An Update on Photodynamic Therapy of Psoriasis-Current Strategies and Nanotechnology as a Future Perspective

Abstract

Psoriasis (PS) is an immune-mediated skin disease with substantial negative effects on patient quality of life. Despite significant progress in the development of novel treatment options over the past few decades, a high percentage of patients with psoriasis remain undertreated and require new medications with superior long-term efficacy and safety. One of the most promising treatment options against psoriatic lesions is a form of phototherapy known as photodynamic therapy (PDT), which involves either the systemic or local application of a cell-targeting photosensitizing compound, followed by selective illumination of the lesion with visible light. However, the effectiveness of clinically incorporated photosensitizers in psoriasis treatment is limited, and adverse effects such as pain or burning sensations are frequently reported. In this study, we performed a literature review and attempted to provide a pooled estimate of the efficacy and short-term safety of targeted PDT in the treatment of psoriasis. Despite some encouraging results, PDT remains clinically underutilized. This highlights the need for further studies that will aim to evaluate the efficacy of a wider spectrum of photosensitizers and the potential of nanotechnology in psoriasis treatment.

Keywords: PDT; nanotechnology; photodynamic therapy; psoriasis.

Figure 1

The role of ALA-PDT in psoriasis treatment. Aminolevulinic acid (ALA) is metabolized by cells into protoporphyrin IX (PpIX), which may be subsequently activated by visible light. The effects of ALA-PDT on a psoriasis model and the affected genes have been summarized.

Figure 2

Diagram showing the use of analyzed nanocarriers in psoriasis treatment. Nanocarriers were classified by various studies reporting their use in PDT-based psoriasis treatment and studies proving their great potential in the treatment of other skin diseases.