Comparative Efficacy of hUCMSC-Secretome Delivered Via Microneedling and Intradermal Microinjection as Adjuvant Therapy to NB-UVB in Nonsegmental Vitiligo: A Quasi-Experimental Study

The goal of this clinical trial is to analyze the effectiveness of SM-hUCMSC secretome administered via microneedling and intradermal microinjection as adjuvant therapy to NB-UVB, compared with NB-UVB alone, in terms of repigmentation, onset of improvement, safety, patient satisfaction, and vitiligo recurrence. The main questions it aims to answer are: * Are there differences in the level of vitiligo lesion repigmentation among the secretome therapy via microneedling, intradermal microinjection, and NB-UVB phototherapy groups? * Are there differences in the time to onset of repigmentation among the treatment groups? What are the safety profiles and adverse events associated with each treatment modality? * Are there differences in patient satisfaction and quality of life after undergoing each therapy? * Are there differences in vitiligo recurrence rates during the follow-up period among the treatment groups? Participants will be allocated into three groups as follows: * Group A receives NB-UVB combined with microneedling and topical 10% secretome. * Group B receives NB-UVB combined with intradermal secretome injection. * Group C receives NB-UVB alone. The intervention period lasts 12 weeks, with follow-up until week 24.