Organic Conjugated Molecules: Driving Recent Progress in Phototherapeutic Antimicrobial Applications

Most infectious diseases are caused by pathogenic infections, which pose significant threats to human health due to their ubiquitous presence and high transmissibility. While antibiotics initially demonstrated excellent therapeutic effects, their widespread misuse has led to the emergence of drug-resistant pathogens, creating even greater challenges. Conventional therapeutic agents often struggle to balance efficacy with biosafety. Organic conjugated molecules (OCM) have attracted considerable attention owing to their excellent biocompatibility and photophysical properties. This has led to the development of phototherapy, which offers numerous advantages including non-invasiveness, avoidance of drug resistance, low toxicity, and superior therapeutic outcomes. Currently widely applied in biomedical fields, phototherapy has seen numerous design strategies emerging in recent years that have yet to be systematically reviewed. This review comprehensively summarizes the latest research advances over the past five years in OCM design strategies and major phototherapeutic approaches for antimicrobial applications. We categorize and discuss current research achievements according to different phototherapy modalities, with particular focus on treatments for superficial tissue infections (e.g., wound, periodontal, and intraocular infections). Simultaneously, we critically analyze the innovation, limitations, and practical applicability of various studies, while also outlining potential challenges for future development in phototherapy.