@article{PereiraTrivanovićHerrmann2019,
  author    = {Pereira, A. R. and Trivanović, D. and Herrmann, M.},
  title     = {Approaches to mimic the complexity of the skeletal mesenchymal stem/stromal cell niche in vitro},
  series = {European Cells and Materials},
  volume    = {37},
  journal   = {European Cells and Materials},
  issn      = {1473-2262},
  doi       = {10.22203/eCM.v037a07},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268823},
  pages     = {88-112},
  year      = {2019},
  abstract  = {Mesenchymal stem/stromal cells (MSCs) are an essential element of most modern tissue engineering and regenerative medicine approaches due to their multipotency and immunoregulatory functions. Despite the prospective value of MSCs for the clinics, the stem cells community is questioning their developmental origin, in vivo localization, identification, and regenerative potential after several years of far-reaching research in the field. Although several major progresses have been made in mimicking the complexity of the MSC niche in vitro, there is need for comprehensive studies of fundamental mechanisms triggered by microenvironmental cues before moving to regenerative medicine cell therapy applications. The present comprehensive review extensively discusses the microenvironmental cues that influence MSC phenotype and function in health and disease - including cellular, chemical and physical interactions. The most recent and relevant illustrative examples of novel bioengineering approaches to mimic biological, chemical, and mechanical microenvironmental signals present in the native MSC niche are summarized, with special emphasis on the forefront techniques to achieve bio-chemical complexity and dynamic cultures. In particular, the skeletal MSC niche and applications focusing on the bone regenerative potential of MSC are addressed. The aim of the review was to recognize the limitations of the current MSC niche in vitro models and to identify potential opportunities to fill the bridge between fundamental science and clinical application of MSCs.},
  language  = {en}
}
@article{FuchsHeiligMcDonoghetal.2020,
  author    = {Fuchs, Konrad F. and Heilig, Philipp and McDonogh, Miriam and Boelch, Sebastian and Gbureck, Uwe and Meffert, Rainer H. and Hoelscher-Doht, Stefanie and Jordan, Martin C.},
  title     = {Cement-augmented screw fixation for calcaneal fracture treatment: a biomechanical study comparing two injectable bone substitutes},
  series = {Journal of Orthopaedic Surgery and Research},
  volume    = {15},
  journal   = {Journal of Orthopaedic Surgery and Research},
  doi       = {10.1186/s13018-020-02009-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230336},
  year      = {2020},
  abstract  = {Background The role of cement-augmented screw fixation for calcaneal fracture treatment remains unclear. Therefore, this study was performed to biomechanically analyze screw osteosynthesis by reinforcement with either a calcium phosphate (CP)-based or polymethylmethacrylate (PMMA)-based injectable bone cement. Methods A calcaneal fracture (Sanders type IIA) including a central cancellous bone defect was generated in 27 synthetic bones, and the specimens were assigned to 3 groups. The first group was fixed with four screws (3.5 mm and 6.5 mm), the second group with screws and CP-based cement (Graftys (R) QuickSet; Graftys, Aix-en-Provence, France), and the third group with screws and PMMA-based cement (Traumacem (TM) V+; DePuy Synthes, Warsaw, IN, USA). Biomechanical testing was conducted to analyze peak-to-peak displacement, total displacement, and stiffness in following a standardized protocol. Results The peak-to-peak displacement under a 200-N load was not significantly different among the groups; however, peak-to-peak displacement under a 600- and 1000-N load as well as total displacement exhibited better stability in PMMA-augmented screw osteosynthesis compared to screw fixation without augmentation. The stiffness of the construct was increased by both CP- and PMMA-based cements. Conclusion Addition of an injectable bone cement to screw osteosynthesis is able to increase fixation strength in a biomechanical calcaneal fracture model with synthetic bones. In such cases, PMMA-based cements are more effective than CP-based cements because of their inherently higher compressive strength. However, whether this high strength is required in the clinical setting for early weight-bearing remains controversial, and the non-degradable properties of PMMA might cause difficulties during subsequent interventions in younger patients.},
  language  = {en}
}
@article{StratosRinasSchroepferetal.2023,
  author    = {Stratos, Ioannis and Rinas, Ingmar and Schr{\"o}pfer, Konrad and Hink, Katharina and Herlyn, Philipp and B{\"a}umler, Mario and Histing, Tina and Bruhn, Sven and M{\"u}ller-Hilke, Brigitte and Menger, Michael D. and Vollmar, Brigitte and Mittlmeier, Thomas},
  title     = {Effects on bone and muscle upon treadmill interval training in hypogonadal male rats},
  series = {Biomedicines},
  volume    = {11},
  journal   = {Biomedicines},
  number    = {5},
  issn      = {2227-9059},
  doi       = {10.3390/biomedicines11051370},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319266},
  year      = {2023},
