Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety

Salvianolic acid B protects against UVB-induced HaCaT cell senescence and skin aging through NRF2 activation and ROS scavenging

BACKGROUND

Prolonged sunlight exposure can cause skin photoaging. The epidermis, the outermost layer of the skin, protects the body from the environment. This study explored the protective effect of salvianolic acid B (Sal-B), a bioactive compound from Salvia miltiorrhiza, against photoaging and examined its specific mechanism.

METHODS

In vitro, HaCaT cells were treated with various doses of Sal-B before ultraviolet B (UVB) light exposure. Assessments in HaCaT cells included cellular senescence, apoptotic cell ratio, reactive oxygen species (ROS) levels, mitochondrial function, superoxide dismutase activity, and gene and protein expression. Immunofluorescence labeling, nuclear factor erythroid 2-related factor 2 (NRF2) knockdown, and Western blotting analysis were used. To assess Sal-B's protective effects on skin photoaging in vivo, we employed a nude mouse model and an ex vivo human skin model.

RESULTS

In vitro, Sal-B significantly activated NRF2, scavenged ROS, protected mitochondrial function, and inhibited nuclear factor kappa B and mitogen-activated protein kinase pathways. Ultimately, Sal-B prevented UVB-induced photoaging and keratinocyte apoptosis. In vivo, we confirmed that Sal-B improved skin wrinkles and epidermal thickness in nude mice following UVB irradiation, displaying greater efficacy than tretinoin.

CONCLUSION

We identified the preventive implications of Sal-B against UVB-induced senescence in skin photoaging and revealed its potential as a regulator of the NRF2 signaling pathway.

Photoaging: Current Concepts on Molecular Mechanisms, Prevention, and Treatment

Photoaging is the consequence of chronic exposure to solar irradiation, encompassing ultraviolet (UV), visible, and infrared wavelengths. Over time, this exposure causes cumulative damage, leading to both aesthetic changes and structural degradation of the skin. These effects manifest as rhytids, dyschromia, textural changes, elastosis, volume loss, telangiectasias, and hyperkeratosis, collectively contributing to a prematurely aged appearance that exceeds the skin's chronological age. The hallmarks of photoaging vary significantly by skin phototype. Skin of color tends to exhibit dyschromia and features associated with "intrinsic" aging, such as volume loss, while white skin is more prone to "extrinsic" aging characteristics, including rhytids and elastosis. Moreover, susceptibility to different wavelengths within the electromagnetic spectrum also differs by skin phototype, influencing the clinical presentation of photoaging, as well as prevention and treatment strategies. Fortunately, photoaging-and its associated adverse effects-is largely preventable and, to some extent, reversible. However, effective prevention and treatment strategies require careful tailoring to an individual's skin type. In this review, we summarize molecular mechanisms underlying photoaging, examine its clinical manifestations, outline risk factors and prevention strategies, and highlight recent advancements in its treatment.

A new ex vivo human skin model for the topographic and biological analysis of cosmetic formulas

OBJECTIVE

Existing methods to evaluate skin care products suffer limitations. This is the case for ex vivo skin explants, a first-choice 3D model. While essential to analyse mid- to long-term biological effects, this classical model hinders assessing microrelief variations. To circumvent these limitations, we developed an ex vivo PERFused EXplant setup (Perfex) that maintains the outer skin surface in the open air, closely mirroring physiological conditions.

METHODS

A custom-designed reservoir enables perfusing the dermal side of explants with buffered, temperature-controlled medium, while the epidermis is subjected to "normal" conditions. Skin tension and characteristics of the stratum corneum, microrelief, histology and immunohistology (collagen types I and III, elastin and fibrillin-1) were analysed and compared to those of explants maintained under conventional conditions or in vivo skin. The effects of skin care formulas intended to induce short- and/or mid- to long-term effects were also assessed.

RESULTS

Skin explants maintained with the Perfex setup exhibit characteristics (firmness, elasticity, hydration and barrier function) closer to those of in vivo skin than with conventional conditions. Moreover, Perfex-maintained explants present no alteration in histology after 7 days and slight variation in the expression of key protein markers. Microrelief characteristics also remain mostly stable over 7 days. Formula applications corroborate that skin tensor-containing products primarily induce short-term changes in the microrelief, while those with biologically active ingredients mainly lead to mid- to long-term effects on the histology and expression of molecular markers. Furthermore, maintaining skin explants with a physiologically relevant skin surface enabled analysing the relationship between microrelief and key markers, showing that fibrillin-1 is the protein most correlated with microrelief characteristics.

CONCLUSIONS

The Perfex setup allows for similar preservation of skin explant histology and key protein expression as the conventional system, yet it maintains a skin surface close to that of in vivo skin. Therefore, it is valuable to analyse both the short- and mid- to long-term impacts of skin care formulas and better comprehend their effects. The Perfex system also offers a new tool for investigating fundamental questions, such as the link that can exist between dermal proteins and skin surface properties.

Combination of Botulinum Toxin A and Hyaluronic Acid Improved Facial Pore Enlargement Caused by Acne

BACKGROUND

Acne often leads to enlarged pores on the facial skin, seriously affecting the patient's appearance. Topical and oral medications have poor efficacy in some cases of severe pore enlargement.

OBJECTIVE

This study aimed to explore the clinical efficacy and safety of botulinum toxin A combined with hyaluronic acid in improving facial pore enlargement.

METHOD

A retrospective study was conducted on 40 acne patients with enlarged pores. Botulinum toxin A and non-cross-linked hyaluronic acid compound were injected into the patient's face using mesotherapy with nine 32-gauge microneedles. VISIA was used to record the conditions of facial pores, texture, and porphyrins. The physician's assessment of the improvement score and the patient satisfaction evaluation are used to evaluate the treatment effect.

RESULT

One month after treatment, the combination of botulinum toxin and non-cross-linked hyaluronic acid compound significantly improved facial pore enlargement. Although the effects decreased, the conditions of facial pores, texture, and porphyrins 4 months after treatment still had a significant difference from those at baseline.

CONCLUSION

The combination of botulinum toxin A and non-cross-linked hyaluronic acid compound is safe and effective in treating enlarged pores, indicating its promotional value.

Recommendations to Improve Outcomes in Acne and Acne Sequelae: A Focus on Trifarotene and Other Retinoids

Acne vulgaris affects nearly 50 million people in the USA, ranking as the eighth most prevalent disease globally. This chronic inflammatory skin condition often results in sequelae, including atrophic acne scars, acne-induced macular erythema and acne-induced hyperpigmentation, impacting patients' quality of life. This commentary article reviews the use of topical retinoids, with a particular emphasis on trifarotene cream 0.005%, for managing both acne and acne sequelae. Topical retinoids are considered central to improving treatment outcomes because of their established efficacy, safety and tolerability. Adapalene, tretinoin and tazarotene have demonstrated efficacy in reducing acne and acne sequelae in several studies. Trifarotene has been extensively studied in Phase 3 trials, demonstrating notable success in treating mild-to-moderate acne. Recently, two large-scale, randomized, blinded, Phase 4 clinical trials investigated trifarotene cream 0.005% in patients with atrophic acne scarring and acne-induced hyperpigmentation across all Fitzpatrick phototypes. The START study found that there was a greater reduction in total atrophic acne scar count in the trifarotene group compared with the vehicle group at Week 24 (55.2% vs 29.9%) with statistical significance established as early as Week 2 (P = 0.001). Based on this evidence, we recommend that topical retinoids should be introduced as first-line therapy for the treatment of acne and acne sequelae. Retinoids should be implemented into a treatment routine as early as possible, especially for patients with darker Fitzpatrick phototypes or patients at risk of atrophic acne scarring. Furthermore, retinoids should be incorporated within a comprehensive skincare regimen that includes adequate photoprotection when treating patients with darker Fitzpatrick phototypes. Finally, management of acne and acne sequelae should include maintenance therapy with topical retinoids. This article supports the American Academy of Dermatology's call for acne sequelae treatment guidance and emphasizes the need for continued research to optimize patient care.

A Functional Skincare Formulation Mixed With Retinyl Propionate, Hydroxypinacolone Retinoate, and Vitamin C on Antiaging and Whitening Han Women in Shanghai, China

BACKGROUND

Human skin is remodeled as a result of aging. Retinoids (or retinol derivatives) can intervene in this process, which can be optimally formulated and concentrated by providing maximum antiaging effects with minimal irritation.

AIMS

To determine the optimal ratio of two retinol derivatives hydroxypinacolone retinoate (HPR), retinol propionate (RP), and vitamin C (VitC) in dermal remodeling and preventing skin aging, and to investigate their synergistic antiaging and whitening effects in vitro and in vivo.

METHODS

An in vitro model of human skin fibroblast (HSF) was established to evaluate the cellular viability of VitC and/or RP/HPR treatment. We quantified the expression of genes associated with antiaging and retinol receptors in HSFs treated with VitC and/or RP/HPR. The research was conducted on 120 volunteer women to quantify the antiaging efficacy of functional skincare formulation.

RESULTS

A combination of VitC and RP/HPR at a weight ratio of 40:3 achieved the optimal and safe antiaging performance in vitro. Transcription of aging-associated genes and the release of elastin and senescence-associated secretory phenotypes (SASPs) increased significantly after UV irradiation, whereas VitC and RP/HPR cotreatment can inhibit this increase. The synergistic stimulation of VitC and RP/HPR cotreatment showed higher efficacy in the recovery ability of skin injury.

