Search

Fibroblasts are among the most common cell types in the stroma responsible for creating and maintaining the structural organization of the extracellular matrix in the dermis, skin regeneration, and a range of immune responses. Until now, the processes of fibroblast adaptation and functioning in a varying environment have not been fully understood. Modern laser microscopes are capable of studying fibroblasts in vitro and ex vivo. One‐photon‐ and two‐photon‐excited fluorescence microscopy, Raman spectroscopy/microspectroscopy are well‐suited noninvasive optical methods for fibroblast imaging in vitro and ex vivo. In vivo staining‐free fibroblast imaging is not still implemented. The exception is fibroblast imaging in tattooed skin. Although in vivo noninvasive staining‐free imaging of fibroblasts in the skin has not yet been implemented, it is expected in the future. This review summarizes the state‐of‐the‐art in fibroblast visualization using optical methods and discusses the advantages, limitations, and prospects for future noninvasive imaging. [ABSTRACT FROM AUTHOR]

This randomized, placebo-controlled, double-blind clinical in vivo study aimed to evaluate the clinical efficacy of a cosmetic formulation for non-inflammatory acne using essential oils. Fifty-three male participants were divided into four groups: a formulation containing a mixture of four essential oils (4EO), Melaleuca alternifolia (M.a.), nanoemulsion of M. alternifolia (Nanoem.), and a placebo group. The participants applied the formulation daily for 90 days and non-invasive skin imaging techniques were employed to assess the outcomes. Skin microrelief images and reflectance confocal microscopy images were captured in the malar region, and Raman spectroscopy was used to analyze the terpene composition of the essential oils, oil mixture, and nanoemulsion. The results indicated that the nanoemulsion, M.a. essential oil, and 4EO formulation effectively reduced the overall number of comedone and improved follicular hyperkeratinization. The nanoemulsion of M.a. demonstrated the most promising outcomes in reducing comedone areas, especially in the infundibular region. This effect could be attributed to the presence of terpinene-4-ol in the essential oil and the enhanced penetration provided by the nanoemulsion formulation. These findings suggest that cosmetic formulations containing essential oils, particularly in nanoemulsion form, have potential against mild acne. This study contributes to our understanding of the relationship between terpene composition and clinical activity, highlighting the importance of innovative delivery systems. [ABSTRACT FROM AUTHOR]

The main components of the stratum corneum (SC), water, lipids, and proteins, are non‐homogeneously distributed throughout the depth. The quantitative determination of their concentration profiles and penetration depth of topically applied substances are urgent topics of dermatological and cosmetic research. Confocal Raman micro‐spectroscopy has distinct advantages when determining semi‐quantitative concentrations of SC components and topically applied substances non‐invasively and in vivo. In this work, we applied a tailored multivariate curve resolution‐alternating least squares (tMCR‐ALS) method to analyze Raman spectra of the SC in the 2000–4000 cm−1 region for quantitatively determining the concentrations of water, lipids, proteins, and topically applied oils using substance‐related spectral loadings which were allowed to change depth‐dependently from the SC's surface toward its bottom. tMCR‐ALS makes matching of depth‐dependent signal attenuation, that is, the normalization on keratin, unnecessary and requires only a few additional experiments for calibration – Raman spectra of the pure materials and their densities. [ABSTRACT FROM AUTHOR]

The epidermal protective functions are closely associated with skin hydration homeostasis. The understanding of different states of water binding is a rising concept in assessing topically applied formulations and their interaction within the stratum corneum (SC). In addition to global water content, primary bound water, partially bound water, and unbound water and barrier‐related lipid lateral packing and protein secondary structure can be measured by Raman spectroscopy. This study aimed to establish an in vitro SC model to evaluate differences in the efficacy of a natural sugar‐derived complex in combination with glycerol and a botanical extract in modulating SC water binding and structural proteins and barrier lipids. These compounds were selected due to their water‐binding and soothing properties. The SC water profiles were assessed at the surface and in 8 μm SC depth. After a 12‐hour hyperhydration and subsequent product incubation the measurements were performed during a 6 hours desiccation phase. The maximal water caption and the time until reaching a steady state are measured as well as water retention and resistance against water loss. Global water content, partially bound, and unbound water, as well as lipid and protein structures were assessed with confocal Raman microspectroscopy. Both the natural sugar‐derived mixture and more pronounced, the same mixture with additional glycerol increased all three water‐binding parameters at the surface and in 8 μm SC depth at the beginning and during the desiccation phase. Further addition of botanical extract did not result in an additional increase of the water‐binding. All three formulations showed an increase in the lipid lateral packing values prevented the protein alteration as measured by β‐sheets signal compared to blank. The present model is suited for screening studies comparing the specific effects of different compounds on hydration states. The natural sugar‐derived mixture Aquaxyl showed evidence for an improvement of all SC hydration states, lipid and protein structure which was further enhanced by the addition of glycerol 5%. This improvement was evidenced at the surface and within the SC for all hydration‐related parameters, and the lipid as well the protein structures. The addition of botanical extract phytoessence blue daisy did not show further improvement. [ABSTRACT FROM AUTHOR]