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Light‐activated Antibacterial Surfaces Comprise Photosensitizers
Author(s) -
Cahan Rivka,
Schwartz Ronen,
Langzam Yakov,
Nitzan Yeshayahu
Publication year - 2011
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2011.00989.x
Subject(s) - scanning electron microscope , methylene blue , contact angle , nuclear chemistry , materials science , chemistry , toluidine , rose bengal , antibacterial activity , bacteria , organic chemistry , composite material , photocatalysis , biology , genetics , catalysis
Antibacterial surfaces were prepared using a base polyethylene sheet topped with a layer containing a mixed powder of poly (vinylidene fluoride) and photosensitizers (PSs). A crimpled stamp was placed on the mixed powder, and then it was passed through a heating and pressing device. The three chosen PSs were rose bengal, toluidine blue O and methylene blue. Scanning electron microscope analysis showed that the PS surface texture was coarse and highly developed. Measurement of the apparent contact angles of the droplets deposited on the PS surfaces using goniometry showed that all three surfaces were hydrophobic. Photodynamic analysis of the surfaces into which the PSs were incorporated indicated significant reactive oxygen species formation after illumination with light fluency rate of 1.46 mW cm −2 for 30 min. Photodynamic inactivation assays performed in nutrient broth demonstrated more than 4 log reduction of the attached Escherichia coli after illumination (1.46 mW cm −2 ) for 24 h when the inoculum was 10 3 CFU mL −1 . However, more than 4 log reduction of Staphylococcus aureus occurred even when the cultures were illuminated for only 6 h. Our results provide an inexpensive, simple, state‐of‐the‐art method for preparing antibacterial surfaces that may help prevent infections in hospital surroundings and in some medical devices.