Norbert Kübler

Publications of Norbert Kübler

• Impact of DAG stimulation on mineral synthesis, mineral structure and osteogenic differentiation of human cord blood stem cells.

  Authors: Lydia Lammers, Christian Naujoks, Karin Berr, Rita Depprich, Norbert Kübler, Ulrich Meyer, Fabian Langenbach, Beate Lüttenberg, Gesine Kögler, Hans-Peter Wiesmann, Jörg Handschel

  Stem cell research. 03/2012; 8(2):193-205.

  It remains unexplored in what way osteogenic stimulation with dexamethasone, ascorbic acid and β-glycerol phosphate (DAG) influences the process of mineralization, the composition and structure ofIt remains unexplored in what way osteogenic stimulation with dexamethasone, ascorbic acid and β-glycerol phosphate (DAG) influences the process of mineralization, the composition and structure of the assembled mineral. Therefore, we analyzed and characterized biomineralization in DAG-stimulated and unstimulated 3D human unrestricted somatic stem cell (USSC) cultures. Microspheres were analyzed by histological staining, scanning electron microscopy (SEM), semi-quantitative energy-dispersive X-ray spectroscopy (EDX), quantitative wavelength-dispersive X-ray spectroscopy (WDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and Raman spectroscopy. Mineral material was detected by SEM and histological staining in both groups, and showed structural differences. DAG influenced the differentiation of USSCs and the formation, structure and composition of the assembled mineral. SEM showed that cells of the +DAG spheres exhibited morphological signs of osteoblast-like cells. EDX and WDX confirmed a Ca-P mineral in both groups. Overall, the mineral material found showed structural similarities to the mineral substance of bony material.

• Improvement of the cell-loading efficiency of biomaterials by inoculation with stem cell-based microspheres, in osteogenesis.

  Authors: Fabian Langenbach, Christian Naujoks, Andrea Laser, Michael Kelz, Pia Kersten-Thiele, Karin Berr, Rita Depprich, Norbert Kübler, Gesine Kögler, Jörg Handschel

  Journal of biomaterials applications. 01/2012; 26(5):549-64.

  In critical-size bone defects, autologous or allogenic cells are required in addition to compatible biomaterials for the successful defect healing. State of the art inoculation methods ofIn critical-size bone defects, autologous or allogenic cells are required in addition to compatible biomaterials for the successful defect healing. State of the art inoculation methods of biomaterials are based on the application of cell suspensions to the biomaterial. However, only less amounts of cells can be applied and sufficient adhesion to the material is required. Therefore, it was investigated whether the advantages of stem cell-based microspheres and insoluble collagenous bone matrix (ICBM) scaffolds can be combined which can lead to an advancement in cell seeding on biomaterials. Microspheres were produced from unrestricted somatic stem cells from human umbilical cord blood and were mounted on ICBM scaffolds. Following the incubation with osteogenic or control medium, the constructs were analyzed histologically after 3, 7, 14, and 28 days. Alizarin Red S and von Kossa staining revealed microsphere mineralization after 3 days in osteogenic and after 14 days in control medium. Meanwhile, a time-dependent increase in tissue, growing out of the microspheres, was detected. Our results provide evidence that microsphere-ICBM constructs are promising candidates for approaches of bone regeneration. They allow the transfer of substantially high numbers of cells in partially mineralized constructs.

• Embryonic stem cells in scaffold-free three-dimensional cell culture: osteogenic differentiation and bone generation.

  Authors: Jörg Handschel, Christian Naujoks, Rita Depprich, Lydia Lammers, Norbert Kübler, Ulrich Meyer, Hans-Peter Wiesmann

  Head & face medicine. 01/2011; 7:12.

  Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be anExtracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs) in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG). After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin.

• Biocompatibility of osteogenic predifferentiated human cord blood stem cells with biomaterials and the influence of the biomaterial on the process of differentiation.

  Authors: Christian Naujoks, Fabian Langenbach, Karin Berr, Rita Depprich, Norbert Kübler, Ulrich Meyer, Jörg Handschel, Gesine Kögler

  Journal of biomaterials applications. 03/2010; 25(5):497-512.