  abstract  = {Testosterone deficiency in males is linked to various pathological conditions, including muscle and bone loss. This study evaluated the potential of different training modalities to counteract these losses in hypogonadal male rats. A total of 54 male Wistar rats underwent either castration (ORX, n = 18) or sham castration (n = 18), with 18 castrated rats engaging in uphill, level, or downhill interval treadmill training. Analyses were conducted at 4, 8, and 12 weeks postsurgery. Muscle force of the soleus muscle, muscle tissue samples, and bone characteristics were analyzed. No significant differences were observed in cortical bone characteristics. Castrated rats experienced decreased trabecular bone mineral density compared to sham-operated rats. However, 12 weeks of training increased trabecular bone mineral density, with no significant differences among groups. Muscle force measurements revealed decreased tetanic force in castrated rats at week 12, while uphill and downhill interval training restored force to sham group levels and led to muscle hypertrophy compared to ORX animals. Linear regression analyses showed a positive correlation between bone biomechanical characteristics and muscle force. The findings suggest that running exercise can prevent bone loss in osteoporosis, with similar bone restoration effects observed across different training modalities.},
  language  = {en}
}
@article{HerrmannEngelkeEbertetal.2020,
  author    = {Herrmann, Marietta and Engelke, Klaus and Ebert, Regina and M{\"u}ller-Deubert, Sigrid and Rudert, Maximilian and Ziouti, Fani and Jundt, Franziska and Felsenberg, Dieter and Jakob, Franz},
  title     = {Interactions between muscle and bone — Where physics meets biology},
  series = {Biomolecules},
  volume    = {10},
  journal   = {Biomolecules},
  number    = {3},
  issn      = {2218-273X},
  doi       = {10.3390/biom10030432},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203399},
  year      = {2020},
  abstract  = {Muscle and bone interact via physical forces and secreted osteokines and myokines. Physical forces are generated through gravity, locomotion, exercise, and external devices. Cells sense mechanical strain via adhesion molecules and translate it into biochemical responses, modulating the basic mechanisms of cellular biology such as lineage commitment, tissue formation, and maturation. This may result in the initiation of bone formation, muscle hypertrophy, and the enhanced production of extracellular matrix constituents, adhesion molecules, and cytoskeletal elements. Bone and muscle mass, resistance to strain, and the stiffness of matrix, cells, and tissues are enhanced, influencing fracture resistance and muscle power. This propagates a dynamic and continuous reciprocity of physicochemical interaction. Secreted growth and differentiation factors are important effectors of mutual interaction. The acute effects of exercise induce the secretion of exosomes with cargo molecules that are capable of mediating the endocrine effects between muscle, bone, and the organism. Long-term changes induce adaptations of the respective tissue secretome that maintain adequate homeostatic conditions. Lessons from unloading, microgravity, and disuse teach us that gratuitous tissue is removed or reorganized while immobility and inflammation trigger muscle and bone marrow fatty infiltration and propagate degenerative diseases such as sarcopenia and osteoporosis. Ongoing research will certainly find new therapeutic targets for prevention and treatment.},
  language  = {en}
}
@article{ScorcellettiKaraZangeetal.2022,
  author    = {Scorcelletti, Matteo and Kara, Serhan and Zange, Jochen and Jordan, Jens and Semler, Oliver and Sch{\"o}nau, Eckhard and Rittweger, J{\"o}rn and Ireland, Alex and Seefried, Lothar},
  title     = {Lower limb bone geometry in adult individuals with X-linked hypophosphatemia: an observational study},
  series = {Osteoporosis International},
  volume    = {33},
  journal   = {Osteoporosis International},
  number    = {7},
  doi       = {10.1007/s00198-022-06385-z},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324655},
  pages     = {1601-1611},
  year      = {2022},
  abstract  = {Summary We assessed lower-limb geometry in adults with X-linked hypophosphatemia (XLH) and controls. We found large differences in multiple measures including femoral and tibial torsion, bowing and cross-sectional area and acetabular version and coverage which may contribute to clinical problems such as osteoarthritis, fractures and altered gait common in XLH. Purpose Individuals with X-linked hypophosphatemia (XLH) are at risk of lower-limb deformities and early onset of osteoarthritis. These two factors may be linked, as altered biomechanics is a risk factor for osteoarthritis. This exploratory evaluation aims at providing clues and concepts for this association to facilitate future larger-scale and longitudinal studies on that aspect. Methods For this observational study, 13 patients with XLH, aged 18-65 years (6 female), were compared with sex-, age- and weight-matched healthy individuals at a single German research centre. Femoral and hip joint geometry, including femoral and tibial torsion and femoral and tibial shaft bowing, bone cross-sectional area (CSA) and acetabular version and coverage were measured from magnetic resonance imaging (MRI) scans. Results Total femoral torsion was 29° lower in individuals with XLH than in controls (p < 0.001), mainly resulting from lower intertrochanteric torsion (ITT) (p < 0.001). Femoral lateral and frontal bowing, tibial frontal bowing, mechanical axis, femoral mechanical-anatomical angle, acetabular version and acetabular coverage were all greater and tibial torsion lower in individuals with XLH as compared to controls (all p < 0.05). Greater femoral total and marrow cavity CSA, greater tibial marrow cavity CSA and lower cortical CSA were observed in XLH (all p < 0.05). Discussion We observed large differences in clinically relevant measures of tibia and particularly femur bone geometry in individuals with XLH compared to controls. These differences may plausibly contribute to clinical manifestations of XLH such as early-onset osteoarthritis, pseudofractures and altered gait and therefore should be considered when planning corrective surgeries.},
  language  = {en}
}