Microorganisms are among the greatest concerns of society. Infectious microorganisms cause myriad diseases, while environmental microorganisms cause biofouling of aquatic surfaces. Organic antimicrobial chemicals are conventionally used to kill troublesome microorganisms, although the treatments are disadvantageous for causing eco-toxic residues, for minimally affecting microbial biofilms, and for causing antibacterial resistance. Photodynamic inactivation (PDI) may be an alternative antibiotic method by generating singlet oxygen after the irradiation of photosensitizers. PDI avoids the aforementioned disadvantages yet the technology is fledging; thus, PDI research would be accelerated by simulations that can guide experimental design toward marketable products and social impact.<br/><br/>This study develops a simulation of antibacterial PDI. Our simulation models a user-defined PDI system that contains either a single model bacterium or a multi-cellular biofilm. The bacterial biochemistry is executed through flux balance analysis (FBA) and a compiled database of biochemical reactions as a molecular-level model. Bacterial death from PDI is determined as a fatal threshold of membrane oxidation which represents lysis from singlet oxygen. This simulation is the first to describe a PDI antibacterial system and is the first reported model of a biofilm with rigorous biochemical accuracy. The simulation will be validated by experimental literature and experimental research within our research group that is synthesizing and conducting bacterial assays of photosensitizers in PDI treatments. The validated simulation will guide the development of PDI materials by identifying relevant variables for treatment efficacy, predicting results from experimental conditions, and mechanistically explaining phenomena.<br/><br/>This simulation will expedite the scientific response to antibiotic resistance. The simulation will guide experimental design toward efficient experiments that will ultimately manifest in PDI technologies as a sustainable alternative to organic antibiotic treatments. The simulation applies chemistry, fluid mechanics, physics, and biology to provide practical and fundamental value for experimental progress toward a medically sustainable future society.

A whole cell biofilm model for photodynamic inactivation

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.