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This paper reports the construction of a novel multi‐sensitive chemically crosslinked injectable hydrogel with strong mechanical strength by modifying Pluronic F127 responsive against temperature, pH and redox potential. Crosslinked polymer between benzaldehyde grafted Pluronic (P‐A) and amine end capped Pluronic having disulfide linkage (P‐B) have been synthesized and characterized with 1H NMR spectroscopy and GPC. The hydrogel under physiological conditions significantly altered sol‐gel transition behaviors with much lower critical gelation concentrations and temperatures, compared to Pluronic hydrogels. The rheological characterization demonstrated that the moduli of the hydrogels were able to be tuned depending on molecular weight as well as pH, redox and temperature conditions.

Novel spiropyran-conjugated Pluronic [polyethylene oxide (PEO)-b-polypropylene oxide (PPO)-b-polyethylene oxide (PEO)] micelles are developed as a new colorimetric detector showing photo- or thermo-switchable behavior. Facile conjugation of spiropyran to Pluronic was confirmed by (1)H NMR, UV-Vis, and Fluorescence spectroscopy. A switchable photoluminescence is found depending on the irradiation with either UV or visible light, and temperature resulting from structural isomerization of spiropyran between spiropyran (SP) and merocyanine (MC) form. Cytotoxicity of the spiropyran-conjugated Pluronic (SP-PL) was evaluated following an MTT assay, whereas photo responsiveness of spiropyran within the micelles was determined by confocal laser scanning microscopy.

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Water resistant polymer with adhesive behavior is reported to exhibit long-term antimicrobial activities under diverse conditions. To obtain highly adhesive polymer with prolonged antimicrobial activities and catechol moiety, 2-chloro-3 0 ,4 0 -dihydroxyacetophenone (CCDP) has been quaternized to poly(dimethylaminoethyl methacrylate) (PDMA). Later, for gaining the antimicrobial effects, the polymer (CCDP-q-PDMA) was quaternized with 1-bromododecane (C12) [CCDP/C12-q-PDMA]. X-ray photoelectron spectroscopy rectified the quaternization and adhesion of the polymer onto different substrates. The CCDP/C12-q-PDMA coated substrates exhibited remarkable bacterial killing efficiency against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, after incubation for 24 h. The remarkable antimicrobial activities exhibited in aqueous medium at 60 C for up to 60 days indicate the strong adhesiveness of CCDP/C12-q-PDMA on the substrate. Therefore, the synthesized polymer offers merit as a potential coating material, to protect a broad range of material from microbial contamination, for a prolonged period of time, under a highly stressed water environment.