Abstract / Summary
Introduction: Stimulating collagen production is a key strategy for enhancing skin vitality and counteracting aging. However, current methods to boost collagen synthesis often entail pain and tissue trauma. There is a compelling need for painless, non-invasive approaches to effectively increase skin collagen. Objectives: To investigate the effects of mid-infrared modulation (MIMO) on skin collagen deposition across multiple biological scales, from human and animal models in vivo to human dermal fibroblasts in vitro. Methods: We determined optimal MIMO irradiation parameters (energy, duration) in human and animal skin. Effects on collagen deposition were evaluated in vivo (human, mouse) and in vitro (human dermal fibroblasts). Levels of inflammatory and collagen metabolism-related proteins were measured by ELISA. Results: MIMO irradiation (70 mW/cm 2 ) significantly enhanced collagen deposition in human and mouse skin in vivo without causing excessive heating. This was associated with downregulation of the collagen-degrading enzyme MMP-1 and upregulation of collagen synthesis-promoting factors (TGF-β, HSP47, HSP70) in mouse skin. Furthermore, MIMO stimulated the secretion of multiple collagen subtypes in human dermal fibroblasts in vitro. Conclusions: MIMO represents a safe, non-invasive, and painless approach for effectively enhancing skin collagen deposition in vivo .