Geles Supramoleculares Incorporados de Rosa de Bengala como Plataforma Tópica para Terapia Fotodinámica...

Efficient and localized singlet oxygen (SO) generation is essential for improving antimicrobial photodynamic therapy (aPDT). In this study, a bis-imidazolium-based amphiphilic gelator is used, which self-assembles into a supramolecular gel in a water-ethanol medium and incorporates Rose Bengal (RB) as a photosensitizer. The gel network provides a confined environment that promotes SO formation under light irradiation. RB@Gel was characterized with respect to its morphology, degradation behavior, and swelling properties. Biopharmaceutical assessment included in vitro release, ex vivo permeation studies and Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) assay. Rheological measurements confirmed a viscoelastic profile, indicating structural stability and suitability for localized therapeutic applications. SO production within the gel was quantified using tetrasodium 9,10-anthracenediyl-bis(methylene)dimalonate (NaABMA), showing higher efficiency than that of RB in solution. The RB@Gel exhibited significant aPDT against E. coli in a direct-surface contact assay. Overall, the RB@Gel provides a stable, suitable platform capable of efficient SO generation and potent antibacterial activity, highlighting its promise for localized aPDT applications.