Amphiphilic Fluorine-Containing Block Copolymers as Carriers for Hydrophobic PtTFPP for Dissolved Oxygen Sensing, Cell Respiration Monitoring and In Vivo Hypoxia Imaging with High Quantum Efficiency and Long Lifetime

• Main Authors: Jiaze Li, Yuan Qiao, Tingting Pan, Ke Zhong, Jiaxing Wen, Shanshan Wu, Fengyu Su, Yanqing Tian
• Format: Article
• Language: English
• Published: MDPI AG 2018-11-01
• Series: Sensors
• Subjects: dissolved oxygen sensors; fluoropolymers; micelles; cell respiration monitoring; tumor imaging
• Online Access: https://www.mdpi.com/1424-8220/18/11/3752

New amphiphilic star or multi-arm block copolymers with different structures were synthesized for enabling the use of hydrophobic oxygen probe of platinum (II)-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) for bioanalysis. The amphiphilic star polymers were prepared through the Atom Transfer Radical Polymerization (ATRP) method by using hydrophilic 4-arm polyethylene glycol (4-arm-PEG) as an initiator. Among the five block copolymers, <b>P1</b> series (<b>P1a</b>, <b>P1b</b>, and <b>P1c</b>) and <b>P3</b> possess fluorine-containing moieties to improve the oxygen sensitivity with its excellent capacity to dissolve and carry oxygen. A polymer <b>P2</b> without fluorine units was also synthesized for comparison. The structure-property relationship was investigated. Under nitrogen atmosphere, high quantum efficiency of PtTFPP in fluorine-containing micelles could reach to 22% and long lifetime could reach to 76 μs. One kind of representative PtTFPP-containing micelles was used to detect the respiration of <i>Escherichia coli </i>(<i>E.</i><i> </i><i>coli</i>) JM109 and macrophage cell J774A.1 by a high throughput plate reader. In vivo<i> </i>hypoxic imaging of tumor-bearing mice was also achieved successfully. This study demonstrated that using well-designed fluoropolymers to load PtTFPP could achieve high oxygen sensing properties, and long lifetime, showing the great capability for further in vivo sensing and imaging.