  Modern cell-based bone reconstruction therapies offer new therapeutic opportunities and tissue engineering represents a more biological-oriented approach to heal bone defects of the skeleton. HumanModern cell-based bone reconstruction therapies offer new therapeutic opportunities and tissue engineering represents a more biological-oriented approach to heal bone defects of the skeleton. Human unrestricted somatic stem cells (USSCs) derived form umbilical cord blood offer new promising aspects e.g., can differentiate into osteogenetic cells. Furthermore these cells have fewer ethical and legal restrictions compared to embryonic stem cells (ESCs). The purpose of this study was to evaluate the compatibility of osteogenic pre-differentiated USSCs with various biomaterials and to address the question, whether biomaterials influence the process of differentiation of the USSCs. After osteogenic differentiation with DAG USSCs were cultivated with various biomaterials. To asses the biocompatibility of USSCs the attachment and the proliferation of the cells on the biomaterial were measured by a CyQUANT(®) assay, the morphology was analyzed by scanning electron microscopy and the influence of the gene expression was analyzed by real time PCR. Our results provide evidence that insoluble collagenous bone matrix followed by β-tricalciumphosphate is highly suitable for bone tissue engineering regarding cell attachment and proliferation. The gene expression analysis indicates that biomaterials influence the gene expression of USSCs. These results are in concordance with our previous study with ESCs.

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• Comparison of ectopic bone formation of embryonic stem cells and cord blood stem cells in vivo.

  Authors: Jörg Handschel, Christian Naujoks, Fabian Langenbach, Karin Berr, Rita A Depprich, Michelle A Ommerborn, Norbert R Kübler, Matthias Brinkmann, Gesine Kögler, Ulrich Meyer

  Tissue engineering. Part A. 03/2010; 16(8):2475-83.

  Cell-based reconstruction therapies promise new therapeutic opportunities for bone regeneration. Unrestricted somatic stem cells (USSC) from cord blood and embryonic stem cells (ESCs) can beCell-based reconstruction therapies promise new therapeutic opportunities for bone regeneration. Unrestricted somatic stem cells (USSC) from cord blood and embryonic stem cells (ESCs) can be differentiated into osteogenic cells. The purpose of this in vivo study was to compare their ability to induce ectopic bone formation in vivo. Human USSCs and murine ESCs were cultured as both monolayer cultures and micromasses and seeded on insoluble collagenous bone matrix (ICBM). One week and 1, 2, and 3 months after implanting the constructs in immune-deficient rats, computed tomography scans were performed to detect any calcification. Subsequently, the implanted constructs were examined histologically. The radiological examination showed a steep increase in the mineralized bone-like tissue in the USSC groups. This increase can be considered as statistically significant compared to the basic value. Moreover, the volume and the calcium portion measured by computed tomography scans were about 10 times higher than in the ESC group. The volume of mineralization in the ESC group increased to a much smaller extent over the course of time, and the control group (ICBM without cells) showed almost no alterations during the study. The histological examinations parallel the radiological findings. Cord blood stem cells in combination with ICBM-induced ectopic bone formation in vivo are stronger than ESCs.

• Osteogenic differentiation influence stem cell migration out of scaffold free microspheres.

  Authors: Fabian Langenbach, Christian Naujoks, Pia Valeska Kersten-Thiele, Karin Berr, Rita Depprich, Norbert Kübler, Gesine Kögler, Jörg Handschel

  Tissue engineering. Part A. 09/2009;

  Complete bone regeneration of critical size defects (CSDs) frequently fail due to the use of acellular bone substitutes and due to partially negative influences of artificial scaffolds. However, theComplete bone regeneration of critical size defects (CSDs) frequently fail due to the use of acellular bone substitutes and due to partially negative influences of artificial scaffolds. However, the supply of cells to CSDs is essential for the regeneration. Therefore, engineered scaffold free tissues, with outgrowing cells that fill up spaces in the bony defect, are promising candidates for bone regeneration approaches. Here we demonstrate such a scaffold free tissue construct (microspheres) that, if osteogenic differentiated, mineralizes while maintaining the capability to let cells grow out of the united cell structure. A superior outgrowth capability of microspheres composed of human cord-blood derived USSCs (unrestricted somatic stem cells) compared to murine ESCs (embryonic stem cells) was found and a time dependent reduction in outgrowth was evident, in vitro. Even after five days of osteoinduction and strong mineralization cells migrate out of the microsphere. Since migration of cells out of USSC-microspheres was also found in extracellular matrix gel, we suggest that cells would migrate also in vivo. Thus microspheres could serve as the scaffold and the source of osteogenic cells in future bone regeneration approaches. Furthermore microspheres permit the precise administration of large amount of cells into an area of interest.

