Photodamage in deep tissue two-photon optical biopsy of human skin

• Published in: Journal of biophotonics Vol. 8; no. 10; pp. 816 - 825
• Main Authors: Dalbosco, Luca, Zanini, Giulia, D'Amato, Elvira, Tessarolo, Francesco, Boi, Sebastiana, Bauer, Paolo, Haase, Albrecht, Antolini, Renzo
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-10-2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Alterations; Biomechanical Phenomena - radiation effects; biomedical imaging; Biopsy; Biopsy - adverse effects; Cavitation; Damage; Human; Humans; Lasers; Lesions; Molecular Imaging; multiphoton processes; nonlinear microscopy; Optical Phenomena; Photobleaching; photodamage; Photoionization; Photons - adverse effects; Skin - metabolism; Skin - pathology; Skin - radiation effects; skin imaging; Temperature; Thresholds; biomedical imaging; skin imaging; photodamage; multiphoton processes; nonlinear microscopy
• ISSN: 1864-063X; 1864-0648
• DOI: 10.1002/jbio.201400083

Photodamage, induced by femtosecond laser radiation, was studied in thick samples of human skin tissue (healthy skin and neoplastic lesions). Photobleaching, photoionization, and thermomechanical damage effects were characterized comparatively. The laser power dependence of the damage rates allowed to connect macroscopic effects to underlying molecular processes. Optical effects were correlated to histopathological changes. Tissue alterations were found only from thermomechanical cavitation and limited to superficial layers of the epidermis. From the depth‐dependencies of all damage thresholds a depth‐dependent power‐compensation scheme was defined allowing for damage‐free deep tissue optical biopsy.
Damage‐induced luminescence pattern for different excitation powers and a corresponding threshold analysis.
Photodamage was studied in thick samples of human skin tissue (healthy skin and neoplastic lesions). Photobleaching, photoionization, and thermomechanical damage effects were characterized comparatively. The laser power dependence of the damage rates allowed to connect macroscopic effects to underlying molecular processes. Tissue alterations were found only from thermomechanical cavitation and limited to superficial layers of the epidermis. From the depth‐dependencies of all damage thresholds a depth‐dependent power‐compensation scheme was defined allowing for damage‐free deep tissue optical biopsy.