RESUMO
Genistein is a phytochemical with a broad range of desirable biological activity for wound healing. However, its poor bioavailability requires developing a new method for fabricating an appropriate carrier vehicle to deliver genistein in a sustained manner. Based on the guidance afforded by the ternary phase diagram of poly(D,L-lactic acid) (PDLLA), poly(ethylene oxide) (PEO), and genistein blends, certain selective compositions were electrospun. We obtained a uniformly smooth surface morphology in unmodified and genistein-modified PEO/PDLLA fibers, documented by scanning electron microscopy. Moreover, wide-angle X-ray diffraction and 1H NMR studies revealed that the genistein molecules, successfully incorporated in the blends, remained chemically stable after electrospinning. Besides surface wettability and dimensional stability of the electrospun mats, the released genistein amount has been evaluated as a function of PEO concentration. Our biocompatibility investigations suggest that genistein-modified PEO/PDLLA electrospun mats exhibit strong antioxidant and anti-inflammatory activities which indicate they have potential applications for wound dressings.
Assuntos
Anti-Inflamatórios/química , Antioxidantes/química , Materiais Biocompatíveis/síntese química , Preparações de Ação Retardada/síntese química , Genisteína/química , Ácido Láctico/química , Polímeros/química , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Bandagens , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , Preparações de Ação Retardada/farmacologia , Técnicas Eletroquímicas , Genisteína/farmacologia , Humanos , Cinética , Ácido Láctico/farmacologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Microscopia Eletrônica de Varredura , Poliésteres , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polímeros/farmacologia , Molhabilidade , CicatrizaçãoRESUMO
The emergence of macrolide- and lincosamide-resistant Streptococcus pneumoniae is a worldwide concern. Of particular interest is the increasing prevalence of erythromycin and clindamycin-resistant isolates containing both erm(B) and mef genes. This study determined the prevalence of erythromycin and clindamycin resistance in 596 clinical S. pneumoniae isolates from 2 adult tertiary care hospitals over a 4-year period (2001-2004). Erythromycin resistance increased from 24% to 34%, but S. pneumoniae isolates resistant to clindamycin as well as to erythromycin increased from 3% in 2001 to 15.5% in 2004 (5-fold increase). Among erythromycin-resistant isolates, those also resistant to clindamycin (MLS(B) phenotype) increased 3-fold (12.8-45%). Of forty-one erythromycin/clindamycin-resistant S. pneumoniae isolates tested, 29 (71%) contained both erm(B) and mef(E) genes. Pulsed-field gel electrophoresis performed on 28 erm(B) + mef(E) positive isolates identified 2 predominant and possibly related clones, which made up 64% of the isolates.
