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BackgroundPolymeric micelles attract great attention in drug delivery and therapeutics. Various types of block copolymers have been designed for the application in biomedical fields. If we can introduce additional functional groups to the block copolymers, we can achieve advanced applications. In this regards, we tried to introduce aggregation induced emission enhancement (AIE) unit in the block copolymer.MethodsThe formation of polyion complex micelle was confirmed by dynamic light scattering and transmission electron microscopy. HeLa cells were incubated with polyion complex micelle and broad-band visible light using a halogen lamp (150 W) was irradiated to evaluate photocytotoxicity of polyion complex (PIC) micelle.ResultsFor the design of functional polymeric micelle, aggregation induced emission enhancement unit was introduced in the middle of block copolymer. We newly synthesized a new type block copolymer (PEG-TPE-PEI) possessing tetraphenylethene (TPE) group, as an AIE unit, in the middle of polymeric segments of PEG and PEI, which successfully formed PIC micelle with DP. The formation of PIC micelle was confirmed by dynamic light scattering, ζ potential measurement and transmission electron microscopy.ConclusionsPEG-TPE-PEI successfully formed PIC micelle by mixing with negatively charged dendrimer porphyrin. The PIC micelle exhibited photocytotoxicity upon illumination of broadband visible light.

We have synthesized a flavin‐N(5)‐oxide derivative with a p‐toluenesulfonyl (Ts‐OF) group as a “turn‐on” fluorescent probe for the detection of several antioxidant amino acids and biothiols. Oxidized flavin was synthesized by using dithiothreitol as the reducing agent. Ts‐OF showed a light‐driven fluorescence enhancement in the presence of several amino acids and biothiols such as histidine (His), methionine (Met), cysteine (Cys), glutathione (GSH), and homocysteine (Hcy). The 1H NMR study indicated the reductive elimination of the p‐toluenesulfonyl group from Ts‐OF in the presence of antioxidants and photo‐irradiation.