New strategies to improve skin barrier homeostasis

An Overview of Scaffolds and Biomaterials for Skin Expansion and Soft Tissue Regeneration: Insights on Zinc and Magnesium as New Potential Key Elements

The utilization of materials in medical implants, serving as substitutes for non-functional biological structures, supporting damaged tissues, or reinforcing active organs, holds significant importance in modern healthcare, positively impacting the quality of life for millions of individuals worldwide. However, certain implants may only be required temporarily to aid in the healing process of diseased or injured tissues and tissue expansion. Biodegradable metals, including zinc (Zn), magnesium (Mg), iron, and others, present a new paradigm in the realm of implant materials. Ongoing research focuses on developing optimized materials that meet medical standards, encompassing controllable corrosion rates, sustained mechanical stability, and favorable biocompatibility. Achieving these objectives involves refining alloy compositions and tailoring processing techniques to carefully control microstructures and mechanical properties. Among the materials under investigation, Mg- and Zn-based biodegradable materials and their alloys demonstrate the ability to provide necessary support during tissue regeneration while gradually degrading over time. Furthermore, as essential elements in the human body, Mg and Zn offer additional benefits, including promoting wound healing, facilitating cell growth, and participating in gene generation while interacting with various vital biological functions. This review provides an overview of the physiological function and significance for human health of Mg and Zn and their usage as implants in tissue regeneration using tissue scaffolds. The scaffold qualities, such as biodegradation, mechanical characteristics, and biocompatibility, are also discussed.

Accelerating skin barrier repair using novel bioactive magnesium-doped nanofibers of non-mulberry silk fibroin during wound healing

Novel magnesium doped non-mulberry silk fibroin nanofibers with ability to enhance skin barrier function were successfully fabricated using electrospinning technique for wound healing applications. Magnesium nanoparticles incorporated in the electrospun nanofibers releases Mg2+ ions at the site of implementation. The effect of Mg2+ is of considerable concern in wound healing due to its skin barrier repair ability and its role in blood coagulation. The physicochemical characterization of the scaffold was investigated by determining the morphology and secondary structure confirmation. The effects of Mg2+ ions in silk fibroin microenvironment have been evaluated using SEM, XRD, and FTIR to confirm the incorporation of magnesium in the film. The aim of this study is to see the effect of doped Mg on the structural, physical, and biological properties of non-mulberry silk fibroin (NSF) film. The magnesium doped nanofibrous film exhibited enhanced mechanical property, satisfactory blood clotting ability, and good in vitro degradability. This silk fibroin-based film mimicking extracellular matrix for skin regeneration were constructed using electrospinning technique. The wound healing efficiency of prepared nanofibers were evaluated in full-thickness wound models of rat. The Mg doped silk fibroin film exhibited faster wound healing activity (14 days) among all experimental group. The study indicates the potential of magnesium-doped silk /PVA film as skin substitute film.

Relationship between the skin barrier function of 2-week-old infants after bathing and facial skin problems during the first 6 weeks of life: A prospective observational cohort study

AIM

This study aimed to identify the relationship between the skin barrier function after bathing at 2 weeks of age and subsequent facial skin problems during the first 6 weeks of life.

METHODS

A prospective observational study was conducted from July 2017 to February 2018 on healthy newborns aged 2 weeks. Skin barrier function was evaluated before bathing and at 30 and 90 min after bathing by measuring transepidermal water loss (TEWL), stratum corneum hydration (SCH), sebum secretion, and skin pH. Infantile facial skin problems were assessed using skin condition diaries maintained by a parent for 4 weeks.

RESULTS

Analysis of the data from 56 infants showed that 29 infants (51.8%) experienced facial skin problems from 2 to 6 weeks of age. A lesser change in the sebum secretion on the forehead before bathing to 90 min after bathing and a higher SCH of the forehead before bathing were less likely to result in facial skin problems (adjusted odds ratio [AOR] = 0.98, 95% confidence interval [CI]: 0.97-0.99; AOR = 0.96, 95% CI: 0.92-0.99).

CONCLUSIONS

A greater change in the sebum secretion on the forehead before bathing to 90 min after bathing and a lower SCH of the forehead before bathing were associated with subsequent infantile facial skin problems, indicating that a better ability to recover after bathing is important to prevent facial skin problems. Future studies should identify factors that enhance the recuperative functions of infantile skin.

