Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-...Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-NTA)initiated by amino-terminated PEG.The self-assemblies of three PEG-b-PMeSPG copolymers with different PMeSPG block lengths were first prepared by nanoprecipitation method using THF and DMF,respectively,as the organic solvent,and their morphologies were studied by Cryo-EM and DLS.To prepare polymersomes loaded with glucose oxidase(GOx),double emulsion method followed by extrusion treatment was employed.The oxidation-responsive disruption of polymersomes was achieved upon the introduction of glucose because of the oxidants generated insitu by GOx/glucose.展开更多
In this work, monodisperse giant polymersomes are fabricated by dewetting of water-in-oil-in-water double emulsion droplets which are assembled by amphiphilic block copolymer molecules in a microfluidic device. The de...In this work, monodisperse giant polymersomes are fabricated by dewetting of water-in-oil-in-water double emulsion droplets which are assembled by amphiphilic block copolymer molecules in a microfluidic device. The dewetting process can be tuned by solvation between solvent and amphiphilic block copolymer to get polymersomes with controllable morphology. Good solvent （chloroform and toluene） hinders dewetting process of double emulsion droplets and gets acornlike polymersomes or patched polymersomes. On the other hand, poor solvent （hexane） accelerates the dewetting process and achieves complete separation of inner water phase from oil phase to form complete bilayer polymersomes. In addition, twin polymersomes with bilayer membrane structure are formed by this facile method. The formation mechanism for different polymersomes is discussed in detail.展开更多
Programmed release of small molecular drugs from polymersomes is of great importance in drug delivery.A significant challenge is to adjust the membrane permeability in a well-controlled manner.Herein,we propose a stra...Programmed release of small molecular drugs from polymersomes is of great importance in drug delivery.A significant challenge is to adjust the membrane permeability in a well-controlled manner.Herein,we propose a strategy for controlling membrane phase separation by photo-cross-linking of the membrane-forming blocks with different molecular architectures.We synthesized three amphiphilic block copolymers with different membrane-forming blocks,which are poly(ethylene oxide)_(43)-b-poly((ε-caprolactone)_(45)-stat-((α-(cinnamoyloxymethyl)-1,2,3-triazol)caprolactone)_(25))(PEO_(43)-b-P(CL_(45)-stat-CTCL_(25))),PEO_(43)-b-P(CL_(108)-stat-CTCL_(16)),and PEO_(43)-b-PCTCL_(4)-b-PCL_(79).These polymers were self-assembled into polymersomes using either a solvent-switch or powder rehydration method,and the obtained polymersomes were characterized by dynamic light scattering and transmission electron microscopy.Then the phase separation patterns within the polymersome membranes were investigated by mesoscopic dynamics(MesoDyn)simulations.To further confirm the change of the membrane permeability that resulted from the phase separation within the membrane,doxorubicin,as a small molecular drug,was loaded and released from the polymersomes.Due to the incompatibility between membrane-forming moieties(PCTCL and PCL),phase separation occurs and the release rate can be tuned by controlling the membrane phase pattern or by photo-cross-linking.Moreover,besides the compacting effect by formation of chemical bonds in the membrane,the cross-linking process can act as a driving force to facilitate the rearrangement and re-orientation of the phase pattern,which also influences the drug release behavior by modulating the cross-membrane distribution of the amorphous PCTCL moieties.In this way,the strategy of focusing on the membrane phase separation for the preparation of the polymersomes with finely tunable drug release rate can be envisioned and designed accordingly,which is of great significance in the field of delivery vehicles for programmed drug release.展开更多
