This study aimed to investigate the ability of the novel materials D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate(TPOS) to construct pH-sensitive liposomes. TPOS was initially synthesized and characterized by TLC...This study aimed to investigate the ability of the novel materials D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate(TPOS) to construct pH-sensitive liposomes. TPOS was initially synthesized and characterized by TLC, FTIR, and ~1H-NMR. The buffering capacity of polyethylene glycol-distearoyl phosphatidylethanolamine(PEG-DSPE) and TPOS was determined by acid-base titration, and TPOS displayed a slower downtrend and gentler slope of titration curve than PEG-DSPE within pH 7.4–5.0. Studies on the in vitro drug release demonstrated that TPOS modified docetaxel(DOC) liposomes(TPOS-DOC-L) had a slower drugrelease rate at pH 7.4 similar to PEGylated-DOC liposomes(PEG-DOC-L), whereas the release rate reached approximately 86.92% ± 1.69% at pH 6.4. In vitro cellular uptake assays by microplate reader, and flow cytometry revealed that TPOS modified coumarin 6 liposomes(TPOS-C6-L) had stronger cellular uptake at pH 6.4 than that at pH 7.4( P < 0.01). Conversely, for PEGylated C6 liposomes(PEG-C6-L) and conventional C6 liposomes(C6-L), very similar cellular uptakes were exhibited at different pH values. Confocal laser scanning microscopy images showed that PEG-C6-L and C6-L were mainly located in lysosomes. By contrast, TPOS-C6-L showed broader cytoplasmic release and distribution at 4 h. MTT assay showed that the cytotoxicity of TPOS-DOC-L was similar to that of PEG-DOC-L and conventional DOC liposomes(DOC-L) at the same DOC concentration and at pH 7.4, but was much lower than those at pH 6.4 after 48 h of incubation. The apoptosis of PEG-DOC-L and DOC-L had no remarkable improvement with decreased pH from 7.4 to 6.4. Meanwhile, TPOS-DOC-Lsignificantly induced the apoptosis of HeLa cells with decreased pH. Therefore, TPOS can be a biomaterial for the construction of a pH-sensitive drug delivery system.展开更多
By mechanism-transformation (anionic --> cationic) poly(styrene-6-2-ethyl-2-oxazoline) diblock copolymer, PS-b-PEOx, was synthesized in two steps. The first step is the polymerization of styrene block capped with e...By mechanism-transformation (anionic --> cationic) poly(styrene-6-2-ethyl-2-oxazoline) diblock copolymer, PS-b-PEOx, was synthesized in two steps. The first step is the polymerization of styrene block capped with ethylene oxide and its tosylation; the second step is the cationic ring-opening polymerization of 2-ethyl-2-oxazoline. The products were thoroughly characterized by various methods, such as H-1-NMR, IR, DMA, TEM and SAXS. The results show that the copolymer obtained possesses high molecular weight and narrow molecular weight distribution.展开更多
Peptides exert important biological functions but their application is hindered by their susceptibility to proteolysis and poor stability in vivo.Thus,functional peptide mimics have drawn a great deal of attention to ...Peptides exert important biological functions but their application is hindered by their susceptibility to proteolysis and poor stability in vivo.Thus,functional peptide mimics have drawn a great deal of attention to address this challenge.Poly(2-oxazoline)s,a class of biocompatible and proteolysis-resistant polymer,can work as host defense peptide mimics without following the general membrane-targeting mechanism as shown in our previous work.This observation encouraged us to figure out if poly(2-oxazoline)s are special and break the general membrane-targeting mechanism of host defense peptides and their mimics.In this study,we aimed at the connection between structure and antibacterial mechanism of poly(2-oxazoline)s.A new γ-aminobutyric acid(GABA)-pendent poly(2-oxazoline)was synthesized and investigated to compare with glycine-pendent poly(2-oxazoline)in our previous study,with the former polymer has two extra CH2 groups in the sidechain to increase the hydrophobicity and amphiphilicity.Membrane depolarization assay suggested that incorporating two more CH2 groups into the sidechain of poly(2-oxazoline)resulted in a mechanism switch from DNA-targeting to membrane-targeting,which was supported by the slow time-kill kinetics and slightly distorted and sunken membrane morphology.Besides,GABA-pendent poly(2-oxazoline)showed potent activity against methicillin-resistant S.aureus and low hemolysis on human red blood cells.Moreover,repeated use of the antimicrobial poly(2-oxazoline)did not stimulate bacteria to obtain resistance,which was an obvious advantage of membrane-targeting antimicrobial agents.展开更多
