ACID-LABILE CORE CROSS-LINKED MICELLES FOR pH-TRIGGERED RELEASE OF DOXORUBICIN

2021 ◽  
Vol 36 (06) ◽  
Author(s):  
NHAT THANG THI NGUYEN ◽  
XUAN THANG CAO ◽  
VAN CUONG NGUYEN

A acid-labile core cross-linked micelle system of amphiphilic triblock copolymer of poly(oligo(ethylene glycol) methyl ether methacrylate)-block-poly(styrene-alt-maleic anhydride)-block-poly(styrene) (POEGMA-b-PSMA-b-PS) was prepared. The POEGMA-b-PSMA-b-PS triblock copolymers were synthesized by the reversible addition-fragmentation chain transfer (RAFT) polymerization. Doxorubincin (DOX) was entrapped into micellar structure with POEGMA block as a shell and PSMA-b-PS block as a core. Then, core cross-linking was carried out by amidation reaction between 2,2-bis(aminoethoxy)propane and maleic anhydride group inner core. DOX loading content and efficiency were calculated to be 18 and 90 (wt. %), respectively. Core cross-linked micelles illustrated good stability under physiological condition but disassociated rapidly under acidic pH. The DOX release experiments indicated a rapid DOX release at pH 5.0 compared to pH 7.4.

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1164
Author(s):  
Angeliki Chroni ◽  
Thomas Mavromoustakos ◽  
Stergios Pispas

The focus of this study is the development of highly stable losartan potassium (LSR) polymeric nanocarriers. Two novel amphiphilic poly(n-butyl acrylate)-block-poly(oligo(ethylene glycol) methyl ether acrylate) (PnBA-b-POEGA) copolymers with different molecular weight (Mw) of PnBA are synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by the encapsulation of LSR into both PnBA-b-POEGA micelles. Based on dynamic light scattering (DLS), the PnBA30-b-POEGA70 and PnBA27-b-POEGA73 (where the subscripts denote wt.% composition of the components) copolymers formed micelles of 10 nm and 24 nm in water. The LSR-loaded PnBA-b-POEGA nanocarriers presented increased size and greater mass nanostructures compared to empty micelles, implying the successful loading of LSR into the inner hydrophobic domains. A thorough NMR (nuclear magnetic resonance) characterization of the LSR-loaded PnBA-b-POEGA nanocarriers was conducted. Strong intermolecular interactions between the biphenyl ring and the butyl chain of LSR with the methylene signals of PnBA were evidenced by 2D-NOESY experiments. The highest hydrophobicity of the PnBA27-b-POEGA73 micelles contributed to an efficient encapsulation of LSR into the micelles exhibiting a greater value of %EE compared to PnBA30-b-POEGA70 + 50% LSR nanocarriers. Ultrasound release profiles of LSR signified that a great amount of the encapsulated LSR is strongly attached to both PnBA30-b-POEGA70 and PnBA27-b-POEGA73 micelles.


2006 ◽  
Vol 59 (10) ◽  
pp. 742 ◽  
Author(s):  
Eric T. A. van den Dungen ◽  
Jacques Rinquest ◽  
Nadine O. Pretorius ◽  
Jean M. McKenzie ◽  
James B. McLeary ◽  
...  

The living radical alternating copolymerization of styrene and maleic anhydride mediated by the reversible addition–fragmentation chain transfer (RAFT) polymerization process has been studied at short chain lengths using two different dithiobenzoate RAFT agents. The results indicate specificity of addition of the RAFT-agent leaving groups for either styrene or maleic anhydride. The addition rate of the monomers and the fact that monomers are added individually favour the penultimate unit model of polymer propagation.


2012 ◽  
Vol 486 ◽  
pp. 449-454 ◽  
Author(s):  
Yue Zhao ◽  
Ming Tao Liang ◽  
Yoseop Kim ◽  
Xin Tan ◽  
Ling Zhang ◽  
...  

A polymer drug delivery system was developed using crosslinked self-assembled micelles, which form stable coreshell particles. The block copolymer, composed of poly [poly (ethylene glycol) methyl ether methacrylat-block-[poly (methyl methacrylate-p-nitrophenyl acrylate)] [P(PEGMEMA)-b-P(MMA-NPA)], was synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization. The self-assembled micelles were stabilized by core crosslinking through the reaction of p-nitrophenyl acrylate with 1,8-octandiamine forming stable coreshell particles.


