Electrospun mupirocin loaded polyurethane fiber mats for anti-infection burn wound dressing application

<p>Wound care treatment is a serious issue faced by the medical staffs due to its variety and complexity. Wound dressings are typically used to manage the various types of wounds. In this study, polyurethane (PU) fibers containing mupirocin (Mu), a commonly used antibiotic in wound care, were fabricated via electrospinning technique. The aim of this study was to develop biomedical electrospun fiber scaffolds for preventing wound infections with good compatibility and to demonstrate their applications as anti-infective burn wound dressings. The surface morphology of fibers was obtained by scanning electron microscopy. FT-IR spectra, water vapor transmission rate, and drug release study <i>in vitro</i> were tested to demonstrate the fiber scaffold characteristic. The prepared PU/Mu composite scaffolds had satisfactory antibacterial activity especially against <i>Staphylococcus aureus</i>. The cell studies revealed that the scaffolds were biocompatible and safe for cell attachment. Histological and immunohistochemical examinations were performed in rats, and the results indicated the histological analysis of tissue stained with H&E showed no obvious inflammation reaction. The results indicated that the electrospun scaffolds were capable of loading and delivering drugs, and could be potentially used as novel antibacterial burn wound dressings.</p

Involvement of TGF-β1/Smad3 Signaling in Carbon Tetrachloride-Induced Acute Liver Injury in Mice

<div><p>Transforming growth factor-beta1 (TGF-β1) is a major factor in pathogenesis of chronic hepatic injury. Carbon tetrachloride (CCl₄) is a liver toxicant, and CCl₄-induced liver injury in mouse is a classical animal model of chemical liver injury. However, it is still unclear whether TGF-β1 is involved in the process of CCl₄-induced acute chemical liver injury. The present study aimed to evaluate the role of TGF-β1 and its signaling molecule Smad3 in the acute liver injury induce by CCl₄. The results showed that CCl₄ induced acute liver injury in mice effectively confirmed by H&E staining of liver tissues, and levels of not only liver injury markers serum ALT and AST, but also serum TGF-β1 were elevated significantly in CCl₄-treated mice, compared with the control mice treated with olive oil. Our data further revealed that TGF-β1 levels in hepatic tissue homogenate increased significantly, and type II receptor of <i>TGF-β (TβRII)</i> and signaling molecules <i>Smad2</i>, <i>3</i>, mRNA expressions and Smad3 and phospho-Smad3 protein levels also increased obviously in livers of CCl₄-treated mice. To clarify the effect of the elevated TGF-β1/Smad3 signaling on CCl₄-induced acute liver injury, Smad3 in mouse liver was overexpressed <i>in vivo</i> by tail vein injection of Smad3-expressing plasmids. Upon CCl₄ treatment, Smad3-overexpressing mice showed more severe liver injury identified by H&E staining of liver tissues and higher serum ALT and AST levels. Simultaneously, we found that Smad3-overexpressing mice treated with CCl₄ showed more macrophages and neutrophils infiltration in liver and inflammatory cytokines IL-1β and IL-6 levels increment in serum when compared with those in control mice treated with CCl₄. Moreover, the results showed that the apoptosis of hepatocytes increased significantly, and apoptosis-associated proteins Bax, cytochrome C and the cleaved caspase 3 expressions were up-regulated in CCl₄-treated Smad3-overexpressing mice as well. These results suggested that TGF-β1/Smad3 signaling was activated during CCl₄-induced acute liver injury in mice, and Smad3 overexpression aggravated acute liver injury by promoting inflammatory cells infiltration, inflammatory cytokines release and hepatocytes apoptosis. In conclusion, the activation of TGF-β signaling contributes to the CCl₄-induced acute liver injury. Thus, TGF-β1/Smad3 may serve as a potential target for acute liver injury therapy.</p></div

Pathological changes of livers in CCl₄-treated mice.

<p>Pathological changes of livers were analyzed by H&E staining. Arrows represent lesion area.</p

Analysis of hepatocytes apoptosis in Smad3-overexpressing mice.

<p>(A) The apoptosis of hepatocytes was examined by TUNEL staining in livers of CCl₄-treated Smad3-overexpressing mice (Smad3 + CCl₄) and plasmid control mice (PC + CCl₄). Arrows represent apoptotic cells (red cells). The graph represents the apoptotic index of hepatocytes. *<i>P</i><0.05 and **<i>P</i><0.01. (B) Levels of pSmad3 and apoptosis-associated proteins Bax, Bcl2, Cyt C and the cleaved caspase 3 (cleaved cap3) were evaluated by Western blotting in livers of non-treated mice (Cont), CCl₄-treated plasmid control mice (PC + C) and CCl₄-treated Smad3-overexpressing mice (Sm + C). The graph represents levels of relative protein from triplicate determinations.*<i>P</i><0.01. CCl₄-treated Smad3-overexpressing mice (b) vs CCl₄-treated plasmid control mice (a).</p

Effects of Smad3 overexpression <i>in vivo</i> on liver injury of CCl₄-treated mice.

