Photodynamic therapy improves the ultraviolet-irradiated hairless mice skin

Ana Elisa S. Jorge, Michael R. Hamblin, Nivaldo A. Parizotto, Cristina Kurachi, Vanderlei S. Bagnato

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

2 Citations (Scopus)


Chronic exposure to ultraviolet (UV) sunlight causes premature skin aging. In light of this fact, photodynamic therapy (PDT) is an emerging modality for treating cancer and other skin conditions, however its response on photoaged skin has not been fully illustrated by means of histopathology. For this reason, the aim of this study was analyze whether PDT can play a role on a mouse model of photoaging. Hence, SKH-1 hairless mice were randomly allocated in two groups, UV and UV/PDT. The mice were daily exposed to an UV light source (280-400 nm: peak at 350 nm) for 8 weeks followed by a single PDT session using 20% 5-aminolevulinic acid (ALA) topically. After the proper photosensitizer accumulation within the tissue, a non-coherent red (635 nm) light was performed and, after 14 days, skin samples were excised and processed for light microscopy, and their sections were stained with hematoxylin-eosin (HE) and Massona's Trichrome. As a result, we observed a substantial epidermal thickening and an improvement in dermal collagen density by deposition of new collagen fibers on UV/PDT group. These findings strongly indicate epidermal and dermal restoration, and consequently skin restoration. In conclusion, this study provides suitable evidences that PDT improves the UV-irradiated hairless mice skin, supporting this technique as an efficient treatment for photoaged skin.

Original languageEnglish
Title of host publicationPhotonic Therapeutics and Diagnostics X
ISBN (Print)9780819498397
Publication statusPublished - 2014
Externally publishedYes
EventPhotonic Therapeutics and Diagnostics X - San Francisco, CA, United States
Duration: 1 Feb 20142 Feb 2014

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferencePhotonic Therapeutics and Diagnostics X
Country/TerritoryUnited States
CitySan Francisco, CA


  • Dermal collagen density
  • Epidermal thickening
  • Hairless mice
  • Histopathology
  • Photodynamic therapy
  • UV-irradiated skin

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology, Nuclear Medicine and Imaging


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