Two pH-responsive amphiphilic diblock copolymers, namely polyisobutylene-block-poly[2-（N,N- dimethylamino）ethyl methaerylate] （PIB-b-PDMAEMA） and polyisobutylene-block-poly（metharylic acid） （PIB-b-PMAA）, were ...Two pH-responsive amphiphilic diblock copolymers, namely polyisobutylene-block-poly[2-（N,N- dimethylamino）ethyl methaerylate] （PIB-b-PDMAEMA） and polyisobutylene-block-poly（metharylic acid） （PIB-b-PMAA）, were synthesized via oxyanion-initiated polymerization, and their multiple self-assembly behaviors have been studied. An exo-01efin-terminated highly reactive polyisobutylene （HRPIB） was first changed to hydroxyl-terminated PIB （PIB-OH） via hydroboration-oxidation of C =C double bond in the chain end, and then reacted with KH to yield a potassium alcoholate of PIB （PIB-O-K＋）. PIB-O-K＋ was immediately used as a macroinitiator to polymerize DMAEMA monomer, resulting in a cationic diblock copolymer PIB-b-PDMAEMA. With the similar synthesis procedure, the anionic diblock copolymer PIB-b- PMAA could be prepared via a combination of oxyanion-initiated polymerization of tert-butyl methacrylate （tBMA） and subsequent hydrolysis of tert-butyl ester groups in PtBMA block. The functional PIB and block copolymers have been fully characterized by 1H-NMR, FT-IR spectroscopy, and gel permeation chromatography （GPC）. These samples allowed us to systematically investigate the effects of block composition on the pH responsivity and various self-assembled morphologies of the copolymers in THF/water mixed solvent. Transmission electron microscopy （TEM） images revealed that these diblock copolymers containing small amount of original PIB without exo-olefin-terminated group are able to self-assemble into micelles, vesicles with different particle sizes and cylindrical aggregates, depending on various factors including block copolymer composition, solvent polarity and pH value.展开更多
The structure and properties of functional nanoparticles are important for stabilizing Pickering emulsion polymerization.Recently,cellulose nanocrystals(CNCs)are increasingly favored as a bio-based stabilizer for Pick...The structure and properties of functional nanoparticles are important for stabilizing Pickering emulsion polymerization.Recently,cellulose nanocrystals(CNCs)are increasingly favored as a bio-based stabilizer for Pickering emulsions.In this study,we reported a novel functionalized polyphosphoester-grafted CNCs for the stabilization of oil-in-water Pickering emulsions and the emulsion polymerization of styrene.First,polyphosphoester containing an amino group at one end of the chain,abbreviated as PBYP-NH2,was prepared by ring-opening polymerization(ROP)and hydrolysis reaction,wherein PBYP represents poly[2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane].Subsequently,CNC-COOH was obtained via 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidation of CNCs.The functionalized nanocrystals CNC-PBYP-COOH with carboxyl groups and polyphosphoester on the surface were obtained by the amidation reaction of PBYP-NH2 with CNC-COOH.Finally,we used CNC-PBYP-COOH as sole particle emulsifiers to stabilize styrene-in-water Pickering emulsions and studied its effects on the emulsions in details by using dynamic light scattering(DLS).The results indicated that the properties of these emulsions depended on the concentration of hydrophobically modified CNCs,volume ratios of oil to water,and pH values.The modified CNCs had higher ability to stabilize the styrene-in-water emulsions relative to the unmodified CNCs,and a stable oil-in-water(o/w)Pickering emulsion with diameter of hundreds of nanometers could be obtained.The resulting emulsions could be polymerized to yield nanosized latexes.The polyphosphoester-modified CNCs as green particle emulsifiers can efficiently stabilize nanoemulsions and latexes,which would promote the development of novel environmentally friendly materials.展开更多