Due to the heterogeneity of tumors,single phototherapy cannot completely ablate tumors and inhibit tumor metastasis.To overcome these,we formulated targeted and multifunctional polymersomes ABC@ICGIMQ-LHRH(AIRL)that e...Due to the heterogeneity of tumors,single phototherapy cannot completely ablate tumors and inhibit tumor metastasis.To overcome these,we formulated targeted and multifunctional polymersomes ABC@ICGIMQ-LHRH(AIRL)that encapsulated Toll-like receptor(TLR)7/8 agonist imiquimod(IMQ)and photosensitizer indocyanine green(ICG)in the hydrophobic layer as well as bubble-generator NH_(4)HCO_(3) in the hydrophilic cavity to inhibit the growth of primary and distant tumors,and prevent tumor metastasis through synergistic photoimmunotherapy.The AIRL polymersomes exhibited uniform and stable size,and high drug encapsulation efficiency,acid/reduction/laser responsiveness,excellent photothermal conversion efficiency,effective reactive oxygen species generation,high tumor accumulation.AIRL could be effectively internalized by dendritic cells(DCs),achieve lysosome escape and enhance DCs maturation.The synergistic photoimmunotherapy via AIRL polymersomes remarkably promoted the differentiation and activation of T cells,elevated strong systemic immune response to eradicate primary tumors and inhibit the growth of distant tumors.Simultaneously,the endurable immunological memory prevented tumor metastasis,which provided a promising nanoplatform for the combination therapy of cancer.展开更多
Intelligent nanoplatform that combines multimodal imaging and therapeutic effects holds great promise for precise and efficient cancer therapy.Herein,folate-targeted polymersomes with stimuli-responsiveness were fabri...Intelligent nanoplatform that combines multimodal imaging and therapeutic effects holds great promise for precise and efficient cancer therapy.Herein,folate-targeted polymersomes with stimuli-responsiveness were fabricated and evaluated by near-infrared fluorescence(NIRF)and optical coherence tomography angiography(OCTA)dual-imaging for photo-chemo-antiangiogenic therapy against cancer.The folate-targeted polymersomes(FA-MIT-SIPS)not only integrated ammonium bicarbonate(ABC)and mitoxantrone(MIT)into their hydrophilic cavity but also encapsulated indocyanine green(ICG)and sorafenib(SOR)within their hydrophobic layer.NIRF imaging demonstrated that FA-MIT-SIPS effectively accumulated and retained in the tumors.Upon 808 nm laser irradiation,the ICG produced hyperthermia and reactive oxygen species(ROS)for efficient photothermal and photodynamic therapy.In addition,the decomposition of ABC in responsive to acidic tumor environment and ICG-induced hyperthermia accelerated drug release.The released MIT accumulated in nucleus to inhibit DNA synthesis,while the released SOR destructed tumor vascularization.Notably,OCTA imaging was applied to observe the tumor blood flow upon the combination therapy,demonstrating that FA-MIT-SIPS obviously decreased the vessels area density.Moreover,the synergistic photo-chemo-antiangiogenic therapy of FA-MIT-SIPS achieved excellent antitumor effect with 40%of the 4T1 tumor-bearing mice being completely cured without recurrence.The multifunctional polymersomes provide a promising dual-modal imaging-evaluated synergistic strategy for tumor therapy.展开更多
The asymmetric amphiphilic block copolymer polystyrene962-block-poly（ethylene oxide）227 （PS962-b-PEO227） eanforms mieelles with N, N-dimethylforrnamide （DMF） as co-solvent and water as selected solvent, and when...The asymmetric amphiphilic block copolymer polystyrene962-block-poly（ethylene oxide）227 （PS962-b-PEO227） eanforms mieelles with N, N-dimethylforrnamide （DMF） as co-solvent and water as selected solvent, and when the water content of the mixed solvent is higher than 4.5 wt%, the vesicle will be dominated. This work finds that once vesicles are formed in the DMF-water mixed solvent, the vesicle size and membrane thickness can be tuned by further increasing water content. As the water fraction elevated from 4.8 wt% to 13.0 wt%, the vesicle size dercreases from 246 nm to 150 nm, while the membrane thickness increases from 28 nm to 42 nm. In addition, the block copolymer packing and the free energy are analyzed as the vesicle size becomes small and the membrane becomes thick.展开更多
