[0001] The invention relates to the use of a photosensitive agent, or the precursor thereof, capable of producing reactive oxygen species (ROS) in the production of a drug that can be used for the photodynamic therapy (PDT)-based treatment of a disease related to a patient's stem cells, preferably epidermal stem cells.
1. Use of protoporphyrin IX, or the precursor thereof, capable of producing reactive oxygen species in the production of a drug useful for the photodynamic therapy-based treatment of a disease related to the epidermal stem cells of a subject. 2. Use according to claim 1, wherein said protoporphyrin IX precursor is 5-aminolevulinic acid or the chemical derivatives thereof. 3. Use according to claim 2, wherein said chemical derivative of the 5-aminolevulinic acid is methyl aminolevulinate. 4. Use according to any of claims 1 to 3, wherein said subject is a mammal. 5. Use according to claim 4, wherein said mammal is a human. 6. Use according to any of claims 1 to 5, wherein said disease related to epidermal stem cells is a dermatosis. 7. Use according to claim 6, wherein said dermatosis is a collagen disease. 8. Use according to claim 6, wherein said dermatosis is a hair follicle disease. 9. Use according to claim 8, wherein said hair follicle disease is alopecia. 10. Use according to any of claims 1 to 9, wherein said drug is administered topically. 11. Use of protoporphyrin IX, or the precursor thereof, capable of producing reactive oxygen species and at least another therapeutic agent in the production of a drug useful for the photodynamic therapy-based treatment of a disease related to the epidermal stem cells of a subject. 12. Use of protoporphyrin IX, or the precursor thereof, capable of producing reactive oxygen species for thein vitro activation of epidermal stem cells. 13. Use of protoporphyrin IX, or the precursor thereof, capable of producing reactive oxygen species for thein vitro production of proteins of the prolactin family 2. 14. Use according to claim 13, wherein said protein of the prolactin family 2 is proliferin-2. 15. Use of protoporphyrin IX, or the precursor thereof, capable of producing reactive oxygen species for the generation of dermo-epidermal or epidermal skin equivalents. 16. Cosmetic or pharmaceutical composition comprising a cosmetically or pharmaceutically effective amount of protoporphyrin IX, or the precursor thereof, and at least one cosmetically or pharmaceutically acceptable excipient or adjuvant. 17. A composition according to claim 16, characterized in that said protoporphyrin IX precursor is 5-aminolevulinic acid or the chemical derivatives thereof. 18. A composition according to claim 17, characterized in that said derivative of the 5-aminolevulinic acid is methyl aminolevulinate. 19. A composition according to any of claims 16 to 18, characterized in that said protoporphyrin IX, or the precursor thereof, is incorporated into a cosmetically or pharmaceutically acceptable vehiculization system or into a sustained release system selected from the group consisting of liposomes, mixed liposomes, oleosomes, niosomes, ethosomes, millicapsules, microcapsules, nanocapsules, sponges, cyclodextrins, vesicles, micelles, surfactant mixed micelles, phospholipid-surfactant mixed micelles, millispheres, microspheres, nanospheres, lipospheres, microemulsions, nanoemulsions, miniparticles, milliparticles, microparticles, nanoparticles, lipid solid nanoparticles and nanostructured lipid carriers. 20. A composition according to any of claims 16 to 19, characterized in that it is presented in a formulation selected from the group consisting of creams, multiple emulsions, anhydrous compositions, aqueous dispersions, oils, milks, balms, foams, lotions, gels, cream gels, hydroalcoholic solutions, hydroglycolic solutions, hydrogels, liniments, serums, soaps, shampoos, conditioners, serums, unguents, mousses, ointments, powders, bars, pencils, vaporizers, aerosols, capsules, gelatin capsules, soft capsules, hard capsules, tablets, sugar coated tablets, granulated forms, chewing gums, solutions, suspensions, emulsions, syrups, polysaccharides films, jellies and gelatin. 21. A composition according to any of claims 16 to 20, characterized in that it is incorporated into a product selected from the group consisting of concealers, make-up foundations, cleansing lotions, cleansing milks, eye shadows, lipsticks, lip glosses, lip balms and powders. 22. A composition according to any of claims 16 to 21, characterized in that said protoporphyrin IX, or the precursor thereof, is incorporated into a fabric, nonwoven-fabric or a medical product. 23. A composition according to claim 22, characterized in that said fabric, nonwoven-fabric or medical product is selected from the group consisting of bandages, gauze, shirts, tights, socks, underwear, girdles, gloves, diapers, sanitary napkins, dressings, bedspreads, towels, adhesive patches, non-adhesive patches, occlusive patches, microelectric-patches and face masks. 