In order to overcome the limitation of traditional active nano-therapeutic drugs on tumor targeting efficiency which cannot reach the receptor/target in sufficient amount in the body,in this work,we developed a monocl...In order to overcome the limitation of traditional active nano-therapeutic drugs on tumor targeting efficiency which cannot reach the receptor/target in sufficient amount in the body,in this work,we developed a monoclonal antibody(mAb)and a polymer-hyd-doxorubicin prodrug conjugate,which enables the self-assembled nanoparticles to have precise targeting,tumor tissue aggregation and pH-sensitive drug release.We first prepared an amphiphilic polymer prodrug,abbreviated as H2N-PEEP-b-PBYP-hyd-DOX,via a combination of ring-opening polymerization(ROP)and"click"chemistry,in which PEEP and PBYP represent two kinds of phosphoester segmemts,-hyd-is hydrazone bond.After self-assembly into prodrug nanoparticles(PDNPs)with a diameter of about 93 nm,CD147 mAb was conjugated onto the PDNPs by EDC/NHS chemistry to form mAb-PDNPs.For the PDNPs and mAb-PDNPs,we also investigated their stability,in vitro drug release behavior and cellular uptake.The results showed that the pH-responsive PDNPs can remain relatively stable under the condition of PB 7.4 buffer solution.However,under acidic conditions or in the presence of phosphodiesterase I(PDE I),both the amount and rate of DOX release increased at the same incubation period.Cytotoxicity assay showed that mAb-PDNPs exhibited higher cytotoxicity(IC50:1.12 mg·L^(-1))against HepG2 cells than PDNPs(IC50:2.62 mg·L^(-1))without monoclonal antibody.The nanoparticles with antibodies mAb-PDNPs have relatively better stability and can directly achieve the targeting drug delivery through CD147 mAb.展开更多
The classical hypercube structure is a popular topological architecture in parallel computing environments and a large number of variations based on the hypercube were posed in the past three decades. Reliability eval...The classical hypercube structure is a popular topological architecture in parallel computing environments and a large number of variations based on the hypercube were posed in the past three decades. Reliability evaluation of systems is important to the design and maintenance of multiprocessor systems. The h-extra edge-connectivity of graph G（V, E） is a kind of measure for the reliability of interconnection systems, which is defined as the minimum cardinality of a subset of edge set, if any, whose deletion disconnects G and such that every re- maining component has at least h vertices. This paper shows that the h-extra edge-connectivity 2n-1 2n-1 of the hypercube Qn is a constant 2n-1 for 2n-1/3≤ h2n-1, and n ≥ 4, which extends the result of [Bounding the size of the subgraph induced by m vertices and extra edge-connectivity of hypercubes, Discrete Applied Mathematics, 2013, 161（16）： 2753-2757].展开更多
Due to the non-crystalline properties of short chain perfluoroalkyl groups, using short chain perfluoroalkyl to stabilize low surface free energy polymers has been a challenging task. In this study, we prepare a serie...Due to the non-crystalline properties of short chain perfluoroalkyl groups, using short chain perfluoroalkyl to stabilize low surface free energy polymers has been a challenging task. In this study, we prepare a series of random copolymers poly（perfluorohexylethyl methacrylate）-co-poly（stearyl acrylate） （P13FMA-co-PSA） and block copolymers poly（perfluorohexylethyl methacrylate）-b-poly（stearyl acrylate） （P13FMA-b-PSA）, and systematically investigate the effects of the sequence structure and the content of 13FMA of the fluorinated copolymers on surface free energy and surface reorganization. Static/dynamic contact angle goniometry and water/oil repellency analyses demonstrate that the random polymer P13FMA-co-PSA could not achieve low surface free energy and low surface reorganization at the same time. In contrast, for the block copolymer P13FMA-b-PSA, both low surface free energy and low surface reorganization are acquired simultaneously. The results of X-ray photoelectron spectroscopy （XPS）, dynamic contact angle goniometry and differential scanning calorimetry （DSC） reveal the above-mentioned properties. The consecutive 13FMA segments improve the surface fluorine density, while the consecutive SA chains enhance the crystallinity of the SA segments, and further hinder the surface reorganization of the perfluoroalkyl groups. Therefore, P13FMA-b-PSA exhibits a higher utilization efficiency of fluorine atoms and a better structural stability than P13FMA-co-PSA.展开更多