CONCLUSIONS

Our results indicated the advanced skin antiaging and whitening effects of VitC and RP/HPR cotreatment in vitro and in vivo. A combination of VitC and RP/HPR is a potent strategy to postpone skin aging and improve skin whitening for middle-aged women.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: 2020-LS-023.

Advancements in hyperpigmentation management: exploring conventional methods, phytoconstituents, novel approaches, and instrumental techniques

Hyperpigmentation is a common dermatological condition characterized by the darkening of patches of skin compared to the surrounding areas. It can occur in individuals of all skin types and ethnicities, and is caused by an overproduction or accumulation of melanin, the pigment responsible for the color of our skin, hair, and eyes. This comprehensive overview aims to delve into the various types, causes, risk factors, clinical manifestations, diagnosis, and treatment options for hyperpigmentation. Additionally, it explores the global and national prevalence of hyperpigmentation, its etiology, pathophysiology and diagnosis and treatment strategies. Furthermore, examines the formulations and dosage forms used to treat hyperpigmentation, including their side effects. It also discusses combination drugs and their associated side effects, as well as novel drug delivery systems and nanocarriers employed in the treatment of hyperpigmentation, providing insight into future prospects in this field.

Influences on Skin and Intrinsic Aging: Biological, Environmental, and Therapeutic Insights

BACKGROUND/AIM

Aging involves a progressive deterioration in physiological functions and increased disease susceptibility, impacting all organs and tissues, especially the skin. Skin aging is driven by intrinsic factors (genetics, cellular metabolism) and extrinsic factors (environment, lifestyle). Understanding these mechanisms is vital for promoting healthy aging and mitigating skin aging effects. This review aims to summarize the key factors influencing skin and intrinsic aging, providing a comprehensive understanding of the underlying mechanisms and contributing elements.

METHODS

A comprehensive literature review was conducted, focusing on peer-reviewed journals, clinical studies, and scientific reviews published within the last two decades. The inclusion criteria prioritized studies that addressed intrinsic and extrinsic mechanisms of skin aging. To ensure the relevance and quality of the selected sources, a systematic approach was used to assess study design, sample size, methodology, and the significance of the findings in the context of skin aging.

FINDINGS

The review identifies major internal factors, such as cellular senescence, genetic predisposition, telomere shortening, oxidative stress, hormonal changes, metabolic processes, and immune system decline, as pivotal contributors to intrinsic aging. External factors, including UV radiation, pollution, lifestyle choices (diet, smoking, alcohol consumption, and sleep patterns), and skincare practices, significantly influence extrinsic skin aging. The interplay between these factors accelerates aging processes, leading to various clinical manifestations like wrinkles, loss of skin elasticity, pigmentation changes, and texture alterations.

CONCLUSION

A comprehensive understanding of both extrinsic and intrinsic factors contributing to skin aging is essential for developing effective prevention and intervention strategies. The insights gained from this review highlight the importance of a multifaceted approach, incorporating lifestyle modifications, advanced skincare routines, and emerging therapeutic technologies, to mitigate the effects of aging and promote healthier, more resilient skin.

Steroidogenic acute regulatory protein mediated variations of gender-specific sex neurosteroids in Alzheimer's disease: Relevance to hormonal and neuronal imbalance

The steroidogenic acute regulatory (StAR) protein mediates the rate-liming step in neuro/steroid biosynthesis. Multifaceted and delicate changes during aging, disrupting hormonal and neuronal homeostasis, constitute human senescence, an inevitable phenomenon that attributes to increased morbidity and mortality. Aging, along with progressive decreases in bioactive neurosteroids, is the primary risk factor for Alzheimer's disease (AD), which preferentially impacts two-thirds of women and one-third of men. AD is neuropathologically characterized by the accumulation of extracellular amyloid-β and intracellular phosphorylated Tau containing neurofibrillary tangles, resulting in dementia. Postmortem brains pertaining to gender-specific AD patients exhibit varied suppression of StAR and sex neurosteroid levels compared with age-matched cognitively healthy subjects, in which the attenuation of StAR is inversely correlated with the AD pathological markers. Interestingly, retinoid signaling upregulates StAR-motivated neurosteroid biosynthesis and reinstates various neurodegenerative vulnerabilities that promote AD pathogenesis. This review summarizes current understanding of StAR-driven alterations of sex neurosteroids in gender-specific AD risks and provides biochemical and molecular insights into therapeutic interventions for preventing and/or alleviating dementia for healthy aging.

Cosmetic retinoid use in photoaged skin: A review of the compounds, their use and mechanisms of action

The inevitable attrition of skin due to ultraviolet radiation, termed photoaging, can be partially restored by treatment with retinoid compounds. Photoaged skin in lightly pigmented individuals, clinically presents with the appearance of wrinkles, increased laxity, and hyper- and hypopigmentation. Underlying these visible signs of ageing are histological features such as epidermal thinning, dermal-epidermal junction flattening, solar elastosis and loss of the dermal fibrillin microfibrillar network, fibrillar collagen and glycosaminoglycans. Retinoid compounds are comprised of three main generations with the first generation (all-trans retinoic acid, retinol, retinaldehyde and retinyl esters) primarily used for the clinical and cosmetic treatment of photoaging, with varying degrees of efficacy, tolerance and stability. All-trans retinoic acid is considered the 'gold standard' for skin rejuvenation; however, it is a prescription-only product largely confined to clinical use. Therefore, retinoid derivatives are readily incorporated into cosmeceutical formulations. The literature reported in this review suggests that retinol, retinyl esters and retinaldehyde that are used in many cosmeceutical products, are efficacious, safe and well-tolerated. Once in the skin, retinoids utilize a complex signalling pathway that promotes remodelling of photoaged epidermis and dermis and leads to the improvement of the cutaneous signs of photoaging.

Signaling via retinoic acid receptors mediates decidual angiogenesis in mice and human stromal cell decidualization

At the maternal-fetal interface, tightly regulated levels of retinoic acid (RA), the physiologically active metabolite of vitamin A, are required for embryo implantation and pregnancy success. Herein, we utilize mouse models, primary human cells, and pharmacological tools to demonstrate how depletion of RA signaling via RA receptor (RAR) disrupts implantation and progression of early pregnancy. To inhibit RAR signaling during early pregnancy, BMS493, an inverse pan-RAR agonist that prevents RA-induced differentiation, was administered to pregnant mice during the peri-implantation period. Attenuation of RA/RAR signaling prior to embryo implantation results in implantation failure, whereas attenuation of RA/RAR signaling after embryo implantation disrupts the post-implantation decidual vasculature and results in pregnancy failure by mid-gestation. To inhibit RAR signaling during human endometrial stromal cell (HESC) decidualization, primary HESCs and decidualized primary HESCs were transfected with silencing RNA specific for human RARA. Inhibition of RA/RARA signaling prevents initiation of HESC decidualization, but not maintenance of the decidualized HESC phenotype. These data show that RA/RAR signaling is required for maintenance of the decidual vasculature that supports early pregnancy in mice, and distinct RAR signaling is required for initiation, but not maintenance of primary HESC decidualization in vitro.

Combinational treatment approaches for acanthosis nigricans: a review

Acanthosis Nigricans is characterised by hyperpigmented, hyperkeratotic, dark, rough patches or plaques distributed in intertriginous areas. Hyperkeratosis is the main concern that leads to the darkening of the skin. Numerous treatment options are available. Topical retinoids are first-line therapy given to treat hyperpigmented plaques where the limiting factor is skin irritation. To combat this, combinational therapies have come into existence and are being used. In this state-of-the-art review, the authors summarize the pathophysiology of AN, provide an update on combinational treatment strategies, and describe the other therapeutic options that have been advantageous so far in the literature for this disease. The paper aims to review the use of retinoids as a first line treatment option as well as combinational approaches to treat acanthosis nigricans skin condition.

Enhancing dermal collagen density towards youthfulness: A comparative study of PCL, PLLA, and PDO thread implantation in aging rats model

Objectives

Both intrinsic and extrinsic factors cause skin aging. Intrinsic aging is characterized by decreased collagen density, particularly collagen types I (COL1A1) and III (COL3A1), and an increase in the COL1/COL3 ratio. Extrinsic aging, primarily due to ultraviolet light exposure, leads to photoaging, which causes collagen fragmentation and reduced production, leading to skin sagging. Thread lifts, a nonsurgical method, aim to tighten the skin and stimulate collagen production using biodegradable monofilament threads such as polydioxanone (PDO), poly-lactic acid (PLLA), and polycaprolactone (PCL). This study compared the effectiveness of PDO, PLLA, and PCL threads in reversing aging by enhancing dermal collagen, reducing the COL1/COL3 ratio, and increasing COL3A1 gene expression in UVB-exposed aging model rats.

Materials and Methods

Thirty female Wistar (Rattus norvegicus) rats were divided into six groups, and their back hair was shaved and exposed to 840 mJ/m2 UVB for 4 weeks. Skin biopsy specimens were assessed using Sirius Red staining to determine dermal collagen density and the COL1/COL3 ratio. Furthermore, qRT-PCR was used to examine COL3A1 gene expression.

Results

PDO, PLLA, and PCL threads enhanced skin quality, similar to the young negative control group, based on parameters such as dermal collagen density, COL1/COL3 ratio, and COL3A1 gene expression. PCL thread was more active than PDO and PLLA.

Conclusion

Thread implantation may result in a more youthful collagen profile than negative control and may be used to support skin anti-aging. The most effective thread was PCL compared to PDO and PLLA.

