Cranial vault reconstruction with bone morphogenetic protein, calcium phosphate, acellular dermal matrix, and calcium alginate in mice

PURPOSE: To evaluate experimental cranial vault reconstructions, by combining bone morphogenetic protein type 2 (BMP-2) and different matrices. METHODS: Fourty-nine animals were initially included (seven per group). We designed an experimental, open, prospective and comparative study, divided in seven groups: 1 - BMP-2+calcium phosphate (BT); 2 - BMP-2+acellular dermal matrix (BM); 3 - BMP-2+calcium alginate (BA); 4 - TCP; 5 - MDM; 6 - ALG; 7 - Bone autograft (BAG). A bone failure was created in left parietal bone of adult male mice. At the same procedure reconstruction was performed. After five weeks, animals were sacrificed, and reconstruction area was removed to histological analysis. After exclusion due to death or infection, thirty-eight animals were evaluated (BT=5; BM=6; BA=6; TCP=7; MDM=3; ALG=6; BAG=5). RESULTS: A higher incidence of infection has occurred in MDM group (57%, P=0.037). In cortical fusion, groups BAG, TCP, and BMP-2+TCP (BT) obtained the best scores, comparing to the others (P=0.00846). In new bone formation, groups BT, BAG, and TCP have presented the best scores (P=0.00835). When neovascularization was considered, best groups were BMP-2+MDM (BM), BMP-2+ALG (BA), TCP, and MDM (P=0.001695). BAG group was the best in bone marrow formation, followed by groups BT and TCP (P=0.008317). CONCLUSIONS: Bone morphogenetic protein type 2 increased bone regeneration in experimental skull reconstruction, especially when combined to calcium phosphate. Such association was even comparable to bone autograft, the gold-standard treatment, in some histological criteria. .(AU)

Cimento de alfa-fosfato tricálcico de dupla pega no preenchimento de cavidade anoftálmica estudo clínico / Double-setting a-tricalcium phosphate cement for the completion of anophthalmic cavity clinical study

Foi avaliada a conveniência do emprego do cimento de alfa-fosfato tricálcico de dupla pega como implante para o preenchimento de cavidade anoftálmica de cães. Os animais foram provenientes do Serviço de Oftalmologia do Hos- pital Veterinário, da Universidade Estadual Paulista Câmpus de Jaboticabal e de uma clínica privada. O trabalho foi realizado em dois anos. A idade dos pacientes oscilou entre 2 a 11 anos e o peso de 9 a 50 kg. Os implantes variaram de 19 a 25 mm de diâmetro. O edema local foi observado em todos os animais durante o pós-operatório imediato. Das dez cirurgias realizadas em sete animais, em nove (90%) o resultado estético foi satisfatório, enquanto em um (10%) foi insatisfatório, devido a complicações que levaram à remoção do implante. A utilização do cimento de alfa-fosfato tri- cálcico de dupla pega no preenchimento de cavidade anoftálmica mostrou-se factível e é uma alternativa que possibilita boa aparência estética após a remoção do bulbo do olho.(AU)

The double-setting alpha-tricalcium phosphate bone cement was evaluated as an orbital implant for filling the ano- phthalmic cavity of dogs. The animals were from the Ophthalmology Unit of the Veterinary Hospital, Universidade Estadual Paulista Jaboticabal, and from a private veterinary clinic. The study was conducted during two years. The patients age ranged from 2-11 years old, and their weight from 9-50 kg. The implants ranged from 19 to 25 mm in diameter. Local edema was observed in all animals during the immediate postoperative period. Of the ten performed surgeries in seven animals, a satisfactory, aesthetic result was observed in nine (90%) while in one (10%) of them it was unsatisfactory due to complications that led to the implant removal. The use of the double-setting alpha-tricalcium phosphate bone cement to fill anophthalmic sockets is feasible and could be an alternative to improve the cosmetic appearance after eyeball removal.(AU)

Use of calcium phosphate cement scaffolds for bone tissue engineering: in vitro study / A utilizacao do cimento de fosfato de calcio como arcabouco para engenharia de tecido osseo: estudo in vitro

