Folic acid and creatine improve the firmness of human skin in vivo

Background The decrease in firmness is a hallmark of skin aging. Accelerated by chronic sun exposure, fundamental changes occur within the dermal extracellular matrix over the years, mainly impairing the collagenous network. Aims Based on the qualitative and quantitative assessment of skin firmness, in vitro and in vivo studies were carried out to elucidate the effects of topical folic acid and creatine to counteract this age‐dependent reduction in the amount of collagen. Patients/Methods Topical application of a commercially available formulation containing folic acid and creatine was performed to study effects on skin firmness in vivo using cutometric analysis. Imaging and quantification of collagen density were carried out using multiphoton laser scanning microscopy (MPLSM). To investigate the effects of these compounds on collagen gene expression, procollagen synthesis, and collagen fibril organization, complementary in vitro studies on cultured fibroblast‐populated collagen gels were carried out. Results The underlying structural changes in the collagen network of young and aged sun‐exposed facial skin in vivo were visualized by MPLSM. Topical application of a folic acid‐ and creatine‐containing formulation significantly improved firmness of mature skin in vivo. Treatment of fibroblast‐populated dermal equivalents with folic acid and creatine increased collagen gene expression and procollagen levels and improved collagen fiber density, suggesting that the in vivo effects are based on the overall improvement of the collagen metabolism. Conclusions Employing MPLSM, dermal changes occurring in photo‐aged human skin were visualized in an unprecedented manner and correlated to a loss of firmness. Treatment of aged skin with a topical formulation containing folic acid and creatine counteracted this age‐dependent decline by exerting sustained effects on collagen metabolism. Our results support previous findings on the efficacy of these actives.     

Dermal penetration of creatine from a face-care formulation containing creatine, guarana and glycerol is linked to effective antiwrinkle and antisagging efficacy in male subjects

Background The dermal extracellular matrix provides stability and structure to the skin. With increasing age, however, its major component collagen is subject to degeneration, resulting in a gradual decline in skin elasticity and progression of wrinkle formation. Previous studies suggest that the reduction in cellular energy contributes to the diminished synthesis of cutaneous collagen during aging. Aims To investigate the potential of topically applied creatine to improve the clinical signs of skin aging by stimulating dermal collagen synthesis in vitro and in vivo. Patients/Methods Penetration experiments were performed with a pig skin ex vivo model. Effects of creatine on dermal collagen gene expression and procollagen synthesis were studied in vitro using cultured fibroblast‐populated collagen gels. In a single‐center, controlled study, 43 male Caucasians applied a face‐care formulation containing creatine, guarana extract, and glycerol to determine its influence on facial topometric features. Results Cultured human dermal fibroblasts supplemented with creatine displayed a stimulation of collagen synthesis relative to untreated control cells both on the gene expression and at the protein level. In skin penetration experiments, topically applied creatine rapidly reached the dermis. In addition, topical in vivo application of a creatine‐containing formulation for 6 weeks significantly reduced the sagging cheek intensity in the jowl area as compared to baseline. This result was confirmed by clinical live scoring, which also demonstrated a significant reduction in crow’s feet wrinkles and wrinkles under the eyes. Conclusions In summary, creatine represents a beneficial active ingredient for topical use in the prevention and treatment of human skin aging.     

Topically applied L-carnitine effectively reduces sebum secretion in human skin

Background Oily skin condition is caused by an excessive sebaceous gland activity, resulting in an overproduction of sebum, giving the skin an undesired shiny, oily appearance. Aims To identify an active substance that reduces sebum production in human sebaceous glands by regulating fat metabolism in a natural way. Patients/Methods The effects of l ‐carnitine on β‐oxidation and intracellular lipid content were investigated in vitro using the human sebaceous cell line SZ95. Penetration experiments utilizing pig skin as a model system were performed with a cosmetic formulation containing radioactively labeled l ‐carnitine. To determine the in vivo effects, a vehicle‐controlled, randomized study was carried out using a cosmetic formulation containing 2%l ‐carnitine for 3 weeks. Sebum production was investigated utilizing the lipid‐absorbent Sebutape^®. Results SZ95 cells treated with 0.5% or 1%l ‐carnitine demonstrated a significant concentration‐dependent increase in β‐oxidation compared to control cells. Following the treatment with l ‐carnitine, intracellular lipid concentrations decreased significantly in a dose‐dependent manner compared with untreated control cells. In skin penetration experiments, topically applied l ‐carnitine reached the dermis. In addition, topical in vivo application of a formulation containing 2%l ‐carnitine for 3 weeks significantly decreased the sebum secretion rate compared to the treatment with vehicle. Conclusions Our results show that the treatment of human sebocytes with l ‐carnitine significantly augments β‐oxidation and significantly decreases intracellular lipid content in human sebocytes. Topically applied l ‐carnitine is bioavailable and leads to a significant sebum reduction in vivo. In conclusion, l ‐carnitine represents a valuable compound, produced naturally within the body, for the topical treatment of oily skin in humans.     