A Case Series With Cysteamine-Isobionicamide Complex: Clues for Skin-Rejuvenating Activity

BACKGROUND

Skin aging is inevitable. Wrinkles, skin texture abnormalities, senile hyperpigmentation, loss of skin tone, dryness, atrophy, and telangiectasias represent some of the hallmarks of aged skin. Skin rejuvenation can be addressed by topical therapies, such as topical retinoids and antioxidants or physical modalities with energy-based devices, all providing acceptable outcomes. In this case series, we aimed to test the rejuvenating potential of the combination of cysteamine (a naturally occurring antioxidant) and isobionicamide (a derivative of the anti-aging molecule niacinamide) applied topically.

METHODS

Healthy male and female patients (N = 7) aged between 25 and 70 years and having Fitzpatrick skin types I-VI were recruited. Topical application of a cysteamine-isobionicamide formula was done once daily. Treatment lasted for 16 weeks. Clinical high-resolution photos were acquired using LifeViz 3D at recruitment and after 16 weeks. Blinded dermatological examinations and scoring were performed. Self-assessment and quality of life (QoL) questionnaires were collected.

RESULTS

Clinical photos showed improvement in skin luminosity, increased evenness of skin tone, and reduction of fine wrinkles as well as hyperpigmentation. Patients as well as clinical investigators blinded to the chronology of photos observed the improvements in skin texture, luminosity, and radiance, the brightening of the dark spots, as well as the reduction of both number and volume of wrinkles after 16 weeks of daily application. Furthermore, a significant improvement in patients' quality of life was recorded.

CONCLUSION

This case series represents the first evidence that topical application of cysteamine isobionic-amide complex could be considered as a safe and effective option in the reversal of skin photoaging.

Casting New Light on the Retinol and Retinyl Palmitate Functions as Chemical Enhancers for Transdermal/Topical Drug Delivery

Retinol and retinyl palmitate, with excellent whitening and antioxidant activities, are widely used as essential functional ingredients in transdermal preparations and skincare products. Herein, for the first time, the influence and underlying mechanisms of retinol and retinyl palmitate on the skin penetration of caffeine are investigated. It is found that the penetration of caffeine is very significantly enhanced by retinol and retinyl palmitate with 2.83 and 2.57 folds, respectively. Mechanistic studies showed that they can disrupt the lipids of intercellular orderly arrangement and reduce the content of orthorhombic lattices in the skin, making the skin loose and the barrier function decreased. Furthermore, due to the formation of chemical bonds with the skin keratin, they have a strong affinity with the skin, changing the dense secondary structure of keratin with a reduced skin barrier effect. This study provides new evidence for the potential of retinol and retinyl palmitate as novel skin penetration enhancers with high safety that possess great potential for application in the transdermal delivery of pharmaceutical and cosmetic active substances.

Efficacy of Topical Hydroxypinacolone Retinoate-Peptide Product Versus Fractional CO2 Laser in Facial Aging

BACKGROUND

Many people are interested in addressing visible signs of aging with non-invasive cosmetic treatments. Development of effective topical products will provide options to delay or support cosmetic procedures.

AIMS

This study assessed and compared the efficacy and tolerance of a topical product used over the course of 16 weeks to a single ablative laser treatment on women with moderate global photodamage on the face.

METHODS

Subjects in Cell 1 (Laser Cell) were treated over the entire face with a fractional CO2 laser system. Subjects in Cell 2 (Topical Serum Cell) were treated with a topical serum containing hydroxypinacolone retinoate and peptides over the entire face, twice per day for 16 weeks. The study was composed of 71 women, with 29 in the Laser Cell (mean age 56.2) and 42 in the Topical Serum Cell (mean age 55.0), between 40 and 65 years old. Expert grading was used to determine efficacy parameters.

RESULTS

Participants in the Topical Serum Cell achieved more significant improvement (p < 0.05) in Marionette lines, fine lines (global face), wrinkles (global face), wrinkles (crow's feet), nasolabial folds, texture, smoothness (tactile), global hyperpigmentation, lift, and photodamage compared to participants in the Laser Cell. Participants in the Topical Serum Cell achieved parity in the look of fine lines (crow's feet), forehead lines, glabella, firmness/bounce (tactile), skin tone evenness, radiance.

CONCLUSIONS

While no statistically significant differences in tolerability were observed, treatment with the topical cosmetic product achieved parity or statistically better improvement in parameters compared to laser treatment at 16 weeks.

Effects of Retinol, Natural Pea Peptide and Antioxidant Blend in a Topical Formulation: In Vitro and Clinical Evidence

INTRODUCTION

Retinol has a long history of treating skin conditions, including photoaging. However, skin irritation with repeated use of retinol is well documented. The present study assessed the effectiveness of a novel topical formulation, referred to as retinol topical formulation (RTF), to improve the quality of skin health. The RTF was composed of a low dose retinol, a synthetic retinoid ester, a pea peptide, and an antioxidant blend.

METHODS

In vitro assessment of RTF on human skin co-cultures (human keratinocytes, melanocytes, and dermal fibroblasts) identified gene expression levels and skin biomarkers after 24 h exposure. An 8-week clinical study was conducted to evaluate once-nightly application of the RTF for short-term and long-term benefits in 30 adult subjects between 35 and 70 years of age (21 female, 9 male). Skin evaluations were conducted via bioinstrumentation (for hydration, transepidermal water loss and elasticity) and at 0, 1-, 2-, 4-, and 8-week self-assessment questionnaires and photo-imaging analysis were performed.

RESULTS

RTF treatment of skin in vitro co-cultures upregulated aquaporin-3, PER1, collagen, and elastin, and downregulated expression of MMP1 and the pigmentation genes TYRP1 and MITF. The clinical assessment significantly improved hydration, transepidermal water loss, and elasticity along with incremental but significant increases in nine skin parameters (hydration, clarity, radiance/glow, smoothness, brightness, texture, appearance of pores, dark spots/hyperpigmentation, and skin tone evenness from baseline) with continuous use over 8 weeks compared to baseline values.

CONCLUSIONS

The RTF in vitro analysis showed significant positive changes for several skin biomarkers, and the clinical assessment showed RTF significantly improved the visible signs of dermal aging, without irritation.

Comparing Tretinoin to Other Topical Therapies in the Treatment of Skin Photoaging: A Systematic Review

BACKGROUND

Many morphological and histological changes take place in aging skin. Topical tretinoin is the gold standard anti-aging agent used to reduce signs of aging through stimulation of epidermal growth and differentiation and inhibition of collagenase.

OBJECTIVE

The aim of this systematic review is to summarize studies evaluating the efficacy of tretinoin compared with other topical medications and cosmeceuticals in reducing the appearance of skin aging.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. The literature search was conducted using the PubMed and Embase databases from conception to December 2023. Studies were included if they compared anti-aging outcomes of topical medications with those of topical tretinoin (also called all-trans retinoic acid and retinoic acid). Studies were excluded if they compared non-topical anti-aging treatments with tretinoin or were conducted on animal models.

RESULTS

The literature search resulted in 25 studies that met all inclusion and exclusion criteria. The most common study comparators to tretinoin included other forms of vitamin A. Outcomes were reported on the basis of visual reduction of aging signs, histological assessment of the epidermis and dermis, and protein expression. Although comparators to tretinoin had variable efficacy (greater in 7 studies, equivalent in 13 studies, and less in 3 studies), most studies found the comparator to be less irritating and better tolerated by patients than tretinoin.

DISCUSSION

Tretinoin is currently the gold standard therapy for the treatment of photoaging, but its poor tolerability often limits its use. Unfortunately, given that most studies comparing topical therapies with tretinoin are of poor quality and/or demonstrate bias, there is a lack of substantial evidence to support an alternative first-line therapy. However, given there are some data to support the efficacy of retinoid precursors, namely retinaldehyde, pro-retinal nanoparticles, and conjugated alpha-hydroxy acid and retinoid (AHA-ret), these agents can be considered a second-line option for anti-aging treatment in patients who cannot tolerate tretinoin.

Deciphering the Etiologies of Adult Erythroderma: An Updated Guide to Presentations, Diagnostic Tools, Pathophysiologies, and Treatments

Erythroderma, an inflammatory skin condition characterized by widespread erythema with variable degrees of exfoliation, pustulation, or vesiculobullous formation, is associated with high morbidity and mortality. Determining the underlying cause of erythroderma frequently presents a diagnostic challenge, which may contribute to the condition's relatively poor prognosis. This review covers the clinical presentation, pathophysiology, diagnosis, and treatment of erythroderma. It discusses similarities and differences among the many underlying etiologies of the condition and differences between erythrodermic and non-erythrodermic presentations of the same dermatosis. Finally, this article explores current research that may provide future tools in the diagnosis and management of erythroderma.

Enhancing wound healing through innovative technologies: microneedle patches and iontophoresis

Introduction

Wound healing is a complex process involving multiple stages, including inflammation, proliferation, and remodeling. Effective wound management strategies are essential for accelerating healing and improving outcomes. The CELLADEEP patch, incorporating iontophoresis therapy and microneedle technology, was evaluated for its potential to enhance the wound healing process.

Methods

This study utilized a full-thickness skin defect model in Sprague-Dawley rats, researchers compared wound healing outcomes between rats treated with the CELLADEEP Patch and those left untreated. Various histological staining techniques were employed to examine and assess the wound healing process, such as H&E, MT and immunofluorescence staining. Furthermore, the anti-inflammatory and proliferative capabilities were further investigated using biochemical assays.