Hybrid lipopolymer vesicles are membrane vesicles that can be self-assembled on both the micro-and nano-scale.On the nanoscale,they are potential novel smart materials for drug delivery systems that could combine the ...Hybrid lipopolymer vesicles are membrane vesicles that can be self-assembled on both the micro-and nano-scale.On the nanoscale,they are potential novel smart materials for drug delivery systems that could combine the relative strengths of liposome and polymersome drug delivery systems without their respective weaknesses.However,little is known about their properties and how they could be tailored.Currently,most methods of investigation are limited to the microscale.Here we provide a brief review on hybrid vesicle systems with a specific focus on recent developments demonstrating that nanoscale hybrid vesicles have different properties from their macroscale counterparts.展开更多
Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging,diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of...Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging,diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of active substances. However, fluorescent vesicles containing conventional organic dyes often suffer from the problem of aggregation-caused quenching(ACQ) of fluorescence.Fluorescent vesicles working with aggregation-induced emission(AIE) offer an extraordinary tool to tackle the ACQ issue, showing advantages such as high emission efficiency, superior photophysical stability, low background interference, and high sensitivity. AIE fluorescent vesicles represent a new type of fluorescent and functional nanomaterials. In this review, we summarize the recent advances in the development of AIE fluorescent vesicles. The review is organized according to the chemical structures and architectures of the amphiphilic molecules that constitute the AIE vesicles, i.e., small-molecule amphiphiles, amphiphilic polymers, and amphiphilic supramolecules and supramacromolecules. The studies on the applications of these AIE vesicles as stimuli-responsive vesicles,fluorescence-guided drug release carriers, cell imaging tools, and fluorescent materials based on fluorescence resonance energy transfer(FRET) are also discussed.展开更多
Choline phosphate （CP） as a novel zwitterion possesses specific and excellent properties compared with phosphorylcholine （PC）, as well as its polymer, such as poly（2-（methacryloyloxy）ethyl choline phosphate） ...Choline phosphate （CP） as a novel zwitterion possesses specific and excellent properties compared with phosphorylcholine （PC）, as well as its polymer, such as poly（2-（methacryloyloxy）ethyl choline phosphate） （PMCP）, has been studied extensively due to its unique characteristics of rapid cellular internalization via the special quadrupole interactions with the cell membrane. Recently, we reported a novel PMCP-based drug delivery system to enhance the cellular internalization where the drug was conjugated to the polymer via reversible acylhydrazone bond. Herein, to make full use of this feature of PMCP, we synthesized the diblock copolymer poly（2-（methacryloyloxy）ethyl choline phosphate）-b-poly（2- （diisopropylamino）ethyl methacrylate） （PMCP-b-PDPA）, which could self-assemble into polymersomes with hydrophilic PMCP corona and hydrophobic membrane wall in mild conditions when the pH value is 〉 6.4. It has been found that these polymersomes can be successfully used to load anticancer drug Dox with the loading content of about 11.30 wt%. After the polymersome is rapidly internalized by the cell with the aid of PMCP, the loaded drug can be burst-released in endosomes since PDPA segment is protonated at low pH environment, which renders PDPA to transfer from hydrophobic to hydrophilic, and the subsequent polymersomes collapse thoroughly. Ultimately, the ＂proton sponge＂ effect of PDPA chain can further accelerate the Dox to escape from endosome to cytoplasm to exert cytostatic effects. Meanwhile, the cell viability assays showed that the Dox-loaded polymersomes exhibited significant inhibitory effect on tumor cells, indicating its great potential as a targeted intracellular delivery system with high efficiency.展开更多
