461642-78-4Relevant articles and documents
Initiator-chain transfer agent combo in the RAFT polymerization of styrene
Wu, Ying,Zhang, Wei,Zhang, Zhengbiao,Pan, Xiangqiang,Cheng, Zhenping,Zhu, Jian,Zhu, Xiulin
, p. 9722 - 9724 (2014)
The combo agent with roles of initiator and chain transfer agent was demonstrated in RAFT polymerization of styrene. Polymers with defined structures at both α and ω ends were obtained, which was verified by the successful synthesis of seven-block segment
Nanocrystalline cellulose grafted random copolymers of N- isopropylacrylamide and acrylic acid synthesized by RAFT polymerization: Effect of different acrylic acid contents on LCST behavior
Zeinali, Elnaz,Haddadi-Asl, Vahid,Roghani-Mamaqani, Hossein
, p. 31428 - 31442 (2014)
Free and nanocrystalline cellulose (NCC) attached homopolymers of N-isopropylacrylamide and acrylic acid (AA) as temperature- and pH-sensitive materials and also their dual-sensitive copolymers with different contents of AA were synthesized by RAFT polyme
Synthesis, characterization, and antibacterial properties of a hydroxyapatite adhesive block copolymer
Zhang, Qiang Matthew,Serpe, Michael J.
, p. 8018 - 8025 (2014)
A novel diblock copolymer composed of bisphosphonate and pyridine oligomers has been prepared by reversible addition-fragmentation transfer (RAFT) polymerization. Ag ion was introduced into the polymer via its coordination with the pyridine groups, followed by a reduction process to obtain Ag nanoparticles with diameters of 5-15 nm measured by transmission electron microscopy (TEM). In addition, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) proved successful introduction of Ag nanoparticles into polymer. Ag nanoparticles containing polymer exhibited excellent antibacterial properties toward Lactobacillus plantarum (L. plantarum). In order to investigate its practical application as an antibacterial coating, the synthesized polymer was tethered onto hydroxyapatite (HA, main mineral component of natural bone, teeth, and most of implants for bone repair) surfaces via interaction between the polymers bisphosphonate group and HA, forming ～4 nm thick layers. Ag nanoparticles (5-15 nm in diameter) uniformly distributed around the HA particles were fabricated following the above process. The ability of the coating to kill the bacteria L. plantarum was determined, which revealed strong antibacterial properties.
Preparation of hyperbranched polystyrene-g-poly(N-isopropylacrylamide) copolymers and its application to novel thermo-responsive cell culture dishes
Sudo, Yu,Sakai, Hideaki,Nabae, Yuta,Hayakawa, Teruaki,Kakimoto, Masa-Aki
, p. 307 - 314 (2015)
This paper describes the preparation of hyperbranched polystyrene-g-poly(N-isopropylacrylamide) (HBPSt-g-PNIPAM) and its application as a novel thermo-responsive material for cell sheet preparation. HBPSt-g-PNIPAM was synthesized by grafting PNIPAM from the termini of HBPSt via reversible addition fragmentation transfer polymerization. The resulting HBPSt-g-PNIPAM was cast from a solution onto a commercial polystyrene-based dish (PS-dish) to make a thermo-responsive surface for cell cultivation (P4/PS-dish). Mouse 3T3 fibroblast cells were seeded on the P4/PS-dish with 2.5-3.5 μg/cm2 of PNIPAM and cultured at 37 °C for four days to achieve high confluency. Fairly large cell sheets were successfully collected by cooling the dish to 20 °C. The current material avoids the use of electron beam polymerization, which requires complicated equipment, for fabricating a thermo-responsive surface because PNIPAM is immobilized by the affinity between the hyperbranched polystyrene segment and the PS-dish.
