RESUMEN
Nitric oxide (NO) is involved in several physiological processes including vasodilation, angiogenesis, immune response, and wound healing, as well as preventing ischemia/reperfusion injury in many organs such as the heart, liver, lungs, and kidneys. Recently, various NO delivery systems such as nanoparticles, nanorods, and nanofibers have been widely studied as potential therapeutic agents. In particular, NO-releasing nanofibers have been attracting much attention for various medicinal applications including regenerative medicine, wound dressings, and coatings for implantable medical devices, due to their flexible and open architectures. In this study, we prepared biocompatible NO-releasing nanofibers by electrospinning using mixed solutions of polymers and methylaminopropyltrimethoxysilane (MAP3), which was modified with N-diazeniumdiolate as an NO donor. In addition, we evaluated their protective effects on hypoxia/reoxygenation (HR) injury in H9c2 cells. The total NO amount released from the resulting MAP3 nanofibers was 1.26 µmol ·mg-1. From the cytotoxicity evaluation of various weights of NO-releasing nanofibers (0 to 2 mg), we selected 1 mg NO-releasing nanofibers for the subsequent experiments. Pre-treatment with NO-releasing nanofibers before hypoxia induction could provide a cytoprotective effect against HR-induced injury in H9c2 cells. The nanofibers could also effectively inhibit the generation of hydrogen peroxide, which was one major contributor to oxidative damage, as well as 8-hydroxyl-2-deoxyguanosine level as an indicator of oxidative DNA damage. In addition, pre-treatment with NO-releasing nano-fibers in a wound model showed wound healing effects similar to those of normal cells. As a result, N-diazeniumdiolate-modified MAP3 nanofibers might protect H9c2 cells from DNA damage by inhibiting the generation of oxidative stress in HR injury. Therefore, we expect that NO-releasing nanofibers could be utilized as a therapeutic strategy for protecting cardiomyocytes from HR injury.
Asunto(s)
Miocitos Cardíacos , Nanofibras , Apoptosis , Humanos , Hipoxia/metabolismo , Miocitos Cardíacos/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico/farmacología , Estrés OxidativoRESUMEN
OBJECTIVES: The increasing prevalence of multidrug-resistant microorganisms (MDRO) is increasing the frequency of poor clinical outcomes, prolonging hospitalizations, and raising healthcare costs. This study evaluated the eradication efficacy of fecal microbiota transplantation (FMT) and identified microbial and functional biomarkers of MDRO decolonization. METHODS: Fecal solution obtained from healthy unrelated donors was infused in the participants' guts which had been colonized with carbapenemase-producing enterobacteriacea (CPE), vancomycin-resistant enterococci (VRE), or both CPE and VRE. Fecal samples from recipients were collected and microbiome changes before and after FMT were assessed. RESULTS: Twenty-four (68.6%) out of 35 patients were decolonized within one year of receiving FMT. Multivariate analysis showed that FMT (FMT: hazard ratio (HR)â¯=â¯5.343, 95% confidence interval (CI)â¯=â¯1.877-15.212, pâ¯=â¯0.002) and MDRO types (CPE: HRâ¯=â¯11.146, 95% CIâ¯=â¯2.420-51.340, pâ¯=â¯0.002; CPE/VRE: HRâ¯=â¯2.948, 95% CIâ¯=â¯1.200-7.246, pâ¯=â¯0.018; VRE served as the reference) were significant independent factors associated with time to decolonization. Microbiota analysis showed higher richness and biodiversity before FMT resulted in VRE decolonization. The species Clostridium ramosum and the genuses Anaerostipes and Eisenbergiella could serve as taxonomic biomarkers and K02017 could serve as a functional biomarker for VRE clearance. CONCLUSION: FMT is an effective way to decolonize MDRO and its effectiveness may be predicted by microbiome analysis.