Polye-caprolactone）-b-poly（ethylene glycol）-b-poly（e-caprolactone）（PCL-b-PEG-b-PCL,PCEC） triblock copolymers have been widely investigated in last several decades.Here,by altering the weight ratio of monomers i...Polye-caprolactone）-b-poly（ethylene glycol）-b-poly（e-caprolactone）（PCL-b-PEG-b-PCL,PCEC） triblock copolymers have been widely investigated in last several decades.Here,by altering the weight ratio of monomers in ring-opening polymerization,a series of PCEC triblock copolymers with varying hydrophobicity were synthesized,which were characterized by FTIR,1 H NMR,GPC and DSC.When PCEC copolymers with different weight ratios of PCL/PEG were dispersed in different aqueous solutions,they could self-assemble and form two distinctive nanoparticular structures：micelles or polymersomes.We then chose paclitaxel（PTX） as the model drug and encapsulate PTX into PCEC polymeric micelles and polymersomes.The physicochemical characterizations of the nanoparticles such as morphology,the size and distribution,zeta potential,drug loading content,and encapsulation efficiency were also performed.Our results showed that polymeric micelles or polymersomes from PCEC both displayed narrow size distributions and could achieve high drug loading efficiencies.In vitro cellular uptake results suggested that Nile Red loaded polymeric micelles or polymersomes displayed more internalization after 24 h incubation than those after 4 h incubation.These findings suggest that polymeric micelles and polymersomes based on PCL-b-PEG-b-PCL copolymers have great potential to effectively delivery hydrophobic drugs.展开更多
基金the French National Research Agency(No.ANR16-CE29-0028)the National Natural Science Foundation of China(No.21674091)+2 种基金the Joint Foundation of Shaanxi Province Natural Science Basic Research ProgramShaanxi Coal Chemical Group Co.,Ltd.(No.2019JLM-46)for financial supportthe China Scholarship Council for funding his Ph.D.scholarship in France。
文摘Amphiphilic block copolymers poly(ethylene glycol)-block-poly(N-3-(methylthio)propyl glycine)(PEGb-PMeSPG)were synthesized via ring-opening polymerization of N-3-(methylthio)propyl glycine Nthiocarboxyanhydride(MeSPG-NTA)initiated by amino-terminated PEG.The self-assemblies of three PEG-b-PMeSPG copolymers with different PMeSPG block lengths were first prepared by nanoprecipitation method using THF and DMF,respectively,as the organic solvent,and their morphologies were studied by Cryo-EM and DLS.To prepare polymersomes loaded with glucose oxidase(GOx),double emulsion method followed by extrusion treatment was employed.The oxidation-responsive disruption of polymersomes was achieved upon the introduction of glucose because of the oxidants generated insitu by GOx/glucose.
基金financially supported by the National Natural Science Foundation of China(No.50633030,Innovation Group:50921062)
文摘In this work, monodisperse giant polymersomes are fabricated by dewetting of water-in-oil-in-water double emulsion droplets which are assembled by amphiphilic block copolymer molecules in a microfluidic device. The dewetting process can be tuned by solvation between solvent and amphiphilic block copolymer to get polymersomes with controllable morphology. Good solvent （chloroform and toluene） hinders dewetting process of double emulsion droplets and gets acornlike polymersomes or patched polymersomes. On the other hand, poor solvent （hexane） accelerates the dewetting process and achieves complete separation of inner water phase from oil phase to form complete bilayer polymersomes. In addition, twin polymersomes with bilayer membrane structure are formed by this facile method. The formation mechanism for different polymersomes is discussed in detail.
