BACKGROUND Aplasia cutis congenita (ACC) in newborns is a condition in which congenital defects or hypoplasia is present in part of the epidermis,dermis and even subcutaneous tissue (including muscle and bones).First ...BACKGROUND Aplasia cutis congenita (ACC) in newborns is a condition in which congenital defects or hypoplasia is present in part of the epidermis,dermis and even subcutaneous tissue (including muscle and bones).First reported by Cordon in 1767,ACC is a rare disease with a low incidence of 1/100000 to 3/10000.Currently,there are 500 cases reported worldwide.ACC can be accompanied by other malformations.The onset mechanism of the disease remains unknown but is thought to be correlated to factors such as genetics,narrow uterus,foetal skin and amniotic membrane adhesion,use of teratogenic drugs in early pregnancy and viral infection.CASE SUMMARY In August 2018,we treated a newborn with ACC on the left lower limbs using a combination of ionic silver dressing and moist exposed burn ointment (MEBO) and achieved a satisfactory treatment outcome.The skin defects were observed on the external genitals and on areas from the left foot to 3/4 of the upper left side.Subcutaneous tissue and blood vessels were observed in the regions with skin defects.The following treatments were provided.First,the wound was rinsed with 0.9% sodium chloride solution followed by disinfection with povidone-iodine twice.And then MEBO was applied to the wound at a thickness of approximately 1 mm.After applying ionic silver dressing,the wound was covered with sterile gauze.The wound dressing was replaced every 2-3 d.At the 4-mo follow-up,the treatment outcome was satisfactory.There was minimal scar tissue formation,and limb function was not impaired.CONCLUSION The combination of ionic silver dressing and MEBO to ACC is helpful.展开更多
Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions （Ag^...Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions （Ag^＋） on the proliferation of human skin keratinocytes （HaCaT） and the production of intracellular reactive oxygen species （ROS）. After treating HaCaT cells with Ag^＋ and/or the active oxygen scavenger N-acetyl cysteine （NAC）, cell proliferation and intracellular ROS generation were assessed using CCK-8 reagent and DCFH-DA fluorescent probe, respectively. In addition, 5-bromo-2-deoxyUridine （BrdU） incorporation assays, cell cycle flow cytometry, and proliferating cell nuclear antigen （PCNA） immunocytochemistry were conducted to further evaluate the effects of sub-cytotoxic Ag^＋ concentrations on HaCaT cells. The proliferation of HaCaT cells was promoted in the presence of 10^-6 and 10^-5s mol/L Ag^＋at 24, 48, and 72 h. Intracellular ROS generation also significantly increased for 5 60 min after exposure to Ag^＋ The number of BrdU-positive cells and the presence of PCNA in HaCaT cells increased 48 h after the addition of 10^-6 and 10^-5 mol/L Ag^＋, with 10^-5 mol/L Ag^＋ markedly increasing the cell proliferation index. These effects of sub-cytotoxic Ag^＋ concentrations were repressed by 5 mmol/L NAC. Our results suggest that sub-cytotoxic Ag^＋ concentrations promote the proliferation of human keratinocytes and might be associated with a moderate increase in intracellular ROS levels. This study provides important experimental evidence for developing novel silver-based wound agents or dressings with few or no cytotoxicity.展开更多
Stable silver nanoparticles was successfully synthesized by chemical reduction of silver nitrate in an ionic liquid,1-n-butyl-3-methylimidazolium tetrafluoroborate（[BMIM]·BF4） at room temperature.Results of UV-...Stable silver nanoparticles was successfully synthesized by chemical reduction of silver nitrate in an ionic liquid,1-n-butyl-3-methylimidazolium tetrafluoroborate（[BMIM]·BF4） at room temperature.Results of UV-Vis diffuse reflectance spectroscopy show as-prepared Ag nanoparticles exhibit a typical emission peak at 400―430 nm.By varying the reaction temperature and the precursor concentration,the size and the shape of the silver nanoparticles could be easily controlled under mild conditions.Analyses of transmission electron micrographs,X-ray diffraction pattern and X-ray photoelectron spectrum further reveal that the silver nanoparticles were coated incompletely by [BMIM]·BF4.Microbial experiments indicate that as-prepared silver nanoparticles show a wide spectrum of antimicrobial activities and have better antimicrobial activities to Pseudomonas aeruginosa than silver nitrate with the same concentration of silver.展开更多
