Stem Cell-Derived Exosomes: A New Method for Reversing Skin Aging.

Senescence is an inevitable natural life process that involves structural and functional degeneration of tissues and organs. Recently, the process of skin aging has attracted much attention. Determining a means to delay or even reverse skin aging has become a research hotspot in medical cosmetology and anti-aging. Dysfunction in the epidermis and fibroblasts and changes in the composition and content of the extracellular matrix are common pathophysiological manifestations of skin aging. Reactive oxygen species and matrix metalloproteinases play essential roles in this process. Stem cells are pluripotent cells that possess self-replication abilities and can differentiate into multiple functional cells under certain conditions. These cells also possess a strong ability to facilitate tissue repair and regeneration. Stem cell transplantation has the potential for application in anti-aging therapy. Increasing studies have demonstrated that stem cells perform functions through paracrine processes, particularly those involving exosomes. Exosomes are nano-vesicular substances secreted by stem cells that participate in cell-to-cell communication by transporting their contents into target cells. In this chapter, the biological characteristics of exosomes were reviewed, including their effects on extracellular matrix formation, epidermal cell function, fibroblast function and antioxidation. Exosomes derived from stem cells may provide a new means to reverse skin aging.

UVA1 vs. narrowband UVB phototherapy in the treatment of palmoplantar pustulosis: a pilot randomized controlled study.

UVA1 phototherapy, a new therapeutic approach, has recently been shown good efficacy in the treatment of palmoplantar pustulosis (PPP). The purpose of this study was to compare the efficacy of UVA1 and narrowband UVB (NB-UVB) therapy in the treatment of PPP. Patients with PPP were randomly assigned to either UVA1 or NB-UVB therapy according to a left-right randomization table. Both treatments were performed three times weekly for up to 30 sessions. Clinical evaluation was based on the Palmoplantar Pustular Psoriasis Area and Severity Index (PPPASI) score. Totally 64 patients completed the study. Both UVA1 and NB-UVB therapy showed a statistically significant reduction of PPPASI score compared with the baseline value at the end of the treatment period (P < 0.05). There was a significantly greater mean reduction of PPPASI score in the UVA1 treated group when compared to the NB-UVB treated patients at 30 sessions (6.0 ± 2.4 vs. 4.4 ± 1.4, P < 0.05). No phototoxic reaction or bullous changes were observed in either group. Both NB-UVB and UVA1 phototherapy of PPP resulted in significant improvement. UVA1 phototherapy was more effective than NB-UVB irradiation in the treatment of PPP.