RESUMO
In this study, we prepared a series of silver sulfadiazine (AgSD)-loaded polyvinyl alcohol (PVA) hydrogels via electron beam (e-beam) irradiation. Our objective was to explore the influence of e-beam irradiation on the chemical structure and crystallinity of AgSD and the antibacterial properties of AgSD/PVA hydrogels. Prior to irradiation, we mixed AgSD in PVA solution in 2 forms, either suspended in water (WS) or dissolved in ammonia solution (AS). We noted that nano silver was released from AgSD/PVA-AS hydrogels immersed in deionized water, while it would not happen in AgSD/PVA-WS hydrogels. Both kinds of AgSD/PVA hydrogels exhibited good antibacterial activities against gram-negative Escherichia coli and gram-positive Staphylococcus aureus. And their antibacterial activity was not obviously affected by different dosages of e-beam irradiation. Moreover, the antibacterial activity of the AgSD/PVA-WS hydrogels was stronger than that of AgSD/PVA-AS. Accordingly, the cell cytotoxicity of the AgSD/PVA-WS hydrogels was higher than that of AgSD/PVA-AS. Our study results reveal that e-beam irradiation of PVA solution with dispersed AgSD is a simple and efficient way to prepare AgSD/PVA hydrogels, which might be an ideal antibacterial wound dressing.
Assuntos
Antibacterianos/síntese química , Bandagens , Química Farmacêutica/métodos , Álcool de Polivinil/síntese química , Sulfadiazina de Prata/síntese química , Cicatrização , Animais , Antibacterianos/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Camundongos , Células NIH 3T3 , Álcool de Polivinil/administração & dosagem , Sulfadiazina de Prata/administração & dosagem , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Cicatrização/efeitos dos fármacos , Difração de Raios X/métodosRESUMO
A recombinant strain Escherichia coli DH5alpha(pMD19-glnA) including Bacillus subtilis glnA gene was constructed. Capillary electrophoresis and nuclear magnetic resonance were used to determine qualitatively the product of transformation by recombinant strain, and the relative level of mRNA expression of glnA was also determined by fluorescence quantitative RT-PCR. Subsequently, SDS-PAGE (polyacrylamide gel electrophoresis) was used to analysis the relative level of protein. Surprisingly, there was no increase of glutamine production in this recombinant strain, but an obvious increase in the GABA (gamma-aminobutyric acid ) production. It was showed in the experiment that protein expression of the glutamine synthetase did not increase, although glnA gene can be transcribed normally in this recombined strain. The phenomenon of exogenous glnA gene interfering metabolism of Escherichia coli was worthy of further study.
