Study Of The Damage Effect Of Topical Photodynamic Therapy On Normal Skin Tissue Of Nude Mice After Pretreatment With Calcipotriol Ointment

Part 1 Study of calcipotriol effect on PpIX content after 5-aminolevulinic acid used on normal skin tissue of the nude miceObjective: to investigate the effect of 5-aminolevulinic acid(5-ALA)on the production of protoporphyrin IX(PpIX)in the normal skin tissue of nude mice after the pretreatment with calcipotriol.Methods: The nude mice were divided into ALA group and calcipotriol(CAL)combined with ALA group,CAL group and blank control group.CAL combined with ALA group was pretreatmented with calcipotriol for external use only 3 days in advance,after which the first two groups were treated with ALA topically.The localization of PpIX in normal skin tissue of nude mice was observed under inverted fluorescent contrast phase microscope,and the fluorescence intensity of PpIX was calculated by fluorospectro photometer at different time points.Results: PpIX produced after absorption of ALA increased gradually with time in nude mice tissues.ALA group reached a peak at 5h,peaked at 6h in CAL+ALA group.PpIX content in CAL+ALA group was significantly higher at 5,6,7 hours than that in ALA group(all P<0.05).Frozen sections showed that PpIX localized in the epidermis and dermis,the fluorescence intensity of group CAL+ALA is higher than that of ALA group at 4-7 hours.Conclusions: CAL pretreatment could increase the content of PpIX in the normal skin tissue of nude mice after ALA,which provided a theoretical basis for the clinical application of CAL as a local synergist of ALA-PDT.Part 2 Study of the damage effect of topical photodynamic therapy on the normal skin tissue of nude mice after pretreatment with calcipotriol ointmentObjective: This experiment based on the above results further study on the damage effect of calcipotriol ointment combined with topical ALA-PDT on normal skin tissues in nude mice to determine whether calcipotriol ointment pretreatment can enhance the effect of PDT,which provide a theoretical basis for clinical treatment.Methods: Nude mice were used as experimental subjects,and 42 nude mice were randomly divided into 3 groups.Group A: ALA-PDT group,18 nude mice;group B: CAL combined with ALA-PDT group,18 nude mice;Group C: only light group,6 nude mice.The morphological changes of the nude mice were observed on the 1-7 days after the experiment and the histopathological changes were observed at 24 h,7d and 14 d.Results: The experiment area of group A nude mouse skin appeard different level of erythema,no crusts.Group B nude mouse skin appeard crusts and even scabs on the basis of erythema.Under the microscope,the epidermis and dermis of the two group showed nuclear damage and necrosis,increased fibrosis,reduced capillary,etc.Group B were significantly higher than group A.And the dermis thickness of group B was greater than that of group A.Conclusions: Compared with ALA-PDT group,Calcipotriol Ointment combined with ALA-PDT group had more obvious damage effect on normal skin tissue of nude mice.