Photobiomodul Photomed Laser Surg. 2026 Oct 12.
25785478261493763
BACKGROUND: Energy-based aesthetic devices alter tissue temperature across defined spatial and temporal distributions, producing biological effects commonly described as collagen contraction, neocollagenesis, elastogenesis, adipocyte injury, or tissue tightening. These clinical labels encompass distinct processes including protein damage, cellular stress adaptation, inflammation, cell death, extracellular matrix turnover, and long-term remodeling. Heat-shock proteins (HSPs) and mammalian cold-shock proteins provide a mechanistic framework for interpreting these responses.
OBJECTIVE: To evaluate the roles of heat- and cold-responsive proteins in energy-based aesthetic medicine and propose a temperature-time-depth framework linking device-specific tissue exposure to molecular, histological, and clinical responses.
MATERIALS AND METHODS: A structured narrative review was conducted using targeted PubMed searches and examination of reference lists from pivotal mechanistic and human-tissue studies. Literature through August 2026 was considered. Priority was given to studies reporting tissue-temperature measurements, human skin biopsies, spatial histology, protein or RNA measurements, controls, serial assessments, and late clinical or structural outcomes.
RESULTS: Heat activates heat-shock factor 1 and induces HSP70, HSP27, HSP90, and other chaperones. HSP47 (SERPINH1) is particularly relevant to dermal remodeling because it is an endoplasmic reticulum collagen chaperone required for procollagen folding, trafficking, and secretion. Human studies of fractional laser and radiofrequency, together with emerging microfocused ultrasound histology, support a sequence in which early stress and inflammatory responses precede HSP47-positive fibroblast recruitment and matrix remodeling. However, HSP induction alone does not establish durable clinical tightening, and excessive thermal exposure may cause necrosis, fibrosis, scarring, dyschromia, or injury to nerves and fat. Mammalian cold adaptation involves cold-inducible RNA-binding protein (CIRBP/CIRP) and RNA-binding motif protein 3 (RBM3), best characterized during sustained mild hypothermia near 32°C-34°C. These proteins regulate RNA stability, translation, metabolism, and cell survival. Their adaptive intracellular functions must be distinguished from profound cold injury and extracellular CIRP-mediated inflammation. Direct evidence linking aesthetic cooling to CIRBP- or RBM3-mediated dermal neocollagenesis remains insufficient.
CONCLUSIONS: Mechanistic interpretation should be based on measured biological dose, tissue compartment, and response timing rather than console temperature, surface temperature, or device category alone. Heat-shock mechanisms are supported for several thermal modalities, whereas cold-shock-mediated aesthetic neocollagenesis remains a translational hypothesis requiring direct molecular, histological, and clinical validation.
Keywords: CIRBP; CIRP; HSP47; HSP70; RBM3; aesthetic medicine; cold-shock protein; collagen; cryolipolysis; fibroblast; heat-shock protein; laser; microfocused ultrasound; radiofrequency