RESUMO
We studied the influence of the type and structure of polyethyleneimine on bioavailability and expression of plasmid DNA carrying IGF-1 gene. Polymers with different molecular weights (2.5, 10, 25, and 60 kDa) of linear and branching structure were studied. It was found that the time of polyplex circulation in the blood did not exceed 24 h and the maximum concentration of plasmid DNA was attained with complexes with a molecular weight of 60 kDa. Analysis of liver samples showed that administration of 60-kDa branched polyethyleneimine complex provides DNA protection from degradation for 4 h; in 24 h from the start of the experiment, its concentration was significantly higher than the concentration of other studied polyethyleneimines. The expression of plasmid IGF-1 DNA for this complex attained maximum in 4 h and was equal to 15.50 (7.98; 21.98) arb. units/ml. These results allow us to recommend using polyethyleneimines with branched structure and a molecular weight of 60 kDa for improving plasmid DNA protection and bioavailability.
Assuntos
Portadores de Fármacos/química , Fator de Crescimento Insulin-Like I/farmacocinética , Fígado/química , Plasmídeos/farmacocinética , Polietilenoimina/química , Animais , Animais não Endogâmicos , Disponibilidade Biológica , Expressão Gênica , Injeções Intravenosas , Fator de Crescimento Insulin-Like I/genética , Fígado/metabolismo , Masculino , Estrutura Molecular , Peso Molecular , Plasmídeos/sangue , Ratos , Relação Estrutura-Atividade , Transfecção , TransgenesRESUMO
We compared samples of microencapsulated naloxone prepared by using spray drying technique. 2-Hydroxypropyl-ß-cyclodextrin, sodium alginate, polycaprolactone, and carboxymethyl cellulose were used as the carriers. It was found that the combination of naloxone with sodium alginate was characterized by the highest naloxone content in the matrix and the lowest release rate (100% release time was 60 min). Using the model of respiratory disturbances caused by 10 ED50 fentanyl (anesthetic effect), we studied the effects of naloxone-sodium alginate complex on the dynamics of CO2 concentration in the expired air. It was shown that treatment with the developed microencapsulated naloxone after fentanyl injection allowed reducing the therapeutic dose of the antagonist by more than 2 times and eliminated the necessity of repeated injections.
