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A tensioned ex vivo full-thickness human skin explant platform was used to assess the bioeffects arising from application of several commercial chemexfoliation agents. Although such treatments are well-established, and improved understanding of the underlying mechanistic processes continues to emerge, research into the optimum treatments for specific skin types/conditions is still needed for enhanced efficacy while minimizing recovery time. The 3 commercial chemexfoliation agents employed all contained trichloroacetic acid at well-defined concentrations (6, 10, and 20%) and were applied to the explants' stratum corneum. Subsequently, measurements of dermal remodeling factors (COL1A1, ELN, HAS2, HAS3, and procollagen type I) and inflammatory marker (IL-1b) were undertaken using qPCR and immunofluorescent analyses. Statistical analysis of these data facilitated the establishment of benchmarking biological responses to these trichloroacetic acid-containing agents against untreated controls. The performance of an innovative trichloroacetic acid-free chemexfoliation agent was then measured and, upon comparison with the previous benchmarking data, indicated that dermal remodeling factors could be upregulated in fashion comparable with that of the trichloroacetic acid-containing agents but with significant suppression of inflammatory response. Our measurements thus underscore the promise of the tensioned explant over prolonged study periods and also that potentially valuable insights to guide preclinical strategies may be forthcoming from the protocol developed., (© 2024 Published by Elsevier Inc. on behalf of the Society for Investigative Dermatology.)

Worldwide, prostate cancer sits only behind lung cancer as the most commonly diagnosed form of the disease in men. Even the best diagnostic standards lack precision, presenting issues with false positives and unneeded surgical intervention for patients. This lack of clear cut early diagnostic tools is a significant problem. We present a microfluidic platform, the Time-Resolved Hydrodynamic Stretcher (TR-HS), which allows the investigation of the dynamic mechanical response of thousands of cells per second to a non-destructive stress. The TR-HS integrates high-speed imaging and computer vision to automatically detect and track single cells suspended in a fluid and enables cell classification based on their mechanical properties. We demonstrate the discrimination of healthy and cancerous prostate cell lines based on the whole-cell, time-resolved mechanical response to a hydrodynamic load. Additionally, we implement a finite element method (FEM) model to characterise the forces responsible for the cell deformation in our device. Finally, we report the classification of the two different cell groups based on their time-resolved roundness using a decision tree classifier. This approach introduces a modality for high-throughput assessments of cellular suspensions and may represent a viable application for the development of innovative diagnostic devices.

Scanning probe microscopy facilitates high-resolution noninvasive imaging of surface topography on even the most delicate of biological structures. Moreover, the local probe nature of the instrument architecture lends itself to the measurement of many important physical properties. To date, biological investigations have largely been constrained to imaging surface (membrane)-borne phenomena; however, the advent of extremely high aspect-ratio 'needle' probe tips, as reported by Beard et al. (2013), suggests that the approach can now be extended to address the particular challenges associated with measuring subsurface microscopic targets, including the intracellular components of the stratum corneum.