基金financially supported by the National Natural Science Fund for Distinguished Young Scholars (No. 21925505)Shanghai International Scientific Collaboration Fund (No. 21520710100)+2 种基金supported by the National Natural Science Foundation of China (No. 22101207)the China Postdoctoral Science Foundation (No. 2020M671197)International Postdoctoral Exchange Fellowship Program
文摘Programmed release of small molecular drugs from polymersomes is of great importance in drug delivery.A significant challenge is to adjust the membrane permeability in a well-controlled manner.Herein,we propose a strategy for controlling membrane phase separation by photo-cross-linking of the membrane-forming blocks with different molecular architectures.We synthesized three amphiphilic block copolymers with different membrane-forming blocks,which are poly(ethylene oxide)_(43)-b-poly((ε-caprolactone)_(45)-stat-((α-(cinnamoyloxymethyl)-1,2,3-triazol)caprolactone)_(25))(PEO_(43)-b-P(CL_(45)-stat-CTCL_(25))),PEO_(43)-b-P(CL_(108)-stat-CTCL_(16)),and PEO_(43)-b-PCTCL_(4)-b-PCL_(79).These polymers were self-assembled into polymersomes using either a solvent-switch or powder rehydration method,and the obtained polymersomes were characterized by dynamic light scattering and transmission electron microscopy.Then the phase separation patterns within the polymersome membranes were investigated by mesoscopic dynamics(MesoDyn)simulations.To further confirm the change of the membrane permeability that resulted from the phase separation within the membrane,doxorubicin,as a small molecular drug,was loaded and released from the polymersomes.Due to the incompatibility between membrane-forming moieties(PCTCL and PCL),phase separation occurs and the release rate can be tuned by controlling the membrane phase pattern or by photo-cross-linking.Moreover,besides the compacting effect by formation of chemical bonds in the membrane,the cross-linking process can act as a driving force to facilitate the rearrangement and re-orientation of the phase pattern,which also influences the drug release behavior by modulating the cross-membrane distribution of the amorphous PCTCL moieties.In this way,the strategy of focusing on the membrane phase separation for the preparation of the polymersomes with finely tunable drug release rate can be envisioned and designed accordingly,which is of great significance in the field of delivery vehicles for programmed drug release.
基金financially supported by National Natural Science Foundation of China(Nos.82172090,82302390 and 82072059)CAMS Innovation Fund for Medical Sciences(Nos.2021-I2M-1-058 and 2022-I2M-1-023)+3 种基金China Postdoctoral Science Foundation(No.2022M720502)Tianjin Municipal Natural Science Foundation(No.22JCQNJC00070)CAMS Union Young Scholars Support Program(No.2022051)Fundamental Research Funds for the Central Universities(No.2019PT320028)。
文摘Due to the heterogeneity of tumors,single phototherapy cannot completely ablate tumors and inhibit tumor metastasis.To overcome these,we formulated targeted and multifunctional polymersomes ABC@ICGIMQ-LHRH(AIRL)that encapsulated Toll-like receptor(TLR)7/8 agonist imiquimod(IMQ)and photosensitizer indocyanine green(ICG)in the hydrophobic layer as well as bubble-generator NH_(4)HCO_(3) in the hydrophilic cavity to inhibit the growth of primary and distant tumors,and prevent tumor metastasis through synergistic photoimmunotherapy.The AIRL polymersomes exhibited uniform and stable size,and high drug encapsulation efficiency,acid/reduction/laser responsiveness,excellent photothermal conversion efficiency,effective reactive oxygen species generation,high tumor accumulation.AIRL could be effectively internalized by dendritic cells(DCs),achieve lysosome escape and enhance DCs maturation.The synergistic photoimmunotherapy via AIRL polymersomes remarkably promoted the differentiation and activation of T cells,elevated strong systemic immune response to eradicate primary tumors and inhibit the growth of distant tumors.Simultaneously,the endurable immunological memory prevented tumor metastasis,which provided a promising nanoplatform for the combination therapy of cancer.
基金supported by the National Natural Science Foundation of China(Nos.82072059 and 82172090)the Fundamental Research Funds for the Central Universities(No.2019PT320028)+2 种基金Tianjin Municipal Natural Science Foundation(No.20JCYBJC00030)CAMS Initiative for Innovative Medicine(No.2021-I2M-1-058)Science and Technology Planning Project of Tianjin(No.18ZXSGSY00050).
