Exosome-Based Therapies for Skin Aging: Sources, Mechanisms, and Evidence from Preclinical and Clinical Studies.

Skin aging is an inevitable physiological process co-driven by endogenous genetic programs and exogenous environmental factors, characterized by the progressive deterioration of skin structure and function, which manifests as wrinkles, sagging, pigmentation, and impaired barrier function. Extracellular vesicles, particularly exosomes, are nanoscale membranous vesicles actively secreted by cells, functioning as pivotal mediators of intercellular communication through the transport of diverse bioactive molecules. Exosomes derived from diverse sources, including mesenchymal stem cells, somatic cells, plants, milk, and plasma, can effectively reverse skin aging through multiple mechanisms, such as alleviating oxidative damage, promoting collagen synthesis, inhibiting excessive expression of matrix metalloproteinases (MMPs), clearing senescent cells, and improving mitochondrial function. Additionally, engineering modifications and optimized delivery systems can further enhance the targeting ability and synergistic therapeutic efficacy of exosomes. However, the clinical application of exosomes remains constrained by exosome heterogeneity, the lack of standardized isolation and production methods, limited delivery efficiency, and insufficient long-term clinical evidence regarding safety and efficacy. This review systematically summarizes the fundamental research, mechanisms, and clinical evidence of exosomes in combating skin aging. We comprehensively explore the application prospects and challenges, emphasizing the significant values of different exosomes in combating skin aging.