Silver nanorods have been successfully synthesized in large scale by the ethylene glycol（EG） reduction in the presence of ionic liquid（IL） 1-butyl-3-methylimidazolium tetrafluoroborate（bmimBF_4） and polyvinyl-py...Silver nanorods have been successfully synthesized in large scale by the ethylene glycol（EG） reduction in the presence of ionic liquid（IL） 1-butyl-3-methylimidazolium tetrafluoroborate（bmimBF_4） and polyvinyl-pyrrolidone（PVP）.The silver nanorods were characterized by scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,transmission electron microscopy（TEM）,electron energy disperse spectroscopy（EDS） and UV-vis spectroscopy.The results showed that the uniform silver nanorods have an average diameter of about 100 nm and the aspect ratio from 15 to 20.IL,bmimBF_4 may play a role of capping agent together with PVP in the formation of silver nanorods.On the other band,bmimBF_4 may accelerate nucleation and improve the stability of the resulting Ag nanorods due to the low interface tension of IL.展开更多
Using the ionic liquid（IL）1-octyl-3-methylimidazolium hexafluorophosphate as the extractant and methanol as the dispersion solvent,a dispersive liquid–liquid microextraction method was developed to extract silver n...Using the ionic liquid（IL）1-octyl-3-methylimidazolium hexafluorophosphate as the extractant and methanol as the dispersion solvent,a dispersive liquid–liquid microextraction method was developed to extract silver nanoparticles（AgN Ps）from environmental water samples.Parameters that influenced the extraction efficiency such as IL concentration,pH and extraction time were optimized.Under the optimized conditions,the highest extraction efficiency for AgN Ps was above 90% with an enrichment factor of 〉90.The extracted AgN Ps in the IL phase were identified by transmission electron microscopy and ultraviolet–visible spectroscopy,and quantified by inductively coupled plasma mass spectrometry after microwave digestion,with a detection limit of 0.01 μg/L.The spiked recovery of AgN Ps was 84.4% with a relative standard deviation（RSD）of 3.8%（n = 6）at a spiked level of 5 μg/L,and 89.7% with a RSD of 2.2%（n = 6）at a spiked level of 300 μg/L,respectively.Commonly existed environmental ions had a very limited influence on the extraction efficiency.The developed method was successfully applied to the analysis of Ag NPs in river water,lake water,and the influent and effluent of a wastewater treatment plant,with recoveries in the range of 71.0%–90.9% at spiking levels of 0.11–4.7 μg/L.展开更多
The silver ionic complexes of xanthone glycosides were studied by ESI-MS/MS in the positive ion mode. The fragmentation pathways of silver ionic complexes under collisioninduced dissociation （CID） were investigated ...The silver ionic complexes of xanthone glycosides were studied by ESI-MS/MS in the positive ion mode. The fragmentation pathways of silver ionic complexes under collisioninduced dissociation （CID） were investigated and the differences in MS/MS spectra of different silver ionic complexes of xanthones were correlated to the characterization of saccharide and the coordination pattern of silver ion with xanthones, including the glycosilation position and linkage type of disaccharide （1-2 and 1-6 linkages）.展开更多
文摘BACKGROUND Aplasia cutis congenita (ACC) in newborns is a condition in which congenital defects or hypoplasia is present in part of the epidermis,dermis and even subcutaneous tissue (including muscle and bones).First reported by Cordon in 1767,ACC is a rare disease with a low incidence of 1/100000 to 3/10000.Currently,there are 500 cases reported worldwide.ACC can be accompanied by other malformations.The onset mechanism of the disease remains unknown but is thought to be correlated to factors such as genetics,narrow uterus,foetal skin and amniotic membrane adhesion,use of teratogenic drugs in early pregnancy and viral infection.CASE SUMMARY In August 2018,we treated a newborn with ACC on the left lower limbs using a combination of ionic silver dressing and moist exposed burn ointment (MEBO) and achieved a satisfactory treatment outcome.The skin defects were observed on the external genitals and on areas from the left foot to 3/4 of the upper left side.Subcutaneous tissue and blood vessels were observed in the regions with skin defects.The following treatments were provided.First,the wound was rinsed with 0.9% sodium chloride solution followed by disinfection with povidone-iodine twice.And then MEBO was applied to the wound at a thickness of approximately 1 mm.After applying ionic silver dressing,the wound was covered with sterile gauze.The wound dressing was replaced every 2-3 d.At the 4-mo follow-up,the treatment outcome was satisfactory.There was minimal scar tissue formation,and limb function was not impaired.CONCLUSION The combination of ionic silver dressing and MEBO to ACC is helpful.