• Induction of osteogenic markers in differentially treated cultures of embryonic stem cells

  Authors: Jörg Handschel, Karin Berr, Rita Depprich, Norbert Kübler, Christian Naujoks, Hans-Peter Wiesmann, Michelle Ommerborn, Ulrich Meyer

  Head & Face Medicine. 01/2008;

  Abstract Background Facial trauma or tumor surgery in the head and face area often lead to massive destruction of the facial skeleton. Cell-based bone reconstruction therapies promise to offer newAbstract Background Facial trauma or tumor surgery in the head and face area often lead to massive destruction of the facial skeleton. Cell-based bone reconstruction therapies promise to offer new therapeutic opportunities for the repair of bone damaged by disease or injury. Currently, embryonic stem cells (ESCs) are discussed to be a potential cell source for bone tissue engineering. The purpose of this study was to investigate various supplements in culture media with respect to the induction of osteogenic differentiation. Methods Murine ESCs were cultured in the presence of LIF (leukemia inhibitory factor), DAG (dexamethasone, ascorbic acid and β-glycerophosphate) or bone morphogenetic protein-2 (BMP-2). Microscopical analyses were performed using von Kossa staining, and expression of osteogenic marker genes was determined by real time PCR. Results ESCs cultured with DAG showed by far the largest deposition of calcium phosphate-containing minerals. Starting at day 9 of culture, a strong increase in collagen I mRNA expression was detected in the DAG-treated cells. In BMP-2-treated ESCs the collagen I mRNA induction was less increased. Expression of osteocalcin, a highly specific marker for osteogentic differentiation, showed a double-peaked curve in DAG-treated cells. ESCs cultured in the presence of DAG showed a strong increase in osteocalcin mRNA at day 9 followed by a second peak starting at day 17. Conclusion Supplementation of ESC cell cultures with DAG is effective in inducing osteogenic differentiation and appears to be more potent than stimulation with BMP-2 alone. Thus, DAG treatment can be recommended for generating ESC populations with osteogenic differentiation that are intended for use in bone tissue engineering.

• Hyperbaric oxygen for adjuvant therapy for chronically recurrent mandibular osteomyelitis in childhood and adolescence.

  Authors: Stefan Lentrodt, Jürgen Lentrodt, Norbert Kübler, Ulrich Mödder

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 03/2007; 65(2):186-91.

  PURPOSE: In this article, the question of whether adjuvant hyperbaric oxygen therapy (HBO) has a positive effect when treating chronically recurrent mandibular osteomyelitis in children andPURPOSE: In this article, the question of whether adjuvant hyperbaric oxygen therapy (HBO) has a positive effect when treating chronically recurrent mandibular osteomyelitis in children and adolescents is discussed. PATIENTS AND METHODS: Over a period of 5 years, 4 cases were observed, 3 of which were submitted to adjuvant HBO. Details on the modalities of this type of treatment and the simultaneous intravenous administration of high doses of antibiotics are reported. RESULTS: All 3 patients have been free of any symptoms from 20 to 74 months (mean, 41 months) and therefore may most likely be regarded as healed. CONCLUSION: The small number of cases does not allow a final statement on the extent to which HBO contributed to the positive outcome. However, in our opinion, HBO is a most promising therapeutic option. Finally, the problems involved in prospective randomized studies of this rare disease are discussed in detail.

• Sinus lifting before Le Fort I maxillary osteotomy: a suitable method for oral rehabilitation of edentulous patients with skelettal class-III conditions: review of the literature and report of a case

  Authors: Rita Depprich, Jörg Handschel, Christian Naujoks, Tobias Hahn, Ulrich Meyer, Norbert Kübler

  Head & Face Medicine. 01/2007;

  Abstract Background Functional rehabilitation of patients afflicted with severe mandibular and maxillary alveolar atrophy might be challenging especially in malformed patients. Methods TreatmentAbstract Background Functional rehabilitation of patients afflicted with severe mandibular and maxillary alveolar atrophy might be challenging especially in malformed patients. Methods Treatment planning using sinus lifting and implant placement before Le Fort I maxillary osteotomy in a patient with severe mandibular and posterior maxillary alveolar atrophy and skelettal class-III conditions due to cleft palate are described. Results A full functional and esthetic rehabilitation of the patient was achieved by a stepwise surgical approach performed through sinus lifting as the primary approach followed by implant placement and subsequent Le Fort I maxillary osteotomy to correct the maxillo-mandibular relation. Conclusion Stabilisation of the maxillary complex by a sinus lifting procedure in combination with computer aided implant placement as preorthodontic planning procedure before Le Fort I maxillary osteotomy seems to be suitable in order to allow ideal oral rehabilitation especially in malformed patients.

