Research Progress of Polyvinyl Alcohol (PVA) Based on Hydrogel Dressings / 中国医疗器械杂志

This review introduces a brief description on the featured properties of polyvinyl alcohol based on hydrogel dressings. During past ten years many new artificial polymeric dressings have been developed, which meet requirements of wound healing. This review mainly focuses on one representative of ideal polymeric wound dressing membranes, polyvinyl alcohol based hydrogel dressings. But as the hydrogels with single component have low mechanical strength, recent trends have offered composite hydrogel membranes to achieve the ideal wound dressing requirements.

Prostaglandin E2 receptor subtype 3?siRNA reduces the mesangial cell damage induced by TGF ?β1 through inhibiting MAPK pathway in mice / 中华肾脏病杂志

Objective To investigate the effects and mechanisms of prostaglandin E2 receptor subtype 3 (EP3) on transforming growth factor β1 (TGF-β1)-induced mouse mesangial cells damage. Methods Primary mouse mesangial cells were separated and cultured. Three siRNAs were synthesized and transfected into mesangial cells for silencing EP3 by LipofectamineTM 2000 and the best one was chosen. MCs were grouped into: (1)control group; (2)TGF-β1 (10 μg/L) group; (3)NC-siRNA plus TGF-β1 (10 μg/L) group; (4) EP3-siRNA group; (5)EP3-siRNA plus TGF-β1 (10 μg/L). Then the proliferation of MCs was evaluated by CCK-8 assay. The expression of PGE2 and cAMP in cell supernatant were detected by ELISA. The mRNA and protein expression of fibronectin (FN), connective tissue growth factor (CTGF), cyclooxygenase-2 (COX2), membrane-bound prostaglandin E2 synthase 1 (mPGES1) were detected by real - time quantitative PCR and Western blotting. The phosphorylation of p38 MAPK and ERK1/2 was decected by Western blotting. Results Compared with control group, the cell proliferation induced by TGF-β1 was increased (P<0.05), the expression of PGE2 and cAMP were improved, mRNA and protein expression of FN, CTGF, COX2 and mPGES1 were up-regulated (all P<0.05). Compared with TGF-β1 group, the cell proliferation in EP3-siRNA plus TGF-β1 group was reduced, the expression of FN, CTGF, COX2 and mPGES1 mRNA and protein were downregulated (all P<0.05), the phosphorylation of ERK1/2, p38 MAPK were also declined (P<0.05). Conclusion EP3-siRNA may reduce TGF-β1-induced cell damage through upregulating the expression of cAMP, repressing the activity of ERK1/2 and p38 MAPK, inhibiting the expression of COX2 mPGES1 and PGE2 by feedback, then decreased the expression of FN and CTGF.

Prostaglandin E2 receptor 1 antagonist attenuates mesangial cell lesion induced by TGF-β1 in mice through inhibiting ERK signal pathway / 中华肾脏病杂志

Objective To explore the effects and mechanisms of prostaglandin E2 (PGE2) receptor 1 antagonist (SC-19220) on proliferation,prostaglandin synthase and extracellular regulated protein kinases (ERK) signal pathway induced by transforming growth factor β1(TGF-β1) in glomerular mesangial cells.Methods Mouse glomerular mesangial cells (GMCs) were divided into 5 groups:control group,TGF-β1 (10 μg/L) group,TGF-β1 (10 μg/L) plus SC-19220 group (0.1,0.5,1.0 μmol/L).The proliferation of GMCs was measured by CCK-8.The PGE2 in supernatant was measured by ELISA.The expression of connective tissue growth factor (CTGF),laminin (LN),cyclooxygenase 2(COX2),membrane-bound prostaglandin E2 synthase 1 (mPGES1) protein and mRNA was examined by Westem blotting and real-time quantitative PCR,ERK1/2 or phospho-ERK1/2 was measured by Western blotting as well.Results TGF-β1 induced the proliferation of GMCs and increased the secretion of PGE2.Besides,TGF-β1 significantly up-regulated the expression of CTGF,LN,COX2 and mPGES1 mRNA and protein (P ＜ 0.05),and increased the expression of phospho-ERK1/2 protein (P ＜ 0.05).However,SC-19220 significantly attenuated the changes of above-mentioned parameters and their activities (P ＜ 0.05).All the effects of SC-19220 were in dose-dependent manner.Conclusions SC19220 may reduce TGF-β1-induced cell damage by suppressing the activity of ERK1/2,and feedback inhibition of COX2,mPGES1 and PGE2,thus decreases the expression of LN and CTGF.

The performance of the microbial barrier of needleless positive pressure closed connectors / 中国医疗器械杂志

<p><b>OBJECTIVE</b>Analyzing the performance of microbial barrier of needleless positive pressure closed connectors.</p><p><b>METHODS</b>Three kinds of brand needleless positive pressure closed connectors were chosen to do the access of microorganisms test.</p><p><b>RESULTS</b>Positive results were detected in the three experimental groups.</p><p><b>CONCLUSIONS</b>So far, lots of the connectors are not qualified strictly on the market, some improvement is required in the structure design and process.</p>