Results

Macroscopic and microscopic analyses revealed that the CELLADEEP patch significantly accelerated wound closure, reduced wound width, and increased epidermal thickness and collagen deposition compared to an untreated group. The CELLADEEP patch decreased nitric oxide and reactive oxygen species levels, as well as pro-inflammatory cytokines IL-6 and TNF-α, indicating effective modulation of the inflammatory response. Immunofluorescence staining showed reduced markers of macrophage activity (CD68, F4/80, MCP-1) in the patch group, suggesting a controlled inflammation process. Increased levels of vimentin, α-SMA, VEGF, collagen I, and TGF-β1 were observed, indicating enhanced fibroblast activity, angiogenesis, and extracellular matrix production.

Discussion

The CELLADEEP patch demonstrated potential in promoting effective wound healing by accelerating wound closure, modulating the inflammatory response, and enhancing tissue proliferation and remodeling. The CELLADEEP patch offers a promising non-invasive treatment option for improving wound healing outcomes.

Topical, light-based, and complementary interventions for acne: an overview of systematic reviews

BACKGROUND

Acne is a chronic inflammatory and immune-mediated disease of the pilosebaceous unit (the skin structure consisting of a hair follicle and its associated sebaceous gland). It is characterised by non-inflammatory lesions (open and closed comedones) and inflammatory lesions (papules, pustules, nodules, and cysts). Lesions may be present on the face, thorax, and back, with variable severity. Acne exhibits a global distribution and has a growing prevalence. Acne vulgaris is the most common form. Acne gives rise to complications such as scars and can seriously affect people's mental health, especially those with severe acne. Acne has a huge impact on the quality of life and self-esteem of those affected.

OBJECTIVES

To synthesise the existing evidence on the efficacy and safety of non-systemic pharmacological interventions and non-pharmacological interventions (physical therapy and complementary therapies) in the treatment of acne vulgaris and related skin complications.

METHODS

We searched the Cochrane Database of Systematic Reviews, Epistemonikos, MEDLINE, and Embase to 2 December 2021, and checked the reference lists of included reviews. At least two authors were responsible for screening, data extraction, and critical appraisal. We excluded reviews with high risk of bias as assessed with the ROBIS tool. We evaluated the overall certainty of the evidence according to GRADE (as carried out by the authors of the included reviews or ourselves). We provide comprehensive evidence from the review data, including summary of findings tables, summary of results tables, and evidence maps.

MAIN RESULTS

We retrieved and assessed a total of 733 records; however, only six reviews (five Cochrane reviews and one non-Cochrane review) with low risk of bias met the overview inclusion criteria. The six reviews involved 40,910 people with acne from 275 trials and 1316 people with acne scars from 37 trials. The age of the participants ranged from 10 to 59 years, with an average age range from 18 to 30 years. Four reviews included original trials involving only female participants and three reviews included original trials with only male participants. Main results for clinically important comparisons: Benzoyl peroxide versus placebo or no treatment: In two trials involving 1012 participants over 12 weeks, benzoyl peroxide may reduce the total (mean difference (MD) -16.14, 95% confidence interval (CI) -26.51 to -5.78), inflammatory (MD -6.12, 95% CI -11.02 to -1.22), and non-inflammatory lesion counts (MD -9.69, 95% CI -15.08 to -4.29) when compared to placebo (long-term treatment), but the evidence is very uncertain (very low-certainty evidence). Two trials including 1073 participants (time point: 10 and 12 weeks) suggested benzoyl peroxide may have little to no effect in improving participants' global self-assessment compared to placebo (long-term treatment), but the evidence is very uncertain (risk ratio (RR) 1.44, 95% CI 0.94 to 2.22; very low-certainty evidence). Very low-certainty evidence suggested that benzoyl peroxide may improve investigators' global assessment (RR 1.77, 95% CI 1.37 to 2.28; 6 trials, 4110 participants, long-term treatment (12 weeks)) compared to placebo. Thirteen trials including 4287 participants over 10 to 12 weeks suggested benzoyl peroxide may increase the risk of a less serious adverse event compared to placebo (long-term treatment), but the evidence is very uncertain (RR 1.46, 95% CI 1.01 to 2.11; very low-certainty evidence). Benzoyl peroxide versus topical retinoids: Benzoyl peroxide may increase the percentage change in total lesion count compared to adapalene (long-term treatment), but the evidence is very uncertain (MD 10.8, 95% CI 3.38 to 18.22; 1 trial, 205 participants, 12 weeks; very low-certainty evidence). When compared to adapalene, benzoyl peroxide may have little to no effect on the following outcomes (long-term treatment): percentage change in inflammatory lesion counts (MD -7.7, 95% CI -16.46 to 1.06; 1 trial, 142 participants, 11 weeks; very low-certainty evidence), percentage change in non-inflammatory lesion counts (MD -3.9, 95% CI -13.31 to 5.51; 1 trial, 142 participants, 11 weeks; very low-certainty evidence), participant's global self-assessment (RR 0.96, 95% CI 0.86 to 1.06; 4 trials, 1123 participants, 11 to 12 weeks; low-certainty evidence), investigators' global assessment (RR 1.16, 95% CI 0.98 to 1.37; 3 trials, 1965 participants, 12 weeks; low-certainty evidence), and incidence of a less serious adverse event (RR 0.77, 95% CI 0.48 to 1.25, 1573 participants, 5 trials, 11 to 12 weeks; very low-certainty evidence). Benzoyl peroxide versus topical antibiotics: When compared to clindamycin, benzoyl peroxide may have little to no effect on the following outcomes (long-term treatment): total lesion counts (MD -3.50, 95% CI -7.54 to 0.54; 1 trial, 641 participants, 12 weeks; very low-certainty evidence), inflammatory lesion counts (MD -1.20, 95% CI -2.99 to 0.59; 1 trial, 641 participants, 12 weeks; very low-certainty evidence), non-inflammatory lesion counts (MD -2.4, 95% CI -5.3 to 0.5; 1 trial, 641 participants, 12 weeks; very low-certainty evidence), participant's global self-assessment (RR 0.95, 95% CI 0.68 to 1.34; 1 trial, 240 participants, 10 weeks; low-certainty evidence), investigator's global assessment (RR 1.10, 95% CI 0.83 to 1.45; 2 trials, 2277 participants, 12 weeks; very low-certainty evidence), and incidence of a less serious adverse event (RR 1.27, 95% CI 0.98 to 1.64; 5 trials, 2842 participants, 10 to 12 weeks; low-certainty evidence). For these clinically important comparisons, no review collected data for the following outcomes: frequency of participants experiencing at least one serious adverse event or quality of life. No review collected data for the following comparisons: topical antibiotics versus placebo or no treatment, topical retinoids versus placebo or no treatment, or topical retinoids versus topical antibiotics.

AUTHORS' CONCLUSIONS

This overview summarises the evidence for topical therapy, phototherapy, and complementary therapy for acne and acne scars. We found no high-certainty evidence for the effects of any therapy included. Randomised controlled trials and systematic reviews related to acne and acne scars had limitations (low methodological quality). We could not summarise the evidence for topical retinoids and topical antibiotics due to insufficient high-quality systematic reviews. Future research should consider pooled analysis of data on new emerging drugs for acne treatment (e.g. clascoterone) and focus more on acne complications.

Alpha-Tocopherol-Infused Flexible Liposomal Nanocomposite Pressure-Sensitive Adhesive: Enhancing Skin Permeation of Retinaldehyde

Retinaldehyde (RAL), or retinal, is a vitamin A derivative that is widely used for several skin conditions. However, it is light sensitive and has low water solubility, limiting its efficiency in transdermal delivery. This study developed a novel delivery system for retinal (RAL) using flexible liposomes (FLPs) infused with α-tocopherol succinate (α-TS) to improve stability, and enhance skin permeability. The RAL-FLPs were embedded in pressure-sensitive adhesive (PSA) hydrogels, creating a delivery platform that supports prolonged skin residence and efficient permeation of RAL. The stability and skin permeation as well as human skin irritation and adhesion capabilities were assessed to determine the formulation's safety and efficacy. Our findings suggested that the addition of α-TS could improve liposomal stability and RAL chemical stability. Moreover, the skin permeation and fluorescence microscopic-based studies suggested that the addition of α-TS could enhance skin permeability of RAL through hair follicles. The RAL-FLP was embedded in PSA hydrogels fabricated from 25% GantrezTM S-97 (GT) and 1% hyaluronic acid (Hya) with aluminum as a crosslinker. The PSA hydrogel exhibited desirable peeling and tacking strengths. The developed hydrogels also demonstrated greater skin deposition of RAL compared with its aqueous formulation. Additionally, the RAL-FLP-embedded PSA hydrogels showed no skin irritation and maintained better adhesion for up to 24 h compared to commercial patches. Hence, the developed hydrogels could serve as a beneficial platform for delivering RAL in treating skin conditions.

Topical application of retinyl propionate, 4 hexyl resorcinol, and niacinamide reverses molecular and clinical features of ageing

OBJECTIVE

Topical tretinoin is the mainstay of treatment for photoageing, despite the risk of skin irritation. Cosmetic combination anti-ageing formulations may offer similar efficacy to tretinoin, while improving on tolerability. We aim to demonstrate facial appearance benefits of a novel triple-active cosmetic formulation containing 4-hexylresorcinol, retinyl propionate, and niacinamide and to identify transcriptomic biomarkers underpinning these benefits.