文摘Intelligent nanoplatform that combines multimodal imaging and therapeutic effects holds great promise for precise and efficient cancer therapy.Herein,folate-targeted polymersomes with stimuli-responsiveness were fabricated and evaluated by near-infrared fluorescence(NIRF)and optical coherence tomography angiography(OCTA)dual-imaging for photo-chemo-antiangiogenic therapy against cancer.The folate-targeted polymersomes(FA-MIT-SIPS)not only integrated ammonium bicarbonate(ABC)and mitoxantrone(MIT)into their hydrophilic cavity but also encapsulated indocyanine green(ICG)and sorafenib(SOR)within their hydrophobic layer.NIRF imaging demonstrated that FA-MIT-SIPS effectively accumulated and retained in the tumors.Upon 808 nm laser irradiation,the ICG produced hyperthermia and reactive oxygen species(ROS)for efficient photothermal and photodynamic therapy.In addition,the decomposition of ABC in responsive to acidic tumor environment and ICG-induced hyperthermia accelerated drug release.The released MIT accumulated in nucleus to inhibit DNA synthesis,while the released SOR destructed tumor vascularization.Notably,OCTA imaging was applied to observe the tumor blood flow upon the combination therapy,demonstrating that FA-MIT-SIPS obviously decreased the vessels area density.Moreover,the synergistic photo-chemo-antiangiogenic therapy of FA-MIT-SIPS achieved excellent antitumor effect with 40%of the 4T1 tumor-bearing mice being completely cured without recurrence.The multifunctional polymersomes provide a promising dual-modal imaging-evaluated synergistic strategy for tumor therapy.
基金financially supported by the National Natural Science Foundation of China(No.51103022)Science and Technology Commission of Shanghai Municipality(STCSM,Pujiang Talent Plan,No.12PJ1400100)Innovation Program of Shanghai Municipal Education Commission,Fundamental Research Funds for the Central University and DHU Distinguished Young Professor Program and Chinese Universities Scientific Fund(No.CUSF-DH-D-2013004)
文摘The asymmetric amphiphilic block copolymer polystyrene962-block-poly（ethylene oxide）227 （PS962-b-PEO227） eanforms mieelles with N, N-dimethylforrnamide （DMF） as co-solvent and water as selected solvent, and when the water content of the mixed solvent is higher than 4.5 wt%, the vesicle will be dominated. This work finds that once vesicles are formed in the DMF-water mixed solvent, the vesicle size and membrane thickness can be tuned by further increasing water content. As the water fraction elevated from 4.8 wt% to 13.0 wt%, the vesicle size dercreases from 246 nm to 150 nm, while the membrane thickness increases from 28 nm to 42 nm. In addition, the block copolymer packing and the free energy are analyzed as the vesicle size becomes small and the membrane becomes thick.
基金supported by the National Natural Science Foundation of China(21374080,21674081,21611130175)Shanghai International Scientific Collaboration Fund,China(15230724500)+1 种基金Shanghai 1000 Talents PlanFundamental Research Funds for the Central Universities,China(0500219211,1500219107)
基金the work from the European Research Council under the European Union's Seventh Framework Program(FP/2007-2013)/ERC grant agreement No.310034the Austrian Science Fund(FWF)grant No.I 3064.
文摘Hybrid lipopolymer vesicles are membrane vesicles that can be self-assembled on both the micro-and nano-scale.On the nanoscale,they are potential novel smart materials for drug delivery systems that could combine the relative strengths of liposome and polymersome drug delivery systems without their respective weaknesses.However,little is known about their properties and how they could be tailored.Currently,most methods of investigation are limited to the microscale.Here we provide a brief review on hybrid vesicle systems with a specific focus on recent developments demonstrating that nanoscale hybrid vesicles have different properties from their macroscale counterparts.
