At present,the development trend of dressing materials is being multifunctional for convenient and long-term nursing care process of some complicated wounds.Here,basing on the theory of wound moist healing,an injectab...At present,the development trend of dressing materials is being multifunctional for convenient and long-term nursing care process of some complicated wounds.Here,basing on the theory of wound moist healing,an injectable and self-healing hydrogel comprising of collagen(COL),chitosan(CS)and oxidation modified Konjac glucomannan(OKGM),which acts as a macromolecular cross-linker to construct dynamic Schiff-base bonds was smartly designed.The strategy of introducing the silver nanoparticles(Ag NPs)into the COL-CS-OKGM hydrogel matrix achieved a markedly enhanced antibacterial activity derived from the synergistical effect between the Ag^(+)and the mild photothermal efficacy of Ag NPs,which also improved the local capillary blood circulation of the wound area to further facilitate wound healing process.The excellent syringeability and self-healing behaviors endowed the COL-CS-OKGM-Ag hydrogel with self-adapting ability for the wounds with irregular and large area needing frequent applying and changing without secondary injuries.In vitro and in vivo evaluations verified that so-designed COL-CS-OKGM-Ag hydrogel also with hemostatic performance is a promising multifunctional dressing for the treatments of infected wound with not only good biocompatibility and convenient use,but also with desired regenerative healing prognoses benefited from hydrogel moist environment and physiotherapy.展开更多
Early diagnosis of osteoarthritis(OA)is critical for effective cartilage repair.However,lack of blood vessels in articular cartilage poses a barrier to contrast agent delivery and subsequent diagnostic imaging.To addr...Early diagnosis of osteoarthritis(OA)is critical for effective cartilage repair.However,lack of blood vessels in articular cartilage poses a barrier to contrast agent delivery and subsequent diagnostic imaging.To address this challenge,we proposed to develop ultra-small superparamagnetic iron oxide nanoparticles(SPIONs,4 nm)that can penetrate into the matrix of articular cartilage,and further modified with the peptide ligand WYRGRL(particle size,5.9 nm),which allows SPIONs to bind to type II collagen in the cartilage matrix and increase the retention of probes.Type II collagen in the cartilage matrix is gradually lost with the progression of OA,consequently,the binding of peptide-modified ultra-small SPIONs to type II collagen in the OA cartilage matrix is less,thus presenting different magnetic resonance(MR)signals in OA group from the normal ones.By introducing the AND logical operation,damaged cartilage can be differentiated from the surrounding normal tissue on T1 and T2 AND logical map of MR images,and this was also verified in histology studies.Overall,this work provides an effective strategy for delivering nanosized imaging agents to articular cartilage,which could potentially be used to diagnosis joint-related diseases such as osteoarthritis.展开更多
The localization and differential diagnosis of the sentinel lymph nodes(SLNs)are particularly important for tumor staging,surgical planning and prognosis.In this work,kinetically inert manganese(II)-based hybrid micel...The localization and differential diagnosis of the sentinel lymph nodes(SLNs)are particularly important for tumor staging,surgical planning and prognosis.In this work,kinetically inert manganese(II)-based hybrid micellar complexes(MnCs)for magnetic resonance imaging(MRI)were developed using an amphiphilic manganese-based chelate(C18-PhDTA-Mn)with reliable kinetic stability and self-assembled with a series of amphiphilic PEG-C18 polymers of different molecular weights(C18En,n=10,20,50).Among them,the probes composed by 1:10 mass ratio of manganese chelate/C18En had slightly different hydrodynamic particle sizes with similar surface charges as well as considerable relaxivities(∼13 mM^(−1)s^(−1)at 1.5 T).In vivo lymph node imaging in mice revealed that the MnC MnC-20 formed by C18E20 with C18-PhDTA-Mn at a hydrodynamic particle size of 5.5 nm had significant signal intensity brightening effect and shortened T1 relaxation time.At an imaging probe dosage of 125μg Mn/kg,lymph nodes still had significant signal enhancement in 2 h,while there is no obvious signal intensity alteration in non-lymphoid regions.In 4T1 tumor metastatic mice model,SLNs showed less signal enhancement and smaller T1 relaxation time variation at 30 min post-injection,when compared with normal lymph nodes.This was favorable to differentiate normal lymph nodes from SLN under a 3.0-T clinical MRI scanner.In conclusion,the strategy of developing manganese-based MR nanoprobes was useful in lymph node imaging.展开更多
The past several years have witnessed the rapid development in effectively transforming randomly distributed water kinetic energy into electrical energy,especially triggered by the emergence of droplet‐based electric...The past several years have witnessed the rapid development in effectively transforming randomly distributed water kinetic energy into electrical energy,especially triggered by the emergence of droplet‐based electricity generators(DEG).Despite this,it still suffers from relatively low average power density,which is also achieved at the cost of long charging time,the time to reach stable and saturated surface charge density either through continuous droplet impingement or precharging.Although the harvested energy per droplet in DEG remains as the dominant metric,ultrahigh instantaneous output and short charging time are equally important in some specialized applications such as instantaneous luminescence.Here,we conduct systematical modeling and optimization to build the link between the hydrodynamic and electrical systems,which enables us to determine ultrahigh instantaneous output and short charging time by tailoring parameters such as dielectric layer thickness,droplet ion concentration,and external load.We envision that this strategy in achieving ultrahigh instantaneous output as well as shortening charging time would provide insights and design routes for water energy harvesting.展开更多
基金supported by Sichuan Province Key Research and Development Project(2018SZ0046)the National Natural Science Foundation of China(51373105).
