Publicação
Mechanical evaluation of implanted calcium phosphate cement incorporated with PLGA microparticles
| Resumo: | In this study, the mechanical properties of an implanted calcium phosphate (CaP) cement incorporated with 20wt% poly (DL-lactic-coglycolic acid) (PLGA) microparticles were investigated in a rat cranial defect. After 2, 4 and 8 weeks of implantation, implants were evaluated mechanically (push-out test) and morphologically (Scanning Electron Microscopy (SEM) and histology). The results of the push-out test showed that after 2 weeks the shear strength of the implants was 0.4470.44MPa (average7sd), which increased to 1.3471.05MPa at 4 weeks and finally resulted in 2.6072.78MPa at 8 weeks. SEM examination showed a fracture plane at the bone–cement interface at 2 weeks, while the 4- and 8-week specimens created a fracture plane into the CaP/PLGA composites, indicating an increased strength of the bone–cement interface. Histological evaluation revealed that the two weeks implantation period resulted in minimal bone ingrowth, while at 4 weeks of implantation the peripheral PLGA microparticles were degraded and replaced by deposition of newly formed bone. Finally, after 8 weeks of implantation the degradation of the PLGA microparticles was almost completed, which was observed by the bone ingrowth throughout the CaP/PLGA composites. On basis of our results, we conclude that the shear strength of the bone–cement interface increased over time due to bone ingrowth into the CaP/PLGA composites. Although the bone–cement contact could be optimized with an injectable CaP cement to enhance bone ingrowth, still the mechanical properties of the composites after 8 weeks of implantation are insufficient for load-bearing purpose. |
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| Autores principais: | Link, Dennis P. |
| Outros Autores: | Van den Dolder, Juliette; Jurgens, J. F. M.; Wolke, Joop G.; Jansen, John A. |
| Assunto: | Injectable CaP/PLGA cement Mechanical properties; Bone ingrowth |
| Ano: | 2006 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | In this study, the mechanical properties of an implanted calcium phosphate (CaP) cement incorporated with 20wt% poly (DL-lactic-coglycolic acid) (PLGA) microparticles were investigated in a rat cranial defect. After 2, 4 and 8 weeks of implantation, implants were evaluated mechanically (push-out test) and morphologically (Scanning Electron Microscopy (SEM) and histology). The results of the push-out test showed that after 2 weeks the shear strength of the implants was 0.4470.44MPa (average7sd), which increased to 1.3471.05MPa at 4 weeks and finally resulted in 2.6072.78MPa at 8 weeks. SEM examination showed a fracture plane at the bone–cement interface at 2 weeks, while the 4- and 8-week specimens created a fracture plane into the CaP/PLGA composites, indicating an increased strength of the bone–cement interface. Histological evaluation revealed that the two weeks implantation period resulted in minimal bone ingrowth, while at 4 weeks of implantation the peripheral PLGA microparticles were degraded and replaced by deposition of newly formed bone. Finally, after 8 weeks of implantation the degradation of the PLGA microparticles was almost completed, which was observed by the bone ingrowth throughout the CaP/PLGA composites. On basis of our results, we conclude that the shear strength of the bone–cement interface increased over time due to bone ingrowth into the CaP/PLGA composites. Although the bone–cement contact could be optimized with an injectable CaP cement to enhance bone ingrowth, still the mechanical properties of the composites after 8 weeks of implantation are insufficient for load-bearing purpose. |
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