Palmitoyl Tetrapeptide-7 Research & Studies

Diabetic wounds face challenges like infection, prolonged inflammation, and poor vascularization. To address these, we developed an injectable hydrogel for diabetic wound dressing by grafting palmitoyl tetrapeptide-7 (Pal-7) onto chitosan (CS) to form CS/Pal-7 (CP7). Glutaraldehyde (GA) was used to enhance crosslinking between CS, creating the CP7 hydrogel. The hydrogel showed rapid gelation, good mechanical properties, biocompatibility, and strong antibacterial effects. Additionally, stem cells derived from human deciduous teeth (SHED) were loaded into the CP7 hydrogel to form SHED@CP7. This complex promoted human umbilical vein endothelial cell (HUVEC) migration and tube formation, aiding angiogenesis, and induced macrophage polarization toward the M2 phenotype, exerting anti-inflammatory effects. In streptozotocin-induced diabetic mouse wounds, SHED@CP7 significantly improved wound healing with over 95 % wound closure, increased collagen deposition, and reduced tumor necrosis factor-α (TNF-α) expression by approximately 75 % and Interleukin-6 (IL-6) expression by around 81 %. It also increased Interleukin-10 (IL-10) expression by approximately 58 %, modulating the inflammatory microenvironment for regeneration. Moreover, SHED@CP7 enhanced angiogenesis, as shown by a 69 % increase in endothelial cell marker CD31 staining, supporting faster wound healing. These results highlight the potential of SHED@CP7 as an effective treatment for diabetic wounds.

Sensitive skin is characterized by symptoms of discomfort when exposed to environmental factors. Peptides are used in cosmetics for sensitive skin and stand out as active ingredients for their ability to interact with skin cells by multiple mechanisms, high potency at low dosage and the ability to penetrate the stratum corneum. This study aimed to analyze the composition of 88 facial cosmetics for sensitive skin from multinational brands regarding usage of peptides, reviewing their synthetic pathways and the scientific evidence that supports their efficacy. Peptides were found in 17% of the products analyzed, namely: acetyl dipeptide-1 cetyl ester, palmitoyl tripeptide-8, acetyl tetrapeptide-15, palmitoyl tripeptide-5, acetyl hexapeptide-49, palmitoyl tetrapeptide-7 and palmitoyl oligopeptide. Three out of seven peptides have a neurotransmitter-inhibiting mechanism of action, while another three are signal peptides. Only five peptides present evidence supporting their use in sensitive skin, with only one clinical study including volunteers having this condition. Noteworthy, the available data is mostly found in patents and supplier brochures, and not in randomized placebo-controlled studies. Peptides are useful active ingredients in cosmetics for sensitive skin. Knowing their efficacy and synthetic pathways provides meaningful insight for the development of new and more effective ingredients.

This study was conducted to establish a new methodology for evaluating elements of dermal extracellular matrix (ECM), of epidermal-dermal junction (EDJ), and effects of molecules which can modulate their synthesis. This methodology is based on matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI). In vivo reflectance confocal microscopy (in vivo RCM) and echography were also used. Using immunohistochemistry methods on explants, age-related modification data were obtained for selected dermal ECM and EDJ proteins (collagen I, collagen IV, collagen VII, collagen XVII, nidogen I, decorin/decorunt) and used as reference for MALDI-MSI studies. A methodology was developed with MALDI-MSI to map epidermis and dermis proteins. Then MALDI-MSI was used to study age modifications. In vivo RCM and high-frequency ultrasounds were used to evaluate ECM and EDJ undulation modifications caused by aging. Anti-aging molecule evaluations were performed with a blend of palmitoyl oligopeptide and palmitoyl tetrapeptide-7. Immunohistochemistry studies demonstrated that the selected proteins were found to be less abundant in aged group explants vs. young group except for decorin. MALDI-MSI studies correlated the results obtained for decorin. In vivo RCM measurements indicated a decrease of EDJ undulation depth with age and ECM modifications in the upper part of dermis. Echography demonstrated that the peptide blend reduced subepidermal low-echogenic band thickness and improved its density. In vivo RCM studies indicated that the peptides improved the ECM structure vs. placebo. This preliminary MALDI-MSI study raised some technical difficulties that were overcome. Further studies will be conducted to identify more proteins and to demonstrate the interest of this method for cosmetic evaluations.