文摘At present,the development trend of dressing materials is being multifunctional for convenient and long-term nursing care process of some complicated wounds.Here,basing on the theory of wound moist healing,an injectable and self-healing hydrogel comprising of collagen(COL),chitosan(CS)and oxidation modified Konjac glucomannan(OKGM),which acts as a macromolecular cross-linker to construct dynamic Schiff-base bonds was smartly designed.The strategy of introducing the silver nanoparticles(Ag NPs)into the COL-CS-OKGM hydrogel matrix achieved a markedly enhanced antibacterial activity derived from the synergistical effect between the Ag^(+)and the mild photothermal efficacy of Ag NPs,which also improved the local capillary blood circulation of the wound area to further facilitate wound healing process.The excellent syringeability and self-healing behaviors endowed the COL-CS-OKGM-Ag hydrogel with self-adapting ability for the wounds with irregular and large area needing frequent applying and changing without secondary injuries.In vitro and in vivo evaluations verified that so-designed COL-CS-OKGM-Ag hydrogel also with hemostatic performance is a promising multifunctional dressing for the treatments of infected wound with not only good biocompatibility and convenient use,but also with desired regenerative healing prognoses benefited from hydrogel moist environment and physiotherapy.
基金supported by the National Natural Science Foundation of China(NSFC,No.52073192,81601490)the Innovative Research Groups of the National Natural Science Foundation of China(81621003).
文摘Early diagnosis of osteoarthritis(OA)is critical for effective cartilage repair.However,lack of blood vessels in articular cartilage poses a barrier to contrast agent delivery and subsequent diagnostic imaging.To address this challenge,we proposed to develop ultra-small superparamagnetic iron oxide nanoparticles(SPIONs,4 nm)that can penetrate into the matrix of articular cartilage,and further modified with the peptide ligand WYRGRL(particle size,5.9 nm),which allows SPIONs to bind to type II collagen in the cartilage matrix and increase the retention of probes.Type II collagen in the cartilage matrix is gradually lost with the progression of OA,consequently,the binding of peptide-modified ultra-small SPIONs to type II collagen in the OA cartilage matrix is less,thus presenting different magnetic resonance(MR)signals in OA group from the normal ones.By introducing the AND logical operation,damaged cartilage can be differentiated from the surrounding normal tissue on T1 and T2 AND logical map of MR images,and this was also verified in histology studies.Overall,this work provides an effective strategy for delivering nanosized imaging agents to articular cartilage,which could potentially be used to diagnosis joint-related diseases such as osteoarthritis.
基金supported by the National Natural Science Foundation of China(NSFC,52073192)the Innovative Research Groups of the National Natural Science Foundation of China(81621003).
文摘The localization and differential diagnosis of the sentinel lymph nodes(SLNs)are particularly important for tumor staging,surgical planning and prognosis.In this work,kinetically inert manganese(II)-based hybrid micellar complexes(MnCs)for magnetic resonance imaging(MRI)were developed using an amphiphilic manganese-based chelate(C18-PhDTA-Mn)with reliable kinetic stability and self-assembled with a series of amphiphilic PEG-C18 polymers of different molecular weights(C18En,n=10,20,50).Among them,the probes composed by 1:10 mass ratio of manganese chelate/C18En had slightly different hydrodynamic particle sizes with similar surface charges as well as considerable relaxivities(∼13 mM^(−1)s^(−1)at 1.5 T).In vivo lymph node imaging in mice revealed that the MnC MnC-20 formed by C18E20 with C18-PhDTA-Mn at a hydrodynamic particle size of 5.5 nm had significant signal intensity brightening effect and shortened T1 relaxation time.At an imaging probe dosage of 125μg Mn/kg,lymph nodes still had significant signal enhancement in 2 h,while there is no obvious signal intensity alteration in non-lymphoid regions.In 4T1 tumor metastatic mice model,SLNs showed less signal enhancement and smaller T1 relaxation time variation at 30 min post-injection,when compared with normal lymph nodes.This was favorable to differentiate normal lymph nodes from SLN under a 3.0-T clinical MRI scanner.In conclusion,the strategy of developing manganese-based MR nanoprobes was useful in lymph node imaging.
基金National Natural Science Foundation of China,Grant/Award Numbers:31771083,51975215Natural Science Foundation of Shanghai,Grant/Award Number:20ZR1418600。
文摘The past several years have witnessed the rapid development in effectively transforming randomly distributed water kinetic energy into electrical energy,especially triggered by the emergence of droplet‐based electricity generators(DEG).Despite this,it still suffers from relatively low average power density,which is also achieved at the cost of long charging time,the time to reach stable and saturated surface charge density either through continuous droplet impingement or precharging.Although the harvested energy per droplet in DEG remains as the dominant metric,ultrahigh instantaneous output and short charging time are equally important in some specialized applications such as instantaneous luminescence.Here,we conduct systematical modeling and optimization to build the link between the hydrodynamic and electrical systems,which enables us to determine ultrahigh instantaneous output and short charging time by tailoring parameters such as dielectric layer thickness,droplet ion concentration,and external load.We envision that this strategy in achieving ultrahigh instantaneous output as well as shortening charging time would provide insights and design routes for water energy harvesting.
