Usefulness of a Nanostructured Fibrin-Agarose Bone Substitute in a Model of Severely Critical Mandible Bone Defect Martín Piedra, Miguel Ángel Gironés Camarasa, Belén España López, Antonio Fernández-Valadés Gámez, Ricardo Blanco Elices, Cristina Garzón Bello, Ingrid Johanna Alaminos Mingorance, Miguel Fernández Valadés, Ricardo Bone Tissue engineering Fibrin-agarose Mandible Regeneration Critical defects of the mandibular bone are very difficult to manage with currently available materials and technology. In the present work, we generated acellular and cellular substitutes for human bone by tissue engineering using nanostructured fibrin–agarose biomaterials, with and without adipose-tissue-derived mesenchymal stem cells differentiated to the osteogenic lineage using inductive media. Then, these substitutes were evaluated in an immunodeficient animal model of severely critical mandibular bone damage in order to assess the potential of the bioartificial tissues to enable bone regeneration. The results showed that the use of a cellular bone substitute was associated with a morpho-functional improvement of maxillofacial structures as compared to negative controls. Analysis of the defect site showed that none of the study groups fully succeeded in generating dense bone tissue at the regeneration area. However, the use of a cellular substitute was able to improve the density of the regenerated tissue (as determined via CT radiodensity) and form isolated islands of bone and cartilage. Histologically, the regenerated bone islands were comparable to control bone for alizarin red and versican staining, and superior to control bone for toluidine blue and osteocalcin in animals grafted with the cellular substitute. Although these results are preliminary, cellular fibrin–agarose bone substitutes show preliminary signs of usefulness in this animal model of severely critical mandibular bone defect. 2021-11-15T13:27:21Z 2021-11-15T13:27:21Z 2021 info:eu-repo/semantics/article Martin-Piedra, M.-A.; Gironés-Camarasa, B.; España-López, A.; Fernández-Valadés Gámez, R.; Blanco-Elices, C.; Garzón, I.; Alaminos, M.; Fernández-Valadés, R. Usefulness of a Nanostructured Fibrin-Agarose Bone Substitute in a Model of Severely Critical Mandible Bone Defect. Polymers 2021, 13, 3939. https://doi.org/10.3390/polym1322 3939 http://hdl.handle.net/10481/71523 10.3390/polym13223939 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI