The Effect of Anti-aging Peptides on Mechanical and Biological Properties of HaCaT Keratinocytes

Abstract

Atomic force microscopy (AFM) and fluorescence microscopy was applied to determine the influence of the anti-aging peptides on the morphology and the mechanical properties of keratinocytes. Immortalized human keratinocytes (HaCaT) were treated with two anti-aging bioactive peptides: Acetyl Tetrapeptide-2 and Acetyl Hexapeptide-50 (Lipotec). The AFM measurement of the keratinocyte stiffness were carried after 48 h exposure at an indentation depth of 200 nm. AFM analysis showed increase of the cell stiffness for cells treated with Acetyl Tetrapeptide-2 (P1) in concentration range. Acetyl Hexapeptide-50 (P2) at concentration of 0.05 µg/ml also increased the stiffness of HaCaT cells but at higher concentrations 0.5 and 5 µg/ml cell stiffness was lower as compared to untreated control. Fluorescence microscopy revealed remodeling of actin filaments dependent on the concentration of P2 peptide. The mechanical response of HaCaT cells treated with P2 peptide corresponds to change of transcription level of ACTN1 and SOD2 which activity was expected to be modulated by P2 treatment.

Usage of Synthetic Peptides in Cosmetics for Sensitive Skin

“…In the cosmetic industry, peptides have been used since the late 1980s, with growing notoriety during the first decade of the XXI century [ 17 , 18 , 19 ]. Peptides used in cosmetic products present a molecular weight lower than 500 Da and hydrophilic properties, thus achieving a moderate penetration through the stratum corneum [ 20 ]. Focusing on this challenge, chemical modifications such as esterification with alkyl chains, are usually required.…”

Cell Adhesion, Morphology, and Metabolism Variation via Acoustic Exposure within Microfluidic Cell Handling Systems

“…Studies suggesting roles for cholesterol in cell membrane stiffness and tension have been conducted; [73] however, further investigation would be required to validate these theories. Interestingly, the data variability of each cell consistently decreases as cell stiffness increases, showing the smallest variance in HaCaT (10 kPa [59] ) and L929 (4 kPa [74] ) and larger variance for the softer MG63 and MSCs (0.3-0.8 kPa [57,58] ) respectively (see Table S4 in the Supporting Information for tabulated values). This is indicative of the inherent heterogeneity which is known to be more prevalent in softer cell types (i.e., MSCs) than stiffer ones (i.e., HaCaT).…”

“…They were HaCaT (human keratinocytes), L929 (mouse fibroblast), MSCs (mesenchymal stromal cells, human bone marrow‐derived primary cells), and MG63 (mouse osteosarcoma). The selected cells represent not only species and source tissue variability but also vast differences in predicted cell stiffness values, ranging from 0.8 kPa (MSCs) to 10 kPa (HaCaT) to better understand the impact of acoustic exposure on cell heterogeneity. Experiments we have performed show no significant differences in nuclear morphology and proliferation rates across all cell types and conditions studied.…”

Elasticity Profile of Skin, Neuronal, Cardiac, and Skeletal Muscle Cells after Treatment with the Biofield Energy Healing-Based Proprietary Test Formulation

“…Elasticity of the cells can be measured by investigating deformability of the cells using techniques such as Atomic Force Microscopy (AFM) [2]. AFM is used to determine the Young's modulus (YM) which is a measure of the stiffness of the biological sample in response to an applied load [1,3,4]. Cell and tissue stiffness (elasticity) are considered as an important characteristic of normal and diseased cellular states [5].…”