TY - CONF A1 - Knabe, C. A1 - Gildenhaar, Renate A1 - Berger, R. A1 - Ostapowicz, W. A1 - Fitzner, R. A1 - Radlanski, R. A1 - Gross, U. A1 - Siebert, G. T1 - In vitro examination of novel calcium phosphates using osteogenic cultures T2 - 5th World Biomaterials Congress CY - Toronto, Canada DA - 1996-05-29 KW - In-vitro Untersuchung KW - Kalzium-Phosphat KW - Zahnersatz KW - Knochen PY - 1996 VL - 1 SP - 890 CY - Toronto AN - OPUS4-672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winkler, T. A1 - Hoenig, E. A1 - Huber, G. A1 - Janssen, R. A1 - Fritsch, D. A1 - Gildenhaar, Renate A1 - Berger, Georg A1 - Morlock, M.M. A1 - Schilling, A.F. T1 - Osteoclastic bioresorption of biomaterials: Two- and three-dimensional imaging and quantification N2 - Purpose: Bioresorbable materials have been developed in the hope that the body will replace them with newly formed tissue. The first step of this remodeling process in bone is the bioresorption of the material by osteoclasts. The aim of this study was to analyze osteoclastic resorption of biomaterials in vitro using the commonly used two-dimensional methods of light-microscopy (LM) and scanning electron microscopy (SEM) in comparison with infinite focus microscopy (IFM), a recently developed imaging method allowing for three-dimensional surface analysis. Methods: Human hematopoietic stem cells were cultivated in the presence of the cytokines M-CSF and RANK-L for 4 weeks directly on dentin and a calcium phosphate cement. Osteoclast development was surveyed with standard techniques. After removal of the cells, resorption was characterized and quantified by LM, SEM and IFM. Results: Osteoclast cultures on the biomaterials presented the typical osteoclast-specific markers. On dentin samples LM, SEM as well as IFM allowed for discrimination of resorption. Quantification of the resorbed area showed a linear correlation between the results (LM vs. SEM: r=0.996, p=0.004; SEM vs. IFM: r=0.989, p=0.011; IFM vs. LM: r=0.995). It was not possible to demarcate resorption pits on GB14 using LM or SEM. With IFM, resorption on GB14 could be visualized and quantified two- and three-dimensionally. KW - Biomaterial KW - Three-dimensional KW - IFM KW - Osteoclast KW - Dentin KW - Calcium phosphate PY - 2010 SN - 0391-3988 VL - 33 IS - 4 SP - 198 EP - 203 PB - Wichtig Ed. CY - Milano [u.a.] AN - OPUS4-21621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winkler, T. A1 - Hoenig, E. A1 - Gildenhaar, Renate A1 - Berger, Georg A1 - Fritsch, D. A1 - Janssen, R. A1 - Morlock, M.M. A1 - Schilling, A.F. T1 - Volumetric analysis of osteoclastic bioresorption of calcium phosphate ceramics with different solubilities N2 - Commonly, to determine osteoclastic resorption of biomaterials only the resorbed area is measured. The depth of the resorption pit, however, may also be important for the performance of a material. To generate such data we used two calcium phosphate ceramics (Ca10 and Ca2). The solubility of the materials was determined according to DIN EN ISO 10993-14. They were scanned three-dimensionally using infinite focus microscopy and subsequently cultivated for 4 weeks in simulated body fluid without (control) or with human osteoclasts. After this cultivation period osteoclasts number was determined and surface changes were evaluated two- and three-dimensionally. Ca10 and Ca2 showed solubilities of 11.0 ± 0.5 and 23.0 ± 2.2 mg g-1, respectively. Both materials induced a significant increase in osteoclast number. While Ca10 did not show osteoclastic resorption, Ca2 showed an increased pit area and pit volume due to osteoclastic action. This was caused by an increased average pit depth and an increased number of pits, while the average area of single pits did not change significantly. The deduced volumetric osteoclastic resorption rate (vORR) of Ca2 (0.01–0.02 µm3 µm-2 day-1) was lower than the remodelling speed observed in vivo (0.08 µm3 µm-2 day-1), which is in line with the observation that implanted resorbable materials remain in the body longer than originally expected. Determination of volumetric indices of osteoclastic resorption might be valuable in obtaining additional information about cellular resorption of bone substitute materials. This may help facilitate the development of novel materials for bone substitution. KW - Biodegradation KW - Surface analysis KW - Simulated body fluid KW - Osteoclasts