METHODS

A cosmetic prototype formulation containing 4-hexylresorcinol, retinyl propionate, and niacinamide was evaluated ex vivo and in a clinical study. For ex vivo experiments, the cosmetic formulation was applied for 3 days to healthy surgical discard skin from female donors aged 31-51 years, with tissues harvested for gene expression and histologic analyses. In the clinical study, females aged 47-66 years with moderate-to-severe overall visual photodamage on the face applied either topical 0.02% tretinoin or the cosmetic formulation to the face for 16 weeks and to forearms for 1 week, with forearm biopsies taken for gene expression analyses. Visual grading for facial photodamage and VISIA-CR images was taken throughout the clinical study. Safety was visually assessed during site visits, and adverse event monitoring was conducted throughout.

RESULTS

Gene expression analyses in both studies revealed modulation of pathways associated with skin rejuvenation, with several genes of interest identified due to being implicated in ageing and differentially expressed following the application of the cosmetic formulation. Reversal of a consensus skin ageing gene signature was observed with the cosmetic formulation and tretinoin in the ex vivo and clinical studies. Both the cosmetic formulation and tretinoin clinically improved the overall appearance of photoageing, crow's feet, lines, wrinkles, and pores. Adverse event reporting showed that the cosmetic formulation caused less skin irritation than tretinoin.

CONCLUSION

In a double-blind clinical study, the novel triple-active cosmetic combination formulation improved the visual appearance of photoageing similarly to prescription tretinoin. The cosmetic formulation and tretinoin reversed a consensus gene signature associated with ageing. Together with adverse event reporting, these results suggest that the cosmetic formulation may be a well-tolerated and efficacious alternative to tretinoin for improving the visual features of photoageing.

Topical retinoids: Novel derivatives, nano lipid-based carriers, and combinations to improve chemical instability and skin irritation

BACKGROUND

Retinoids, defined as synthetic or natural derivatives of vitamin A, have been extensively studied as anti-aging molecules that are widely applied in cosmetics. However, due to their physicochemical property, retinoids are highly unstable and extremely sensitive to light, oxygen, and temperature. Moreover, topical application of retinoids often leads to cutaneous irritation. These instabilities and irritant properties of retinoids limit their application in cosmetic and pharmaceutical products.

AIM

Our study aimed to provide a systematic review to summarize the mechanisms underlying the instability and irritant properties of retinoids, as well as recent developments in addressing these challenges.

METHODS

A comprehensive PubMed search was conducted using the following keywords: retinoids, chemical instability, skin irritation, retinoid derivatives, nano lipid-based carriers, liposomes, penetration-enhancer vesicles, ethosomes, niosomes, nanoemulsions, solid lipid nanoparticles, vitamins, soothing and hydrating agents, antioxidants and metal chelator and retinol combinations. Relevant researches published between 1968 and 2023 and studies related to these reports were reviewed.

RESULTS

The development of new retinoid derivatives, the utilization of new delivery systems like nano lipid-based carriers and the combination with other compounds like vitamins, soothing agents, antioxidants and metal chelator have been explored to improve the stability, bioavailability, and toxicity of the retinoid family.

CONCLUSIONS

Through advancements in formulation techniques, structure modification of retinoid derivatives and development of novel nano lipid-based carriers, the chemical instability and skin irritation of retinoids has been mitigated, ensuring their efficacy and potency over extended periods.

The Influence of Retinol Ointment on Rabbit Skin (Oryctolagus cuniculus) Ion Transport-An In Vitro Study

Retinoids are known to improve the condition of the skin. Transepithelial transport of sodium and chloride ions is important for proper skin function. So far, the effect of applying vitamin A preparations to the skin on ion transport has not been evaluated. In the study, electrophysiological parameters, including transepithelial electric potential (PD) and transepithelial resistance (R), of rabbit skin specimens after 24 h exposure to retinol ointment (800 mass units/g) were measured in a modified Ussing chamber. The R of the fragments incubated with retinol was significantly different than that of the control skin samples incubated in iso-osmotic Ringer solution. For the controls, the PD values were negative, whereas the retinol-treated specimens revealed positive PD values. Mechanical-chemical stimulation with the use of inhibitors of the transport of sodium (amiloride) or chloride (bumetanide) ions revealed specific changes in the maximal and minimal PD values measured for the retinol-treated samples. Retinol was shown to slightly modify the transport pathways of sodium and chloride ions. In particular, an intensification of the chloride ion secretion from keratinocytes was observed. The proposed action may contribute to deep hydration and increase skin tightness, limiting the action of other substances on its surface.

The pathogenic role of retinoid nuclear receptor signaling in cancer and metabolic syndromes

The retinoid nuclear receptor pathway, activated by the vitamin A metabolite retinoic acid, has been extensively investigated for over a century. This study has resulted in conflicting hypotheses about how the pathway regulates health and how it should be pharmaceutically manipulated. These disagreements arise from a fundamental contradiction: retinoid agonists offer clear benefits to select patients with rare bone growth disorders, acute promyelocytic leukemia, and some dermatologic diseases, yet therapeutic retinoid pathway activation frequently causes more harm than good, both through acute metabolic dysregulation and a delayed cancer-promoting effect. In this review, we discuss controlled clinical, mechanistic, and genetic data to suggest several disease settings where inhibition of the retinoid pathway may be a compelling therapeutic strategy, such as solid cancers or metabolic syndromes, and also caution against continued testing of retinoid agonists in cancer patients. Considerable evidence suggests a central role for retinoid regulation of immunity and metabolism, with therapeutic opportunities to antagonize retinoid signaling proposed in cancer, diabetes, and obesity.

Iberia Consensus on Strategies to Prevent and Manage Irritation by Topical Retinoids in Facial and Trunk Acne

OBJECTIVE

To assess the level of agreement on various prevention and management strategies for irritation caused by topical retinoids in facial and trunk acne in an attempt to alleviate it and minimize treatment discontinuations as much as possible.

METHOD

After reviewing the scientific medical literatura currently available, 4 different areas of uncertainty in the management of irritation caused by topical retinoids in acne were identified. A questionnaire with 34 recommendations was created and evaluated by a group of 133 dermatologists (Delphi methodology).

RESULTS

In 82.3% of the recommendations (28 out of 34), some level of agreement was reached (≥85% agreement in 22 recommendations and≥70% agreement in 6). The results with the highest level of agreement focused on specific patient education strategies (explaining that irritation is an expected reaction at the beginning of treatment and tends to decrease over time), gradual and/or spaced application of topical retinoids (at night time to prevent and/or reduce skin irritation), and the importance of using adjuvant products, specific for acne-prone skin, hydration, photoprotection, and skin cleansing. These recommendations reflect a comprehensive approach to managing irritation associated with topical retinoids and promoting long-term adherence.

CONCLUSIONS

Skin irritation caused by topical retinoids in facial and trunk acne is an expected, mild, and controllable reaction if proper prevention and management guidelines are followed, meaning that it should not be a reason for treatment discontinuation.

[Translated article] Iberia Consensus on Strategies to Prevent and Manage Irritation by Topical Retinoids in Facial and Trunk Acne

OBJECTIVE

To assess the level of agreement on various prevention and management strategies for irritation caused by topical retinoids in facial and trunk acne in an attempt to alleviate it and minimize treatment discontinuations as much as possible.

METHOD

After reviewing the scientific medical literatura currently available, 4 different areas of uncertainty in the management of irritation caused by topical retinoids in acne were identified. A questionnaire with 34 recommendations was created and evaluated by a group of 133 dermatologists (Delphi methodology).

RESULTS

In 82.3% of the recommendations (28 out of 34), some level of agreement was reached (≥85% agreement in 22 recommendations and≥70% agreement in 6). The results with the highest level of agreement focused on specific patient education strategies (explaining that irritation is an expected reaction at the beginning of treatment and tends to decrease over time), gradual and/or spaced application of topical retinoids (at night time to prevent and/or reduce skin irritation), and the importance of using adjuvant products, specific for acne-prone skin, hydration, photoprotection, and skin cleansing. These recommendations reflect a comprehensive approach to managing irritation associated with topical retinoids and promoting long-term adherence.

CONCLUSIONS

Skin irritation caused by topical retinoids in facial and trunk acne is an expected, mild, and controllable reaction if proper prevention and management guidelines are followed, meaning that it should not be a reason for treatment discontinuation.

A Comprehensive Review of the Strategies to Reduce Retinoid-Induced Skin Irritation in Topical Formulation

Currently, retinoids are known for their abundant benefits to skin health, ranging from reducing signs of aging and decreasing hyperpigmentation to treating acne. However, it cannot be denied that there are various side effects associated with the use of retinoids on the skin, one of which is irritation. Several approaches can be employed to minimize the irritation caused by retinoids. This review article discusses topical retinoid formulation technology strategies to reduce skin irritation effects. The methodology used in this study is a literature review of 21 reference journals. The sources used in compiling this review are from PubMed, Scopus, ScienceDirect, and MEDLINE. The findings obtained indicate that the following methods can be used to lessen retinoid-induced irritation in topical formulations: developing drug delivery systems in the formulation, such as encapsulating retinoids, transforming retinoids into nanoparticles, forming complexes (e.g., with cyclodextrin), and binding retinoids with carriers (e.g., polymers, NLC, SLN), adding ingredients with anti-irritation activity, skin barrier improvement, and increased skin hydration to retinoid formulations (e.g., combinations of glucosamine, trehalose, ectoine, sucralfate, omega-9, and 4-t-butylcyclohexanol, addition of ethanolic bark extract of Alstonia scholaris R. Br).

