Poly(ethylene glycol)-poly(lactic acid)block copolymer(PEG-PLA)is one of the most widely used biomedical polymers in clinical drug delivery owing to its biocompatibility and biodegradability.However,endowing PEG-PLA m...Poly(ethylene glycol)-poly(lactic acid)block copolymer(PEG-PLA)is one of the most widely used biomedical polymers in clinical drug delivery owing to its biocompatibility and biodegradability.However,endowing PEG-PLA micelles with high drug loading,self-assembly stability and fast intracellular drug release is still challenging.Redox-responsive diblock copolymers(MPEG-SS-PMLA)of poly(ethylene glycol)and phenyl-functionalized poly(lactic acid)with disulfide bond as the linker are synthesized to prepare PLA-based micelles that demonstrate excellent colloidal stability and high Ru loading.Notably,MPEGSS-PMLA achieved a remarkably high Ru loading efficiency of 84.3%due to the existence of strongπ-πstacking between phenyl and Ru complex.MPEG-SS-PMLA exhibited good colloidal stability in physiological condition but quickly destabilized by reductive tumor microenvironment.Interestingly,about 74%of Ru complex was released under 10 mmol/L GSH concentration.Ru-loaded MEPG-SS-PMLA showed efficient delivery and release of Ru complex into MCF-7 cancer cells,achieving enhanced in vitro and in vivo antitumor activity of photodynamic therapy.This feasible functionalization method of MPEG-PLA has appeared to be a clinically viable platform for controlled delivery therapeutic agents and enhanced phototherapy.展开更多
The valveless piezoelectric pump integrates driving and transmitting into one operating element,and characterizes easy micro-miniaturization.But,there is the original sin of low pressure and low flow.Thus,it must avoi...The valveless piezoelectric pump integrates driving and transmitting into one operating element,and characterizes easy micro-miniaturization.But,there is the original sin of low pressure and low flow.Thus,it must avoid weakness to choose applications field.This paper analyzes the flow characteristics in the rotary spiral-tube,which will cause the Coriolis force,and subsequently influence the fluid moving.The principle of the pump is deduced,and the spiral-tube-type valveless piezoelectric pump is invented.The angular velocity variation can be obtained when the pump attitude changes,which theoretically verifies the gyroscopic effect of the pump.A pump is fabricated for experimental testing.Experiments has shown that when Archimedes spiral h?4p is selected for the tube design,and the rotation speed of the plate is 70 r/min,the pressure differential is 9 mm H2O,which is 1.5 times that of 0 r/min rotation speed.If introduced the low-cost and miniaturized gyroscope,then this may promise potential application in these areas such as smart cars,robots,and home health care.展开更多
基金financially supported by the National Science Foundation of China(Nos.22022803,22078046,21808028)Science and Technology Foundation of Liaoning Province(Nos.2019BS-047,2021-YGJC-17)Fundamental Research Funds for the Central Universities(No.DUT20YG131)。
文摘Poly(ethylene glycol)-poly(lactic acid)block copolymer(PEG-PLA)is one of the most widely used biomedical polymers in clinical drug delivery owing to its biocompatibility and biodegradability.However,endowing PEG-PLA micelles with high drug loading,self-assembly stability and fast intracellular drug release is still challenging.Redox-responsive diblock copolymers(MPEG-SS-PMLA)of poly(ethylene glycol)and phenyl-functionalized poly(lactic acid)with disulfide bond as the linker are synthesized to prepare PLA-based micelles that demonstrate excellent colloidal stability and high Ru loading.Notably,MPEGSS-PMLA achieved a remarkably high Ru loading efficiency of 84.3%due to the existence of strongπ-πstacking between phenyl and Ru complex.MPEG-SS-PMLA exhibited good colloidal stability in physiological condition but quickly destabilized by reductive tumor microenvironment.Interestingly,about 74%of Ru complex was released under 10 mmol/L GSH concentration.Ru-loaded MEPG-SS-PMLA showed efficient delivery and release of Ru complex into MCF-7 cancer cells,achieving enhanced in vitro and in vivo antitumor activity of photodynamic therapy.This feasible functionalization method of MPEG-PLA has appeared to be a clinically viable platform for controlled delivery therapeutic agents and enhanced phototherapy.
基金supported by the National Natural Science Foundation of China(51075201,51205193)
文摘The valveless piezoelectric pump integrates driving and transmitting into one operating element,and characterizes easy micro-miniaturization.But,there is the original sin of low pressure and low flow.Thus,it must avoid weakness to choose applications field.This paper analyzes the flow characteristics in the rotary spiral-tube,which will cause the Coriolis force,and subsequently influence the fluid moving.The principle of the pump is deduced,and the spiral-tube-type valveless piezoelectric pump is invented.The angular velocity variation can be obtained when the pump attitude changes,which theoretically verifies the gyroscopic effect of the pump.A pump is fabricated for experimental testing.Experiments has shown that when Archimedes spiral h?4p is selected for the tube design,and the rotation speed of the plate is 70 r/min,the pressure differential is 9 mm H2O,which is 1.5 times that of 0 r/min rotation speed.If introduced the low-cost and miniaturized gyroscope,then this may promise potential application in these areas such as smart cars,robots,and home health care.