Visualizing CD4 T‐cell migration into inflamed skin and its inhibition by CCR4/CCR10 blockades using in vivo imaging model

Background Chemokines are critical mediators of T‐cell homing into inflamed skin. The complex nature of this multicellular response makes it difficult to analyse mechanisms mediating the early responses in vivo. Objectives To visualize directly T‐cell homing into inflamed skin and its inhibition by blockades using a unique noninvasive confocal microscopy. Materials and methods A mouse model of allergic contact dermatitis was used. T cells from oxazolone‐sensitized and ‐challenged Balb/c mice were first analysed phenotypically in vitro. CD4 T cells were then labelled with a tracker dye and transferred into Balb/c‐SCID mice. The recipient mice were challenged with oxazolone and CD4 T‐cell homing into inflamed skin was visualized. Results T cells with the skin homing receptors CCR4 and CCR10 were increased in the affected skin and draining lymph nodes, and effectively attracted by their specific chemokines CCL17, CCL22 and CCL27 in vitro. Using in vivo imaging, T‐cell migration into the inflamed skin was observed at 2 h after application, peaking at 12 h and continuing for 48 h. Simultaneous systemic administration of neutralizing antibodies against CCR4 ligands (CCL17 and CCL22) and CCR10 ligand (CCL27) led to a significant suppression of T‐cell migration and skin inflammation. Conclusions Our data indicate that these tissue‐selective adhesion molecules and chemokine/receptor pathways act in concert to attract specialized T‐cell populations to mediate cutaneous inflammation. The in vivo imaging technique can be applicable to other models of cutaneous diseases to help with better understanding of the pathogenesis and monitoring the therapeutic effects.     

Natural Arctium lappa fruit extract improves the clinical signs of aging skin

Background Subclinical, chronic tissue inflammation involving the generation of cytokines (e.g., interleukin‐6 and tumor necrosis factor‐alpha) might contribute to the cutaneous aging process. Aims This study aims to screen for an active ingredient with anti‐inflammatory (i.e., reduction of interleukin‐6 and tumor necrosis factor‐alpha) and matrix‐stimulating efficacy which improves the clinical signs of skin aging in vivo. Patients/methods In vitro studies with pure Arctiin were performed investigating the inhibition of cytokine induction and stimulation of collagen neosynthesis. In vivo home‐in‐use studies using an Arctium lappa fruit extract–containing formulation were carried out to determine procollagen and hyaluronan synthesis, hyaluronan synthase‐2 gene expression, and reduction of wrinkle volume after treatment. Results In vitro studies on human dermal fibroblasts and monocyte‐derived dendritic cells supplemented with pure Arctiin showed relative to untreated control cells a stimulation of collagen synthesis and a decrease in interleukin‐6 and tumor necrosis factor‐alpha concentration, respectively. In addition, topical in vivo application of an A. lappa fruit extract–containing formulation for 12 weeks significantly stimulated procollagen synthesis and increased hyaluronan synthase‐2 expression as well as hyaluronan levels compared to vehicle‐treated control areas. Similarly, after a 4‐week treatment with an A. lappa fruit extract–containing formulation, wrinkle volume in the crow's feet area was significantly reduced as compared to treatment with the vehicle. Conclusions Our data show that topical treatment with a natural A. lappa fruit extract significantly improves the metabolism of the dermal extracellular matrix and leads to a visible wrinkle reduction in vivo. In conclusion, A. lappa fruit extract represents a targeted means to regenerate dermal structures and, thus, offers an effective treatment option for mature skin.     