Therapeutic-driven framework for bioequivalence assessment of complex topical generic drug products

Despite the continuous research on understanding how topical drugs and the skin interact, the development of a topical generic product remains a challenge. Due to their local action effect rather than systemic, establishing suitable frameworks for documenting bioequivalence between reference and test formulations is anything but straightforward. In previous years, clinical endpoint trials were considered the gold standard method to demonstrate bioequivalence between topical products. Nevertheless, significant financial and time resources were required to be allocated owing to the inherent complexity of these studies. To address this problem, regulatory authorities have begun to accept alternative approaches that could lead to a biowaiver, avoiding the need for clinical endpoint trials. These alternatives encompass various in vitro and/or in vivo techniques that have been analysed and the benefits and drawbacks of each method have been considered. Furthermore, other factors like the integration of a quality by design framework to ensure a comprehensive understanding of the product and process quality attributes have also been taken into account. This review delves into international regulatory recommendations for semisolid topical products, with a focus on those established by the European Medicines Agency, as well as the Food and Drug Administration. Both approaches were carefully examined, discussing aspects such as acceptance criteria, sample size, and microstructure evaluation. Additionally, novel and innovative therapeutic-driven approaches based on in vitro disease models for the rapid and effective development of topical generic products are presented.

Photoprotective activities of Capsosiphon fulvescens in UVB-induced SKH-1 mice and human keratinocytes

Capsosiphon fulvescens (CF) is a green alga widely consumed in East Asian countries, particularly in Korea. It has a rich composition of vitamins, minerals, dietary fibers, and bioactive compounds, which contribute to its multiple therapeutic properties. Its application ranges from acting as an antioxidant and anti-inflammatory agent to supporting the skin system. Despite these benefits of CF, the effects and mechanisms of action related to photoaging of the skin have not yet been elucidated. To investigate the photoprotective effects of CF against photoaging, both animal (SKH-1 mouse) and cell models (HaCaT cell line) were used in this study. As a result, administering the CF extract over a period of 10 weeks, which included times of Ultraviolet B (UVB) exposure, significantly reduced erythema and various UVB-induced skin changes, such as wrinkle formation, and the thickening of the epidermis and dermis, as well as alterations in the length and depth of wrinkles. Furthermore, our investigation into CF extract's antiwrinkle properties revealed its efficacy in enhancing skin hydration and collagen content, counteracting the collagen depletion and moisture loss induced by UVB radiation. Also, the fact that the levels of p-ERK, p-p38, and p-JNK proteins went down shows that the CF extract might have a controlling effect on the MAPK signaling pathways. Our findings suggest that CF holds significant potential for preventing photoaging, providing a foundation for the development of functional foods or botanical drugs targeting skin aging and related skin disorders. PRACTICAL APPLICATION: This research proved that Capsosiphon fulvescen, a green alga widely consumed in East Asian countries, provides photoprotective activities against UV-induced skin aging. Therefore, Capsosiphon fulvescen can be utilized as functional foods or botanical drugs targeting skin aging and related skin disorders.

Transdermal Delivery of Recombinant Human Growth Hormone by Liposomal Gel for Skin Photoaging Therapy

Human growth hormone (hGH) has emerged as a promising therapeutic agent to prevent and treat skin photoaging. However, the success of hGH therapy largely lies in the availability of an optimal delivery system that enables the efficient delivery of hGH to the dermal layer of the skin. Here, we report a delivery system of hyaluronic acid/liposome-gel-encapsulated hGH (HA/HL-Gel) that can transdermally deliver hGH into the skin for hGH-based photoaging therapy through the upregulation of collagen type I (collagen-I). Specifically, hGH-liposomes were prepared by ethanol injection and then modified with HA to achieve specific targeting. The best formulation of HA/hGH-liposomes (HA/HL) had a high encapsulation efficiency (about 20%), with a size of 180 ± 1.2 nm. The optimized HA/HL was further incorporated into the carbomer gel to form an HA/HL-Gel. The biological activity of HA/HL on human dermal fibroblasts (HDFs) was confirmed by the elevated expression level of collagen-I through the enhanced local formation of insulin-like growth factor-1 (IGF-1) in the photoaging model. Moreover, HA/HL-Gel reduced ultraviolet (UV)-induced erythema and wrinkle formation. Meanwhile, immunohistochemical staining further showed higher levels of collagen-I in the HA/HL-Gel group compared to other groups tested. Taken together, these results demonstrate that HA/HL-Gel treatment could significantly ameliorate skin photoaging and thus may be used as a clinical potential for antiaging therapy.

Formulation development of tazarotene-loaded PLGA nanoparticles for follicular delivery in the treatment of inflammatory skin diseases

Tazarotene is a widely prescribed topical retinoid for acne vulgaris and plaque psoriasis and is associated with skin irritation, dryness, flaking, and photosensitivity. In vitro permeation of tazarotene was studied across the dermatomed human and full-thickness porcine skin. The conversion of tazarotene to the active form tazarotenic acid was studied in various skin models. Tazarotene-loaded PLGA nanoparticles were prepared using the nanoprecipitation technique to target skin and hair follicles effectively. The effect of formulation and processing variables on nanoparticle properties, such as particle size and drug loading, was investigated. The optimized nanoparticle batches with particle size <500 µm were characterized further for FT-IR analysis, which indicated no interactions between tazarotene and PLGA. Scanning electron microscopy analysis showed uniform, spherical, and non-agglomerated nanoparticles. In vitro release study using a dialysis membrane indicated a sustained release of 40-70 % for different batches over 36 h, following a diffusion-based release mechanism based on the Higuchi model. In vitro permeation testing (IVPT) in full-thickness porcine skin showed significantly enhanced follicular and skin delivery from nanoparticles compared to solution. The presence of tazarotenic acid in the skin from tazarotene nanoparticles indicated the effectiveness of nanoparticle formulations in retaining bioconversion ability and targeting follicular delivery.

Lapagyl mitigates UV-induced inflammation and immunosuppression via Foxp3+ Tregs and CCL pathway: A single-cell transcriptomics study

BACKGROUND

As the largest organ of the body, the skin is constantly subjected to ultraviolet radiation (UVR), leading to inflammations and changes that mirror those seen in chronological aging. Although various small molecule drugs have been explored for treating skin photoaging, they typically suffer from low stability and a high incidence of adverse reactions. Consequently, the continued investigation of photoaging treatments, particularly those utilizing herbal products, remains a critical clinical endeavor. One such herbal product, Lapagyl, is derived from the bark of the lapacho tree and possesses antioxidant efficacies that could be beneficial in combating skin photoaging.

PURPOSE

This research aimed to evaluate the efficacy of the herbal product Lapagyl in combating UVR-induced skin photoaging. Additionally, it sought to unravel the mechanisms by which Lapagyl promotes the regeneration of the skin extracellular matrix.

METHODS

To investigate whether Lapagyl can alleviate skin aging and damage, a UVR radiation model was established using SKH-1 hairless mice. The dorsal skins of these mice were evaluated for wrinkle formation, texture, moisture, transepidermal water loss (TEWL), and elasticity. Pathological assessments were conducted to determine Lapagyl's efficacy. Additionally, single-cell sequencing and spectrum analysis were employed to elucidate the working mechanisms and primary components of Lapagyl in addressing UVR-induced skin aging and injury.

RESULTS

Lapagyl markedly reduced UVR-induced wrinkles, moisture loss, and elasticity decrease in SKH-1 mice. Single-cell sequencing demonstrated that Lapagyl corrected the imbalance in cell proportions caused by UVR, decreased UVR-induced ROS expression, and protected basal and spinous cells from skin damage. Additionally, Lapagyl effectively prevented the entry of inflammatory cells into the skin by reducing CCL8 expression and curtailed the UVR-induced formation of Foxp3+ regulatory T cells (Tregs) in the skin. Both pathological assessments and ex vivo skin model results demonstrated that Lapagyl effectively reduced UVR-induced damage to collagen and elastin. Spectrum analysis identified Salidroside as the primary compound remaining in the skin following Lapagyl treatment. Taken together, our study elucidated the skin protection mechanism of the herbal product Lapagyl against UVR damage at the cellular level, revealing its immunomodulatory effects, with salidroside identified as the primary active compound for skin.

CONCLUSION

Our study provided a thorough evaluation of Lapagyl's protective effects on skin against UVR damage, delving into the mechanisms at the cellular level. We discovered that Lapagyl mitigates skin inflammation and immunosuppression by regulating Foxp3+ Tregs and the CCL pathway. These insights indicate that Lapagyl has potential as a novel therapeutic option for addressing skin photoaging.

Individual sol-gel microencapsulation of benzoyl peroxide and tretinoin enables controlled release onto the skin

A combination of benzoyl peroxide (BPO) and tretinoin is recommended for treating acne; however, concurrent administration can be irritating, and coformulation is prevented by BPO-mediated oxidation of tretinoin. In rosacea, benzoyl peroxide has been shown to be efficacious; however, its use has been limited by poor tolerability. To overcome these limitations, the active ingredients can be encapsulated within silica microcapsules. The US Food and Drug Administration has approved 2 products using this technology, a combination of encapsulated benzoyl peroxide and encapsulated tretinoin product for acne vulgaris and encapsulated benzoyl peroxide to treat inflammatory lesions in rosacea. The active ingredients are released through small channels in the silica shell, gradually releasing the active ingredients to the skin. This study describes the stability and release profiles of encapsulated tretinoin and encapsulated benzoyl peroxide from the silica shell in physiologically relevant conditions and provides differentiation from traditional formulations.