KW - Calcium phosphate ceramics PY - 2010 DO - https://doi.org/10.1016/j.actbio.2010.04.015 SN - 1742-7061 VL - 6 IS - 10 SP - 4127 EP - 4135 PB - Elsevier CY - Amsterdam AN - OPUS4-22554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernstein, A. A1 - Berger, Georg A1 - Brandt, J. A1 - Wenkel, R. A1 - Gildenhaar, Renate A1 - Zielezinski, T. A1 - Nöbel, D. T1 - Calciumtitanat (Ca4Ti3O10) - ein neues Material für Implantatbeschichtungen KW - Implantatbeschichtung KW - Calciumtitanat KW - Bioaktivität KW - Knochenkontakt KW - Biomaterial-bone-coating of an implant PY - 2004 SN - 1616-0177 SN - 0011-8656 VL - 5 IS - 4 SP - 242 EP - 248 PB - Verl. Neuer Merkur CY - München AN - OPUS4-6010 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knabe, C. A1 - Howlett, C. R. A1 - Markovic, B. A1 - Gildenhaar, Renate A1 - Berger, Georg A1 - Zreiqat, H. T1 - The Functional Expression of Osteoblasts Grown on Rapid Resorbable Calcium Phosphates T2 - 15th International Symposium on Ceramics in Medicine ; 15th Annual meeting of the International Society for Ceramics in Medicine ; 15th Bioceramics CY - Sydney, NSW, Australia DA - 2002-12-04 KW - Guided bone regeneration KW - Calcium alkali orthophosphates KW - Osteoblasts KW - Cell differentiation PY - 2003 SN - 1013-9826 VL - 240-242 SP - 679 EP - 682 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-2115 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knabe, C. A1 - Stiller, M. A1 - Kampschulte, M. A1 - Wilbig, Janka A1 - Peleska, B. A1 - Günster, Jens A1 - Gildenhaar, R. A1 - Berger, G. A1 - Rack, A. A1 - Linow, U. A1 - Heiland, M. A1 - Rendenbach, C. A1 - Koerdt, S. A1 - Steffen, C. A1 - Houshmand, A. A1 - Xiang-Tischhauser, L. A1 - Adel-Khattab, D. T1 - A tissue engineered 3D printed calcium alkali phosphate bioceramic bone graft enables vascularization and regeneration of critical-size discontinuity bony defects in vivo N2 - Recently, efforts towards the development of patient-specific 3D printed scaffolds for bone tissue engineering from bioactive ceramics have continuously intensified. For reconstruction of segmental defects after subtotal mandibulectomy a suitable tissue engineered bioceramic bone graft needs to be endowed with homogenously distributed osteoblasts in order to mimic the advantageous features of vascularized autologous fibula grafts, which represent the standard of care, contain osteogenic cells and are transplanted with the respective blood vessel. Consequently, inducing vascularization early on is pivotal for bone tissue engineering. The current study explored an advanced bone tissue engineering approach combining an advanced 3D printing technique for bioactive resorbable ceramic scaffolds with a perfusion cell culture technique for pre-colonization with mesenchymal stem cells, and with an intrinsic angiogenesis technique for regenerating critical size, segmental discontinuity defects in vivo applying a rat model. To this end, the effect of differing Si-CAOP (silica containing calcium alkali orthophosphate) scaffold microarchitecture arising from 3D powder bed printing (RP) or the Schwarzwalder Somers (SSM) replica fabrication technique on vascularization and bone regeneration was analyzed in vivo. In 80 rats 6-mm segmental discontinuity defects were created in the left femur. KW - Additive Manufacturing KW - Bio active ceramic KW - In-vivo KW - Alcium alkali phosphate PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584555 DO - https://doi.org/10.3389/fbioe.2023.1221314 SN - 2296-4185 VL - 11 SP - 1 EP - 20 PB - Frontiers SA CY - Lausanne AN - OPUS4-58455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adel-Khattab, D. A1 - Giacomini, F. A1 - Gildenhaar, R. A1 - Berger, G. A1 - Gomes, Cynthia A1 - Linow, Ulf A1 - Hardt, M. A1 - Peleska, B. A1 - Günster, Jens A1 - Stiller, M. A1 - Houshmand, A. A1 - Ghaffar, K. A1 - Gamal, A. A1 - El-Mofty, M. A1 - Knabe, C. T1 - Development of a synthetic tissue engineered three- dimensional printed bioceramic-based bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro N2 - Over the last decade there have been increasing efforts to develop three-dimensional (3D) scaffolds for bone tissue Engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizing bone Matrix in vitro, thereby mimicking the advantageous properties of autogenous bone grafts and facilitating usage for reconstructing segmental discontinuity defects