Photodynamic therapy (PDT) has drawn wide attention in intensive preclinical and clinical cancer therapy due to its noninvasive nature. A simple and facile synthesis of highly efficient delivery system for photosensitizers (PS) with visualized tumor environment is hence critical. Herein, a simple, safe and promising fluorescent probe, star-shaped poly(glutamic acid) with a porphyrin core (SPPLGA) was synthesized via ring-opening polymerization of β-benzyl-L-glutamate N-carboxyanhydride monomer with 5, 10, 15, 20-tetrakis-(4-aminophenyl)-21H, 23H-porphyrine (TAPP) as the initator, followed by the deprotection of benzyl groups on poly(benzyl-L-glutamate). The structure of this novel polymer was thoroughly studied by Nuclear magnetic resonance spectroscopy(NMR), Gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FT-IR). Such star-shaped poly(glutamic acid) with porphyrin core could self-assemble into micelles in aqueous solution and exhibit pH-sensitive critical micelle concentration. It was observed that with the decrease in pH, the fluorescence intensity of the SPPLGA increased. On the other hand, the incorporation of poly(glutamic acid) not only improved solubility of porphyrin in water, but also enhanced the production efficiency of the singlet oxygen (about double that of porphyrin). Those results suggest that these polymer, as promising pH-responsive and tumor-selective photosensitizers, are very promising for PDT and can potentially be used as "theranostics" for future cancer prognosis and therapeutic planning.
Surface antibacterial coatings with outstanding antibacterial efficiency have attracted increasing attention in medical protective clothing and cotton surgical clothing. Although nanozymes, as a new generation of antibiotics, are used to combat bacteria, their catalytic performance remains far from satisfactory as alternatives to natural enzymes. Single‐atom nanodots provide a solution to the low catalytic activity bottleneck of nanozymes. Here, atomically thin C3N4 nanodots supported single Cu atom nanozymes (Cu‐CNNDs) are developed by a self‐tailoring approach, which exhibits catalytic efficiency of 8.09 × 105 M−1 s−1, similar to that of natural enzyme. Experimental and theoretical calculations show that excellent peroxidase‐like activity stems from the size effect of carrier optimizing the coordination structure, leading to full exposure of Cu‐N3 active site, which improves the ability of H2O2 to generate hydroxyl radicals (•OH). Notably, Cu‐CNNDs exhibit over 99% superior antibacterial efficacy and are successfully grafted onto cotton fabrics. Thus, Cu‐CNNDs blaze an avenue for exquisite biomimetic nanozyme design and have great potential applications in antibacterial textiles.
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