Femtosecond pulsed laser photodynamic therapy activates melanin and eradicates malignant melanoma.

ABSTRACT: Photodynamic therapy (PDT) relies on a series of photophysical and photochemical reactions leading to cell death. While effective for various cancers, PDT has been less successful in treating pigmented melanoma due to high light absorption by melanin. Here, this limitation is addressed by 2-photon excitation of the photosensitizer (2p-PDT) using ~100 fs pulses of near-infrared laser light. A critical role of melanin in enabling rather than hindering 2p-PDT is elucidated using pigmented and non-pigmented murine melanoma clonal cell lines in vitro. The photocytotoxicities were compared between a clinical photosensitizer (Visudyne) and a porphyrin dimer (Oxdime) with ~600-fold higher σ_2p value. Unexpectedly, while the 1p-PDT responses are similar in both cell lines, 2p activation i

SUBMITTER: Pires L 

PROVIDER: S-EPMC10998568 | biostudies-literature | 2024 Apr

REPOSITORIES: biostudies-literature