title: In situ production of ROS in the skin by photodynamic therapy as a powerful tool in clinical dermatology.
abstract: Photodynamic therapy (PDT) is a clinical modality of photochemotherapy based on the accumulation of a photosensitizer in target cells and subsequent irradiation of the tissue with light of adequate wavelength promoting reactive oxygen species (ROS) formation and cell death. PDT is used in several medical specialties as an organ-specific therapy for different entities. In this review we focus on the current dermatological procedure of PDT. In the most widely used PDT protocol in dermatology, ROS production occurs by accumulation of the endogenous photosensitizer protoporphyrin IX after treatment with the metabolic precursors 5-methylaminolevulinic acid (MAL) or 5-aminolevulinic acid (ALA). To date, current approved dermatological indications of PDT include actinic keratoses (AK), basal cell carcinoma (BCC) and in situ squamous cell carcinoma (SCC) also known as Bowen disease (BD). With regards to AKs, PDT can also treat the cancerization field carrying an oncogenic risk. In addition, an increasing number of pathologies, such as other skin cancers, infectious, inflammatory or pilosebaceous diseases are being considered as potentially treatable entities with PDT. Besides the known therapeutic properties of PDT, there is a modality used for skin rejuvenation and aesthetic purposes defined as photodynamic photorejuvenation. This technique enables the remodelling of collagen, which in turn prevents and treats photoaging stygmata. Finally we explore a new potential treatment field for PDT determined by the activation of follicular bulge stem cells caused by in situ ROS formation.
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain; Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Fonda-Pascual
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain; Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Oscar M
authors.initials: OM
authors.lastname: Moreno-Arrones
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain; Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Adrian
authors.initials: A
authors.lastname: Alegre-Sanchez
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain; Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Saceda-Corralo
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Buendia-Castaño
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Pindado-Ortega
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Fernandez-Gonzalez
authors.affiliation: Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Kyra
authors.initials: K
authors.lastname: Velazquez-Kennedy
authors.affiliation: Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: María I
authors.initials: MI
authors.lastname: Calvo-Sánchez
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Harto-Castaño
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Bibiana
authors.initials: B
authors.lastname: Perez-Garcia
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain; Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Lorea
authors.initials: L
authors.lastname: Bagazgoitia
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain; Grupo de Dermatología Experimental y Biología Cutánea, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Vaño-Galvan
authors.affiliation: Laboratorio de Bionanotecnolgía, Universidad Bernardo ÓHiggins, Santiago, Chile. Electronic address: jespada@iib.uam.es.
authors.forename: Jesus
authors.initials: J
authors.lastname: Espada
authors.affiliation: Servicio de Dermatología, Hospital Universitario Ramón y Cajal, Madrid, Spain. Electronic address: pedro@pjaen.com.
authors.forename: Pedro
authors.initials: P
authors.lastname: Jaen-Olasolo
mesh_terms: D003880:Dermatology / Q000379:methods / Q000639:trends*; D006801:Humans; D010778:Photochemotherapy; D017319:Photosensitizing Agents; D011524:Protoporphyrins / Q000627:therapeutic use; D017382:Reactive Oxygen Species / Q000302:isolation & purification / Q000378:metabolism*; D012867:Skin / Q000473:pathology / Q000528:radiation effects*; D012871:Skin Diseases / Q000628:therapy
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D017382:Reactive Oxygen Species; C028025:protoporphyrin IX
keywords: Clinical indications; Dermatology; Photorejuvenation; Protoporphyrin-IX; Reactive oxygen species; Tissue regeneration