Influence of CaNa2 EDTA on topical 5-aminolaevulinic acid photodynamic therapy.
BACKGROUND
We assessed whether the CaNa2 EDTA could improve the accumulation of protoporphyrin IX (PpIX) and photosensitisation in HEp-2 cells as well as the depth of treatment of skin cancers on the topical 5-Aminolaevulinic acid (5-ALA) PDT.


METHODS
HEp-2 cells were incubated with 5-ALA (0-1 mmol/L) and CaNa2EDTA (0-1 mmol/L) for 4 hours, intracellular protoporphyrin IX content was quantified by extraction, and cell viability was assessed by use of the methyl-tetrazolium (MTT) assay four hours after exposure to light. In comparison with the pictures before and after treatment, depth of treatment could be determined using a Acuson Sequioa 512 phase-array system in paired experiments.


RESULTS
PpIX accumulation increased with increasing extracellular concentrations of ALA (0-1 mmol/L). Adding 1 mmol/L of CaNa2EDTA increased 30% PpIX accumulation over the same period of incubation in the concentration of 1 mmol/L ALA. Significant difference was observed between the 5-ALA alone group and 5-ALA combined CaNa2 EDTA group in the PpIX accumulation (P < 0.01). Cell viability after exposure to light decreased with adding CaNa2 EDTA, a statistical difference in a same fluence above 1.2 J/cm2 between two groups was demonstrated (P < 0.05, P < 0.01 respectively). Depth of treatment of skin cancers were increased in CaNa2 EDTA-treated group.


CONCLUSIONS
CaNa2 EDTA could improve the PpIX accumulation and photosensitisation in HEp-2 cells. Clinically, CaNa2 EDTA could increase the depth of treatment in the cutaneous cancers.
Liu
Hui-feng
HF
Department of Dermatology, Renmin Hospital, Wuhan University, Wuhan 430060, China.
Xu
Shi-zheng
SZ
Zhang
Chun-rong
CR
D000622:Aminolevulinic Acid / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D002470:Cell Survival; D004492:Edetic Acid / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010778:Photochemotherapy; D011524:Protoporphyrins / Q000032:analysis; D012878:Skin Neoplasms / Q000188:drug therapy
D011524:Protoporphyrins; D000622:Aminolevulinic Acid; D004492:Edetic Acid; C028025:protoporphyrin IX