Study of mesenchymal stem cells cultured on a poly(lactic-co-glycolic acid) scaffold containing simvastatin for bone healing.

BACKGROUND: Tissue engineering is a promising alternative for the development of bone substitutes; for this purpose, three things are necessary: stem cells, a scaffold to allow tissue growth and factors that induce tissue regeneration. METHODS: To congregate such efforts, we used the bioresorbable and biocompatible polymer poly(lactic-co-glycolic acid) (PLGA) as scaffold. For the osteoinductive factor, we used simvastatin (SIM), a drug with a pleiotropic effect on bone growth. Mesenchymal stem cells (MSCs) were cultured in PLGA containing SIM, and the bone substitute of PLGA/SIM/MSC was grafted into critical defects of rat calvaria. RESULTS: The in vitro results showed that SIM directly interfered with the proliferation of MSC promoting cell death, while in the pure PLGA scaffold the MSC grew continuously. Scaffolds were implanted in the calvaria of rats and separated into groups: control (empty defect), PLGA pure, PLGA/SIM, PLGA/MSC and PLGA/SIM/MSC. The increase in bone growth was higher in the PLGA/SIM group. CONCLUSIONS: We observed no improvement in the growth of bone tissue after implantation of the PLGA/SIM/MSC scaffold. As compared with in vitro results, our main hypothesis is that the microarchitecture of PLGA associated with low SIM release would have created an in vivo microenvironment of concentrated SIM that might have induced MSC death. However, our findings indicate that once implanted, both PLGA/SIM and PLGA/MSC contributed to bone formation. We suggest that strategies to maintain the viability of MSCs after cultivation in PLGA/SIM will contribute to improvement of bone regeneration.

Polycystic hydatid disease (Echinococcus vogeli): clinical and radiological manifestations and treatment with albendazole of a patient from the Brazilian Amazon region

Apresenta-se um caso de doença hidática policística produzida pelo Echinococcus vogeli em seringueiro do Acre. Dor, crescimento do volume abdominal determinado por massas dolorosas palpáveis, febre e queda do estado geral foram os dados clínicos mais relevantes. Laboratorialmente comprovou-se anemia, eosinofilia, hipoalbuminemia, hipergamaglobulinemia e aumento dos níveis de fosfatase alcalina no plasma. Tomografia computadorizada revelou cistos disseminados pela cavidade peritoneal, até a pelvis, e no interior do fígado, pâncreas e baço. Exame anatomopatológico de cistos obtidos mediante laparotomia firmou o diagnóstico etiológico. Houve regressäo completa da doença com aplicaçäo de Albendazole na dose de 10 mg/kg/dia, durante seis meses