Reduction-Degradable Shell Cross-Linked Micelle with pH-Responsive Cores Prepared via Click Chemistry

2016 ◽  
Vol 848 ◽  
pp. 527-531
Author(s):  
Lu Bin Lin ◽  
Qing Yun Yu ◽  
Zhuo Qun Gu ◽  
Xiao Ze Jiang ◽  
Mei Fang Zhu

A well-defined poly [(ethylene glycol)-block-2-(dimethylamino) ethyl methacrylate-block-2-(diethylamino) methacrylate] (PEG-b-DMA-b-DEA) triblock copolymer was synthesized via atom transfer radical polymerization (ATRP) by successively polymerization of DMA and DEA monomers using a PEG-based macroinitiator, and obtained copolymer was then converted to be PEG-b-P(DMA-co-QDMA)-b-PDEA copolymer with “clickable” moieties in the middle block by the quaternization with propargyl bromide. Those copolymers prepared were characterized by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC), and its self-assembly behavior and subsequently fixation with bis-(azidoethyl) disulfide via click chemistry resulting reduction-sensitive shell-cross-linked (SCL) micelle in purely aqueous solution were investigated by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The results show the micellar structure could be effectively cross-linked via click chemistry and also be dissociated at reduction condition, which may realize it's potential application as novel drug delivery carriers.

2020 ◽  
Vol 20 (11) ◽  
pp. 6968-6974
Author(s):  
Yu Zhang ◽  
Wenliang Song ◽  
Il Kim

Polymeric nano aggregates based on poly(L-lysine)-block-PBLG-graft-poly(ethylene glycol) (PLL-b-PBLG-g-PEG) copolymers were prepared by a dialysis method in deionized water. PLL-b-PBLG-g-PEG copolymers with different degrees of PEG substitution were synthesized by combining the ring-opening polymerization of α-amino acid N-carboxyanhydrides and ester exchange reactions. Proton nuclear magnetic resonance spectroscopy and gel permeation chromatography were employed to confirm the polymer structures and molecular weights. Transmission electron microscopy and dynamic light scattering were used to observe the self-assembly behavior. The experimental results revealed that the volume content of deionized water in the mixture significantly affects the morphology and size of the aggregates formed by PLL-b-PBLG-g-PEG copolymers. Spherical, spindle-like, needle-like, and daisy-like aggregates were observed with an increase in the volume content of deionized water in the mixture.


2015 ◽  
Vol 815 ◽  
pp. 359-366 ◽  
Author(s):  
Qing Yun Yu ◽  
Lu Bin Lin ◽  
Xue Yu Xing ◽  
Hai Liang Dong ◽  
Xiao Ze Jiang ◽  
...  

Two pH-responsive block glycopolymers, poly (ethylene glycol)-b-Poly (2- (diethylamino) ethyl methacrylate-co-2-gluconamidoethyl methacrylate) (PEG113-b-P(DEA55-co-GAMA12)) and poly (ethylene glycol)-b-poly (2-(diethylamino) ethyl methacrylate)-b-poly (2-gluconamido ethyl methacrylate) (PEG113-b-PDEA55-b-PGAMA15), were synthesized via atom transfer radical polymerization (ATRP) by directly or successively polymerization of GAMA and DEA monomers using a PEG-based macroinitiator, respectively, without protecting group chemistry. Those block glycopolymers were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC), and their self-assembly behaviors were characterized by Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and Zeta-potential. The results show both synthetic block glycopolymers were dissolved molecularly in aqueous solution at acidic pH (such as pH 3), thus it can reversibly convert to be two-layer micelles comprising DEA and GAMA cores, PEG coronas with size of around 50 nm, or micelles comprising DEA cores, GAMA and PEG outer coronas with bigger size of 70 nm for PEG113-b- P(DEA55-co-GAMA12) and PEG113-b-PDEA55-b-PGAMA15), respectively, at basic condition. Both glycopolymers have the micellization process at middle pH (pH 6-8), but possess different isoelectric points (pIs) (at pH 8.0 and 7.8) for their pH responsive block of PEG113-b-P(DEA55-co-GAMA12) and PEG113-b-PDEA55-b-PGAMA15 with DEA-co-GAMA random structure or DEA chain only, respectively. This study not only reveals the self-assembly of pH responsive block glycopolymers with different architectures by fixing similar degree polymerization (DP) of their blocks, but also provides a tool to investigate pH induced dynamic covalent interaction between glycopolymers and phenylboronic acid derivatives or a light for designing novel drug delivery carriers.


2013 ◽  
Vol 662 ◽  
pp. 136-139
Author(s):  
Ge Yang ◽  
Ke Shuai Lu ◽  
Xue Yan Su

The paper describes the preparation and characterization of novel biodegradable nanoparticles based on self-assembly of poly-gamma-glutamic acid (γ-PGA) and poly(ethylene glycol) (PEG). The nanosystems were stable in aqueous media at low pH conditions. Solubility of the systems was determined by turbidity measurements. The particle size and the size distribution of the polyelectrolyte complexes were identified by dynamic lightscattering and transmission electron microscopy.It was found that the size and size distribution of the nanosystems depends on the concentrations of γ-PGA and PEG solutions and their ratio as well as on the pH of the mixture and the order of addition. The diameter of individual particles was in the range of 30–270 nm. measured by TEM, and the average hydrodynamic diameters were between 130 and 300 nm. These biodegradable, self-assembling stable nanocomplexes might be useful for several biomedical applications.


