@article{ThibaudeauTaubenbergerHolzapfeletal.2014, author = {Thibaudeau, Laure and Taubenberger, Anna V. and Holzapfel, Boris M. and Quent, Verena M. and Fuehrmann, Tobias and Hesami, Parisa and Brown, Toby D. and Dalton, Paul D. and Power, Carl A. and Hollier, Brett G. and Hutmacher, Dietmar W.}, title = {A tissue-engineered humanized xenograft model of human breast cancer metastasis to bone}, series = {Disease Models \& Mechanisms}, volume = {7}, journal = {Disease Models \& Mechanisms}, number = {2}, doi = {10.1242/dmm.014076}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117466}, pages = {299-309}, year = {2014}, abstract = {The skeleton is a preferred homing site for breast cancer metastasis. To date, treatment options for patients with bone metastases are mostly palliative and the disease is still incurable. Indeed, key mechanisms involved in breast cancer osteotropism are still only partially understood due to the lack of suitable animal models to mimic metastasis of human tumor cells to a human bone microenvironment. In the presented study, we investigate the use of a human tissue-engineered bone construct to develop a humanized xenograft model of breast cancer-induced bone metastasis in a murine host. Primary human osteoblastic cell-seeded melt electrospun scaffolds in combination with recombinant human bone morphogenetic protein 7 were implanted subcutaneously in non-obese diabetic/severe combined immunodeficient mice. The tissue-engineered constructs led to the formation of a morphologically intact 'organ' bone incorporating a high amount of mineralized tissue, live osteocytes and bone marrow spaces. The newly formed bone was largely humanized, as indicated by the incorporation of human bone cells and human-derived matrix proteins. After intracardiac injection, the dissemination of luciferase-expressing human breast cancer cell lines to the humanized bone ossicles was detected by bioluminescent imaging. Histological analysis revealed the presence of metastases with clear osteolysis in the newly formed bone. Thus, human tissue-engineered bone constructs can be applied efficiently as a target tissue for human breast cancer cells injected into the blood circulation and replicate the osteolytic phenotype associated with breast cancer-induced bone lesions. In conclusion, we have developed an appropriate model for investigation of species-specific mechanisms of human breast cancer-related bone metastasis in vivo.}, language = {en} } @article{HettichSchierjottEppleetal.2019, author = {Hettich, Georg and Schierjott, Ronja A. and Epple, Matthias and Gbureck, Uwe and Heinemann, Sascha and Mozaffari-Jovein, Hadi and Grupp, Thomas M.}, title = {Calcium phosphate bone graft substitutes with high mechanical load capacity and high degree of interconnecting porosity}, series = {Materials}, volume = {12}, journal = {Materials}, number = {21}, issn = {1996-1944}, doi = {10.3390/ma12213471}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193233}, pages = {3471}, year = {2019}, abstract = {Bone graft substitutes in orthopedic applications have to fulfill various demanding requirements. Most calcium phosphate (CaP) bone graft substitutes are highly porous to achieve bone regeneration, but typically lack mechanical stability. This study presents a novel approach, in which a scaffold structure with appropriate properties for bone regeneration emerges from the space between specifically shaped granules. The granule types were tetrapods (TEPO) and pyramids (PYRA), which were compared to porous CaP granules (CALC) and morselized bone chips (BC). Bulk materials of the granules were mechanically loaded with a peak pressure of 4 MP; i.e., comparable to the load occurring behind an acetabular cup. Mechanical loading reduced the volume of CALC and BC considerably (89\% and 85\%, respectively), indicating a collapse of the macroporous structure. Volumes of TEPO and PYRA remained almost constant (94\% and 98\%, respectively). After loading, the porosity was highest for BC (46\%), lowest for CALC (25\%) and comparable for TEPO and PYRA (37\%). The pore spaces of TEPO and PYRA were highly interconnected in a way that a virtual object with a diameter of 150 µm could access 34\% of the TEPO volume and 36\% of the PYRA volume. This study shows that a bulk of dense CaP granules in form of tetrapods and pyramids can create a scaffold structure with load capacities suitable for the regeneration of an acetabular bone defect}, language = {en} } @article{OuhaddiCharbonnierPorgeetal.2023, author = {Ouhaddi, Yassine and Charbonnier, Baptiste and Porge, Juliette and Zhang, Yu-Ling and Garcia, Isadora and Gbureck, Uwe and Grover, Liam and Gilardino, Mirko and Harvey, Edward and Makhoul, Nicholas and Barralet, Jake}, title = {Development of neovasculature in axially vascularized calcium phosphate cement scaffolds}, series = {Journal of Functional Biomaterials}, volume = {14}, journal = {Journal of Functional Biomaterials}, number = {2}, issn = {2079-4983}, doi = {10.3390/jfb14020105}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304026}, year = {2023}, abstract = {Augmenting the vascular supply to generate new tissues, a crucial aspect in regenerative medicine, has been challenging. Recently, our group showed that calcium phosphate can induce the formation of a functional neo-angiosome without the need for microsurgical arterial anastomosis. This was a preclinical proof of concept for biomaterial-induced luminal sprouting of large-diameter vessels. In this study, we investigated if sprouting was a general response to surgical injury or placement of an inorganic construct around the vessel. Cylindrical biocement scaffolds of differing chemistries were placed around the femoral vein. A contrast agent was used to visualize vessel ingrowth into the scaffolds. Cell populations in the scaffold were mapped using immunohistochemistry. Calcium phosphate scaffolds induced 2.7-3 times greater volume of blood vessels than calcium sulphate or magnesium phosphate scaffolds. Macrophage and vSMC populations were identified that changed spatially and temporally within the scaffold during implantation. NLRP3 inflammasome activation peaked at weeks 2 and 4 and then declined; however, IL-1β expression was sustained over the course of the experiment. IL-8, a promoter of angiogenesis, was also detected, and together, these responses suggest a role of sterile inflammation. Unexpectedly, the effect was distinct from an injury response as a result of surgical placement and also was not simply a foreign body reaction as a result of placing a rigid bioceramic next to a vein, since, while the materials tested had similar microstructures, only the calcium phosphates tested elicited an angiogenic response. This finding then reveals a potential path towards a new strategy for creating better pro-regenerative biomaterials.}, language = {en} } @article{RoedelBaumannGrolletal.2018, author = {R{\"o}del, Michaela and Baumann, Katrin and Groll, J{\"u}rgen and Gbureck, Uwe}, title = {Simultaneous structuring and mineralization of silk fibroin scaffolds}, series = {Journal of Tissue Engineering}, volume = {9}, journal = {Journal of Tissue Engineering}, doi = {10.1177/2041731418788509}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226427}, pages = {1-16}, year = {2018}, abstract = {Silk fibroin is commonly used as scaffold material for tissue engineering applications. In combination with a mineralization with different calcium phosphate phases, it can also be applied as material for bone regeneration. Here, we present a study which was performed to produce mineralized silk fibroin scaffolds with controlled macroporosity. In contrast to former studies, our approach focused on a simultaneous gelation and mineralization of silk fibroin by immersion of frozen silk fibroin monoliths in acidic calcium phosphate solutions. This was achieved by thawing frozen silk fibroin monoliths in acidic calcium phosphate solution, leading to the precipitation of monocalcium phosphate within the silk fibroin matrix. In the second approach, a conversion of incorporated -tricalcium phosphate particles into brushite was successfully achieved. Furthermore, a controlled cryostructuring process of silk fibroin scaffolds was carried out leading to the formation of parallel-oriented pores with diameters of 30-50 mu m.}, language = {en} }