Enumeration of perfect matchings on graphs has a longstanding interest in combinatorial mathematics. In this paper, we obtain some explicit expressions of the number of perfect matchings for a type of Archimedean latt...Enumeration of perfect matchings on graphs has a longstanding interest in combinatorial mathematics. In this paper, we obtain some explicit expressions of the number of perfect matchings for a type of Archimedean lattices with toroidal boundary by applying Tesler's crossing orientations to obtain some Pfaffan orientations and enumerating their Pfaffans.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 20974074 and 21074078)Natural Science Foundation of Jiangsu Province for Rolling Support Project (BK2011045)+1 种基金a project funded by the PriorityAcademic Program Development of Jiangsu Higher Education Institutions, State Key Lab of Chemical Resource Engineering(Beijing University of Chemical Technology)the Innovation Project of Graduate Students of Jiangsu Province, China(CXZZ11_0091)
文摘Two pH-responsive amphiphilic diblock copolymers, namely polyisobutylene-block-poly[2-（N,N- dimethylamino）ethyl methaerylate] （PIB-b-PDMAEMA） and polyisobutylene-block-poly（metharylic acid） （PIB-b-PMAA）, were synthesized via oxyanion-initiated polymerization, and their multiple self-assembly behaviors have been studied. An exo-01efin-terminated highly reactive polyisobutylene （HRPIB） was first changed to hydroxyl-terminated PIB （PIB-OH） via hydroboration-oxidation of C =C double bond in the chain end, and then reacted with KH to yield a potassium alcoholate of PIB （PIB-O-K＋）. PIB-O-K＋ was immediately used as a macroinitiator to polymerize DMAEMA monomer, resulting in a cationic diblock copolymer PIB-b-PDMAEMA. With the similar synthesis procedure, the anionic diblock copolymer PIB-b- PMAA could be prepared via a combination of oxyanion-initiated polymerization of tert-butyl methacrylate （tBMA） and subsequent hydrolysis of tert-butyl ester groups in PtBMA block. The functional PIB and block copolymers have been fully characterized by 1H-NMR, FT-IR spectroscopy, and gel permeation chromatography （GPC）. These samples allowed us to systematically investigate the effects of block composition on the pH responsivity and various self-assembled morphologies of the copolymers in THF/water mixed solvent. Transmission electron microscopy （TEM） images revealed that these diblock copolymers containing small amount of original PIB without exo-olefin-terminated group are able to self-assemble into micelles, vesicles with different particle sizes and cylindrical aggregates, depending on various factors including block copolymer composition, solvent polarity and pH value.
基金the National Natural Science Foundation of China(Nos.21975169 and 21374066)the Major Program of the Natural Science Project of Jiangsu Higher Education Institutions(No.15KJA150007)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20171212)a Project Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education InstitutionsSoochow-Waterloo University Joint Project for Nanotechnology from Suzhou Industrial Park.
文摘The structure and properties of functional nanoparticles are important for stabilizing Pickering emulsion polymerization.Recently,cellulose nanocrystals(CNCs)are increasingly favored as a bio-based stabilizer for Pickering emulsions.In this study,we reported a novel functionalized polyphosphoester-grafted CNCs for the stabilization of oil-in-water Pickering emulsions and the emulsion polymerization of styrene.First,polyphosphoester containing an amino group at one end of the chain,abbreviated as PBYP-NH2,was prepared by ring-opening polymerization(ROP)and hydrolysis reaction,wherein PBYP represents poly[2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane].Subsequently,CNC-COOH was obtained via 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidation of CNCs.The functionalized nanocrystals CNC-PBYP-COOH with carboxyl groups and polyphosphoester on the surface were obtained by the amidation reaction of PBYP-NH2 with CNC-COOH.Finally,we used CNC-PBYP-COOH as sole particle emulsifiers to stabilize styrene-in-water Pickering emulsions and studied its effects on the emulsions in details by using dynamic light scattering(DLS).The results indicated that the properties of these emulsions depended on the concentration of hydrophobically modified CNCs,volume ratios of oil to water,and pH values.The modified CNCs had higher ability to stabilize the styrene-in-water emulsions relative to the unmodified CNCs,and a stable oil-in-water(o/w)Pickering emulsion with diameter of hundreds of nanometers could be obtained.The resulting emulsions could be polymerized to yield nanosized latexes.The polyphosphoester-modified CNCs as green particle emulsifiers can efficiently stabilize nanoemulsions and latexes,which would promote the development of novel environmentally friendly materials.
