furthermore, a novel proton signal at -0.6 ppm was found which is directly associated with the borate incorporation. No specific correlation of the two structurally different borate units with the two phosphate groups is found. KW - Apatite KW - Borate KW - Biomaterials KW - Solid-state NMR PY - 2009 UR - http://www.scientific.net/0-87849-353-0/205/ DO - https://doi.org/10.4028/3-908453-07-0.205 SN - 1013-9826 VL - 396-398 SP - 205 EP - 208 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-18914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jäger, Christian A1 - Barheine, Sabrina T1 - A NMR investigation of borate incorpation in apatitic biomaterials T2 - 21st International Symposium of Ceramics in Medicine - Bioceramics 21 CY - Búzios, Brazil DA - 2008-10-21 PY - 2008 AN - OPUS4-17884 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barheine, Sabrina A1 - Jäger, Christian T1 - Surface, interface and bulk structure of borate containing apatitic biomaterials T2 - The Alpine Conference on Solid-State NMR CY - Chamonix, France DA - 2009-09-13 PY - 2009 AN - OPUS4-19370 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Barheine, Sabrina A1 - Hayakawa, S. A1 - Jäger, Christian A1 - Shirosaki, Y. A1 - Osaka, A. T1 - Effect of disordered structure of boron-containing calcium phosphates on their in vitro biodegradability N2 - This study proposes a new guideline for designing biodegradable apatite ceramics. Boron-containing hydroxyapatite (BHAp) particles were prepared by a high-temperature solid-state reaction processing method and were characterized in terms of their chemical composition, apatite lattice defects and in vitro biodegradability. Solid-state nuclear magnetic resonance analysis showed that boron-incorporation into hydroxyapatite (HAp) derived by thermo-chemical reactions between borate and calcium phosphate phases led to disordered phases (BCaP) of a CaO–P2O5–B2O3–OH system covering the crystalline HAp core. X-ray diffraction analysis indicated that the BCaP phase must consist mainly of a crystalline oxyboroapatite (OBAp) phase. An in vitro biodegradability test showed that BHAp degraded quicker than HAp or ß-tricalcium phosphate. The biodegradability of BHAp particles can be controlled by boron incorporation into a HAp lattice leading to the formation of a disordered OBAp phase. KW - Boron KW - Hydroxyapatite KW - Calcium phosphate KW - NMR KW - Biodegradability KW - Disorder KW - Oxyboboapatite PY - 2011 DO - https://doi.org/10.1111/j.1551-2916.2011.04400.x SN - 0002-7820 SN - 1551-2916 VL - 94 IS - 8 SP - 2656 EP - 2662 PB - Blackwell Publishing CY - Malden AN - OPUS4-26244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -