1421969-30-3Relevant academic research and scientific papers
Synthesis and properties of multicleavable amphiphilic dendritic comblike and toothbrushlike copolymers comprising alternating PEG and PCL grafts
Zhang, Meijing,Liu, Huanhuan,Shao, Wei,Miao, Ke,Zhao, Youliang
, p. 1325 - 1336 (2013)
Facile construction of novel functional dendritic copolymers by combination of self-condensing vinyl polymerization, sequence-controlled copolymerization and RAFT process was presented. RAFT copolymerization of a disulfide-linked polymerizable RAFT agent and equimolar feed ratio of styrenic and maleimidic macromonomers afforded multicleavable AmBn dendritic comblike copolymers with alternating PEG (A) and PCL (B) grafts, and a subsequent chain extension polymerization of styrene, tert-butyl acrylate, methyl methacrylate, and N-isopropylacrylamide gave AmB nCo dendritic toothbrushlike copolymers. (PEG) m(PCL)n copolymers obtained were of adjustable molecular weight, relatively low polydispersity (PDI = 1.10-1.32), variable CTA functionality (fCTA = 4.3-7.5), and similar segment numbers of PEG and PCL grafts, evident from 1H NMR and GPC-MALLS analyses. Their branched architecture was confirmed by (a) reduction-triggered degradation, (b) decreased intrinsic viscosities and Mark-Houwink-Sakurada exponent than their linear analogue, and (c) lowered glass transition and melting temperatures and broadened melting range as compared with normal A mBn comblike copolymer. In vitro drug release results revealed that the drug release kinetics of the disulfide-linked A mBn copolymer aggregates was significantly affected by macromolecular architecture, end group and reductive stimulus. These stimuli-responsive and biodegradable dendritic copolymer aggregates had a great potential as controlled delivery vehicles.
