Reported in this study is the successful incorporation of a hydrophilic antibiotic drug, tetracycline hydrochloride (TCH), into electrospun PEG-PLA nanofibrous membrane without loss of its bioactivity. Degradation behavior of the copolymer was studied in vitro. Release behavior of TCH from the electrospun membrane and antimicrobial effects of the TCH-loaded membrane against Staphylococcus aureus culture were investigated. The medicated nanofibrous membrane demonstrated sustained release of TCH over 6 days and was found to be effective in inhibiting growth of S. aureus. In addition, increasing the antibiotic drug content in the electrospun membranes was found to enhance the anti-bacterial effectiveness of the medicated fiber mats. And the combination of mechanical barriers provided by the electrospun biodegradable nanofibrous membranes and their capability of local sustained delivery of antibiotics made these membranes more useful in biomedical applications, particularly as new wound dressings for ulcers caused by diabetes or other diseases, and to provide a better means of treatment for these malignant wounds and ulcers.

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During HIV infection, large amounts of progeny viral particles, including infectious virus and a large proportion of defective viral particles, are produced. Despite of the critical role of the infectious viruses in infection and pathogenesis in vivo, whether and how those defective viral particles, especially the virus-associated envelope glycoprotein (vEnv), would impact viral infection remains elusive. In this study, we investigated the effect of vEnv on HIV-infected T cells and demonstrated that the vEnv was able to stimulate HIV transcription in HIV-infected cells, including peripheral blood mononuclear cells (PBMCs) isolated from HIV patients. This vEnv-mediated HIV transcription activation is mediated primarily through the interaction between vEnv and CD4/coreceptors (CCR5 or CXCR4). Through transcriptome analysis, we found that numerous cellular gene products involved in various signaling pathways were modulated by vEnv. Among them, we have further identified a cellular microRNA miR181A2, which is downregulated upon vEnv treatment, resulting in increased HIV LTR histone H3 acetylation and HIV transcription. Furthermore, we also found a vEnv-modulated cellular histone deacetylase, HDAC10, whose downregulation is associated with the increased infectivity of progeny viruses. Altogether, these findings provide evidence of the important role vEnv plays in modulating cellular environments and facilitating HIV expression and infection.

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