Study Of The Treatment Of Melasma By Stem Cell-Derived Exosomes And Its Transdermal Permeation

Background: As one of the refractory skin diseases,melasma is characterized by complex pathogenesis and difficult treatment.However,recent studies have found that human umbilical cord mesenchymal stem cell exsomes(h UCMSC-Exos)have regenerative,repair,anti-inflammatory,anti-oxidative and whitening effects,which is expected to treat melasma from the root.However,in order to make h UCMSC-Exos permeate to melasma lesions through the skin,it is necessary to overcome the barrier effect of skin barrier,and to explore the means to promote h UCMSC-Exos permeation through skin without changing the properties and efficacy,which has become a major problem.Objective: To explore the effect of 1565 nm nonablative fractional laser and blue aurora sumin master on promoting the transdermal penetration of h UCMSC-Exos,and to compare it with microneedle.At the same time,study the safety and effectiveness of1565 nm nonablative fractional laser、blue auroras、microneedles combines with h UCMSC-Exos in the treatment of melasma.Methods: 1、The preparation of h UCMSC-Exos:Human umbilical cord mesenchymal stem cells(h UCMSCs)were isolated and purified from human umbilical cord tissue and identified by morphology,cell surface markers,and multidimensional differentiation ability of stem cells.Exosomes derived from human umbilical cord mesenchymal stem cells were isolated and purified by serum-free conditional medium,and identified by electron microscopy,NTA and nanometer flow.2、Study on the effect of penetration enhancer in animal model:SD rats were anaesthetized and divided into 4 groups: blank,1565 nm nonablative fractional laser,blue auroras,microneedles treatment combined with h UCMSC-Exos.Rats’ skins were taken 2 and 4 hours after applying h UCMSC-Exos,respectively,and the results were observed under laser scanning confocal microscope in real-time,and frozen sections were made and observed under inverted fluorescence microscope.3、clinical study:Eighty patients receiving melasma treatment in our department were selected,and after informed consent,they were divided into 1565 nm nonablative fractional laser treatment group(group A),microneedles +h UCMSC-Exos treatment group(group B),1565 nm nonablative fractional laser+h UCMSC-Exos treatment group(group C),blue auroras+h UCMSC-Exos treatment group(group D),each with 20 cases.A course of treatment was 4 times,with an interval of 1 month.The therapeutic effect was observed at 1,2,3 and 4 months after treatment.Pain degree immediately after treatment,MASI score,improvement rate,satisfaction and complications after treatment 4 months were counted.Results: 1.The h UCMSCs was identified as mesenchymal stem cells by morphological observation,flow cytometry,adipoblast and osteoblast differentiation.The extracted umbilical cord mesenchymal stem cell-derived exosomes were observed by electron microscope,NTA and nanometer flow.2.Under laser scanning confocal microscope and fluorescence microscope,the fluorescently labeled exosomes in the three treatment groups all penetrated into the dermis,and the fluorescence signals penetrated deeper at4 h than at 2h,and dispersed to the surrounding areas.Fluorescence signals in the untreated group were mainly concentrated in the superficial layer and failed to penetrate into the deep skin.3.The treatment of melasma by 1565 nm nonablative fractional laser,blue auroras,microneedles combined with h UCMSC-Exos was significantly improved(P<0.05),No recurrence was observed during the follow-up period.The therapeutic effect and patient satisfaction were better than that of 1565 nm nonablative fractional laser therapy alone,and the difference was statistically significant(P<0.05).1565 nm nonablative fractional laser and blue auroras combined with h UCMSC-Exos had no significant difference in therapeutic effect and patient satisfaction compared with the microneedles intervention group(P > 0.05).The pain degree of the microneedles intervention group was higher than that of the other three groups(P<0.05),Patients had better experience in the process of blue auroras treatment.Conclusion: 1565 nm nonablative fractional laser and blue auroras can achieve a good effect on promoting the percutaneous penetration of exosomes and can effectively improve the symptoms of melasma when combined with h UCMSC-Exos,compared with microneedles which is the traditional penetration promotion method,shows no statistical difference,which is worthy of clinical application and promotion.Compared with microneedles,they can achieve no bleeding,low pain and promote drug penetration on the basis of their own therapeutic effect,which complements each other.