<p>(A) Levels of ALT and AST were examined by ELISA in sera of CCl₄-treated Smad3-overexpressing mice (■) and plasmid control mice (●). *<i>P</i><0.05, **<i>P</i><0.01, compared with control group (n = 6). (B) Pathological changes of livers were analyzed by H&E staining in 1 day olive oil-treated control mice (Olive), plasmid control mice (PC + Olive) and Smad3-overexpressing mice (Smad3 + Olive) (x40). (C) Pathological changes of livers were analyzed by H&E staining in CCl₄-treated Smad3-overexpressing mice (Smad3 + CCl₄) and plasmid control mice (PC + CCl₄). Arrows represent lesion area (x40). The graph represents liver injury index. *<i>P</i><0.05.</p

Expression of TGF-β1 in livers of mice treated with CCl₄.

<p>(A) Levels of TGF-β1 were examined by ELISA in hepatic homogenates of mice with CCl₄ (●) and control mice treated with olive oil (○). *<i>P</i><0.01, compared with control group (n = 6). (B) Expression of <i>TGF-β1</i> mRNA was examined by RT-PCR in livers of mice treated with CCl₄ and control mice treated with olive oil. The graph represents relative levels of <i>TGF-β1</i> mRNA from triplicate determinations. *<i>P</i><0.01, compared with olive oil control group.</p

Expression of Smad3 in livers of Smad3-overexpressing mice.

<p>(A) <i>Smad3</i> mRNA expressions were evaluated by RT-PCR in livers of CCl₄-treated Smad3-overexpressing mice (Smad3 + CCl₄) and plasmid control mice (PC + CCl₄). The graph represents relative levels of <i>Smad3</i> mRNA from triplicate determinations. *<i>P</i><0.05, **<i>P</i><0.01, compared with plasmid control group. (B) pSmad3 protein levels were examined by Western blotting in livers of CCl₄-treated Smad3-overexpressing mice (Smad3 + CCl₄) and plasmid control mice (PC + CCl₄). The graph represents relative protein levels of pSmad3 from triplicate determinations. *<i>P</i><0.01, compared with plasmid control group. (C) Expression of Smad3 protein was examined by immunohistochemical staining with rabbit anti-mouse Smad3 antibody in livers of Smad3-overexpressing mice (Smad3 + CCl₄) and plasmid control mice (PC + CCl₄) treated with CCl₄ for 1 day. A procedural control staining in the liver was performed using normal rabbit IgG instead of anti-Smad3 antibody (Control). Arrows represent Smad3 positive cells (x100).</p

Expressions of TβRII and Smads mRNA and protein in livers of mice treated with CCl₄.

<p>(A) Expressions of <i>TβRII</i> and signaling molecules <i>Smad2</i>, <i>3</i>, <i>4</i>, <i>6</i>, <i>7</i> mRNA were examined by RT-PCR in livers of mice treated with CCl₄ and control mice treated with olive oil. The graph represents relative levels of mRNA from triplicate determinations. Olive oil (grey bars), CCl₄ (black bars). *<i>P</i><0.01, compared with olive oil control group. (B) pSmad3 and Smad3 protein levels were analyzed by Western blotting in livers of mice treated with CCl₄ and control mice treated with olive oil. The graph represents relative protein levels of pSmad3 and Smad3 from triplicate determinations. *<i>P</i><0.01, compared with olive oil control group.</p

Assay of inflammatory cytokines and inflammatory cells in Smad3-overexpressing mice.

<p>(A) Levels of IL-1β and IL-6 were examined by ELISA in sera of CCl₄-treated Smad3-overexpressing mice (■) and plasmid control mice (●). *<i>P</i><0.05, compared with control group (n = 6). (B) The infiltration of neutrophils and macrophages in livers of plasmid control mice (PC + CCl₄) and Smad3-overexpressing mice (Smad3 + CCl₄) treated with CCl₄ for 3 days were examined by MPO staining and F4/80 immunofluorescence staining. Arrows represent neutrophils (dark blue cells) (x400) and macrophages cells (red cells) (x200). (C) The inflammatory cells were examined in livers of CCl₄-treated plasmid control mice (PC + CCl₄) and Smad3-overexpressing mice (Smad3 + CCl₄) by flow cytometry with anti-CD14/CD11b and anti-Ly-6G/CD11b antibodies. *<i>P</i><0.05, **<i>P</i><0.01, compared with control group (n = 6).</p

MOESM1 of Serum and thyroid tissue level of let-7b and their correlation with TRAb in Graves’ disease

Additional file 1: Table S1. The predicted candidate gene, pathway and related other inflammatory disease of the selected microRNA candidates