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Orientador(es)
Resumo(s)
The hypothesis behind this work is that fibrinogen (Fg), classically considered a pro-inflammatory
protein, can promote bone repair/regeneration. Injury and biomaterial implantation naturally lead to
an inflammatory response, which should be under control, but not necessarily minimized. Herein, porous
scaffolds entirely constituted of Fg (Fg-3D) were implanted in a femoral rat bone defect and investigated
at two important time points, addressing the bone regenerative process and the local and systemic
immune responses, both crucial to elucidate the mechanisms of tissue remodelling. Fg-3D led to early
infiltration of granulation tissue (6 days post-implantation), followed by bone defect closure, including
periosteum repair (8 weeks post-injury). In the acute inflammatory phase (6 days) local gene expression
analysis revealed significant increases of pro-inflammatory cytokines IL-6 and IL-8, when compared with
non-operated animals. This correlated with modified proportions of systemic immune cell populations,
namely increased T cells and decreased B, NK and NKT lymphocytes and myeloid cell, including the Mac-
1þ (CD18þ/CD11bþ) subpopulation. At 8 weeks, Fg-3D led to decreased plasma levels of IL-1b and
increased TGF-b1. Thus, our data supports the hypothesis, establishing a link between bone repair
induced by Fg-3D and the immune response. In this sense, Fg-3D scaffolds may be considered immunomodulatory
biomaterials.
Descrição
Palavras-chave
Fibrinogen In vivo Bone repair/regeneration Inflammation Biomaterial
Contexto Educativo
Citação
Editora
Elsevier