Research Projects

Worldwide antimicrobial resistance (AMR) is a critical problem, and its rise among clinical pathogens, particularly multidrug-resistant strains like Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, poses a critical threat to global health. Conventional antibiotics are increasingly ineffective due to their extensive use. It creates pressure for the development of drug resistance, leading to higher morbidity, mortality, and healthcare costs. Antibiotic resistance in infections leads to sepsis results in inflammation and organ failure [1]. Antimicrobial photodynamic therapy (APDT) is an emerging alternative to overcome AMR. APDT utilises light-activated photosensitizers (PSs) that can capture photon energy from the light and transfer it to other surrounding molecules, causing the formation of radicals such as radical oxygen species (ROS) that destroy microbial cells [2, 3]. Therefore, this proposal aims to investigate plant-derived pigments, specifically chlorophylls and carotenoids, as natural photo-responsive PSs in APDT ([4,5,6]. These pigments, absorbing in visible and near-infrared (NIR) ranges, will be extracted, characterized, and evaluated for their antimicrobial efficacy against AMR pathogens. The project also seeks to enhance APDT activity against Gram-negative bacteria and yeast, which traditionally show resistance due to membrane permeability barriers [7]. The rationale of the proposal is a comprehensive study of pigment extraction, photophysical analysis, antimicrobial assays, and mechanistic evaluations that will contribute to the development of novel, eco-friendly, and effective APDT strategies. This approach builds upon early photodynamic discoveries and aims to offer modern, sustainable solutions to combat AMR [8,9]. [1] Polat, E., & Kang, K. (2021). Natural Photosensitizers in Antimicrobial Photodynamic Therapy. Biomedicines. [2] Diogo, P., et al (2019). An Insight into Advanced Approaches for Photosensitizer Optimization in Endodontics—A Critical Review. J. Funct. Biomater. [3] Evan Austin, et al (2025). Photodynamic Therapy: Overview and Mechanism of Action. JAAD. [4] Suvorov, N., et al (2021). Derivatives of natural chlorophylls as agents for antimicrobial photodynamic therapy. Int. J. Mol. Sci. [5] Mikulich, A. V., et al (2024). Potential of using medicinal plant extracts as photosensitizers for antimicrobial photodynamic therapy. J Photochem Photobiol [6] Kustov, A. V., et al (2018). Synthesis and investigation of water-soluble chlorophyll pigments for antimicrobial photodynamic therapy. Dyes and Pigments. [7] Correia, J. H., et al (2021). Photodynamic Therapy Review: Principles, Photosensitizers, Applications, and Future Directions. Pharmaceutics [8] Daniell, M. D., & Hill, J. S. (1991). A history of photodynamic therapy. ANZ J. Surg [9] Akansha. M, et al (2023). Photodynamic therapy for ESKAPE pathogens: An emerging approach to combat antimicrobial resistance (AMR). Microb. Pathog.