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UV Irradiation-Induced Shell Cross-Linked Micelles with pH-Responsive Cores Using ABC Triblock Copolymers
| Content Provider | Semantic Scholar |
|---|---|
| Author | Jiang, Xiaoze Luo, Shizhong Armes, Steven P. Shi, Wenfang Liu, Shiyong |
| Abstract | A triblock copolymer, poly(ethylene glycol)b-poly(glycerol monomethacrylate)b-poly(2-(diethylamino)ethyl methacrylate) (PEG -PGMA-PDEA), was synthesized via atom transfer radical polymerization (ATRP) by successive polymerization of glycerol monomethacrylate (GMA) and 2-(diethylamino)ethyl methacrylate (DEA) using a PEG-based ATRP macroinitiator. Reacting the obtained triblock copolymer with varying amounts of cinnamoyl chloride in anhydrous pyridine yielded PEG -(PCGMA-co-PGMA)-PDEA triblock copolymer with photo-cross-linkable moieties, where PCGMA is poly(3-cinnamoyl glycerol monomethacrylate) and the mean degree of cinnamoylation ranges from 5 to 50 mol % relative to the PGMA block. All PEG -(PCGMAco-PGMA)-PDEA triblock copolymers molecularly dissolve in aqueous media at acidic pH; upon addition of NaOH, micellization occurred above pH 7 -8 to form three-layer “onionlike” micelles comprising PDEA cores, PCGMA-co-PGMA inner shells, and PEG outer coronas. The pH-induced micellization kinetics of PEG 113(CGMA0.5-co-GMA0.5)50-DEA65 triblock copolymers was investigated by stopped-flow light scattering upon a pH jump from 3 to 10, and compared to that of PEG 113-PGMA50-PDEA65. Facile cross-linking of the PCGMAco-PGMA inner shell was then conducted via UV irradiation. The PDEA cores of the resulting shell cross-linked (SCL) micelles exhibited reversible pH-responsive behavior. The extent of pH-induced swelling/shrinking and the colloidal stability of SCL micelles were mainly determined by the extent of cross-linking. The dissociation kinetics of the triblock copolymer micelles before and after shell cross-linking was also investigated employing the stopped-flow technique. It was found that SCL micelles prepared at higher degrees ( >20 mol %) of crosslinking exhibited excellent colloidal stability to external pH changes. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://staff.ustc.edu.cn/~sliu/Papers/Macromolecules_2006_39_5987.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | ABC Acids Chloride Ion Citric Acid, Anhydrous Copolymer Cross link Edema Glycerin Glycerol Kinase Intel GMA Kinetics Internet Protocol Methacrylates Methylmethacrylate Mole, unit of measurement Multitier architecture N,N-diethylaminoethyl methacrylate PDE6A gene Parsing expression grammar Polyethylene Glycols Pyridines Structured text Transfer RNA Aminoacylation UV mapping cinnamoyl chloride lactosyl-mercapto-poly(ethylene glycol) peginterferon alfa-2b |
| Content Type | Text |
| Resource Type | Article |
