Optimization of Photodynamic Therapy Using Negative Pressure
| Autor: | Vanderlei Salvador Bagnato, Michelle Barreto Requena, Priscila Fernanda Campos de Menezes |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
medicine.medical_specialty
medicine.medical_treatment Skin Cream Biomedical Engineering Protoporphyrins Photodynamic therapy chemistry.chemical_compound Negative-pressure wound therapy medicine Humans Radiology Nuclear Medicine and imaging integumentary system Protoporphyrin IX business.industry Background data FLUORESCÊNCIA Aminolevulinic Acid Penetration (firestop) Dermatology Occlusive dressing Photochemotherapy chemistry Skin penetration business Negative-Pressure Wound Therapy |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1557-8550 1549-5418 |
| Popis: | The goal of this study is to demonstrate an alternative procedure to perform topical photodynamic therapy (PDT). Here, we propose the combined use of negative pressure and a 5-Aminolevulinic acid (5-ALA) cream occlusion to increase protoporphyrin IX (PPIX) formation.PDT using topical 5-ALA as a prodrug and precursor of PPIX has been used in the treatment and diagnosis of different types of cancer and skin diseases. The use of 5-ALA offers many advantages as a localized and non-systemic application, but it shows limitations in relation to skin penetration. Many authors have discussed the limitations of 5-ALA penetration through the skin. The skin penetration of 5-ALA can be optimized using mechanical devices associated with typical PDT procedure.For this study, 20% 5-ALA cream was applied to a 9 cm(2) area of skin, and an occlusive dressing was placed. The PPIX production was collected at the skin surface, using fluorescence spectroscopy and widefield fluorescence imaging, for 7 h, and after 24 h.We observed that in the presence of negative pressure therapy, the PPIX production, distribution, and elimination are greater and faster than in the control group. The PPIX formation was ∼30% in deeper skin layers, quantified by fluorescence spectroscopy analysis, and ∼20% in surface skin layers, quantified by widefield fluorescence imaging analysis.Negative pressure induction can also help PDT application in the case of inefficient PPIX production. These results can be useful for optimizing the PDT. |
| Databáze: | OpenAIRE |
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