ABSTRACT
Vitiligo is a common acquired disease of pigment loss. In lesions recalcitrant to non-invasive treatment, transplantation of cultured autologous melanocytes is an emerging choice. Conventionally, the recipient site is often prepared by laser-mediated or mechanical dermabrasion. Such preparation procedures have disadvantages including prolonged transplantation duration, long period for reepithelialization and potential scarring. We propose a method of preparing recipient sites by psoralen and controlled ultraviolet A (PUVA)-induced blistering followed by transplanting suspended melanocytes. We introduced this method in 10 patients with segmental vitiligo on their recipient site 3 to 5 days before transplantation and blistering developed in 2 to 3 days afterwards. On the day of transplantation, the blister roof could be peeled off easily without bleeding and the recipient site preparation could be completed in 20 min. The recipient site became reepithelialized within 1 week. Progressive repigmentation was observed for up to 6 months, with an average of 65.06% repigmentation in the recipient site without scarring at the end of follow-up. Hence, preparation of the recipient site by controlled PUVA-induced sunburn-like blistering can potentially facilitate melanocyte transplantation and prevent scarring.
ABSTRACT
In adult mammals, wound healing predominantly follows a fibrotic pathway, culminating in scar formation. However, cutaneous microwounds generated through fractional photothermolysis, a modality that produces a constellation of microthermal zones, exhibit a markedly different healing trajectory. Our study delineates the cellular attributes of these microthermal zones, underscoring a temporally limited, subclinical inflammatory milieu concomitant with rapid re-epithelialization within 24 hours. This wound closure is facilitated by the activation of genes associated with keratinocyte migration and differentiation. In contrast to macrothermal wounds, which predominantly heal through a robust myofibroblast-mediated collagen deposition, microthermal zones are characterized by absence of wound contraction and feature delayed collagen remodeling, initiating 5-6 weeks after injury. This distinct wound healing is characterized by a rapid re-epithelialization process and a muted inflammatory response, which collectively serve to mitigate excessive myofibroblast activation. Furthermore, we identify an initial reparative phase characterized by a heterogeneous extracellular matrix protein composition, which precedes the delayed collagen remodeling. These findings extend our understanding of cutaneous wound healing and may have significant implications for the optimization of therapeutic strategies aimed at mitigating scar formation.
ABSTRACT
BACKGROUND: Previous studies have reported the benefits of low-level/light laser therapy (LLLT) for the promotion of hair regrowth. However, the effectiveness of LLLT for the treatment of androgenetic alopecia (AGA) is still a topic of debate. OBJECTIVE: To investigate the efficacy and safety of LLLT on hair regrowth in patients with AGA. METHODS: This 24-week, randomized, double-blind, self-comparison, sham device-controlled trial enrolled 100 patients with AGA. All participants were randomly assigned to receive the investigational LLLT on one side of the head and sham light treatment on the contralateral side, 3 times weekly for 30 minutes each, over a 24-week period. Global scalp photography, phototrichogram assessment, the investigator's global assessment (IGA) of hair regrowth, and the subject's assessment of the treatment satisfaction were used for evaluation. RESULTS: After 24 weeks of treatment, the LLLT-treated scalp exhibited significantly greater hair coverage than the sham light-treated side (14.2% vs. 11.8%, p < .001). A significantly greater improvement from baseline in hair thickness, hair count, hair coverage, and IGA were also observed in the LLLT-treated side than in the sham light-treated side at the 12- and 24-week visits. No serious adverse events were observed. CONCLUSION: The use of LLLT might be an effective, safe, well-tolerated treatment for AGA.