基金financial supports from the National Natural Science Foundation of China(Nos.21975169 and 21374066)the Natural Science Foundation of Jiangsu Province(No.BK20171212)Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘In order to overcome the limitation of traditional active nano-therapeutic drugs on tumor targeting efficiency which cannot reach the receptor/target in sufficient amount in the body,in this work,we developed a monoclonal antibody(mAb)and a polymer-hyd-doxorubicin prodrug conjugate,which enables the self-assembled nanoparticles to have precise targeting,tumor tissue aggregation and pH-sensitive drug release.We first prepared an amphiphilic polymer prodrug,abbreviated as H2N-PEEP-b-PBYP-hyd-DOX,via a combination of ring-opening polymerization(ROP)and"click"chemistry,in which PEEP and PBYP represent two kinds of phosphoester segmemts,-hyd-is hydrazone bond.After self-assembly into prodrug nanoparticles(PDNPs)with a diameter of about 93 nm,CD147 mAb was conjugated onto the PDNPs by EDC/NHS chemistry to form mAb-PDNPs.For the PDNPs and mAb-PDNPs,we also investigated their stability,in vitro drug release behavior and cellular uptake.The results showed that the pH-responsive PDNPs can remain relatively stable under the condition of PB 7.4 buffer solution.However,under acidic conditions or in the presence of phosphodiesterase I(PDE I),both the amount and rate of DOX release increased at the same incubation period.Cytotoxicity assay showed that mAb-PDNPs exhibited higher cytotoxicity(IC50:1.12 mg·L^(-1))against HepG2 cells than PDNPs(IC50:2.62 mg·L^(-1))without monoclonal antibody.The nanoparticles with antibodies mAb-PDNPs have relatively better stability and can directly achieve the targeting drug delivery through CD147 mAb.
基金Supported by the National Natural Science Foundation of China(11171283,11471273,11461038,11301440)Natural Sciences Foundation of Shanxi Province(2014021010-2)
文摘The classical hypercube structure is a popular topological architecture in parallel computing environments and a large number of variations based on the hypercube were posed in the past three decades. Reliability evaluation of systems is important to the design and maintenance of multiprocessor systems. The h-extra edge-connectivity of graph G（V, E） is a kind of measure for the reliability of interconnection systems, which is defined as the minimum cardinality of a subset of edge set, if any, whose deletion disconnects G and such that every re- maining component has at least h vertices. This paper shows that the h-extra edge-connectivity 2n-1 2n-1 of the hypercube Qn is a constant 2n-1 for 2n-1/3≤ h2n-1, and n ≥ 4, which extends the result of [Bounding the size of the subgraph induced by m vertices and extra edge-connectivity of hypercubes, Discrete Applied Mathematics, 2013, 161（16）： 2753-2757].
基金National Natural Science Foundation of China(Nos.21374066 and 20474041)the Major Program of the Natural Science Project of Jiangsu Higher Education+2 种基金 Institutions(No.15KJA150007)the Natural Science Foundation of Jiangsu Province(No.BK20151263)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions,and Soochow-Waterloo University Joint Project for Nanotechnology from Suzhou Industrial Park
文摘Due to the non-crystalline properties of short chain perfluoroalkyl groups, using short chain perfluoroalkyl to stabilize low surface free energy polymers has been a challenging task. In this study, we prepare a series of random copolymers poly（perfluorohexylethyl methacrylate）-co-poly（stearyl acrylate） （P13FMA-co-PSA） and block copolymers poly（perfluorohexylethyl methacrylate）-b-poly（stearyl acrylate） （P13FMA-b-PSA）, and systematically investigate the effects of the sequence structure and the content of 13FMA of the fluorinated copolymers on surface free energy and surface reorganization. Static/dynamic contact angle goniometry and water/oil repellency analyses demonstrate that the random polymer P13FMA-co-PSA could not achieve low surface free energy and low surface reorganization at the same time. In contrast, for the block copolymer P13FMA-b-PSA, both low surface free energy and low surface reorganization are acquired simultaneously. The results of X-ray photoelectron spectroscopy （XPS）, dynamic contact angle goniometry and differential scanning calorimetry （DSC） reveal the above-mentioned properties. The consecutive 13FMA segments improve the surface fluorine density, while the consecutive SA chains enhance the crystallinity of the SA segments, and further hinder the surface reorganization of the perfluoroalkyl groups. Therefore, P13FMA-b-PSA exhibits a higher utilization efficiency of fluorine atoms and a better structural stability than P13FMA-co-PSA.
基金Supported by the National Natural Science Foundation of China(Grant No.11471273 11671186)
文摘Enumeration of perfect matchings on graphs has a longstanding interest in combinatorial mathematics. In this paper, we obtain some explicit expressions of the number of perfect matchings for a type of Archimedean lattices with toroidal boundary by applying Tesler's crossing orientations to obtain some Pfaffan orientations and enumerating their Pfaffans.