文摘Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions （Ag^＋） on the proliferation of human skin keratinocytes （HaCaT） and the production of intracellular reactive oxygen species （ROS）. After treating HaCaT cells with Ag^＋ and/or the active oxygen scavenger N-acetyl cysteine （NAC）, cell proliferation and intracellular ROS generation were assessed using CCK-8 reagent and DCFH-DA fluorescent probe, respectively. In addition, 5-bromo-2-deoxyUridine （BrdU） incorporation assays, cell cycle flow cytometry, and proliferating cell nuclear antigen （PCNA） immunocytochemistry were conducted to further evaluate the effects of sub-cytotoxic Ag^＋ concentrations on HaCaT cells. The proliferation of HaCaT cells was promoted in the presence of 10^-6 and 10^-5s mol/L Ag^＋at 24, 48, and 72 h. Intracellular ROS generation also significantly increased for 5 60 min after exposure to Ag^＋ The number of BrdU-positive cells and the presence of PCNA in HaCaT cells increased 48 h after the addition of 10^-6 and 10^-5 mol/L Ag^＋, with 10^-5 mol/L Ag^＋ markedly increasing the cell proliferation index. These effects of sub-cytotoxic Ag^＋ concentrations were repressed by 5 mmol/L NAC. Our results suggest that sub-cytotoxic Ag^＋ concentrations promote the proliferation of human keratinocytes and might be associated with a moderate increase in intracellular ROS levels. This study provides important experimental evidence for developing novel silver-based wound agents or dressings with few or no cytotoxicity.
文摘Stable silver nanoparticles was successfully synthesized by chemical reduction of silver nitrate in an ionic liquid,1-n-butyl-3-methylimidazolium tetrafluoroborate（[BMIM]·BF4） at room temperature.Results of UV-Vis diffuse reflectance spectroscopy show as-prepared Ag nanoparticles exhibit a typical emission peak at 400―430 nm.By varying the reaction temperature and the precursor concentration,the size and the shape of the silver nanoparticles could be easily controlled under mild conditions.Analyses of transmission electron micrographs,X-ray diffraction pattern and X-ray photoelectron spectrum further reveal that the silver nanoparticles were coated incompletely by [BMIM]·BF4.Microbial experiments indicate that as-prepared silver nanoparticles show a wide spectrum of antimicrobial activities and have better antimicrobial activities to Pseudomonas aeruginosa than silver nitrate with the same concentration of silver.
基金supported by the National Natural Science Foundation of China(No.20773081 and 20873074)National Basic Research Program(No.2007CB808004 and 2009CB930101)Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering,TIPC,CAS.
文摘Silver nanorods have been successfully synthesized in large scale by the ethylene glycol（EG） reduction in the presence of ionic liquid（IL） 1-butyl-3-methylimidazolium tetrafluoroborate（bmimBF_4） and polyvinyl-pyrrolidone（PVP）.The silver nanorods were characterized by scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,transmission electron microscopy（TEM）,electron energy disperse spectroscopy（EDS） and UV-vis spectroscopy.The results showed that the uniform silver nanorods have an average diameter of about 100 nm and the aspect ratio from 15 to 20.IL,bmimBF_4 may play a role of capping agent together with PVP in the formation of silver nanorods.On the other band,bmimBF_4 may accelerate nucleation and improve the stability of the resulting Ag nanorods due to the low interface tension of IL.
基金supported by the National Natural Science Foundation of China(No.21207124)Research Project of Beijing Municipal Education Commission(No.KM201110005009)the Special Fund for Quality Inspection Administration Public Welfare Scientific Research Funding(No.2012104001)
文摘Using the ionic liquid（IL）1-octyl-3-methylimidazolium hexafluorophosphate as the extractant and methanol as the dispersion solvent,a dispersive liquid–liquid microextraction method was developed to extract silver nanoparticles（AgN Ps）from environmental water samples.Parameters that influenced the extraction efficiency such as IL concentration,pH and extraction time were optimized.Under the optimized conditions,the highest extraction efficiency for AgN Ps was above 90% with an enrichment factor of 〉90.The extracted AgN Ps in the IL phase were identified by transmission electron microscopy and ultraviolet–visible spectroscopy,and quantified by inductively coupled plasma mass spectrometry after microwave digestion,with a detection limit of 0.01 μg/L.The spiked recovery of AgN Ps was 84.4% with a relative standard deviation（RSD）of 3.8%（n = 6）at a spiked level of 5 μg/L,and 89.7% with a RSD of 2.2%（n = 6）at a spiked level of 300 μg/L,respectively.Commonly existed environmental ions had a very limited influence on the extraction efficiency.The developed method was successfully applied to the analysis of Ag NPs in river water,lake water,and the influent and effluent of a wastewater treatment plant,with recoveries in the range of 71.0%–90.9% at spiking levels of 0.11–4.7 μg/L.
文摘The silver ionic complexes of xanthone glycosides were studied by ESI-MS/MS in the positive ion mode. The fragmentation pathways of silver ionic complexes under collisioninduced dissociation （CID） were investigated and the differences in MS/MS spectra of different silver ionic complexes of xanthones were correlated to the characterization of saccharide and the coordination pattern of silver ion with xanthones, including the glycosilation position and linkage type of disaccharide （1-2 and 1-6 linkages）.
