Innovative Photodynamic Strategies for Antimicrobial Treatments: Biosafety and Effectiveness in a Cnidarian Model

\nThiophene-based materials (TMs) have emerged as promising candidates in the field of photodynamic therapy (PDT) as photosensitizers agents owing to their remarkable electron transport properties, which facilitate efficient energy transfer processes crucial for PDT. In detail, TMs exhibit favourable optical characteristics, making them suitable candidates for the absorption and conversion of light energy into reactive oxygen species (ROS), thereby inducing cytotoxic effects in targeted cells. Recent studies have explored natural carriers, including proteins and phages, for enhanced cell uptake and permeation of photosensitizers, thereby enabling the induction of apoptosis across various cell lines. Despite the remarkable potential of this approach for PDT purposes, clinical translation necessitates in vivo models to validate these innovative tools. Here, we investigated the nanosafety and in vivo efficacy of these phototheranostic agents using the tissue-like animal model Hydra vulgaris. The transparency, softness, structural simplicity, and ethical neutrality of Hydra collectively render it an exemplary model for such inquiries. These features facilitate rapid screening of cytotoxicity and the effectiveness for photodinamic purposes.\n