Purpose: To evaluate the ability of macroporous tricalcium phosphate cement (CPC) scaffolds to enable the adhesion, proliferation, and differentiation of mesenchymal stem cells derived from human bone marrow. Methods: Cells from the iliac crest of an adult human donor were processed and cultured on macroporous CPC discs. Paraffin spheres sized between 100 and 250µm were used as porogens. Cells were cultured for 5, 10, and 15 days. Next, we assessed cells' behavior and morphology on the biomaterial by scanning electron microscopy. The expression levels of the BGLA and SSP1 genes and the alkaline phosphatase (ALP) activity were quantified by the quantitative real-time polymerase chain reaction technique (QT-PCR) using the fluorophore SYBR GREEN®. Results: QT-PCR detected the expression of the BGLA and SSP1 genes and the ALP activity in the periods of 10 and 15 days of culture. Thus, we found out that there was cell proliferation and differentiation in osteogenic cells. Conclusion: Macroporous CPC, with pore sized between 100 and 250µm and developed using paraffin spheres, enables adhesion, proliferation, and differentiation of mesenchymal stem cells in osteogenic cells and can be used as a scaffold for bone tissue engineering.(AU)

Objetivo: Avaliar a capacidade de suportes tridimensionais macroporosos de cimento de fosfato de calcio (CFC), de permitir a adesao, proliferacao e diferenciacao de celulas-tronco mesenquimais derivadas da medula ossea humana. Metodos: celulas obtidas da crista iliaca de um doador humano adulto foram processadas e cultivadas sobre suportes de CFC, macroporosos, que tiveram como corpo gerador de poros, microesferas de parafina, com tamanho entre 100 e 250µm. Os periodos de cultura estabelecidos foram de cinco, 10 e 15 dias. Apos estes periodos, o comportamento e a morfologia das celulas junto ao biomaterial foram avaliados por meio de Microscopia Eletronica de Varredura. Os niveis de expressao dos genes BGLA e SSP1 bem como a atividade da Fosfatase Alcalina (ALP) foram quantificados pela tecnica de PCR em Tempo Real (QT-PCR) utilizando o fluoroforo SYBR Green®. Resultados: O QT-PCR detectou a expressao dos genes BGLA e SSP1 e a atividade da fosfatase alcalina nos periodos de 10 e 15 dias de cultura. No periodo de cinco dias, nao foi observada a expressao de nenhum dos genes investigados. Conclusao: O CFC, macroporoso, com tamanho de poros entre 100 e 250µm, criados por meio da utilizacao de microesferas de parafina, permite a adesao, proliferacao e diferenciacao de celulas-tronco mesenquimais em celulas osteogenicas, podendo ser utilizado como arcabouco para engenharia de tecido osseo.(AU)

Cimento de alfa-tricálcio-fosfato na reconstrução de defeitos ósseos em ratos / Alpha-tricalcium phosphate cement in the reconstruction of bone defects in rats

PURPOSE: To evaluate the ability of a mixture of α-TCP and autogenous bone (AB) vs. α-TCP alone and AB alone to promote new bone formation and tissue repair in bone defects. METHODS: Bone defects surgically created in 15 male Wistar rats were divided into four groups: Group I (AB), Group II (α-TCP), Group III (α-TCP+AB assessed by light microscopy), and Group IV (α-TCP+AB assessed by scanning electron microscopy). Bone repair findings were assessed at 30, 60, and 120 days postoperatively. RESULTS: The histological findings obtained in Groups I (p=0.459), II (p=0.368), and III (p=0.459) and at 30 days (p=0.717), 60 days (p=0.717), and 120 days (p=0.779) did not show statistically significant differences. Scanning electron microscopy revealed direct contact between the α-TCP+AB implant and the bone tissue at 120 days. CONCLUSION: The α-TCP implant is effective alternative bone substitutes for the treatment of critical size bone defects.(AU)

OBJETIVO: Avaliar a capacidade da mistura de α-TCP e osso autógeno (OA) Vs somente α-TCP e somente OA em promover a neoformação óssea e reparo tecidual em defeitos ósseos. MÉTODOS: Foram criados cirurgicamente defeitos ósseos em 15 ratos Wistar machos, distribuídos em quatro grupos: Grupo I (OA), Grupo II (α-TCP), Grupo III (α-TCP + OA avaliado por microscopia de luz) e Grupo IV (α-TCP + OA avaliado por microscopia eletrônica de varredura). Os resultados da reparação óssea foram avaliados em 30, 60 e 120 dias. RESULTADOS:os achados histológicos obtidos nos grupos I (p = 0,459), II (p = 0,368) e III (p = 0,459) e aos 30 dias (p = 0,717), 60 dias (p = 0,717), e 120 dias (p = 0,779) não apresentaram diferenças estatisticamente significativas. A análise por microscopia eletrônica de varredura revelou contacto direto entre o implante de α-TCP + AO e o tecido ósseo aos 120 dias. CONCLUSÃO: O implante de α-TCP é alternativa eficaz como substitutos ósseos para o tratamento de defeitos ósseos de tamanho crítico.(AU)