Molecular interactions of plant oil components with stratum corneum lipids correlate with clinical measures of skin barrier function

Plant‐derived oils consisting of triglycerides and small amounts of free fatty acids (FFAs) are commonly used in skincare regimens. FFAs are known to disrupt skin barrier function. The objective of this study was to mechanistically study the effects of FFAs, triglycerides and their mixtures on skin barrier function. The effects of oleic acid (OA), glyceryl trioleate (GT) and OA/GT mixtures on skin barrier were assessed in vivo through measurement of transepidermal water loss (TEWL) and fluorescein dye penetration before and after a single application. OA's effects on stratum corneum (SC) lipid order in vivo were measured with infrared spectroscopy through application of perdeuterated OA (OA‐d₃₄). Studies of the interaction of OA and GT with skin lipids included imaging the distribution of OA‐d₃₄ and GT ex vivo with IR microspectroscopy and thermodynamic analysis of mixtures in aqueous monolayers. The oil mixtures increased both TEWL and fluorescein penetration 24 h after a single application in an OA dose‐dependent manner, with the highest increase from treatment with pure OA. OA‐d₃₄ penetrated into skin and disordered SC lipids. Furthermore, the ex vivo IR imaging studies showed that OA‐d₃₄ permeated to the dermal/epidermal junction while GT remained in the SC. The monolayer experiments showed preferential interspecies interactions between OA and SC lipids, while the mixing between GT and SC lipids was not thermodynamically preferred. The FFA component of plant oils may disrupt skin barrier function. The affinity between plant oil components and SC lipids likely determines the extent of their penetration and clinically measurable effects on skin barrier functions.     

Efficacy and cosmetic results of contact gel cooling of the skin during non‐ablative laser procedures

Background: Aesthetic laser treatments of the skin result in collateral thermal damage to the adjacent tissue if it is not cooled.A recently developed gel cooling pad is designed to be applied to the treated area and then penetrated by the laser beam during treatment. Patients and methods: 97 treatments of 61 patients were documented.Vascular malformations (telangiectasia, hemangioma, spider nevi, nevi flammei, scars) were treated 52 times with the LBO laser Idas (532 nm).With the alexandrite laser Arion (755 nm), 13 treatments for hypertrichosis were evaluated. Pigmentation disorders (tattoos,lentigines,segmented melanocytic hyperpla‐sia, nevus of Ota) were treated 32 times with the ruby laser Sinon (694 nm). Additionally, we measured the energy of the laser systems through a glass plate with and without the hydrogel pad. Furthermore, we examined patient satisfaction as well as noting application experiences of the treating doctors. Results: Our examinations showed a negligible loss of energy in clinical use, with good patient satisfaction and good cosmetic results. Conclusions:Use of the hydrogel pad is recommended during non‐ablative cosmetic laser treatments of the skin.It is especially convenient for the treatment of vascular malformations of the face.     

In vitro antioxidant activity and in vivo efficacy of topical formulations containing vitamin C and its derivatives studied by non-invasive methods

Background/purpose: Vitamins C and its derivatives, mainly due to their antioxidant properties, are being used in cosmetic products to protect and to reduce the signs of ageing. However, there are no studies comparing the effects of vitamin C [ascorbic acid (AA)] and its derivatives, magnesium ascorbyl phosphate (MAP) and ascorbyl tetra‐isopalmitate (ATIP), when vehiculated in topical formulations, mainly using objective measurements, which are an important tool in clinical efficacy studies. Thus, the objective of this study was to determine the in vitro antioxidant activity of AA and its derivatives, MAP and ATIP, as well as their in vivo efficacy on human skin, when vehiculated in topical formulations. Methods: The study of antioxidant activity in vitro was performed with an aqueous and a lipid system. The in vivo methodology consisted of the application of these formulations on human volunteers' forearm skin and the analysis of the skin conditions after 4‐week period daily applications in terms of transepidermal water loss (TEWL), stratum corneum moisture content and viscoelasticity using a Tewameter^®, Corneometer^® and Cutometer^®, respectively. Results: In vitro experiments demonstrated that in an aqueous system, AA had the best antioxidant potential, and MAP was more effective than ATIP, whereas in the lipid system ATIP was more effective than MAP. In in vivo studies, all formulations enhanced stratum corneum moisture content after a 4‐week period daily applications when compared with baseline values; however, only the formulation containing AA caused alterations in TEWL values. The formulations containing MAP caused alterations in the viscoelastic‐to‐elastic ratio, which suggested its action in the deeper layers of the skin. Conclusion: AA and its derivates presented an in vitro antioxidant activity but AA had the best antioxidant effect. In in vivo efficacy studies, only the formulation containing AA caused alterations in TEWL values and the formulation containing MAP caused alterations in the viscoelastic‐to‐elastic ratio. This way, vitamin C derivatives did not present the same effects of AA on human skin; however, MAP showed other significant effect‐improving skin hydration, which is very important for the normal cutaneous metabolism and also to prevent skin alterations and early ageing.     