Stackable Medical-Grade Skincare for the Cosmetic Medicine Patient: A Long-Term Pilot Assessment

Background

Multiple intrinsic and extrinsic factors influence aging and lead to visible changes in the skin, including dryness, fine lines and wrinkles, loss of elasticity, surface roughness, uneven pigmentation, and loss of luminosity. Although it is well established that a single combination of topicals can address multiple signs of skin aging, it is common for patients' at-home skin treatment routines to include multiple different topicals with different active ingredients. The layering of active ingredients can cause skin irritation, and lead to noncompliance with a consistent routine. Further, multiple active ingredients may exacerbate irritation from in-office aesthetic treatments.

Objectives

To assess the long-term efficacy, safety, tolerability, and patient adherence to a Stackable Treatment topical routine consisting of 4 complementary topical formulations.

Methods

This study examined a daily topical routine (Stackable Treatment routine) consisting of 4 topical formulas with different active ingredients, and evaluated the routine's safety, tolerability, and efficacy in a composite of in-office treatment patients who applied the routine for a minimum of 1 year.

Results

Of the 14 patients, 0 experienced adverse reactions. Improvements to multiple skin parameters were observed, including improvements to skin hydration, surface texture, pigmentation, vasculature, and the appearance of scars. The majority of patients continue to use the Stackable Treatment routine after the study's conclusion.

Conclusions

The combination of low incidence of irritation, high patient satisfaction, and overall efficacy of the routine indicates the Stackable Treatment routine may be well suited as a foundational skin care regimen that can complement in-office aesthetic treatments.

Level of Evidence 4

The Effect of Retinoic Acid on Neutrophil Innate Immune Interactions With Cutaneous Bacterial Pathogens

Vitamin A and its biologically active derivative, retinoic acid (RA), are important for many immune processes. RA, in particular, is essential for the development of immune cells, including neutrophils, which serve as a front-line defense against infection. While vitamin A deficiency has been linked to higher susceptibility to infections, the precise role of vitamin A/RA in host-pathogen interactions remains poorly understood. Here, we provided evidence that RA boosts neutrophil killing of methicillin-resistant Staphylococcus aureus (MRSA). RA treatment stimulated primary human neutrophils to produce reactive oxygen species, neutrophil extracellular traps, and the antimicrobial peptide cathelicidin (LL-37). Because RA treatment was insufficient to reduce MRSA burden in an in vivo murine model of skin infection, we expanded our analysis to other infectious agents. RA did not affect the growth of a number of common bacterial pathogens, including MRSA, Escherichia coli K1 and Pseudomonas aeruginosa; however, RA directly inhibited the growth of group A Streptococcus (GAS). This antimicrobial effect, likely in combination with RA-mediated neutrophil boosting, resulted in substantial GAS killing in neutrophil killing assays conducted in the presence of RA. Furthermore, in a murine model of GAS skin infection, topical RA treatment showed therapeutic potential by reducing both skin lesion size and bacterial burden. These findings suggest that RA may hold promise as a therapeutic agent against GAS and perhaps other clinically significant human pathogens.

Comparison of five retinoids for anti-photoaging therapy: Evaluation of anti-inflammatory and anti-oxidative activities in vitro and therapeutic efficacy in vivo

Over the past decades, increasing evidences have demonstrated that five retinoids, including retinol (ROL), retinol acetate (RAc), retinol propionate (RP), retinol palmitate (RPalm), and hydroxypinacolone retinoate (HPR), can be potential therapeutic agents for skin photoaging. However, therapeutic efficacies and biosafety have never been compared to these compounds. This study aimed to determine the optimal retinoid type(s) for anti-photoaging therapy both in vitro and in vivo. Our data demonstrated that four retinoids (RPalm, RP, HPR and ROL) but not RAc were effective for anti-photoaging treatment at 5 μg/mL in vitro, with action mechanisms associated with antioxidative, anti-inflammatory and anti-skin ECM degradation activities. Notably, both RPalm and RP appeared superior to HPR and ROL for those activities. Importantly, both RPalm and RP were shown to be optimal for anti-photoaging therapy when topically applied at 5 mg/kg in a UVB-induced mice model of photoaging, which is consistent with their high anti-photoaging activities in vitro. Additionally, topical application of these five retinoids showed satisfactory biosafety without causing significant apoptosis in animal organs, although RP application led to a slight decline in animal body weights. Collectively, these data have laid a good foundation for the next development of the clinical application of these retinoids for skin healthcare.

Topical and Systemic Retinoids in the Management of Hidradenitis Suppurativa: A Comprehensive Literature Review

Hidradenitis suppurativa (HS) is a debilitating chronic skin disorder characterized by painful inflammatory nodules, abscesses and sinus tracts involving intertriginous areas and has an adverse impact on patient quality of life. Over the past decade, the therapeutic options of HS have increased significantly to comprise multiple modalities, including topical medication, systemic therapies (mainly antibiotics, retinoids, and biologics), surgical approaches, and lifestyle modifications. Biologics alone or in combination with surgery remain the treatment of choice for moderate to severe disease. However, non-biologic therapies (including retinoids) may be used as monotherapy for mild disease and in combination with biologics and surgical treatment in moderate to severe disease. Retinoids, specifically isotretinoin, acitretin, and alitretinoin, are historically used in the management of HS, supported by anecdotal evidence and with variable treatment response. Although the current American and European guidelines offer different recommendations on the use of retinoids in HS, retinoids remain a valuable ally in HS management. This review provides a comprehensive analysis of the current scientific literature on retinoid therapy (topical and systemic) in HS, highlighting disparities in mechanisms of action, efficacy, and safety to clarify their role in HS treatment.

Influence of the modification of the cosmetic peptide Argireline on the affinity toward copper(II) ions

Argireline (Ac-EEMQRR-NH2 ), a well-known neurotransmitter peptide with a potency similar to botulinum neurotoxins, reveals a proven affinity toward Cu(II) ions. We report herein Cu(II) chelating properties of three new Argireline derivatives, namely, AN4 (Ac-EAHRR-NH2 ), AN5 (Ac-EEHQRR-NH2 ), and AN6 (Ac-EAHQRK-NH2 ). Two complementary experimental techniques, i.e., potentiometric titration (PT) and isothermal titration calorimetry (ITC), have been employed to describe the acid-base properties of the investigated peptides as well as the thermodynamic parameters of the Cu(II) complex formation. Additionally, based on density functional theory (DFT) calculations, we propose the most likely structures of the resulting Cu-peptide complexes. Finally, the cytotoxicity of the free peptides and the corresponding Cu(II) complexes was estimated in human skin cells for their possible future cosmetic application. The biological results were subsequently compared with free Argireline, its Cu(II)-complexes, and the previously studied AN2 derivative (EAHQRR).

Microneedles: A novel clinical technology for evaluating skin characteristics

BACKGROUND

Current methods for evaluating efficacy of cosmetics have limitations because they cannot accurately measure changes in the dermis. Skin sampling using microneedles allows identification of skin-type biomarkers, monitoring treatment for skin inflammatory diseases, and evaluating efficacy of anti-aging and anti-pigmentation products.

MATERIALS AND METHODS

Two studies were conducted: First, 20 participants received anti-aging treatment; second, 20 participants received anti-pigmentation treatment. Non-invasive devices measured skin aging (using high-resolution 3D-imaging in the anti-aging study) or pigmentation (using spectrophotometry in the anti-pigmentation study) at weeks 0 and 4, and adverse skin reactions were monitored. Skin samples were collected with biocompatible microneedle patches. Changes in expression of biomarkers for skin aging and pigmentation were analyzed using qRT-PCR.

RESULTS

No adverse events were reported. In the anti-aging study, after 4 weeks, skin roughness significantly improved in 17 out of 20 participants. qRT-PCR showed significantly increased expression of skin-aging related biomarkers: PINK1 in 16/20 participants, COL1A1 in 17/20 participants, and MSN in 16/20 participants. In the anti-pigmentation study, after 4 weeks, skin lightness significantly improved in 16/20 participants. qRT-PCR showed significantly increased expression of skin-pigmentation-related biomarkers: SOD1 in 15/20 participants and Vitamin D Receptor (VDR) in 15/20 participants. No significant change in TFAP2A was observed.

CONCLUSION

Skin sampling and mRNA analysis for biomarkers provides a novel, objective, quantitative method for measuring changes in the dermis and evaluating the efficacy of cosmetics. This approach complements existing evaluation methods and has potential application in assessing the effectiveness of medical devices, medications, cosmeceuticals, healthy foods, and beauty devices.

Cosmetic Dermatology Concerns in Older Adults

It is important to understand that each layer of facial tissue, from the underlying facial skeleton to the overlying skin, undergoes significant changes during the aging process. Bony support is lost along the mandible and maxilla and the orbital aperture widens. Superficial and deep fat pads undergo volume loss and migration and the overlying skin begins to reveal signs of both intrinsic aging with skin laxity and fine rhytids as well as extrinsic aging in the form of coarse, deeper rhytids and dyspigmentation.

L-4-thiazolylalanine (Protinol), a novel non-proteinogenic amino acid, demonstrates epidermal and dermal efficacy with clinically observable benefits

OBJECTIVE

Facial skin undergoes major structural and functional changes as a result of intrinsic and extrinsic factors. The goal of the current work is to demonstrate L-4-thiazolylalaine (L4, Protinol), a non-proteinogenic amino acid shown to stimulate the production of dermal proteins by fibroblasts, is an alternative efficacious topical ingredient for visible signs of ageing.

