Photodynamic Therapy for the Treatment of Fungal Infections

Abstract

Cutaneous fungal infections are common in humans and are associated with significant physical and psychological distress to patients. Although conventional topical and/or oral anti-fungal medications are commonly recommended treatments, drug resistance has emerged as a significant concern in this patient population, and safer, more efficacious, and cost-effective alternatives are warranted. Recent studies have reported effectiveness of photodynamic therapy (PDT) against fungal infections without severe adverse effects. In this review, we briefly discuss the mechanisms underlying PDT, current progress, adverse effects, and limitations of this treatment in the management of superficial and deep fungal infections.

Keywords: fungal infection; photodynamic therapy; review.

Figure 1

Mechanisms of action of photodynamic therapy. Following light absorption, excited state ³PS* reacts with O₂ to produce ROS and ¹O₂ (type I and II reactions). Type III PSs combine properties leading to the generation of ¹O₂ and reduction of native free radicals in target cells. Type IV mechanism involves a structural change from excited state ¹PS* by photoisomerization to enable molecular target binding of the activated PS* to its cellular target site. (* represents the excited state).