• Prospects of micromass culture technology in tissue engineering

  Authors: Jörg Handschel, Rita Depprich, Norbert Kübler, Hans-Peter Wiesmann, Michelle Ommerborn, Ulrich Meyer

  Head & Face Medicine. 01/2007;

  Abstract Tissue engineering of bone and cartilage tissue for subsequent implantation is of growing interest in cranio- and maxillofacial surgery. Commonly it is performed by using cells coaxed withAbstract Tissue engineering of bone and cartilage tissue for subsequent implantation is of growing interest in cranio- and maxillofacial surgery. Commonly it is performed by using cells coaxed with scaffolds. Recently, there is a controversy concerning the use of artificial scaffolds compared to the use of a natural matrix. Therefore, new approaches called micromass technology have been invented to overcome these problems by avoiding the need for scaffolds. Technically, cells are dissociated and the dispersed cells are then reaggregated into cellular spheres. The micromass technology approach enables investigators to follow tissue formation from single cell sources to organised spheres in a controlled environment. Thus, the inherent fundamentals of tissue engineering are better revealed. Additionally, as the newly formed tissue is devoid of an artificial material, it resembles more closely the in vivo situation. The purpose of this review is to provide an insight into the fundamentals and the technique of micromass cell culture used to study bone tissue engineering.

• Dentin dysplasia type I: a challenge for treatment with dental implants

  Authors: Rita Depprich, Michelle Ommerborn, Jörg Handschel, Christian Naujoks, Ulrich Meyer, Norbert Kübler

  Head & Face Medicine. 01/2007;

  Abstract Background Dentin dysplasia type I is characterized by a defect of dentin development with clinical normal appearance of the permanent teeth but no or only rudimentary root formation.Abstract Background Dentin dysplasia type I is characterized by a defect of dentin development with clinical normal appearance of the permanent teeth but no or only rudimentary root formation. Early loss of all teeth and concomitant underdevelopment of the jaws are challenging for successful treatment with dental implants. Methods A combination of sinus lifting and onlay bone augmentation based on treatment planning using stereolithographic templates was used in a patient with dentin dysplasia type I to rehabilitate the masticatory function. Results (i) a predisposition for an increased and accelerated bone resorption was observed in our patient, (ii) bone augmentation was successful using a mixture of allogenic graft material with autogenous bone preventing fast bone resorption, (iii) surgical planning, based on stereolithographic models and surgical templates, facilitated the accurate placement of dental implants. Conclusion Bony augmentation and elaborate treatment planning is helpful for oral rehabilitation of patients with dentin dysplasia type I.

• Adenomatoid odontogenic tumor of the mandible: review of the literature and report of a rare case

  Authors: Jörg Handschel, Rita Depprich, André Zimmermann, Stefan Braunstein, Norbert Kübler

  Head & Face Medicine. 01/2005;

  Abstract Adenomatoid odontogenic tumor (AOT) is a rare odontogenic tumor which is often misdiagnosed as odontogenic cyst. To acquire additional information about AOT, all reports regarding AOT andAbstract Adenomatoid odontogenic tumor (AOT) is a rare odontogenic tumor which is often misdiagnosed as odontogenic cyst. To acquire additional information about AOT, all reports regarding AOT and cited in "pubmed" since 1990 onward were reviewed. AOT accounts for about 1% until 9% of all odontogenic tumors. It is predominantly found in young and female patients, located more often in the maxilla in most cases associated with an uneruppted permanent tooth. For radiological diagnose the intraoral periapical radiograph seems to be more useful than panoramic. However, AOT frequently resemble other odontogenic lesions such as dentigerous cysts or ameloblastoma. Immunohistochemically AOT is characterized by positive reactions with certain cytokeratins. Treatment is conservative and the prognosis is excellent. For illustration a rare case of an AOT in the mandible is presented.