Conjugated Star Polymers from Multidirectional Suzuki鈥揗iyaura Polymerization for Live Cell Imaging

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• 作者：Christoph S. Fischer ; Christian Jenewein ; Stefan Mecking
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：February 10, 2015
• 年：2015
• 卷：48
• 期：3
• 页码：483-491
• 全文大小：614K
• ISSN：1520-5835

文摘

Comparative Suzuki鈥揗iyaura coupling polymerization (SMCP) studies with initiators generated in situ from 4-iododiphenylether (1), 4,4鈥?diiododiphenylether (2), 1,6-bis(4-iodophenoxy)hexane (3) and 1,4-bis(4-iodophenoxy)cyclohexane (4) result in bidirectional growth for 2, versus preferred monodirectional growth for 3 and 4 with their aliphatic spacers, in agreement with a 鈥渃hain walking鈥?of the metal along the aromatic system. Multidirectional controlled SMCP was initiated on a 1,6,9,14-tetra(4-iodophenoxy)-N,N鈥?(2,6-diisopropylphenyl) terrylene-3,4:11,12-tetracarboxidiimide (TDI-ArI₄) near-infrared fluorescent dye as a tetrafunctional core. MALDI鈥揟OF characterization and end group analysis reveal that four-armed polyfluorene-star-terrylenediimide (PF-star-TDI) polymers are formed with narrow molecular weight distributions (e.g., M_w/M_n = 1.29 at M_n = 1.8 脳 10⁴ g mol^鈥? from GPC). An efficient energy transfer results in a virtually exclusive NIR emission from the core upon excitation of the stars鈥?polyfluorene arms. Consequently, 鈥渄oping鈥?of self-stabilized nanoparticles (NP) from polyfluorene鈥損oly(ethylene glycol) (PF鈥揚EG) diblock copolymers with PF-star-TDI dye afforded particles with a bright emission in the red and NIR regime upon excitation at 位_exc = 380 nm. The utility of the 鈥渄oped鈥?particles for cell imaging was demonstrated by differentiation experiments with J774 macrophages and NIH-3T3 mouse fibroblast cells. In cocultures of both cell types, they can be differentiated by their emission color via confocal fluorescence microscopy due to their size-dependent uptake.