A straightforward coassembly strategy was developed for the preparation of polymeric nanoparticles driving by the intermolecular hydrogen bond between neutral poly(2-methyl-2-oxaozline)(PMeOx),tannic acid(TA) and doxo...A straightforward coassembly strategy was developed for the preparation of polymeric nanoparticles driving by the intermolecular hydrogen bond between neutral poly(2-methyl-2-oxaozline)(PMeOx),tannic acid(TA) and doxorubicin hydrochloride(Dox).The occurrence of the hydrogen-bonding amongst the different functionalities within the formed nanoparticles was verified by infrared(IR) spectroscopy.Scanning electron microscopy(SEM),dynamic light scattering(DLS),UV-vis absorption and photoluminescent measurements indicated the rapid formation of uniform and water dispersible/stable nanoparticles.The relative poor stability of PMeOx-TA-Dox in fetal bovine serum(FBS) solution enabled the rapid separation of Dox and PMeOx-TA,facilitating the release of Dox and its entrance into cellular nuclei as revealed by confocal laser scanning microscopy(CLSM).The presented strategy may provide an efficient alternative for the construction of multifunctional nanomedicines.展开更多
Neoantigen cancer vaccines have been envisioned as one of the most promising means for cancer therapies.However,identifying neoantigens for tumor types with low tumor mutation burdens continues to limit the effectiven...Neoantigen cancer vaccines have been envisioned as one of the most promising means for cancer therapies.However,identifying neoantigens for tumor types with low tumor mutation burdens continues to limit the effectiveness of neoantigen vaccines.Herein,we proposed a "hit-and-run" vaccine strategy which primes T cells to attack tumor cells decorated with exogenous "neo-antigens".This vaccine strategy utilizes a peptide nanovaccine to elicit antigen-specific T cell responses after tumor-specific decoration with a nanocarrier containing the same peptide antigens.We demonstrated that a poly(2-oxazoline)s(POx) conjugated with OVA_(257-264) peptide through a matrix metalloprotease 2(MMP-2) sensitive linker could efficiently and selectively decorate tumor cells with OVA peptides in vivo.Then,a POx-based nanovaccine containing OVA_(257-264) peptides to elicit OVA-specific T cell responses was designed.In combination with this hit-and-run vaccine system,an effective vaccine therapy was demonstrated across tumor types even without OVA antigen expression.This approach provides a promising and uniform vaccine strategy against tumors with a low tumor mutation burden.展开更多
基金supported by National Natural Science Foundation of China (81102394)Natural Science Foundation of Liaoning Province (20170540575)
文摘This study aimed to investigate the ability of the novel materials D-α-tocopheryl poly(2-ethyl-2-oxazoline) succinate(TPOS) to construct pH-sensitive liposomes. TPOS was initially synthesized and characterized by TLC, FTIR, and ~1H-NMR. The buffering capacity of polyethylene glycol-distearoyl phosphatidylethanolamine(PEG-DSPE) and TPOS was determined by acid-base titration, and TPOS displayed a slower downtrend and gentler slope of titration curve than PEG-DSPE within pH 7.4–5.0. Studies on the in vitro drug release demonstrated that TPOS modified docetaxel(DOC) liposomes(TPOS-DOC-L) had a slower drugrelease rate at pH 7.4 similar to PEGylated-DOC liposomes(PEG-DOC-L), whereas the release rate reached approximately 86.92% ± 1.69% at pH 6.4. In vitro cellular uptake assays by microplate reader, and flow cytometry revealed that TPOS modified coumarin 6 liposomes(TPOS-C6-L) had stronger cellular uptake at pH 6.4 than that at pH 7.4( P < 0.01). Conversely, for PEGylated C6 liposomes(PEG-C6-L) and conventional C6 liposomes(C6-L), very similar cellular uptakes were exhibited at different pH values. Confocal laser scanning microscopy images showed that PEG-C6-L and C6-L were mainly located in lysosomes. By contrast, TPOS-C6-L showed broader cytoplasmic release and distribution at 4 h. MTT assay showed that the cytotoxicity of TPOS-DOC-L was similar to that of PEG-DOC-L and conventional DOC liposomes(DOC-L) at the same DOC concentration and at pH 7.4, but was much lower than those at pH 6.4 after 48 h of incubation. The apoptosis of PEG-DOC-L and DOC-L had no remarkable improvement with decreased pH from 7.4 to 6.4. Meanwhile, TPOS-DOC-Lsignificantly induced the apoptosis of HeLa cells with decreased pH. Therefore, TPOS can be a biomaterial for the construction of a pH-sensitive drug delivery system.
基金Supported by the National Natural Science Foundation of China(Grant no.59503002)and Polymer Physics Laboratory of Changchun Institute of Applied Chemistry,Chinese Academy of Sciences
文摘By mechanism-transformation (anionic --> cationic) poly(styrene-6-2-ethyl-2-oxazoline) diblock copolymer, PS-b-PEOx, was synthesized in two steps. The first step is the polymerization of styrene block capped with ethylene oxide and its tosylation; the second step is the cationic ring-opening polymerization of 2-ethyl-2-oxazoline. The products were thoroughly characterized by various methods, such as H-1-NMR, IR, DMA, TEM and SAXS. The results show that the copolymer obtained possesses high molecular weight and narrow molecular weight distribution.