基金financially supported by the French National Research Agency (No. ANR-16-CE29-0028)the National Natural Science Foundation of China (Nos. 21604001 and 21528402)
文摘Fluorescent vesicles have recently attracted increasing attention because of their potential applications in bioimaging,diagnostics, and theranostics, for example, in vivo study of the delivery and the distribution of active substances. However, fluorescent vesicles containing conventional organic dyes often suffer from the problem of aggregation-caused quenching(ACQ) of fluorescence.Fluorescent vesicles working with aggregation-induced emission(AIE) offer an extraordinary tool to tackle the ACQ issue, showing advantages such as high emission efficiency, superior photophysical stability, low background interference, and high sensitivity. AIE fluorescent vesicles represent a new type of fluorescent and functional nanomaterials. In this review, we summarize the recent advances in the development of AIE fluorescent vesicles. The review is organized according to the chemical structures and architectures of the amphiphilic molecules that constitute the AIE vesicles, i.e., small-molecule amphiphiles, amphiphilic polymers, and amphiphilic supramolecules and supramacromolecules. The studies on the applications of these AIE vesicles as stimuli-responsive vesicles,fluorescence-guided drug release carriers, cell imaging tools, and fluorescent materials based on fluorescence resonance energy transfer(FRET) are also discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.21304096,21474103,21603214 and 21674109)
文摘Choline phosphate （CP） as a novel zwitterion possesses specific and excellent properties compared with phosphorylcholine （PC）, as well as its polymer, such as poly（2-（methacryloyloxy）ethyl choline phosphate） （PMCP）, has been studied extensively due to its unique characteristics of rapid cellular internalization via the special quadrupole interactions with the cell membrane. Recently, we reported a novel PMCP-based drug delivery system to enhance the cellular internalization where the drug was conjugated to the polymer via reversible acylhydrazone bond. Herein, to make full use of this feature of PMCP, we synthesized the diblock copolymer poly（2-（methacryloyloxy）ethyl choline phosphate）-b-poly（2- （diisopropylamino）ethyl methacrylate） （PMCP-b-PDPA）, which could self-assemble into polymersomes with hydrophilic PMCP corona and hydrophobic membrane wall in mild conditions when the pH value is 〉 6.4. It has been found that these polymersomes can be successfully used to load anticancer drug Dox with the loading content of about 11.30 wt%. After the polymersome is rapidly internalized by the cell with the aid of PMCP, the loaded drug can be burst-released in endosomes since PDPA segment is protonated at low pH environment, which renders PDPA to transfer from hydrophobic to hydrophilic, and the subsequent polymersomes collapse thoroughly. Ultimately, the ＂proton sponge＂ effect of PDPA chain can further accelerate the Dox to escape from endosome to cytoplasm to exert cytostatic effects. Meanwhile, the cell viability assays showed that the Dox-loaded polymersomes exhibited significant inhibitory effect on tumor cells, indicating its great potential as a targeted intracellular delivery system with high efficiency.
基金supported by National Natural Science Foundation of China(Nos.81571793,81671806 and 51373199)CAMS Innovation Fund for Medical Sciences,Tianjin Municipal Natural Science Foundation(No.15JCZDJC38300)Science and Technology Support Program of Tianjin(No.15RCGFSY00146)
文摘Polye-caprolactone）-b-poly（ethylene glycol）-b-poly（e-caprolactone）（PCL-b-PEG-b-PCL,PCEC） triblock copolymers have been widely investigated in last several decades.Here,by altering the weight ratio of monomers in ring-opening polymerization,a series of PCEC triblock copolymers with varying hydrophobicity were synthesized,which were characterized by FTIR,1 H NMR,GPC and DSC.When PCEC copolymers with different weight ratios of PCL/PEG were dispersed in different aqueous solutions,they could self-assemble and form two distinctive nanoparticular structures：micelles or polymersomes.We then chose paclitaxel（PTX） as the model drug and encapsulate PTX into PCEC polymeric micelles and polymersomes.The physicochemical characterizations of the nanoparticles such as morphology,the size and distribution,zeta potential,drug loading content,and encapsulation efficiency were also performed.Our results showed that polymeric micelles or polymersomes from PCEC both displayed narrow size distributions and could achieve high drug loading efficiencies.In vitro cellular uptake results suggested that Nile Red loaded polymeric micelles or polymersomes displayed more internalization after 24 h incubation than those after 4 h incubation.These findings suggest that polymeric micelles and polymersomes based on PCL-b-PEG-b-PCL copolymers have great potential to effectively delivery hydrophobic drugs.
