Angelw: a new nano photosensitizer for photodynamic therapy

Nano photosensitizers are widely concerned in the field of photodynamic therapy because of their unique optical properties However, most nano photosensitizers have very strong quenching effect, which limits their application in photodynamic therapy Recently, Professor Huang Jiandong of Fuzhou University, China and Professor juyoung Yoon of Lihua women ', Asymmetric zinc (II) phthalocyanine (PCA) substituted by N-Dimethylaminomethyl) phenoxy can self assemble into nanopcs in aqueous solution The photodynamic effects of nanopca are not affected by aggregation (Figure 1a) The results of dynamic light diffraction and transmission electron microscopy show that the particle size of nanopca is about 50 nm (Fig 1b, 1c) The related results are published on angel Chem Int ed (DOI: 10.1002 / anie 201806551) under the title of "phytoyanine assembled nanodots as photosensors for high efficient type I Photonics inphotodynamic therapy" Fig 1 The self-assembly and characterization of nanopca (source: angel Chem Int ed.) In the dynamic light diffraction experiment, the DMF solution of PCA forms molecular clusters under the dilution of water, and then forms the nano point structure through the stacking effect of π bond The size of nanopca increases gradually with time and reaches the maximum value after 30 minutes (Fig 2a) Nanopca is quite stable in water and its average size does not change after being placed in darkness for a week (Fig 2b) In addition, the zeta potential of nanopca is about 30 mV (Fig 2C) Moreover, the change of concentration does not affect the size of nanopca (Fig 2D) Fig 2 After the characterization of the stability of nanopca (source: angel Chem Int ed.), the author conducted a series of comparative experiments between nanopca and the photosensitizer methylene blue (MB) for clinical use, which proved that nanopca promotes the production of reactive oxygen species through type I photoreaction (Fig 3a, 3b, 3C) Then, the author compared the ability of different kinds of nanopcs to promote the formation of superoxide anion O 2 · - and concluded that the more amino groups connected to nanopcs, the stronger their ability to promote type I photoreaction (Fig 3E, 3F, 3G), and the more O 2 · - generated Figure 3 Photophysical and photochemical properties of nanopca (source: angel Chem Int ed.) harmful bacteria with strong resistance have been threatening human life and health, which urgently needs new antibacterial drugs and therapies In order to verify the feasibility of nanopc a as a photodynamic antibacterial agent, the author conducted a comparative experiment in bacterial cell culture by nanopc A and clinical photosensitizer methylene blue (MB), and confirmed that nanopc a has a strong inhibitory effect on the growth of Gram-negative bacteria (E coli) and Gram-positive bacteria (S aureus) (Figure 4) Fig 4 Comparison of antibacterial activity of nanopca (source: angel Chem Int ed.) in order to explore the antibacterial activity mechanism of nanopca, the author observed the morphological changes of E.coli cells through cryoTEM Nanopca carries a positive charge on its own and adheres to the surface of negatively charged bacteria through the mutual attraction of positive and negative charges Under the irradiation of near-infrared light, nanopc a can promote the production of reactive oxygen species and induce apoptosis or necrosis of bacterial cells (Fig 5) Fig 5 Cryo TEM image of E.coli cells treated with NanoPcA (source: Angew Chem Int Ed.) Summary: the author developed a new nano photosensitizer NanoPcA for photodynamic therapy, which shows excellent photodynamic antibacterial activity against common gram-negative and Gram-positive bacteria.