Repair of critical-size defects with autogenous periosteum-derived cells combined with bovine anorganic apatite/collagen: an experimental study in rat calvaria

The aim of this study was to evaluate the bone repair using autogenous periosteum-derived cells (PDC) and bovine anorganic apatite and collagen (HA-COL). PDC from Wistar rats (n=10) were seeded on HA-COL discs and subjected to osteoinduction during 6 days. Critical-size defects in rat calvarias were treated with blood clot (G1), autogenous bone (G2), HA-COL (G3) and HA-COL combined with PDC (G4) (n=40), and then analyzed 1 and 3 months after surgeries. Radiographic analysis exhibited no significant temporal change. G1 and G2 had discrete new marginal bone, but the radiopacity of graft materials in G2, G3 and G4 impaired the detection of osteogenesis. At 3 months, histopathological analysis showed the presence of ossification islets in G1, which was more evident in G2, homogeneous new bone around HA-COL in G3 and heterogeneous new bone around HA-COL in G4 in addition to moderate presence of foreign body cells in G3 and G4. Histomorphometric analysis showed no change in the volume density of xenograft (p>0.05) and bone volume density in G2 was twice greater than in G1 and G4 after 3 months (p<0.05), but similar to G3. The PDC did not increase bone formation in vivo, although the biomaterial alone showed biocompatibility and osteoconduction capacity.

Newly Formed Bone in Mandible Decortication Experimental Model Using rhBMP-2 Evaluated by Densitometric Study

The purpose of this study was to evaluate the newly formed bone, comparing two different carriers for rhBMP-2, using the decortication and nondecorticatication surgical technique in Wistar rat mandibles, evaluated by radiographic densitometry method. It was used fifty six animals according to specific treatment, which were sacrificed after 3 and 6 weeks after this. It was concluded that the decortication surgical technique was able to optimize the osteoinduction properties of the rhBMP-2, independently of the material carrier used and the period of time, according to radiographic densitometry technique.

Osteoinductivity potential of rhBMP-2 associated with two carriers in different dosages

The objective of this study was to evaluate bone formation after application of different doses of recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with monoolein or poloxamer gels, in critical bone defects of rats. Forty-five Wistar rats were divided into nine treatment groups with five animals each: I: application of 1 A mu g rhBMP-2 + monoolein; II: 3 A mu g rhBMP-2 + monoolein; III: 7 A mu g rhBMP-2 + monoolein; IV: 1 A mu g rhBMP-2 + poloxamer; V: 3 A mu g rhBMP-2 + poloxamer; VI: 7 A mu g rhBMP-2 + poloxamer; VII: monoolein only; VIII: poloxamer only; and IX: critical bone defect only. A critical-sized defect of 6 mm diameter was produced in the left parietal bone and it was filled with gels of the above mentioned treatments. After 2 weeks, the calvarial bones were removed for histological processing. Bone formation in the groups that received poloxamer gel and rhBMP-2 was not significantly different from the control group (IX). Groups receiving monoolein and rhBMP-2 (1 and 3 A mu g) and those that received only the carriers (VII and VIII) had less bone formation in relation to the control. The association of rhBMP-2 to both poloxamer and monoolein did not exhibit any significant differentiation in bone formation in comparison with the control group.

The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.

The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this combinatorial stem cell niche is a novel mechanism that may also explain cancer cell osteotropism and local interference with hematopoiesis (myelophthisis). Accordingly, these stem cell niche components may represent innovative therapeutic targets and/or serum biomarkers in osteoblastic bone metastasis.

Repair of critical-size defects with autogenous periosteum-derived cells combined with bovine anorganic apatite/collagen: an experimental study in rat calvaria

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Função osteoindutora de fragmentos ósseos conservados em glicerina a 98%: estudo experimental em ratos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento do implante contendo bone morphogenetic protein (bmp) associado ao plasma rico em plaquetas na reparação de fraturas orbitárias

Purpose: This study intends to evaluate BMP (Bone Morphogenetic Protein) implant and BMP implant plus PRP (Platelet Rich Plasma) in rabbit orbital fractures, searching for tissue reaction, by radiological and morfometrical analysis. Methods:Third six white rabbits were submitted to orbital floor fracture and distributed in three groups: G1, with rabbits receiving a plate containing decalcified bone matrix and BMP; G2, with rabbits receiving the implant with BMP wrapped by PRP; G3, the control group where it was made the fracture only. The animals were evaluated radiologically after surgery and at sacrifice time in 7, 30, 90 and 180th day after surgery. After sacrifice, a block containing the right orbital tissue was extracted and prepared to morphological and morphometrical analysis. Results: An intensive linfomononuclear inflammatory reaction was observed at 7th day in G1 e G2, witch decreased after the 30th day; mesenchimal cells, osteoblasts, new bone and progressive cavitation of the implant were also observed, besides signs of calcium deposition by radiological study. In the control group fibrosis at the site of fracture was identified only. Conclusion: BMP seemed a good orbital implant producing new bone at the implant site and correcting bone defect.There was not observed acceleration of osteoinduction when the implant was associated with PRP.

Evaluation of the presence of VEGF, BMP2 and CBFA1 proteins in autogenous bone graft: Histometric and immunohistochemical analysis

Aims: The purpose of this study was to evaluate the expression of proteins that participate in the osteoinduction stage (VEGF, BMP2 and CBFA1) of the process of bone regeneration of defects created in rat calvariae and filled with autogenous bone block grafts. Materials and methods: 10 adult male rats (Rattus norvegicus albinus, Wistar) were used, who received two bone defects measuring 5 mm each in the calvariae. The bone defects constituted two experimental groups (n = 10): Control Group (CONT) (defects filled with a coagulum); Graft Group (GR) (defects filled with autogenous bone removed from the contralateral defect). The animals were submitted to euthanasia at 7 and 30 days post-operatively. Results: Quantitative analysis demonstrated significantly greater bone formation in Group GR, but the presence of the studied proteins was significantly greater in the CONT Group in both time intervals of observation. Conclusion: It was not possible in this study in cortical bone block groups to detect the osteoinductive proteins in a significant amount during the repair process. © 2013 European Association for Cranio-Maxillo-Facial Surgery.

Reparação óssea de cavidades cirurgicamente criadas e preenchidas com uma associação de vidro bioativo e osso autógeno: análise histométrica e imunoistoquímica

Pós-graduação em Odontologia - FOA

Avaliação do copolímero de ácido polilático e poliglicólico associado ao vidro bioativo no processo de regeneração óssea: análise histomorfométrica e imunoistoquímica em ratos

Pós-graduação em Odontologia - FOA

Implantação da técnica para diferenciação osteoblástica a partir de células tronco mesenquimais humanas derivadas do tecido adiposo

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Estudo comparativo do Titânio versus Polímero vegetal para fixação interna rígida de fraturas orbitárias de coelhos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Avaliação da presença das proteínas VEGF, BMP2 e CBFA1 no enxerto ósseo autógeno: análise histométrica e imunoistoquímica em calotas de ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Implante de tecido prostático do cão na ostectomia parcial do rádio em coelhos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da incorporação de enxertos ósseos homógenos em humanos: análises histológica e imunoistoquímica

Pós-graduação em Odontologia - FOA