title: Comparing the efficacy of photodynamic and sonodynamic therapy in non-melanoma and melanoma skin cancer.
abstract: Sonodynamic therapy (SDT) involves the activation of a non-toxic sensitiser drug using low-intensity ultrasound to produce cytotoxic reactive oxygen species (ROS). Given the low tissue attenuation of ultrasound, SDT provides a significant benefit over the more established photodynamic therapy (PDT) as it enables activation of sensitisers at a greater depth within human tissue. In this manuscript, we compare the efficacy of aminolevulinic acid (ALA) mediated PDT and SDT in a squamous cell carcinoma (A431) cell line as well as the ability of these treatments to reduce the size of A431 ectopic tumours in mice. Similarly, the relative cytotoxic ability of Rose Bengal mediated PDT and SDT was investigated in a B16-melanoma cell line and also in a B16 ectopic tumour model. The results reveal no statistically significant difference in efficacy between ALA mediated PDT or SDT in the non-melanoma model while Rose Bengal mediated SDT was significantly more efficacious than PDT in the melanoma model. This difference in efficacy was, at least in part, attributed to the dark pigmentation of the melanoma cells that effectively filtered the excitation light preventing it from activating the sensitiser while the use of ultrasound circumvented this problem. These results suggest SDT may provide a better outcome than PDT when treating highly pigmented cancerous skin lesions.
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
authors.forename: Conor
authors.initials: C
authors.lastname: McEwan
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
authors.forename: Heather
authors.initials: H
authors.lastname: Nesbitt
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
authors.forename: Dean
authors.initials: D
authors.lastname: Nicholas
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
authors.forename: Oisin N
authors.initials: ON
authors.lastname: Kavanagh
authors.affiliation: Department of Dermatology, Belfast City Hospital, Belfast, Northern Ireland BT9 7AB, UK.
authors.forename: Kevin
authors.initials: K
authors.lastname: McKenna
authors.affiliation: Regional Medical Physics Service, Forster Green Hospital, 110 Saintfield Road, Belfast BT8 8HD, UK.
authors.forename: Philip
authors.initials: P
authors.lastname: Loan
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
authors.forename: Iain G
authors.initials: IG
authors.lastname: Jack
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK. Electronic address: ap.mchale@ulster.ac.uk.
authors.forename: Anthony P
authors.initials: AP
authors.lastname: McHale
authors.affiliation: Biomedical Sciences Research Institute, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK. Electronic address: j.callan@ulster.ac.uk.
authors.forename: John F
authors.initials: JF
authors.lastname: Callan
mesh_terms: D000622:Aminolevulinic Acid / Q000627:therapeutic use*; D000818:Animals; D064593:Heterografts; D006801:Humans; D008545:Melanoma / Q000628:therapy*; D016513:Mice, SCID; D010778:Photochemotherapy; D012878:Skin Neoplasms / Q000628:therapy*; D014464:Ultrasonic Therapy
chemical_list: D000622:Aminolevulinic Acid
keywords: Light; Melanin; Melanoma; PDT; SDT; Squamous cell carcinoma; Ultrasound