posted on 2020-03-25, 13:37authored byBinqian Yang, Feng Gao, Zhiyuan Li, Mingyang Li, Liang Chen, Yong Guan, Gang Liu, Lihua Yang
Narrow-spectrum antimicrobials
specifically eradicate the target
pathogens but suffer from significantly lagging development. Photodynamic
therapy eliminates cells with reactive oxygen species (ROS) generated
upon light irradiation but is intrinsically a wide-spectrum modality.
We herein converted photodynamic therapy into a narrow-spectrum modality
by taking advantage of a previously unnoticed physics recognition
pathway. We found that negatively charged nanospheres undergo selective
entropy gain-driven adsorption onto spherical bacteria, but not onto
rod-like bacteria. This bacterial morphology-targeting selectivity,
combined with the extremely limited effective radii of action of ROS,
enabled photodynamic nanospheres to kill >99% of inoculated spherical
bacteria upon light irradiation and <1% of rod-like bacteria under
comparable conditions, indicative of narrow-spectrum activity against
spherical bacteria. This work unveils the bacterial morphology selectivity
in the adsorption of negatively charged nanospheres and suggests a
new approach for treating infections characterized by overthriving
spherical bacteria in niches naturally dominated by rod-like bacteria.