title: An ex vivo study of photobiostimulation in the treatment of skin pathologies.
abstract: Photodynamic therapy (PDT) and low level laser therapy (LLLT) may mutually improve the outcomes on the healing process of chronic wounds and other skin pathologies, through processes known to stimulate the proliferation of dermal cellular structures, as well as antimicrobial application. This study proposes the use of nanoemulsion containing aluminium phthalocyanine chloride (ClAlPc) as photosensitizer (PS), to establish the most appropriate protocol for photostimulation in human skin biopsies, associated to type I collagen and elastin production. The combined effect of PS and light (diode laser at 670 nm) at three different doses is compared to the effect of light itself at doses of 70, 140 and 700 mJ ċ cm-2, 7 and 14 days after irradiation. Histological analysis reveals the increase in collagen and elastin, higher than 20%, 14 days after treatment with PS and light at 140 mJ ċ cm-2. Higher doses of light promote an inhibitory effect, leading to tissue degradation. In addition, the expression levels of the enzymes MMP-2 and MMP-9 (Gelatinases A and B - participant in various processes including tumoral progression and wound healing) are detected by gelatin zymography, reinforcing the efficacy of the combined treatment with PS and light at the intermediate dose.
authors.affiliation: Department of Chemistry, Center of Nanotechnology, Tissue Engineering and Photoprocesses, University of Sao Paulo, 14040-901, Ribeirao Preto, Sao Paulo, Brazil.
authors.forename: Priscila da Costa C
authors.initials: PD
authors.lastname: de Jesus
authors.affiliation: Department of Chemistry, Center of Nanotechnology, Tissue Engineering and Photoprocesses, University of Sao Paulo, 14040-901, Ribeirao Preto, Sao Paulo, Brazil.
authors.forename: Sabrina Ikeda N
authors.initials: SI
authors.lastname: Saeki
authors.affiliation: Department of Chemistry, Center of Nanotechnology, Tissue Engineering and Photoprocesses, University of Sao Paulo, 14040-901, Ribeirao Preto, Sao Paulo, Brazil.
authors.forename: Antonio Claudio
authors.initials: AC
authors.lastname: Tedesco
mesh_terms: D024042:Collagen Type I / Q000096:biosynthesis; D004549:Elastin / Q000096:biosynthesis; D006801:Humans; D066298:In Vitro Techniques; D028022:Low-Level Light Therapy; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D012867:Skin / Q000473:pathology* / Q000528:radiation effects*; D014945:Wound Healing
chemical_list: D024042:Collagen Type I; D017319:Photosensitizing Agents; D004549:Elastin; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9
keywords: laser; nanoemulsion; photobiostimulation; phthalocyanine; skin