Application And Mechanism Of Combination Therapy Based On Microneedle Fractional Radiofrequency In Facial Rejuvenation

Research background and purposeLong-term exposure to solar ultraviolet(UV)radiation is the main factor of skin aging,which is called skin photoaging,accounting for about 80% of facial aging.Photoaging is characterized by facial wrinkles,telangiectasia,color disorders,relaxation and rough texture,which affects patients’ facial beauty,and has a negative impact on patients’ self-confidence and quality of life.At present,there are a variety of treatments for facial rejuvenation treatment,including anti-photoaging drugs,chemical exfoliators,physiotherapy and injection fillers.With the increasing demand for medical cosmetology,exploring more effective methods of facial rejuvenation has become a hot topic of dermatology research,and the combined application of different treatment methods brings more possibilities for patients and dermatologists.Microneedle fractional radiofrequency(MFR),a minimally invasive treatment,has been rapidly developed in recent years.This treatment induces the production of new collagens via mechanically creating perforations in the epidermis and directly delivering radiofrequencygenerated thermal energy into the underlying dermis.At the same time,the mechanical effects of microneedles on the skin also improve transcutaneous absorption of topical products,and promote secretion of growth factors to stimulate migration and proliferation of adjacent keratinocytes and fibroblast for skin remodeling.Nowadays it has been widely used in the treatment of skin rejuvenation,acne vulgaris,scars,and more.Supramolecular salicylic acid(SSA)is a widely used chemical skin rejuvenation agent in clinic,and both of them have positive therapeutic effects on photoaging.However,there is still a lack of research on the combination of MFR and SSA in the treatment of photoaging.Meanwhile,botulinum toxin type A(BoNT/A)is one of the most widely used biological toxin in clinical practice,and it is the most effective non-surgical treatment for improving facial dynamic wrinkles.The combination of MFR and BoNT/A has been widely used in the treatment of facial rejuvenation,and good results have been obtained.But the optimal strategy for combining these two treatments is elusive,and people hold different views on whether the energy of MFR affects the activity of botulinum toxin.In summary,in order to explore a more safe and efficient method for facial rejuvenation and provide a strong theoretical support for clinical work,this study first compared the clinical efficacy of MFR combined with SSA and MFR alone in the treatment of facial photoaging.Then,the clinical efficacy of several common strategies of MFR combined with BoNT/A for periorbital wrinkles was retrospectively analyzed.Finally,the effect of MFR on botulinum toxin activity was further verified in the mouse model.Research method1.A total of 30 patients with moderate facial photoaging in the Department of Dermatology,the First Affiliated Hospital(Southwest Hospital)of Army Medical University,who met the inclusion and exclusion criteria from June,2021 to March,2022 were collected.They were randomly divided into the MFR + SSA group and the MFR group.The MFR +SSA group was treated with MFR combined with SSA,and the MFR group was treated with MFR alone.The patients were followed up 3 days,7 days,14 days,28 days and 3 months after treatment.The results of VISIA,skin physiology and patient satisfaction were used to evaluate the clinical efficacy of the two groups after treatment.2.A total of 45 females with moderate-to-severe periorbital wrinkles were selected by retrospectively assessing medical records at the Department of Dermatology,the First Affiliated Hospital(Southwest Hospital)of Army Medical University.They were divided into3 groups according to the different treatment methods and intervals.including the BoNT/A group(BoNT/A injection alone),the MFR + BoNT/A(immediately)group(BoNT/A was injected immediately after MFR treatment)and the MFR + BoNT/A(interval of 7-day)group(BoNT/A was injected 7 days apart after MFR treatment).The clinical efficacy of each group was compared by evaluating the improvement of periorbital wrinkles and patient satisfaction before and after treatment.3.To establish the mouse model of MFR combined with BoNT/A at different time intervals,and to evaluate the expression of muscle strength,muscle mass,muscle nutrition markers and important cytokines at neuromuscular junction(NMJ)after treatment.Research result1.After treatment,the skin pores,brown spots,porphyrin,skin physiological status,elasticity,epidermal thickness,skin color improvement and patients’ satisfaction in the MFR+SSA group were significantly superior than those in the MFR group,and the differences were statistically significant(P<0.05).No adverse hyperpigmentation events were reported in either group after treatment.2.All patients in each group had high satisfaction.The MFR + BoNT/A(immediately)group could improve dynamic wrinkles,but the effect was not as good as that of the BoNT/A group and the MFR + BoNT/A(interval of 7-day)group(P<0.05).3.The results of mouse model showed that all BoNT/A groups induced different degrees of muscle paralysis in vivo,but the paralytic effect induced by the BoNT/A group,MFR + BoNT/A(interval of 3-day)group and MFR + BoNT/A(interval of 7-day)group were higher than others,and the expression levels of muscle nutrition markers and NMJ related cytokines were significantly up-regulated.Conclusion1.The combination of MFR and SSA in the treatment of facial photoaging has definite clinical effect and high safety,which is worthy of clinical application.2.The combination of MFR and BoNT/A has more significant clinical effect when the treatment interval is 3 and 7 days,and it is recommended that the combined application should be at least 3 days apart.3.MFR therapy has a certain reduction effect on the activity of BoNT/A in a short period of time,and this reduction effect would last for about 3 days after MFR treatment.