METHODS

In vitro studies using 3D human skin tissue models were performed to show changes in protein and gene expression of key dermal markers in samples treated with 0.3% L4 compared to vehicle control. In vivo evaluation of skin turnover was measured in volunteers after treatment with L4 compared to retinol. Skin biopsies (n = 30) were taken to investigate epidermal and dermal changes in cases treated with L4 and compared to retinol. Finally, a clinical evaluation (n = 28) was conducted to assess the efficacy of L4 over a base formulation using various ageing parameters within a population of women 46-66 years old with mild-to-moderate wrinkles.

RESULTS

In vitro studies on 3D tissues displayed significant changes in the dermal matrix via an increase in HA and pro-collagen I production and a decrease in the expression of inflammatory genes. In vivo biopsy studies demonstrated that L4 and retinol independently increased epidermal thickness and collagen remodelling significantly more compared with the base formula. Clinical evaluation showed firmer and smoother skin at day 28 post-treatment with L4 over the vehicle control without causing side effects such as redness or irritation.

CONCLUSION

L4 is a novel, multi-functional ingredient which offers a superior alternative to currently available technologies for improving epidermal and dermal parameters that change during ageing and photodamage.

Marine Bioactive Peptides: Anti-Photoaging Mechanisms and Potential Skin Protective Effects

Skin photoaging, resulting from prolonged exposure to ultraviolet radiation, is a form of exogenous aging that not only impacts the aesthetic aspect of the skin but also exhibits a strong correlation with the onset of skin cancer. Nonetheless, the safety profile of non-natural anti-photoaging medications and the underlying physiological alterations during the process of photoaging remain inadequately elucidated. Consequently, there exists a pressing necessity to devise more secure interventions involving anti-photoaging drugs. Multiple studies have demonstrated the noteworthy significance of marine biomolecules in addressing safety concerns related to anti-photoaging and safeguarding the skin. Notably, bioactive peptides have gained considerable attention in anti-photoaging research due to their capacity to mitigate the physiological alterations associated with photoaging, including oxidative stress; inflammatory response; the abnormal expression of matrix metalloproteinase, hyaluronidase, and elastase; and excessive melanin synthesis. This review provides a systematic description of the research progress on the anti-photoaging and skin protection mechanism of marine bioactive peptides. The focus is on the utilization of marine bioactive peptides as anti-photoaging agents, aiming to offer theoretical references for the development of novel anti-photoaging drugs and methodologies. Additionally, the future prospects of anti-aging drugs are discussed, providing an initial reference for further research in this field.

A proof of concept: Clinical anti-aging efficacy and safety of Lactiplantibacillus plantarum LB244R® applied topically in a double-blinded placebo-controlled study

BACKGROUND

With the increasing age of the westernized population, there is also increasing economic and aesthetic interest in reducing the signs of skin aging. Additionally, the physical aspect of aging can be displeasing and have detrimental effects psychologically in individuals. Probiotics have shown potential as anti-aging agents, albeit proper studies are needed to confirm their potential.

AIMS

Proving that Lactiplantibacillus plantarum LB244R® could alleviate aging signs relative to its placebo vehicle.

PATIENTS/METHODS

In total, 46 subjects were randomly assigned either the ointment with live bacteria, L. plantarum LB244R® or its vehicle ointment, and had to use the assigned ointment twice daily for 56 days. On Day 0, Day 28, and Day 56 subepidermal low echogenic band (SLEB) thickness, dermal density, skin firmness and elasticity, skin hydration, transepidermal water loss (TEWL), skin pH, collagen fiber visualization using confocal microscopy, Crow's feet, spot score, skin smoothness, and complexion radiance were assessed by dermatologists.

RESULTS

All parameters except TEWL improved relative to their baseline (D0) for the active group. L. plantarum LB244R® improved SLEB thickness, dermal density, skin elasticity, skin hydration, and Crow's feet wrinkle score relative to the placebo vehicle ointment.

CONCLUSION

The study demonstrates an anti-aging effect of L. plantarum LB244R® for topical skin use in the first double-blinded, vehicle-ointment placebo-controlled clinical study.

From Traditional Medicine to Advanced Therapeutics: The Renaissance of Phyto-nano Interventions in Psoriasis

Psoriasis is an autoimmune systemic chronic inflammatory disease that exhibits characteristic detrimental effects on the skin, often leading to infections or comorbid conditions. The multifaceted nature of psoriasis has made it very challenging to treat, especially with current chemotherapy options. Therefore, it is essential to consider phytoconstituents as novel alternatives. However, despite demonstrating higher anti-inflammatory, anti-psoriasis, and immunomodulatory potential, their clinical usage is hindered due to their poor physicochemical properties. To address these drawbacks, nanoparticulate drug delivery systems have been developed, helping to achieve better permeation of phytoconstituents through topical administration. This has breathed new life into traditional systems of medicine, particularly in the context of treating psoriasis. In this current review, we present a detailed, comprehensive, and up-to-date analysis of the literature, which will contribute to affirming the clinical role of phyto-nano interventions against psoriasis.

Decreased oxidative stress response and oxidant detoxification of skin during aging

Oxidative stress plays an important role in the skin aging process; however, the mechanisms are not fully elucidated. Especially the changes in various types of skin cells with aging and the key oxidative stress-related genes that play a regulatory role are not clear. In this study, single-cell RNA sequencing data and microarray transcriptome data were used to explore the changes in oxidative stress response and oxidant detoxification capacity of skin cells during aging and oxidative stress-related genes potentially involved in regulating skin aging were searched. The oxidative stress response and oxidant detoxification ability were weakened in the elderly compared with those of the young. Among the different types of skin cells, keratinocytes, melanocytes, vascular endothelial cells, fibroblasts, and lymphatic endothelial cells exhibited a stronger oxidative stress response and oxidant detoxification ability, while immune cells exhibited a weaker oxidative stress response and detoxification capacity. During aging, the oxidative stress response and oxidant detoxification capacity of keratinocytes, fibroblasts, macrophages, and vascular endothelial cells were significantly weakened. Annexin A1 (ANXA1) and Apolipoprotein E (APOE) may be key oxidative stress-related genes affecting skin aging.

Effect of L-4-Thiazolylalanine (Protinol™) on skin barrier strength and skin protection

OBJECTIVES

Skin barrier properties are critical for maintaining epidermal water content, protecting from environmental factors and providing the first line of defense against pathogens. In this study, we investigated the non-proteinogenic amino acid L-4-Thiazolylalanine (L4) as a potential active ingredient in skin protection and barrier strength.

METHODS

L4 on wound healing, anti-inflammatory and anti-oxidant properties were evaluated using monolayers and 3D skin equivalents. The transepithelial electrical resistance (TEER) value was used in vitro as a strong indicator of barrier strength and integrity. Clinical L4 efficacy was assessed for the evaluation of the skin barrier integrity and soothing benefits.

RESULTS

In vitro treatments of L4 show beneficial effects in wound closure mechanism, and we demonstrate that L4 anti-oxidant benefits with markedly increased HSP70 and decreased reactive oxygen species production induced by UVs exposure. Barrier strength and integrity were significantly improved by L4, confirmed clinically by an increase in 12R-lipoxygenase enzymatic activity in the stratum corneum. In addition, soothing benefits of L4 have been shown clinically with the decrease in redness after methyl nicotinate application on the inner arm and the significant reduction of the erythema and the skin desquamation on the scalp.

CONCLUSION

L4 delivered multiple skin benefits by strengthening the skin barrier, accelerating the skin repair process as well as soothing the skin and the scalp with anti-inflammaging effects. The observed efficacy validates L4 as a desirable skincare ingredient for topical treatment.

Advances in the Applications of Extracellular Vesicle for the Treatment of Skin Photoaging: A Comprehensive Review

Skin photoaging is a complex biological process characterized by the accumulation of oxidative damage and structural changes in the skin, resulting from chronic exposure to ultraviolet (UV) radiation. Despite the growing demand for effective treatments, current therapeutic options for skin photoaging remain limited. However, emerging research has highlighted the potential of extracellular vesicles (EVs), including exosomes, micro-vesicles, apoptotic bodies and liposomes, as promising therapeutic agents in skin rejuvenation. EVs are involved in intercellular communication and can deliver bioactive molecules, including proteins, nucleic acids, and lipids, to recipient cells, thereby influencing various cellular processes. This comprehensive review aims to summarize the current research progress in the application of EVs for the treatment of skin photoaging, including their isolation and characterization methods, roles in skin homeostasis, therapeutic potential and clinical applications for skin photoaging. Additionally, challenges and future directions in EVs-based therapies for skin rejuvenation are discussed.

Human Skin Aging and the Anti-Aging Properties of Retinol

The skin is the most-extensive and -abundant tissue in the human body. Like many organs, as we age, human skin experiences gradual atrophy in both the epidermis and dermis. This can be primarily attributed to the diminishing population of epidermal stem cells and the reduction in collagen, which is the primary structural protein in the human body. The alterations occurring in the epidermis and dermis due to the aging process result in disruptions to the structure and functionality of the skin. This creates a microenvironment conducive to age-related skin conditions such as a compromised skin barrier, slowed wound healing, and the onset of skin cancer. This review emphasizes the recent molecular discoveries related to skin aging and evaluates preventive approaches, such as the use of topical retinoids. Topical retinoids have demonstrated promise in enhancing skin texture, diminishing fine lines, and augmenting the thickness of both the epidermal and dermal layers.