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1.
Biomacromolecules ; 24(8): 3450-3462, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37458386

RESUMO

Recent advancements in decellularization have seen the development of extracellular matrix (ECM)-decorated scaffolds for bone regeneration; however, little is understood of the impact of in vitro culture prior to decellularization on the performances of these constructs. Therefore, this study investigated the effect of in vitro culture on ECM-decorated melt electrowritten polycaprolactone scaffold bioactivity. The scaffolds were seeded with osteoblasts and cultured for 1, 2, or 4 weeks to facilitate bone-specific ECM deposition and subsequently decellularized to form an acellular ECM-decorated scaffold. The utilization of mild chemicals and DNase was highly efficient in removing DNA while preserving ECM structure and composition. ECM decoration of the melt electrowritten fibers was observed within the first week of culture, with increased ECM at 2 and 4 week culture periods. Infiltration of re-seeded cells as well as overall bone regeneration in a rodent calvarial model was impeded by a longer culture period. Thus, it was demonstrated that the length of culture has a key influence on the osteogenic properties of decellularized ECM-decorated scaffolds, with long-term culture (2+ weeks) causing pore obstruction and creating a physical barrier which interfered with bone formation. These findings have important implications for the development of effective ECM-decorated scaffolds for bone regeneration.

2.
Acta ortop. bras ; 23(5): 263-267, Sep.-Oct. 2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-762863

RESUMO

Objetivo: Comparar os resultados funcionais de fraturas de tornozelo tratadascom placas metálicas e absorvíveis. Métodos: Vinte pacientes foramrandomizados e seguidos de forma prospectiva em dois grupos, metálicoe absorvível. No período pós-operatório imediato os pacientes foram imobilizadoscom tala gessada por uma semana, que foi substituída por órteseremovível por quatro semanas adicionais. Carga parcial foi autorizada comtrês semanas, e carga total com seis semanas. Os vinte pacientes foramseguidos por nove meses e avaliados funcionalmente aos seis e nove meses.Resultados: A recuperação funcional foi similar nos dois grupos. Aosseis meses, três pacientes no grupo metálico queixaram-se de problemaslocais, e tiveram seus implantes removidos. Um paciente do grupo absorvívelteve uma deiscência precoce da sutura, submetida a desbridamentoe sutura com boa evolução. Aos seis e nove meses o escore da AmericanOrthopaedic Foot and Ankle Society (AOFAS) foi aplicado para todosexceto um paciente do grupo metálico, que foi perdido do seguimento.Os resultados funcionais foram semelhantes nos dois grupos, nos doismomentos. Conclusão: Os implantes absorvíveis permitiram resultadosclínicos e funcionais semelhantes aos metálicos em fraturas de tornozelo.Nível de Evidência II, Estudo Prospectivo Comparativo.


Objective: To compare the functional results of ankle fracturestreated with metallic and absorbable plates. Twentypatients were randomized into two groups (metallic and absorbableimplant groups) and followed prospectively. In theimmediate postoperative period, patients were immobilizedwith plaster casts for one week, which was replaced by aremovable cast for another four weeks. Partial weight-bearingwas allowed after three weeks, and full weight-bearing aftersix weeks. Functional recovery was similar in both groups. Atsix months, three patients in the metallic group complainedof local pain, and had their implants removed. One patientin the absorbable group exhibited early dehiscence of thesuture and underwent debridement and suturing with goodevolution. The American Orthopaedic Foot and Ankle Society(AOFAS) score was similar between the two groups after sixand nine months of follow-up. The absorbable implants showedclinical and functional results that were similar to thoseof metallic implants. Level of Evidence II, ProspectiveComparative Study.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Implantes Absorvíveis , Parafusos Ósseos , Fixação Interna de Fraturas , Fraturas Ósseas/cirurgia , Traumatismos do Tornozelo/cirurgia
3.
Acta Ortop Bras ; 23(5): 263-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26981035

RESUMO

OBJECTIVE: To compare the functional results of ankle fractures treated with metallic and absorbable plates. Twenty patients were randomized into two groups (metallic and absorbable implant groups) and followed prospectively. In the immediate postoperative period, patients were immobilized with plaster casts for one week, which was replaced by a removable cast for another four weeks. Partial weight-bearing was allowed after three weeks, and full weight-bearing after six weeks. Functional recovery was similar in both groups. At six months, three patients in the metallic group complained of local pain, and had their implants removed. One patient in the absorbable group exhibited early dehiscence of the suture and underwent debridement and suturing with good evolution. The American Orthopaedic Foot and Ankle Society (AOFAS) score was similar between the two groups after six and nine months of follow-up. The absorbable implants showed clinical and functional results that were similar to those of metallic implants. Level of Evidence II, Prospective Comparative Study.

4.
Tissue Eng Part A ; 20(13-14): 1948-60, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24460696

RESUMO

Vascularization of an artificial graft represents one of the most significant challenges facing the field of bone tissue engineering. Over the past decade, strategies to vascularize artificial scaffolds have been intensively evaluated using osteoinductive calcium phosphate (CaP) biomaterials in animal models. In this work, we observed that CaP-based biomaterials implanted into rat calvarial defects showed remarkably accelerated formation and mineralization of new woven bone in defects in the initial stages, at a rate of ∼60 µm/day (0.8 mg/day), which was considerably higher than normal bone growth rates (several µm/day, 0.1 mg/day) in implant-free controls of the same age. Surprisingly, we also observed histological evidence of primary osteon formation, indicated by blood vessels in early-region fibrous tissue, which was encapsulated by lamellar osteocyte structures. These were later fully replaced by compact bone, indicating complete regeneration of calvarial bone. Thus, the CaP biomaterial used here is not only osteoinductive, but vasculogenic, and it may have contributed to the bone regeneration, despite an absence of osteons in normal rat calvaria. Further investigation will involve how this strategy can regulate formation of vascularized cortical bone such as by control of degradation rate, and use of models of long, dense bones, to more closely approximate repair of human cortical bone.


Assuntos
Osso e Ossos/fisiologia , Fosfatos de Cálcio/farmacologia , Quitosana/farmacologia , Ósteon/fisiologia , Cicatrização/efeitos dos fármacos , Animais , Materiais Biocompatíveis/farmacologia , Osso e Ossos/efeitos dos fármacos , Ósteon/efeitos dos fármacos , Humanos , Implantes Experimentais , Masculino , Ratos Wistar , Crânio/efeitos dos fármacos , Crânio/cirurgia , Crânio/ultraestrutura
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