RESUMO
The purpose of this study was to develop a novel ß-tricalcium phosphate (TCP)/poly (D,L-lactic-co-glycolic acid) (PLGA) composite scaffold loaded with rapamycin that can regulate the activity of osteoblasts and osteoclasts for lumbar fusion. The TCP/PLGA composite scaffold was fabricated by cryogenic three-dimensional printing techniques and then loaded with rapamycin in situ. The structural surface morphology of the composite scaffold was tested with scanning electron microscope. To evaluate the biocompatibility of the composite scaffold in vitro, bone marrow mesenchymal stem cells (BMSCs) were cultured on the TCP/PLGA composite scaffold slide and tested with Live/Dead Viability Kit. The effect of rapamycin on osteoclast and osteoblast was studied with staining and Western blotting. The in vitro results showed that the rapamycin-loaded TCP/PLGA composite scaffold showed good biocompatibility with BMSC and released rapamycin obviously promoted the osteoblast differentiation and mineralization. In vivo study, the TCP/PLGA composite scaffold loaded with rapamycin were implanted in lumbar fusion model and study with micro-computed tomography scanning, hematoxylin-eosin, Masson, and immune-histological staining, to evaluate the effect of rapamycin on bone fusion. The in vivo results demonstrated that rapamycin-loaded TCP/PLGA composite scaffold could enhance bone formation by regulating osteoblast and osteoclast activity, respectively. In this study, the TCP/PLGA composite scaffold loaded with rapamycin was confirmed to provide great compatibility and improved performance in lumbar fusion by regulating osteoblastic and osteoclastic activity and would be a promising composite biomaterial for bone tissue engineering.
Assuntos
Fosfatos de Cálcio/química , Vértebras Lombares/cirurgia , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Sirolimo/farmacologia , Fusão Vertebral , Alicerces Teciduais/química , Animais , Diferenciação Celular/efeitos dos fármacos , Feminino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Osteoblastos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteopontina/metabolismo , Impressão Tridimensional , Células RAW 264.7 , Ratos Sprague-Dawley , Fosfatase Ácida Resistente a Tartarato/metabolismo , Microtomografia por Raio-XRESUMO
Polybutylcyanoacrylate nanoparticles (PBCA-NP) were prepared by addition of the monomer to an aqueous phase containing dextran 70 and loaded with mitomycin C (MMC-PBCA-NP), a highly effective anticancer drug. When injected into mice, MMC-PBCA-NP accumulated more in the liver than did free MMC. In contrast, MMC-PBCA-NP accumulated less in the heart and kidney than did free MMC. However, when MMC-PBCA-NP and MMC were administered to rabbits bearing VX2 cells implanted into the liver, the antiproliferative effects on the tumor cells of both drugs were similar. Histological analyses indicated that organization of myocardial filaments was disrupted and vacuolization was observed in the MMC treated group, whereas MMC-PBCA-NP treatment did not appear to damage the host's heart. Hydropic degeneration of renal tubular epithelia was observed in the MMC treated group and not in the control group, whereas MMC-PBCA-NP treatment did not appear to damage the host's kidney.