Quantitative multilayered assessment of skin lightening by photoacoustic microscopy.

Background: With the emergence of various new skin-lightening products, there is an urgent need to scientifically evaluate the efficacy and toxicology of these products, and provide scientific guidance for their use based on physiological differences between individuals. Visualized imaging methods and quantitative evaluation criteria play key roles in evaluating the efficacy of skin-lightening products. In order to quantify the changes in the multilayered morphology and endogenous components of human skin before and after the use of lightening products, high-resolution three-dimensional (3D) imaging of human skin is required.

Quantitative and anatomical imaging of dermal angiopathy by noninvasive photoacoustic microscopic biopsy.

The ability to noninvasively acquire the fine structure of deep tissues is highly valuable but remains a challenge. Here, a photoacoustic microscopic biopsy (PAMB) combined switchable spatial-scale optical excitation with single-element depth-resolved acoustic detection mode was developed, which effectively coordinated the spatial resolution and the penetration depth for visualizations of skin delamination and chromophore structures up to reticular dermis depth, with the lateral resolution from 1.5 to 104 μm and the axial resolution from 34 to 57 μm.

Nanoscale microenvironment engineering for expanding human hair follicle stem cell and revealing their plasticity.

Background: Periodically regenerated hair follicles provide an excellent research model for studying tissue regeneration and stem cell homeostasis. Periodic activation and differentiation of hair follicle stem cells (HFSCs) fuel cyclical bouts of hair regeneration. HFSCs represent an excellent paradigm for studying tissue regeneration and somatic stem cell homeostasis.

Ciliary Mechanism of Regulating Hedgehog and Wnt/-Catenin Signaling Modulates Ultraviolet B Irradiation-Induced Photodamage in HaCaT Cells.

Skin undergoes photoaging, typically characterized by UV-damage lesions with matrix degradation and inflammatory changes. This process involves Hedgehog (Hh) signaling and the canonical Wnt pathway. Recently, primary cilia-microtubule-based organelles-have been implicated in the transduction of Hh and Wnt signaling.

Exogenous growth factors enhance the expression of cola1, cola3, and Elastin in fibroblasts via activating MAPK signaling pathway.

Exogenous growth factors could accelerate the process of wound healing. However, the underlying mechanisms have not been clearly clarified. The aim of the present study was to investigate the effect of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) on the expression of type I collagen (cola1), type III collagen (cola3), and Elastin in fibroblasts, which are widely expressed in fibroblasts and promote the function of fibroblasts.