RESUMO
Injectable bone substitutes and techniques have been developed for use in minimally invasive procedures for bone augmentation. Objective : To develop a novel injectable thermo-sensitive alginate hydrogel (TSAH) as a scaffold to induce bone regeneration, using a minimally invasive tunnelling technique. Material and Methods : An injectable TSAH was prepared from a copolymer solution of 8.0 wt% Poly(N-isopropylacrylamide) (PNIPAAm) and 8.0 wt% AAlg-g-PNIPAAm. In vitro properties of the material, such as its microstructure and the sustained release of recombinant human bone morphogenetic protein-2 (rhBMP-2), were investigated. Then, with the subperiosteal tunnelling technique, this material, carrying rhBMP-2, was injected under the labial periosteum of the maxillary anterior alveolar ridge in a rabbit model. New bone formation was evaluated by means of X-ray, micro-computed tomography (micro-CT), fluorescence labelling, histological study, and immunohistochemistry study. Results : The material exhibited good injectability and thermo-irreversible properties. SEM showed an interconnected porous microstructure of the TSAH. The result of ALP activity indicated sustained delivery of BMP-2 from the TSAH from days 3 to 15. In a rabbit model, both TSAH and TSAH/rhBMP-2 induced alveolar ridge augmentation. The percentage of mineralised tissue in the TSAH/rhBMP-2 group (41.6±3.79%) was significantly higher than in the TSAH group (31.3±7.21%; p<0.05). The density of the regenerating tissue was higher in the TSAH/rhBMP-2 group than in the other groups (TSAH group, positive control, blank control; p<0.05). Conclusions : The TSAH provided convenient handling properties for clinical application. To some extent, TSAH could induce ridge augmentation and mineral deposition, which can be enhanced when combined with rhBMP-2 for a minimally invasive tunnelling injection. .
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Lesões Encefálicas/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Receptores de Interleucina-1/antagonistas & inibidores , Lesões Encefálicas/imunologia , Lesões Encefálicas/patologia , Encéfalo/imunologia , Encéfalo/patologia , Citocinas/análise , Citocinas/imunologia , Proteína Antagonista do Receptor de Interleucina 1/administração & dosagem , Proteína Antagonista do Receptor de Interleucina 1/efeitos adversos , Receptores de Interleucina-1/imunologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêuticoRESUMO
Os autores abordam a importância e a frequência do traumatismo cranioencefálico (TCE) associado ao traumatismo bucomaxilofacial (TBMF), descrevendo quais as lesões e condutas a serem tomadas frente a um paciente portador de TCE, ressaltando qual a posição do cirurgião bucomaxilofacial neste contexto
