title: A comparative study on the enhancement efficacy of specific and non-specific iron chelators for protoporphyrin IX production and photosensitization in HaCat cells.
abstract: The iron chelators can be utilized in target cells to improve 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT). The purpose of this study is to compare the effect of two kinds of iron chelators, desferrioxamine (DFO) and ethylenediaminetetraacetic acid (EDTA) on the enhancement of ALA-PDT. HaCat cells were cultured in medium containing 2.0 mmol/L of ALA and 0.5 mmol/L of DFO or EDTA. After 3-h incubation in the dark, the concentration of cellular protoporphyrin IX (PpIX) was detected by high performance liquid chromatography (HPLC), and the fluorescence of PpIX was observed at 630 nm emission under confocal laser scanning microscope. For PDT, HaCat cells were irradiated using 632.8 nm laser, and the fractions of apoptotic and necrotic cells were flow cytometrically assayed. Related differences in morphology and ultrastructure of Ha-Cat cells were observed using optical microscope or transmission electron microscope. Compared to incubation with ALA alone, the addition of DFO or EDTA increased the concentration of cellular PpIX and the fluorescent density of PpIX, and also increased cell death ratio after PDT. PDT using ALA plus DFO produced the highest cellular PpIX level, greatest cell death ratio and most severe structural damage to the cells. It was concluded that both DFO and EDTA could enhance ALA-based PpIX production and PDT. Compared to the non-specific iron chelator of EDTA, the specific chelator, DFO, showed more potential for the enhancement.
authors.affiliation: Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan 430060, China. ymxia@whu.edu.cn
authors.forename: Yumin
authors.initials: Y
authors.lastname: Xia
authors.forename: Yingying
authors.initials: Y
authors.lastname: Huang
authors.forename: Longde
authors.initials: L
authors.lastname: Lin
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liu
authors.forename: Shan
authors.initials: S
authors.lastname: Jiang
authors.forename: Layuan
authors.initials: L
authors.lastname: Xiong
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology; D002461:Cell Line, Transformed; D003676:Deferoxamine / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006801:Humans; D007502:Iron Chelating Agents / Q000494:pharmacology*; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D010787:Photosensitivity Disorders / Q000378:metabolism*; D017319:Photosensitizing Agents / Q000494:pharmacology; D011524:Protoporphyrins / Q000096:biosynthesis*
chemical_list: D007502:Iron Chelating Agents; D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; D004492:Edetic Acid; C028025:protoporphyrin IX; D003676:Deferoxamine