Liquid-Crystalline Nanodispersions Containing Monoolein for Photodynamic Therapy of Skin Diseases: A Mini-Review

Background: Photodynamic therapy is an approach in which a photosensitizer is activated by light for treatment of diseases such as skin cancer and psoriasis. Because photo irradiation is applied only in the disease area, photodynamic therapy offers the possibility of decreased side effects and good cosmetic results, with consequent better patient compliance with the treatment, thus enhancing the therapeutic outcome. For successful topical photodynamic therapy, the photosensitizer must be able to penetrate into the skin and pass through the stratum corneum barrier which controls the entry of molecules. For enhanced transdermal delivery, nanoparticles have been evaluated as carriers of drugs, including photosensitizers. Methods: In this work, we have developed a review article from structured search of bibliographic databases using a focused in vivo and in vitro use of liquid crystalline nanodispersions based on monoolein, an effective penetration enhancer, to improve photodynamic therapy efficacy. Results: Emphasis is given to photodynamic therapy principles and photosensitizers of different classes which have been loaded into liquid crystalline nanodispersions of different structures. A conceptual framework for understanding the improved photosensitizer skin penetration from monoolein is demonstrated. The main components and characterization techniques of the nanodispersions systems containing different photosensitizer and mechanisms of obtaining each system are discussed as well the components that influence the formation of its internal structure. Finally, a summary of major in vitro and in vivo findings on these nanodispersions in the field of topical photodynamic therapy is discussed. Conclusion: This article briefly outlined recent advances in the field of liquid crystallines nanodispersions based on monoolein. The results demonstrate that their applications on photodynamic therapy of skin diseases are highly effective due to their role on increasing photosensitizer skin uptake without causing healthy cells cytotoxicity. These characteristics make them excellent nanostructured systems potentially applicable for non melanoma cancer and recurrent basal cell carcinoma therapy.