24. A composition according to any of claims 16 to 23, characterized in that said adjuvant is selected from the group consisting of heat shock proteins, other stimulatory agents of the synthesis of the heat shock proteins, inhibitors of the aggregation of the acetylcholine receptors, inhibitors of muscle contraction, anticholinergic agents, elastase inhibitors, inhibitors of the matrix metalloproteinases, inhibitors or agents stimulating the synthesis of melanin, depigmenting or bleaching agents, propigmenting agents, self-tanning agents, antiaging agents, inhibitors of the NO-synthase, inhibitors of the 5α-reductase, lysyl- and/or prolyl-hydroxylase inhibitors, antioxidants, free radical scavenging and/or anti air pollution agents, reactive carbonyl species scavenging agents, anti-glycation agents, antihistamines, antiviral agents, antiparasitic agents, emulsifiers, emollients, organic solvents, liquid propellants, skin conditioners, humectants, moisture retaining substances, alpha hydroxy acids, beta hydroxy acids, moisturizers, epidermal hydrolytic enzymes, vitamins, amino acids, proteins, pigments or colorants, dyes, gelling polymers, thickeners, surfactants, softeners, anti-wrinkle agents, agents capable of reducing or treating the bags under the eyes, exfoliating agents, antimicrobial agents, antifungal agents, fungistatic agents, bactericidal agents, bacteriostatic agents, agents stimulating the synthesis of dermal or epidermal macromolecules and/or able to inhibit or prevent their degradation, agents stimulating the synthesis of collagen, agents stimulating the synthesis of elastin, agents stimulating the synthesis of decorin, agents stimulating the synthesis of laminin, agents stimulating the synthesis of defensins, agents stimulating the synthesis of aquaporins, agents stimulating the synthesis of hyaluronic acid, agents stimulating the synthesis of fibronectin, agents stimulating the synthesis of sirtuins, agents stimulating the synthesis of lipids and components of the stratum corneum, ceramides, fatty acids, inhibitors of the degradation of collagen, inhibitors of the degradation of elastin, inhibitors of serine proteases such as cathepsin G, agents stimulating the proliferation of fibroblasts, agents stimulating the proliferation of keratinocytes, agents stimulating the proliferation of adipocytes, agents stimulating the proliferation of melanocytes, agents stimulating the differentiation of keratinocytes, agents stimulating the differentiation of adipocytes, inhibitors of the acetylcholinesterase, skin relaxing agents, agents stimulating the synthesis of glycosaminoglycans, anti hyperkeratosis agents, comedolytic agents, anti-psoriasis agents, DNA repairing agents, DNA protecting agents, stabilizers, antipruritic agents, agents for the treatment and/or care of sensitive skin, firming agents, anti-stretch mark agents, astringent agents, agents regulating sebum production, lipolytic agents or agents stimulating lipolysis, anti-cellulite agents, anti-perspirant agents, agents stimulating wound healing, wound healing coadjuvant agents, agents stimulating reepithelialization, reepithelialization coadjuvant agents, cytokine growth factors, soothing agents, anti-inflammatory and/or analgesic agents, anesthetic agents, agents acting on capillary circulation and/or microcirculation, agents stimulating the angiogenesis, inhibitors of the vascular permeability, venotonic agents, agents acting on the metabolism of the cells, agents intended to improve the dermal-epidermal junction, agents inducing hair growth, agents inhibiting or retarding hair growth, agents delaying hair loss, preservatives, perfumes, chelating agents, plant extracts, essential oils, marine extracts, agents coming from a biofermentation process, mineral salts, cell extracts, sunscreens and photoprotective agents of mineral or organic nature active against ultraviolet rays A and/or B, or mixtures thereof. 25. A composition according to claim 24, characterized in that said adjuvant is selected from the group consisting of anti-wrinkle agents and/or anti-aging agents. 26. A composition according to claim 25, characterized in that said anti-wrinkle agents and/or anti-aging agents are selected from the group consisting of Acetyl Hexapeptide-8, Acetyl Heptapeptide-4, Acetyl Octapeptide-3, Pentapeptide-18, Acetyl Hexapeptide-25, Diaminopropionoyl tripeptide-33, Tripeptide-10 Citrulline, Acetyl Tetrapeptide-5, Acetyl Tripeptide-30 Citrulline, Acetyl Tetrapeptide-30, Dimethylmethoxy chromanol, Dimethylmethoxy Chromanyl palmitate, Pseudoalteromonas ferment extract, Ca2+ channel antagonists, retinol and its derivatives, idebenone and its derivatives, Coenzyme Q10 and its derivatives, boswellic acid and its derivatives, GHK and its derivatives and/or salts, carnosine and its derivatives, DNA repair enzymes, chloride channel agonists, the mixture of Hydrolyzed Wheat Protein, Hydrolyzed Soy Protein and Tripeptide-1, the mixture of Lysine HCl, Lecithin and Tripeptide-10 Citrulline and the mixture of Pseudoalteromonas ferment extract, Hydrolyzed Wheat Protein, Hydrolyzed Soy Protein, Tripeptide-10 Citrulline and Tripeptide-1. 27. A composition according to claim 24, characterized in that said adjuvant is selected from the group consisting of agents stimulating wound healing and/or reepithelialization and wound healing and/or reepithelialization coadjuvant agents. 28. A composition according to claim 27, characterized in that said agent stimulating wound healing and/or reepithelialization or wound healing and/or reepithelialization coadjuvant agent is selected from the group consisting of Pseudoalteromonas ferment extract and Tripeptide-10 Citrulline. 29. A composition according to claim 24, characterized in that said adjuvant is selected from the group consisting of agents delaying hair loss or agents inducing hair growth. 30. A composition according to claim 24, characterized in that said adjuvant is selected from the group consisting of sunscreens. 31. A composition according to any of claims 16 to 30, characterized in that said adjuvant is of synthetic origin or is a plant extract or is derived from a biotechnological process or is derived from a combination of a synthetic procedure and a biotechnological process.