2021 ◽  
Author(s):  
Hyun Suk Wang ◽  
Nghia P. Truong ◽  
Athina Anastasaki

The ability to reverse controlled radical polymerization and regenerate the monomer would be highly beneficial for both fundamental research and applications, yet has remained very challenging to achieve. Herein, we report a near-quantitative (up to 92%) and catalyst-free depolymerization of various linear, bulky, crosslinked, and functional polymethacrylates made by reversible addition-fragmentation chain-transfer (RAFT) polymerization. Key to our approach is to exploit the high end-group fidelity of RAFT polymers to generate chain-end radicals via thermal homolytic cleavage of carbon-sulfur bond of the RAFT end-group at 120 °C. These radicals trigger a rapid unzipping of both conventional (e.g. poly(methyl methacrylate)) and bulky polymers (e.g. poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)). Importantly, the depolymerization product can be utilized to either reconstruct the linear polymer or create an entirely new insoluble gel that can also be subjected to depolymerization. This work expands the potential of polymers made by CRP, pushes the boundaries of depolymerization, offers intriguing mechanistic aspects, and enables new applications.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1181
Author(s):  
Lan Yao ◽  
Haihui Li ◽  
Kai Tu ◽  
Lifen Zhang ◽  
Zhenping Cheng ◽  
...  

Polymeric nanomaterials made from amphiphilic block copolymers are increasingly used in the treatment of tumor tissues. In this work, we firstly synthesized the amphiphilic block copolymer PBnMA-b-P(BAPMA-co-PEGMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization using benzyl methacrylate (BnMA), poly (ethylene glycol) methyl ether methacrylate (PEGMA), and 3-((tert-butoxycarbonyl)amino)propyl methacrylate (BAPMA) as the monomers. Subsequently, PBnMA-b-P(APMA-co-PEGMA)@NIR 800 with photothermal conversion property was obtained by deprotection of the tert-butoxycarbonyl (BOC) groups of PBAPMA chains with trifluoroacetic acid (TFA) and post-modification with carboxyl functionalized ketocyanine dye (NIR 800), and it could self-assemble into micelles in CH3OH/water mixed solvent. The NIR photothermal conversion property of the post-modified micelles were investigated. Under irradiation with NIR light (λmax = 810 nm, 0.028 W/cm2) for 1 h, the temperature of the modified micelles aqueous solution increased to 53 °C from 20 °C, which showed the excellent NIR photothermal conversion property.


2011 ◽  
Vol 322 ◽  
pp. 219-223
Author(s):  
Lian Lai Cui ◽  
Tao Yu ◽  
Xin Tan ◽  
Yue Zhao ◽  
Jian Ping Li ◽  
...  

Block copolymers D,L-Polylactide-b-poly(poly(ethylene glycol) methyl ether acrylate) (D,L- P(LA)-b-P(PEGMA)) were prepared via ring-opening polymerization and reversible addition fragmentation chain transfer (RAFT) polymerization. The block polymers generated in the reaction reveal the living behavior with the molecular weight increasing with time. The copolymer D,L-P(LA)200-b-P(PEGMA)225 was synthesized successfully with D,L-P(LA) macro-RAFT agent, and was self-assembled in an aqueous environment, leading to the formation of self-assembly micelles. A distinct critical micelle concentration (CMC) was observed of the self-assembly system. The size of it was characterized by both DLS and TEM.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 229
Author(s):  
Marija Kavaliauskaite ◽  
Medeina Steponaviciute ◽  
Justina Kievisaite ◽  
Arturas Katelnikovas ◽  
Vaidas Klimkevicius

Synthesis and study of well-defined thermoresponsive amphiphilic copolymers with various compositions were reported. Kinetics of the reversible addition-fragmentation chain transfer (RAFT) (co)polymerization of styrene (St) and oligo(ethylene glycol) methyl ether methacrylate (PEO5MEMA) was studied by size exclusion chromatography (SEC) and 1H NMR spectroscopy, which allows calculating not only (co)polymerization parameters but also gives valuable information on RAFT (co)polymerization kinetics, process control, and chain propagation. Molecular weight Mn and dispersity Đ of the copolymers were determined by SEC with triple detection. The detailed investigation of styrene and PEO5MEMA (co)polymerization showed that both monomers prefer cross-polymerization due to their low reactivity ratios (r1 < 1, r2 < 1); therefore, the distribution of monomeric units across the copolymer chain of p(St-co-PEO5MEMA) with various compositions is almost ideally statistical or azeotropic. The thermoresponsive properties of p(St-co-PEO5MEMA) copolymers in aqueous solutions as a function of different hydrophilic/hydrophobic substituent ratios were evaluated by measuring the changes in hydrodynamic parameters under applied temperature using the dynamic light scattering method (DLS).


2021 ◽  
Author(s):  
Siva Ponnupandian ◽  
Prantik Mondal ◽  
Thomas Becker ◽  
Richard Hoogenboom ◽  
Andrew B Lowe ◽  
...  

This investigation reports the preparation of a tailor-made copolymer of furfuryl methacrylate (FMA) and trifluoroethyl methacrylate (TFEMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The furfuryl groups of the copolymer...


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