Low-power NIR-mediated photothermal and photodynamic therapy as a synergistic strategy against superbugs

Antibiotic resistance is overburdening the health crisis around the globe. Misuse or overuse of antibiotics is one of the reasons for this issue. Therefore, it urges an alternative treatment strategy that can overcome the issue of bacteria being resistant. Photothermal and photodynamic therapies are emerging strategies, being an antibiotic-free solution to treat infections. This method utilizes antimicrobial treatment with heat and ROS, which makes it challenging for bacteria to become resistant. Earlier photothermal therapies required high-power laser sources, which had a significant risk of damaging healthy tissues in the vicinity. Recent research has shown that low-power NIR sources have great potential to achieve equivalent photothermal conversion efficiency when used with different sets of engineered photothermal agents and are also safe for use. A synergistic, low-power antimicrobial strategy combining the photodynamic properties and photothermal properties of the materials results in better efficiency. Additionally, leveraging the NIR-II range allows for deeper penetration into tissues, making it effective to treat deep-seated infections. This review highlights recent advancements in low-power NIR mediated PTT/PDT for mitigating drug-resistant bacteria, focusing on mechanisms, therapeutic outcomes, challenges, and future prospects.