2020 ◽  
Vol 8 (16) ◽  
pp. 4626-4637 ◽  
Author(s):  
Anne Nguyen ◽  
Hidenori Ando ◽  
Roland Böttger ◽  
K. K. DurgaRao Viswanadham ◽  
Elham Rouhollahi ◽  
...  

Click chemistry was used to study the effect of varied PEG molecular weights on the self-assembly of PEG-gambogic acid (GA) conjugates into nanoparticles.


2019 ◽  
Vol 944 ◽  
pp. 557-564
Author(s):  
Jia Ming Xu ◽  
Dan Yue Wang ◽  
Han Tong ◽  
Xiao Ze Jiang ◽  
Mei Fang Zhu

Two kinds of diblock copolymers containing glucose and phenylboronic acid moieties, respectively, poly (ethylene glycol)-b-poly (gluconamidoethyl methacrylate) (PEG-b-PGAMA) and poly (ethylene glycol)-b-poly (2-aminoethyl methacrylate-co-3-nitrophenyboronic acid methacrylate) (PEG-b-P(AMA-co-NPBMA)) were synthesized via atom transfer radical polymerization (ATRP) and post polymerization modification (PPM). Well-defined structure and narrow molecular weight distribution of the polymers were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Gel Permeation Chromatography (GPC). Based on the cross-linking between the diol groups of the glycopolymer and phenylboronic acid under physiological pH (7.4), complex micelles composed of PEG outer shell and boronate ester cross-linking core with a hydrodynamic diameter around 20nm were formed. Morphology, size and assembly behavior of the complex micelles were investigated by 1H NMR, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The results showed the formation/cleavage of boronate ester linkage is reversible upon the variation of solution pH, the complex micelles displayed pH sentiveties of assembling/disassembling behavior. Above pH 7.4, stable spherical micelles can be formed, whereas pH less than 5.5, the micelles dissociated into unimers. Therefore, such pH-responsive micelles based on dynamic complexation of phenyl boronate bonds are expected to be applied to pH-responsive nanodrug carriers


2014 ◽  
Vol 998-999 ◽  
pp. 95-98
Author(s):  
Xu Du ◽  
Qin Wang ◽  
Chuan Dong Wang ◽  
Yang Liu

Three biodegradable amphiphilic triblock copolymers: polylactide-poly (ethylene glycol)-polylactide (PLA-PEG-PLA), poly (ε-caprolactone)-poly (ethylene glycol)-poly (ε-caprolactone) (PCL-PEG-PCL) and poly (lactide-glycolide)-poly (ethylene glycol)-poly (lactide-glycolide) (PLGA-PEG-PLGA) were synthesized. Their chemical structures were characterized. In aqueous solution, their self-assembly and degradation were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Spherical micelles were formed in aqueous solution via self-assembly of the amphiphilic triblock copolymers. After degradation, the PLA-PEG-PLA and PCL-PEG-PCL micelles became smaller and the PLGA-PEG-PLGA micelles change to vesicles, which should mainly attribute to their different degradation speed.


2012 ◽  
Vol 8 ◽  
pp. 2176-2183 ◽  
Author(s):  
Melanie Kemnitz ◽  
Helmut Ritter

Triton® X-100 (poly(ethylene glycol) tert-octylphenyl ether) was (meth)acrylated and polymerized in the absence and presence of randomly methylated β-cyclodextrin (RAMEB-CD). Triton®-polymers that were polymerized with RAMEB-CD in water were compared with polymers that were synthesized in organic solvents after the addition of RAMEB-CD. The polymers were characterized by 1H NMR and FTIR spectroscopy, matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF MS), dynamic light scattering (DLS), gel-permeation chromatography (GPC) and turbidity measurements. Additionally, the viscosity change of the methacrylic homopolymer with RAMEB-CD was evaluated.


RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 50993-51004 ◽  
Author(s):  
Beibei Lu ◽  
Lei Li ◽  
Lulu Wei ◽  
Xuhong Guo ◽  
Jun Hou ◽  
...  

Well-defined amphiphilic β-cyclodextrin star-shaped copolymers with poly(ε-caprolactone)–poly(2-(2-methoxyethoxy)ethyl methacrylate)-co-poly(ethylene glycol)methacrylate) (β-CD–(PCL–P(MEO2MA-co-PEGMA))21 were synthesized via (ROP) and (ATRP).


2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Guo-Quan Zhu

AbstractPoly(γ-benzyl l-glutamate)-graft-poly(ethylene glycol) (PBLG-graft-PEG) copolymer was synthesized by the ester exchange reaction of the PBLG homopolymer with PEG. NMR spectroscopy was used to confirm the composition of the PBLG-graft-PEG copolymer. FTIR spectroscopy was used to characterize the chain conformation of polypeptide segments in the PBLG-graft-PEG copolymer in solid state. The self-assembly behavior of PBLG-graft-PEG and its mixtures with PBLG in ethanol were investigated by transmission electron microscopy (TEM) and viscometry. Experimental results showed that the PBLG-graft-PEG copolymer can self-assemble to form polymeric micelles with a core-shell structure of a thin shuttle-like shape. The introduction of the PBLG homopolymer into the mixed system not only decreases the critical micelle concentration (CMC) but also changes the morphology of the micelles from their shuttle-like shape to cylindrical shape. The effects of test temperature on the critical micelle concentration of PBLG-graft-PEG were also studied.


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