Oxygen-Initiated and Regulated Controlled Radical Polymerization under Ambient Conditions
Lv, Chunna,He, Congze,Pan, Xiangcheng
, p. 9430 - 9433 (2018)
A rapid oxygen-initiated and -regulated controlled radical polymerization was conducted under ambient temperature and atmosphere. The reaction between triethylborane and oxygen provides ethyl radicals, which initiate and mediate the radical polymerization. The controlled radical polymerization was achieved using RAFT chain transfer agents (CTA) without any process of removing oxygen, providing well-defined polymers with almost full conversion (>95 %) in a short period (15 min). High-throughput screening was used to discover the suitable conditions for various CTA and monomers. To show the versatility of this method, a polymer library containing 25 well-defined polymers with different compositions (block and statistical copolymers) and molecular weights were synthesized in 1 h via high-throughput synthesis technique. A polymer-painting technique was developed using this method, forming films with spatial control and excellent control in molecular weight and dispersity.
Isothermal LCST transitions triggered by bioreduction of single polymer end-groups
Summers, Matthew J.,Phillips, Daniel J.,Gibson, Matthew I.
, p. 4223 - 4225 (2013)
The α-termini of RAFT-derived thermoresponsive polymers were functionalised via thiol exchange with pyridyl disulfide. Addition of hydrophilic end-groups dramatically increased the observed cloud point of the polymers, without changing the composition of the main chain. Selective cleavage of the disulfide-linked end-groups was observed under conditions intended to mimic intracellular glutathione concentration. This allowed the thermoresponsive behaviour to be 'switched on' without the need for a temperature stimulus-an 'isothermal' switch.
Hypoxia and temperature dual-stimuli-responsive random copolymers: Facile synthesis, self-assembly and controlled release of drug
Deng, Yinlu,Ji, Chenming,Wu, Yongzhen,Yuan, Hua,Yuan, Weizhong
, p. 10229 - 10238 (2020)
Amphiphilic random copolymers poly(isopropylacryamide-co-acrylic acid-co-2-nitroimidazole acrylate) (P(NIPAM-co-AA-co-NIA)) with different contents of the 2-nitroimidazole (NI) group were facilely synthesized through RAFT and EDC reactions. These random c
Mitochondria-targeted polymer-celastrol conjugate with enhanced anticancer efficacy
Geng, Yu,Xiang, Jiajia,Shao, Shiqun,Tang, Jianbin,Shen, Youqing
, p. 122 - 133 (2022/01/11)
Celastrol, a natural triterpene extracted from traditional Chinese medicine, shows anticancer effects on various cancer cells. However, its poor water-solubility, short plasma half-life, and high systemic toxicity impede its applications in vivo, necessitating a stable drug delivery system to overcome these critical drawbacks. We present here a block copolymer, poly(2-(N-oxide-N,N-dimethylamino)ethyl methacrylate)-block-poly(2-hydroxyethyl methacrylate) (OPDMA-HEMA), as the carrier for celastrol delivery. The amphiphilic polymer-celastrol conjugate can self-assemble into nanoparticles in aqueous solutions. The OPDMA outer shell confers the nanoparticles with improved pharmacokinetics and efficient mitochondria targeting capacity, and profoundly potentiates celastrol's induction of immunogenic cell death, which collectively contribute to the enhanced therapeutic effects of celastrol in vivo. This mitochondria-targeted polymer-celastrol conjugate may promise the applications of celastrol in cancer treatment.
Anti-tumor active multifunctional polymer micelle with tumor pH and H2O2 specific activation and preparation method
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Paragraph 0131-0133, (2020/12/31)
The invention provides an anti-tumor active multifunctional polymer micelle with tumor pH and H2O2 specific activation and a preparation method. A polymer micelle (TBPBA-PEGVI-FA) which can be self-assembled in a water phase is synthesized by utilizing pH and H2O2 double sensitivities of a borate bond at a tumor site, AglnS2 quantum dots are synthesized by a hydrothermal method, vinyl imidazole with a coordination function is used for carrying the AglnS2 quantum dots with fluorescence imaging and photodynamic therapy, and folic acid is used for targeting a tumor cell surface receptor (targeting an overexpressed tumor cell surface folate receptor (FR alpha (+))). In-vitro simulated release results show that the core-loaded DOX.HCl polymer can well release drugs in slightly acidic and H2O2 environments of tumor tissues, has good pH and H2O2 responsiveness, and is a smart nano-drug delivery system with wide application prospects.
