title: Spiropyran-based hyperbranched star copolymer: synthesis, phototropy, FRET, and bioapplication.
abstract: Photo- and pH-responsive amphiphilic hyperbranched star copolymers, poly(6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-d-galactopyranose)[poly(2-(N,N-dimethylaminoethyl) methacrylate)-co-poly(1'-(2-methacryloxyethyl)-3',3'-dimethyl-6-nitro-spiro(2H-1-benzo-pyran-2,2'-indoline))](n)s [HPMAlpGP(PDMAEMA-co-PSPMA)(n)], were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of the DMAEMA and the SPMA using hyperbranched PMAlpGP as a macro RAFT agent. In aqueous solution, the copolymers self-assembled to form core-shell micelles with HPMAlpGP core and PDMAEMA-co-PSPMA shell. The hydrophobic fluorescent dye nitrobenzoxadiazolyl derivative (NBD) was loaded into the spiropyran-containing micelles. The obtained micelles not only have the photochromic properties, but also modulate the fluorescence of NBD through fluorescence resonance energy transfer (FRET), which was also observed in living cells. Slight fluorescence intensity decrease of the spiropyran in merocyanine (ME) form was observed after five UV-visible light irradiation cycles. The cytotoxicity of the HPMAlpGP(PDMAEMA-co-PSPMA)(n) micelles was lower than that of 25k PEI. All the results revealed that these photoresponsive nanoparticles are a good candidate for cell imaging and may find broad applications in biological areas such as biological diagnosis, imaging, and detection.
authors: CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, P R China.
authors: Ying
authors: Y
authors: Wang
authors: Chun-Yan
authors: CY
authors: Hong
authors: Cai-Yuan
authors: CY
authors: Pan
mesh_terms: D001393:Azoles / Q000737:chemistry; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D002470:Cell Survival; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D008689:Methacrylates / Q000737:chemistry; D008823:Micelles; D015394:Molecular Structure; D008970:Molecular Weight; D009574:Nitro Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D009578:Nitrobenzenes / Q000737:chemistry; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity; D013194:Staining and Labeling
chemical_list: C510797:7-nitrobenz-2-oxa-1,3-diazol-4-yl; D001393:Azoles; D001578:Benzopyrans; D004337:Drug Carriers; D005456:Fluorescent Dyes; D007211:Indoles; D008689:Methacrylates; D008823:Micelles; D009574:Nitro Compounds; D009578:Nitrobenzenes; D011109:Polymethacrylic Acids; C088184:spiropyran; C049840:2-(dimethylamino)ethyl methacrylate