基金financially supported by the Natural Science Foundation of Shanghai(18ZR1410300)the National Natural Science Foundation of China(No.21861162010,21774031)+2 种基金the National Key Research and Development Program of China(No.2016YFC1100401)the Research Program of State Key Laboratory of Bioreactor Engineeringthe Fundamental Research Funds for the Central Universities(No.22221818014,50321041917001)。
文摘Peptides exert important biological functions but their application is hindered by their susceptibility to proteolysis and poor stability in vivo.Thus,functional peptide mimics have drawn a great deal of attention to address this challenge.Poly(2-oxazoline)s,a class of biocompatible and proteolysis-resistant polymer,can work as host defense peptide mimics without following the general membrane-targeting mechanism as shown in our previous work.This observation encouraged us to figure out if poly(2-oxazoline)s are special and break the general membrane-targeting mechanism of host defense peptides and their mimics.In this study,we aimed at the connection between structure and antibacterial mechanism of poly(2-oxazoline)s.A new γ-aminobutyric acid(GABA)-pendent poly(2-oxazoline)was synthesized and investigated to compare with glycine-pendent poly(2-oxazoline)in our previous study,with the former polymer has two extra CH2 groups in the sidechain to increase the hydrophobicity and amphiphilicity.Membrane depolarization assay suggested that incorporating two more CH2 groups into the sidechain of poly(2-oxazoline)resulted in a mechanism switch from DNA-targeting to membrane-targeting,which was supported by the slow time-kill kinetics and slightly distorted and sunken membrane morphology.Besides,GABA-pendent poly(2-oxazoline)showed potent activity against methicillin-resistant S.aureus and low hemolysis on human red blood cells.Moreover,repeated use of the antimicrobial poly(2-oxazoline)did not stimulate bacteria to obtain resistance,which was an obvious advantage of membrane-targeting antimicrobial agents.
基金The financial support of this work from the National Natural Science Foundation of China(No.51673194)Department of Science and Technology of Jilin Province(Nos.20180101196JC and 20180101170JC)。
文摘A straightforward coassembly strategy was developed for the preparation of polymeric nanoparticles driving by the intermolecular hydrogen bond between neutral poly(2-methyl-2-oxaozline)(PMeOx),tannic acid(TA) and doxorubicin hydrochloride(Dox).The occurrence of the hydrogen-bonding amongst the different functionalities within the formed nanoparticles was verified by infrared(IR) spectroscopy.Scanning electron microscopy(SEM),dynamic light scattering(DLS),UV-vis absorption and photoluminescent measurements indicated the rapid formation of uniform and water dispersible/stable nanoparticles.The relative poor stability of PMeOx-TA-Dox in fetal bovine serum(FBS) solution enabled the rapid separation of Dox and PMeOx-TA,facilitating the release of Dox and its entrance into cellular nuclei as revealed by confocal laser scanning microscopy(CLSM).The presented strategy may provide an efficient alternative for the construction of multifunctional nanomedicines.
基金supported by the National Key Research and Development Program of China (2022YFC2303100)the National Natural Science Foundation of China (T2325010, 22305082, 52203162, and 22075078)+6 种基金Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism (Shanghai Municipal Education Commission)the Program of Shanghai Academic/Technology Research Leader (20XD1421400)the Open Research Fund of the State Key Laboratory of Polymer Physics and Chemistry (Changchun Institute of Applied Chemistry, Chinese Academy of Sciences)the Open Project of Engineering Research Center of Dairy Quality and Safety Control Technology (Ministry of Education, R202201)China National Postdoctoral Program for Innovative Talents (BX2021102)China Postdoctoral Science Foundation (2022M710050)the support of the Analysis and Testing Center of School of Chemical Engineering, East China university of Science and Technology。
基金supported by the National Natural Science Foundation of China (22222509, 52025035, 52103194, and 22105199)The Ministry of Science and Technology of China (2022YFE0110200)+3 种基金Bureau of International Cooperation Chinese Academy of Sciences (121522KYSB20200029)Jilin Province Science and Technology Development Plan (YDZJ202101ZYTS131, 20220402037GH, and 20210508049RQ)Jilin Provincial International Cooperation Key Laboratory of Biomedical Polymers (20210504001GH)The Youth Innovation Promotion Association of Chinese Academy of Sciences (2020232)。
文摘Neoantigen cancer vaccines have been envisioned as one of the most promising means for cancer therapies.However,identifying neoantigens for tumor types with low tumor mutation burdens continues to limit the effectiveness of neoantigen vaccines.Herein,we proposed a "hit-and-run" vaccine strategy which primes T cells to attack tumor cells decorated with exogenous "neo-antigens".This vaccine strategy utilizes a peptide nanovaccine to elicit antigen-specific T cell responses after tumor-specific decoration with a nanocarrier containing the same peptide antigens.We demonstrated that a poly(2-oxazoline)s(POx) conjugated with OVA_(257-264) peptide through a matrix metalloprotease 2(MMP-2) sensitive linker could efficiently and selectively decorate tumor cells with OVA peptides in vivo.Then,a POx-based nanovaccine containing OVA_(257-264) peptides to elicit OVA-specific T cell responses was designed.In combination with this hit-and-run vaccine system,an effective vaccine therapy was demonstrated across tumor types even without OVA antigen expression.This approach provides a promising and uniform vaccine strategy against tumors with a low tumor mutation burden.