in vivo . To this end, 3D scaffolds were developed from a silica-containing calcium alkali orthophosphate, using, fi rst, a replica technique – the Schwartzwalder – Somers method – and, second, 3D printing, (i.e. rapid prototyping). The mechanical and physical scaffold properties and their potential to facilitate homogenous colonization by osteogenic cells and extracellular bone matrix formation throughout the porous scaffold architecture were examined. Osteoblastic cells were dynamically cultured for 7 days on both scaffold types with two different concentrations of 1.5 and 3 × 10⁹ cells/l. The amount of cells and bone matrix formed and osteogenic marker expression were evaluated using hard tissue histology, immunohistochemical and histomorphometric analysis. 3D-printed scaffolds (RPS) exhibited more micropores, greater compressive strength and silica release. RPS seeded with 3 × 10⁹ cells/l displayed greatest cell and extracellular Matrix formation, mineralization and osteocalcin expression. In conclusion, RPS displayed superior mechanical and biological properties and facilitated generating a tissue engineered synthetic bone graft in vitro, which mimics the advantageous properties of autogenous bone grafts, by containing homogenously distributed terminally differentiated osteoblasts and mineralizing bone matrix and therefore is suitable for subsequent in vivo implantation for regenerating segmental discontinuity bone defects. KW - Bone tissue engineering KW - Calcium alkali orthophosphate KW - Rapid prototyping KW - Scaffold KW - Mandible PY - 2017 DO - https://doi.org/10.1002/term.2362 SN - 1932-6254 SN - 1932-7005 VL - 12 IS - 1 SP - 44 EP - 58 PB - Wiley Online Library AN - OPUS4-40745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knabe, Ch. A1 - Berger, Georg A1 - Gildenhaar, Renate A1 - Howlett, C.R. A1 - Markovic, B. A1 - Zreiqat, H. T1 - The functional expression of human bone-derived cells grown on rapidly resorbable calcium phosphate ceramics N2 - The use of biodegradable bone substitutes is advantageous for alveolar ridge augmentation, since it avoids second-site surgery for autograft harvesting. This study examines the effect of novel, rapidly resorbable calcium phosphates on the expression of bone-related genes and proteins by human bone-derived cells (HBDC) and compares this behavior to that of tricalciumphosphate (TCP). Test materials were a-TCP, and four materials which were created from ß-Rhenanite and its derivatives: R1-ß-Rhenanite (CaNaPO4); R1/M2 composed of CaNaPO4 and MgNaPO4; R1+SiO2 composed of CaNaPO4 and 9% SiO2 (wt%); and R17-Ca2KNa(PO4)2. HBDC were grown on the substrata for 3, 5, 7, 14 and 21 days, counted and probed for various mRNAs and proteins (Type I collagen, osteocalcin, osteopontin, osteonectin, alkaline phosphatase and bone sialoprotein). All substrata supported continuous cellular growth for 21 days. At day 21, surfaces of R1+SiO2 and R17 had the highest number of HBDC. At 14 and 21 days, cells on R1 and on R1+SiO2 displayed significantly enhanced expression of all osteogenic proteins. Since all novel calcium phosphates supported cellular proliferation together with expression of bone-related proteins at least as much as TCP, these ceramics can be regarded as potential bone substitutes. R1 and R1+SiO2 had the most effect on osteoblastic differentiation, thus suggesting that these materials may possess a higher potency to enhance osteogenesis than TCP. KW - Calcium phosphate ceramics KW - Human bone-derived cells KW - Cell-biomaterial interactions KW - Bone substitutes KW - In situ hybridization PY - 2004 DO - https://doi.org/10.1016/S0142-9612(03)00525-8 SN - 0142-9612 VL - 25 IS - 2 SP - 335 EP - 344 PB - Elsevier CY - Oxford AN - OPUS4-2957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knabe, C. A1 - Howlett, C.R. A1 - Markovic, B. A1 - Gildenhaar, Renate A1 - Berger, Georg A1 - Zreiqat, H. T1 - Beeinflussung der Gen- und Proteinexpression von Osteoblasten durch bioaktive resorbierbare Glaskeramiken T2 - Bericht der 2. gemeinsamen Jahrestagung der Deutschen Gesellschaft für Implantologie im Zahn-, Mund- und Kieferbereich, der Österreichischen Gesellschaft für orale Chirurgie und Implantologie sowie der Schweizerischen Gesellschaft für orale Implantologie CY - München, Deutschland DA - 2002-12-05 PY - 2002 AN - OPUS4-1898 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -