Microneedle Fractional Radiofrequency Associated With Drug Delivery For Atrophic Acne Scars And Facial Rejuvenation

Background: Microneedle fractional radiofrequency（MFRF）is a novel skin cosmetic device.The technique is based on selective electrothermolysis that can stimulate skin collagen denaturation,contraction,remodeling,and regeneration.The combination of MFRF and drug delivery may reduce the adverse effects and optimize the therapy efficacy.Basic fibroblast growth factor（b FGF）can promote skin repair,vascular regeneration,and cell proliferation.The randomized controlled study of MFRF combined with b FGF for atrophic acne scars and skin rejuvenation has rarely been conducted.Besides,reflective confocal microscopy（RCM）has been proved to observe the changes in skin collagen before and after treatment,which is potentially helpful to evaluate the improvement of acne atrophic scar and skin rejuvenation.This study aimed to verify the effectiveness and safety of MFRF for acne atrophic scar and facial rejuvenation in the Chinese population.In addition,this study compared the efficacy and adverse reactions between MFRF combined with b FGF and MFRF alone and explored the changes of dermal fiber compositions in RCM imaging before and after combination therapy.Methods: Thirty subjects were recruited and were randomly divided into a combination therapy group（MFRF + b FGF）and a monotherapy group（MFRF + saline）.The treatment protocol included three sessions with 1-month intervals and a thereafter,a 3-month follow-up.The photographs of the two groups before treatment,after three-sessions treatment,and during the follow-up period after treatment were taken for archiving.The Global Aesthetic Improvement Scale（GAIS）and ECCA Grading Scale were used to evaluate the improvement of facial rejuvenation and atrophic acne scar.The occurrence of adverse reactions and the duration of downtime were recorded,and the subjects were evaluated with a five-level satisfaction score.Finally,the changes of skin tissue in the combined treatment group were observed by RCM.The data were entered into statistical software for analysis.Results: All 30 subjects completed treatment and follow-up period.After three treatments,the mean GAIS score of the combination therapy group was higher than that of the monotherapy group（P < 0.05）.There were no significant differences in the distribution of the mean GAIS scores in the follow-up period between the two groups（P > 0.05）.Before and after treatment,the mean ECCA score of both the combination therapy group and the monotherapy group decreased（P < 0.05）.After three treatment sessions,the mean ECCA score of the combination therapy group decreased more than that of the monotherapy therapy group,and the difference was statistically significant（P < 0.05）.The mean satisfaction score of the combination therapy group was significantly higher than that of the monotherapy group（P < 0.05）.The mean downtime in the combination therapy group was 2.40 ± 1.06 days and in the monotherapy group was 4.07 ± 1.39 days.There was a significant difference in downtime distribution between the two groups（P =0.001）.Some subjects of the two groups had mild adverse reactions after treatment such as scab,scaling,erythema,etc.In RCM imaging,the fiber types were mainly coarse collagen before the combination therapy group.After three-sessions treatment,the dominant fiber types changed to parallel,thin,reticulated collagen.Conclusions: MFRF can be an effective and safe method for acne scars and facial rejuvenation.Compared to using MFRF alone,the combination of MFRF and b FGF can improve the therapeutic effect for acne scars,especially newly formed scars.Combination therapy can shorten the downtime,reduce the side effects,and improve patient satisfaction in the short term.In addition,noninvasive RCM in evaluating cosmetic efficacy has a specific role since RCM imaging suggests that combination therapy can effectively promote the proliferation and remodeling of collagen fibers,which is worthy of further research.