Analysis of gene expression dynamics revealed delayed and abnormal epidermal repair process in aged compared to young skin

With aging, epidermal homeostasis and barrier function are disrupted. In a previous study, we analyzed the transcriptomic response of young skin epidermis after stratum corneum removal, and obtained a global kinetic view of the molecular processes involved in barrier function recovery. In the present study, the same analysis was performed in aged skin in order to better understand the defects which occur with aging. Thirty healthy male volunteers (67 ± 4 years old) were involved. Tape-strippings were carried out on the inner face of one forearm, the other unstripped forearm serving as control. At 2, 6, 18, 30 and 72 h after stripping, TEWL measurements were taken, and epidermis samples were collected. Total RNA was extracted and analyzed using DermArray^® cDNA microarrays. The results highlighted that barrier function recovery and overall kinetics of gene expression were delayed following stripping in aged skin. Indeed, the TEWL measurements showed that barrier recovery in the young group appeared to be dramatically significant during the overall kinetics, while there were no significant evolution in the aged group until 30 h. Moreover, gene expression analysis revealed that the number of modulated genes following tape stripping increased as a function of time and reached a peak at 6 h after tape stripping in young skin, while it was at 30 h in aged skin, showing that cellular activity linked to the repair process may be engaged earlier in young epidermis than in aged epidermis. A total of 370 genes were modulated in the young group. In the aged group, 382 genes were modulated, whose 184 were also modulated in the young group. Only eight genes that were modulated in both groups were significantly differently modulated. The characterization of these genes into 15 functional families helped to draw a scenario for the aging process affecting epidermal repair capacity.

Topical antihistamines display potent anti-inflammatory activity linked in part to enhanced permeability barrier function

Systemic antagonists of the histamine type 1 and 2 receptors (H1/2r) are widely used as anti-pruritics and central sedatives, but demonstrate only modest anti-inflammatory activity. Because many inflammatory dermatoses result from defects in cutaneous barrier function, and because keratinocytes express both Hr1 and Hr2, we hypothesized that H1/2r antagonists might be more effective, if they were used topically to treat inflammatory dermatoses. Topical H1/2r antagonists additively enhanced permeability barrier homeostasis in normal mouse skin by: i) stimulation of epidermal differentiation, leading to thickened cornified envelopes; and ii) enhanced epidermal lipid synthesis and secretion. Since barrier homeostasis was enhanced to a comparable extent in mast cell-deficient mice, with no further improvement following application of topical H1/2r antagonists, H1/2r antagonists likely oppose mast cell-derived histamine. In four immunologically-diverse, murine disease models, characterized by either inflammation alone (acute irritant contact dermatitis, acute allergic contact dermatitis), or by prominent barrier abnormalities (subacute allergic contact dermatitis, atopic dermatitis), topical H1/2r agonists aggravated, while H1/2r antagonists improved inflammation and/or barrier function. The apparent ability of topical H1r/2r antagonists to target epidermal H1/2r could translate into increased efficacy in the treatment of inflammatory dermatoses, likely due to decreased inflammation and enhanced barrier function. These results could shift current paradigms of antihistamine utilization from a predominantly-systemic to a topical approach.

Skin care in the older person: a focus on the use of emollients

This article gives an overview of pathophysiological changes in the older person's skin, with particular focus on dry skin and the important use of emollient therapy. This includes guidance on emollient choice, function and application. Education is emphasized as an important factor in patient/carer concordance, with additional advice also recommended to extend education to other health care professionals in terms of correct usage and prescription amounts. Best practice of the use of emollient therapy is the main objective of this article, promoting the health professional to place skin care assessment high on the patient need agenda, and to recognize this therapy as the first-line treatment in all dry skin management.

Barrier repair trumps immunology in the pathogenesis and therapy of atopic dermatitis

Until recently, the pathogenesis of atopic dermatitis (AD) has been attributed to primary abnormalities of the immune system [1-4]. Intensive study revealed the key roles played by TH1/TH2 cell dysregulation, IgE production, mast cell hyperactivity, and dendritic cell signaling in the evolution of the chronic, pruritic, inflammatory dermatosis that characterizes AD (op. cit). Hence, current therapy has been largely directed towards ameliorating TH2-mediated inflammation and pruritus (e.g.[5]). In this brief review, we will assess emerging evidence that inflammation in AD results from inherited and acquired insults to the barrier, and describe the features of certain barrier-repair alternatives as therapeutic products for the treatment of AD. A recently-developed approach, based upon lipid replacement with a ceramide-dominant, triple-lipid formulation that corrects the underlying lipid biochemical abnormality, potentially represents a new paradigm for therapy of AD.

Biodegradable derivatives of tranexamic acid as transdermal permeation enhancers

The purpose of this work was to develop a novel approach to transdermal permeation enhancer design, based on utilizing some favorable properties of their metabolites. As an example of this concept, a series of carbamic acid salts of tranexamic acid (TXA) esters was synthesized, because TXA was previously shown to improve skin barrier homeostasis. Enhancement activities of 1% TXA derivatives dispersed in both hydrophilic and lipophilic vehicles were evaluated in vitro using human skin and theophylline as a model drug. Dispersed in an aqueous donor vehicle, the dodecyl ester showed the enhancement ratio (ER) of 4.3+/-0.9, which is almost 2 times higher than that of 1-dodecylazepan-2-one (Azone; 2.2+/-0.7). From an isopropyl-myristate suspension, the decyl ester was the most effective enhancer (4.9+/-1.4), while Azone was inactive. Decomposition of the carbamate in a slightly acidic environment was shown by FTIR; hydrolysis of the pertinent ester by porcine esterase was monitored by TLC and HPLC. Biodegradable enhancers of this type could mediate easier and faster recovery of the skin barrier after transdermal delivery through the action of the released TXA.