Treatment of cutaneous lichen planus with ALA-mediated topical photodynamic therapy

Purpose:To evaluate the efectiveness of topical 5-aminolevulinie acid(ALA)-mediated pho-todynamic therapy(PDT)for the treatment of cutaneous lichen planus(LP).Methods:A total of 17 symptomatic LP lesions in 7 Chinese patients were assessed.ALA cream(10%)was applied topically to LP lesions for 3h.The lesions were iradiated with a 635 nm diode laser at the dose level of 100J/cm^(2).The treatment was repeated at two week intervals.Clinical assessmnent was conducted before each treatment.Follow-up was performed once a month for up to six months.Results:Lesions showed significant improvement after one to four courses of treatments.Complete response was achieved in 13 lesions(five patients)and partial remission in four lesions(two patients).The complete response rate was 71%.There was no significant side ffects except the feeling of pain that most patients could tolerate.Follow-up of five patients who achieved complete response showed no signs of recurrence.Conclusion:Topical ALA PDT is effective in the treatment of cutaneous LP.

Drug-delivery and multifunction possibilities of hypocrellin photosensitizers

Photodynamic therapy(PDT)has been a routine treatment of tumors and some microvascular diseases,but clinically available photosensitizers are still scarce.Among all kinds of photo-sensitizers,hypocellins possess the most characteristics of ideal photosensitizers,such as,high photo-activity but low dark toxicity,fast clearance from tssues.This review is focused on two main topics,drug-delivery problem of hypocrellins and how the environment-sensitive fluorescence of bypecrellins was used for recognition of various biomolecules.Drug-delivery of hypocrellins was mainly achieved in two strategies一preparing the drugdelivery vehicles and finding quantitatively amphiphilic derivatives.Hypocrellin fAuorescence originated from the intramolecular proton transfer is very distinct from other kinds of photosensitizers.Recently,it was proved that quan-titative hypocrellin ftuorescence could not only reoognize various biomolecules,including proteins,polysaocharides and lipids,but also distinguish the specific binding from nonspedifie binding with some kind of biomolecules.Meantime,hypocrellin fluorescence was pH sensitive.It is known that tumor cells or tses have the features of a large amount of lipid,neonatal collagen,over expression of polysaccharides,and lower pH values compared to normal tissues.According to the relative but not absolute specifcity,further studies on quantitative recognition of various biomolecules at a cellular level,may find a new clue to treat tumors by joint usage of photodynamic diagnosis(PDD)and PDT.