title: Electric field-enhanced activation of hematoporphyrin derivative: effects on a human tumour cell line.
abstract: In a recent report we described the effects of combined electroactivation and photoactivation of hematoporphyrin derivative (HPD) on human erythrocytes and established that activation-induced cell lysis was more pronounced when both modes of activation were sequentially applied to the system. Here we demonstrate that electric field-induced activation of HPD-treated HeLa cells results in cell death. This effect is shown to be dependant on both electric field strength and on HPD concentration. In addition, we demonstrate that exposure of HPD-treated cells to short and intense electric pulses prior to photoactivation, results in increased cell mortality. The results confirm our earlier suggestion that HPD may be activated in the presence of an applied electric field. The results further suggest that activation of photosensitizers using combined exposure to electric fields and light may play an important role in increasing the efficiency of photodynamic therapy (PDT) in the treatment of cancer.
authors.affiliation: School of Applied Biological and Chemical Sciences, University of Ulster, Coleraine, UK.
authors.forename: T
authors.initials: T
authors.lastname: Ward
authors.forename: D
authors.initials: D
authors.lastname: Mooney
authors.forename: G
authors.initials: G
authors.lastname: Flynn
authors.forename: A P
authors.initials: AP
authors.lastname: McHale
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004599:Electric Stimulation Therapy / Q000379:methods*; D006367:HeLa Cells; D006415:Hematoporphyrins / Q000494:pharmacology*; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy; D010778:Photochemotherapy / Q000379:methods*
chemical_list: D006415:Hematoporphyrins