Exploring photoinactivation of microbial biofilms using laser scanning microscopy and confined 2-photon excitation.

Thomsen H, Graf FE, Farewell A, Ericson MB

J. Biophotonics 11 (10) e201800018 [2018-10-00; online 2018-06-19]

One pertinent complication in bacterial infection is the growth of biofilms, that is, communities of surface-adhered bacteria resilient to antibiotics. Photodynamic inactivation (PDI) has been proposed as an alternative to antibiotic treatment; however, novel techniques complementing standard efficacy measures are required. Herein, we present an approach employing multiphoton microscopy complemented with Airyscan super-resolution microscopy, to visualize the distribution of curcumin in Staphylococcus epidermidis biofilms. The effects of complexation of curcumin with hydroxypropyl-γ-cyclodextrin (HPγCD) were studied. It was shown that HPγCD curcumin demonstrated higher bioavailability in the biofilms compared to curcumin, without affecting the subcellular uptake. Spectral quantification following PDI demonstrates a method for monitoring elimination of biofilms in real time using noninvasive 3D imaging. Additionally, spatially confined 2-photon inactivation was demonstrated for the first time in biofilms. These results support the feasibility of advanced optical microscopy as a sensitive tool for evaluating treatment efficacy in biofilms toward improved mechanistic studies of PDI.

Integrated Microscopy Technologies Gothenburg [Service]

PubMed 29785840

DOI 10.1002/jbio.201800018

Crossref 10.1002/jbio.201800018