Share Email Print

Proceedings Paper

Tracing the spatiotemporally resolved inactivation of optically arranged bacteria by photofunctional microparticles at the single-cell level (Conference Presentation)
Author(s): Alvaro Barroso Peña; Malte Grüner; Taylor Forbes; Cornelia Denz; Cristian A. Strassert

Paper Abstract

Antimicrobial Photodynamic Inactivation (PDI) represents an attractive alternative in the treatment of infections by antibiotic-resistant pathogenic bacteria. In PDI a photosensitizer (PS) is administered to the site of the biological target in order to generate cytotoxic singlet oxygen which reacts with the biological membrane upon application of harmless visible light. Established methods for testing the photoinduced cytotoxicity of PSs rely on the observation of the whole bacterial ensemble providing only a population-averaged information about the overall produced toxicity. However, for a deeper understanding of the processes that take place in PDI, new methods are required that provide simultaneous regulation of the ROS production, monitoring the subsequent damage induced in the bacteria cells, and full control of the distance between the bacteria and the center of the singlet oxygen production. Herein we present a novel method that enables the quantitative spatio-time-resolved analysis at the single cell level of the photoinduced damage produced by transparent microspheres functionalized with PSs. For this purpose, a methodology was introduced to monitor phototriggered changes with spatiotemporal resolution employing holographic optical tweezers and functional fluorescence microscopy. The defined distance between the photoactive particles and individual bacteria can be fixed under the microscope before the photosensitization process, and the photoinduced damage is monitored by tracing the fluorescence turn-on of a suitable marker. Our methodology constitutes a new tool for the in vitro design and analysis of photosensitizers, as it enables a quantitative response evaluation of living systems towards oxidative stress.

Paper Details

Date Published: 10 November 2016
PDF: 1 pages
Proc. SPIE 9922, Optical Trapping and Optical Micromanipulation XIII, 992214 (10 November 2016); doi: 10.1117/12.2237757
Show Author Affiliations
Alvaro Barroso Peña, Westfälische Wilhelms-Univ. Münster (Germany)
Malte Grüner, Westfälische Wilhelms-Univ. Münster (Germany)
Taylor Forbes, Westfälische Wilhelms-Univ. Münster (Germany)
Cornelia Denz, Westfälische Wilhelms-Univ. Münster (Germany)
Cristian A. Strassert, Westfälische Wilhelms-Univ. Münster (Germany)

Published in SPIE Proceedings Vol. 9922:
Optical Trapping and Optical Micromanipulation XIII
Kishan Dholakia; Gabriel C. Spalding, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?