title: Evidence of 5-aminolevulinic acid (ALA) penetration increase due to microdrilling in soft tissue using femtosecond laser ablation.
abstract: Photodynamic therapy (PDT) is a therapeutic technique mainly applied to the treatment of malignant and pre-malignant lesions, which induces cell death by the combined effect of a photosensitizer, irradiation in a proper wavelength, and molecular oxygen. One of the main limitations of PDT using 5-aminolevulinic acid (ALA) is the superficial volume of treatment, mainly due to the limited penetration of topical photosensitization. In this context, the present study investigates if a laser micromachining producing microchannels on the tissue surface could improve ALA penetration and result in an increase in the treatment depth. The laser micromachining under femtosecond regime was performed on the tissue surface of rat livers. Conventional PDT was applied and the induced depth of necrosis with or without laser micromachining was compared. The results showed an increase of more than 20% in the depth of necrosis when the femtosecond laser micromachining was performed before the treatment with the PDT.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador Sancarlense, 400 Caixa, Postal: 369, São Carlos, SP, Brazil. nicolodelli@ursa.ifsc.usp.br
authors.forename: Gustavo
authors.initials: G
authors.lastname: Nicolodelli
authors.forename: Cristina
authors.initials: C
authors.lastname: Kurachi
authors.forename: Raquel Ferreira
authors.initials: RF
authors.lastname: Rego
authors.forename: Tarek
authors.initials: T
authors.lastname: Omairi
authors.forename: Vanderlei Salvador
authors.initials: VS
authors.lastname: Bagnato
mesh_terms: D000622:Aminolevulinic Acid / Q000493:pharmacokinetics*; D000818:Animals; D053685:Laser Therapy / Q000379:methods*; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D008297:Male; D055616:Microtechnology / Q000379:methods; D023421:Models, Animal; D009336:Necrosis; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D017319:Photosensitizing Agents; D000622:Aminolevulinic Acid