A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride ([AMIM]Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in [ AMIM]Cl was better tha...A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride ([AMIM]Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in [ AMIM]Cl was better than in 1-butyl,3-methylimidazolium ([BMIM]Cl).The pris tine cellulose and two cellulose samples regenerated from [AMIM]Cl and [BMIM ]Cl solutions were compared by FTIR,WAXD and TGA measurements.Results show t hat these two RTILs are non-derivatizing solvents for cellulose.After regenera tion from RTIL solutions,the crystalline form of cellulose films is completely transformed from cellulose Ⅰ to cellulose Ⅱ.Compared to pristine cellulose,t he regenerated cellulose exhibits a lower onset temperature of thermal decomposi tion,with a higher char yield.展开更多
Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has b...Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence: materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris(8-hydroxyquinolinate) displayed a bright green emission suitable for organic light emitting diodes (OLEDs) was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibility of using NIR emission of ions such as YbⅢ is now being tested because of deeper penetration in biological tissues.展开更多
In this paper,we present a 3D printed tumor spheroidal model suitable for drug discovery.This model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(...In this paper,we present a 3D printed tumor spheroidal model suitable for drug discovery.This model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(1)the HCSG is similar to the commercial basement membrane extract in Ki67,MUC1,and PARP1 expressions of MCF-7 cells for embedding culture;(2)the HCSG is printable at room temperature;and(3)the HCSG can be large-scale manufactured at an ultralow cost.We printed a 3D MCF-7 spheroid model with HCSG and characterized it in terms of cell viability,spheroid size,key protein expression,and mitochondrial metabolic activity.We used the 3D MCF-7 spheroid model to evaluate the anti-breast cancer activity of 13 amino acid-based flavone phosphoramidates and found that the alanine structure induced a stronger drug resistance,whereas phenylalanine hardly caused drug resistance in the MCF-7 cells.This is the first time that 3D bioprinting technology has been used in a structure–activity relationship study.展开更多
文摘A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride ([AMIM]Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in [ AMIM]Cl was better than in 1-butyl,3-methylimidazolium ([BMIM]Cl).The pris tine cellulose and two cellulose samples regenerated from [AMIM]Cl and [BMIM ]Cl solutions were compared by FTIR,WAXD and TGA measurements.Results show t hat these two RTILs are non-derivatizing solvents for cellulose.After regenera tion from RTIL solutions,the crystalline form of cellulose films is completely transformed from cellulose Ⅰ to cellulose Ⅱ.Compared to pristine cellulose,t he regenerated cellulose exhibits a lower onset temperature of thermal decomposi tion,with a higher char yield.
基金Project supported by the Swiss National Science Foundation
文摘Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence: materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris(8-hydroxyquinolinate) displayed a bright green emission suitable for organic light emitting diodes (OLEDs) was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibility of using NIR emission of ions such as YbⅢ is now being tested because of deeper penetration in biological tissues.
基金This work was supported by the National Natural Science Foundation of China(No.21675017)State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products(KF20190108)the National Key Research and Development Program of China(No.2017YFC1702001).And we thanked Prof.Yueqing Li for the synthesis of the isoflavone derivatives and useful discussions。
文摘In this paper,we present a 3D printed tumor spheroidal model suitable for drug discovery.This model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(1)the HCSG is similar to the commercial basement membrane extract in Ki67,MUC1,and PARP1 expressions of MCF-7 cells for embedding culture;(2)the HCSG is printable at room temperature;and(3)the HCSG can be large-scale manufactured at an ultralow cost.We printed a 3D MCF-7 spheroid model with HCSG and characterized it in terms of cell viability,spheroid size,key protein expression,and mitochondrial metabolic activity.We used the 3D MCF-7 spheroid model to evaluate the anti-breast cancer activity of 13 amino acid-based flavone phosphoramidates and found that the alanine structure induced a stronger drug resistance,whereas phenylalanine hardly caused drug resistance in the MCF-7 cells.This is the first time that 3D bioprinting technology has been used in a structure–activity relationship study.