title: Thermo-responsive shell cross-linked PMMA-b-P(NIPAAm-co-NAS) micelles for drug delivery.
abstract: Thermo-responsive amphiphilic poly(methyl methacrylate)-b-poly(N-isopropylacrylamide-co-N-acryloxysuccinimide) (PMMA-b-P(NIPAAm-co-NAS)) block copolymer was synthesized by successive RAFT polymerizations. The uncross-linked micelles were facilely prepared by directly dissolving the block copolymer in an aqueous medium, and the shell cross-linked (SCL) micelles were further fabricated by the addition of ethylenediamine as a di-functional cross-linker into the micellar solution. Optical absorption measurements showed that the LCST of uncross-linked and cross-linked micelles was 31.0°C and 40.8°C, respectively. Transmission electron microscopy (TEM) showed that both uncross-linked and cross-linked micelles exhibited well-defined spherical shape in aqueous phase at room temperature, while the SCL micelles were able to retain the spherical shape with relatively smaller dimension even at 40°C due to the cross-linked structure. In vitro drug release study demonstrated a slower and more sustained drug release behavior from the SCL micelles at high temperature as compared with the release profile of uncross-linked micelles, indicating the great potential of SCL micelles developed herein as novel smart carriers for controlled drug release.
authors: Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, PR China.
authors: Cong
authors: C
authors: Chang
authors: Hua
authors: H
authors: Wei
authors: De-Qun
authors: DQ
authors: Wu
authors: Bin
authors: B
authors: Yang
authors: Ni
authors: N
authors: Chen
authors: Si-Xue
authors: SX
authors: Cheng
authors: Xian-Zheng
authors: XZ
authors: Zhang
authors: Ren-Xi
authors: RX
authors: Zhuo
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000138:chemical synthesis*; D004337:Drug Carriers / Q000138:chemical synthesis*; D005029:Ethylenediamines / Q000737:chemistry; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D013696:Temperature
chemical_list: D000178:Acrylamides; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D005029:Ethylenediamines; D008823:Micelles; D011108:Polymers; C031234:ethylenediamine; D019904:Polymethyl Methacrylate; C067295:N-isopropylacrylamide