Controlling bacterial biofilms growth through photodynamic action

Abstract Changes in microbial growth kinetics and biofilm formation capacity were evaluated in bacterial cells remaining from PDT. Curcumin (CUR) used as photosensitizer, shows penetration and photodynamic effects on biofilm layers, evaluated considering parameters such as the biofilm complexity (BC), and formation time (FT) of the biofilm. Microbial growth and biofilm reformulation capacity were modified in cells remaining after partial photodynamic action. The photosensitizer (PS) permeation per bacterial biofilm layer showed to be dependent on the FT and BC in addition to the incubation time (IT) of the PS. Post-PDT effects showed (1) a delay in the onset of the exponential phase; (2) limitation of the maximum microbial amount; (3) slowdown of the growth rate. The use of PDT shows to be promising for biofilm control remnants presents slowdown and modification on the growth patterns and penetration of CUR is facilitated through the complex structure of the biofilm.