A three‐dimensional skin equivalent reflecting some aspects of in vivo aged skin

Human skin undergoes morphological, biochemical and functional modifications during the ageing process. This study was designed to produce a 3‐dimensional (3D) skin equivalent in vitro reflecting some aspects of in vivo aged skin. Reconstructed skin was generated by co‐culturing skin fibroblasts and keratinocytes on a collagen–glycosaminoglycan–chitosan scaffold, and ageing was induced by the exposition of fibroblasts to Mitomycin‐C (MMC). Recently published data showed that MMC treatment resulted in a drug‐induced accelerated senescence (DIAS) in human dermal fibroblast cultures. Next to established ageing markers, histological changes were analysed in comparison with in vivo aged skin. In aged epidermis, the filaggrin expression is reduced in vivo and in vitro. Furthermore, in dermal tissue, the amount of elastin and collagen is lowered in aged skin in vivo as well as after the treatment of 3D skin equivalents with MMC in vitro. Our results show histological signs and some aspects of ageing in a 3D skin equivalent in vitro, which mimics aged skin in vivo.     

Neck skin rejuvenation: Histological and clinical changes after combined therapy with a fractional non-ablative laser and stabilized hyaluronic acid-based gel of non-animal origin

Abstract

Background: The laser Affirm? (LA) is a microthermal, non-ablative fractional laser used for skin rejuvenation. Restylane Vital? Light (RVL) in the Restylane^® Injector, a formulation of stabilized hyaluronic acid-based gel of non-animal origin, is indicated for rejuvenation of delicate skin. Objectives: To assess the interaction between the LA and RVL in aging skin of the neck using clinical and histological parameters, and to determine whether combined therapy is effective. Methods: Nine female patients aged 42–62 years received four treatments, each comprising RVL followed immediately by LA treatment. Photographs and skin biopsies were taken before treatment, after the fourth session and 1 month later. Results: Improvements in fine wrinkles, tightness and skin texture were observed. Histologic evaluations showed favourable changes in cellularity, collagen and elastic fibres. Laser-induced effects (400 μm) and an inflammatory reaction (1000 μm) were seen. RVL was present at the mid–deep dermis (1000–1500 μm). Conclusions: Combined treatment with the LA and RVL improved skin appearance and structure as assessed, for the first time, with histology. The LA produced epidermal and superficial dermal changes whereas RVL acted deeper, together treating the full skin thickness.     

Defocused diode laser therapy (830 nm) in the treatment of unresponsive skin ulcers: a preliminary trial

BACKGROUND: Skin ulcers with compromised healing remain a major problem for plastic and dermatological surgeons. Low incident levels of laser energy have been shown to increase the blood flow rate and volume and to accelerate the wound healing process, thus raising the possibility in augmenting treatment for skin ulcers.

METHODS: Preliminary controlled experiments with a 830?nm GaAlAs diode laser in axial pattern flap survival in the rat model showed statistically significant improvement in survival for the irradiated versus unirradiated control animals. In the present study, a newly developed defocused GaAlAs diode laser (830?nm, continuous wave, 669?mW/cm²) was applied once or twice per week in an uncontrolled study of five patients (aged between 5 and 81 years old, average 46.6 years old, doses from 6.3?J/cm² to 21?J/cm²) with previously unresponsive ulcers of various aetiologies.

RESULTS: In all five patients, the ulcers healed completely between 3 weeks and 7 months (22.8±19.3 weeks), without recurrence during a minimum 12‐month follow‐up.

CONCLUSIONS: Defocused 830?nm diode laser therapy was well tolerated, and was very effective in the treatment of this small number of compromised skin ulcers of different aetiologies and in a large range of patient ages. Further controlled studies in larger populations are required. Defocused diode laser therapy nonetheless appears to be a very useful adjunctive method in the treatment of slow‐to‐heal and non‐healing skin ulcers.     

Combination radiofrequency and diode laser for treatment of facial rhytides and skin laxity

Purpose. As the demand for noninvasive procedures to address cutaneous aging issues has increased, novel nonablative lasers and radiofrequency (RF) devices have recently emerged. The objective of this study was to evaluate the safety and efficacy of a combination RF/diode laser device designed to target both skin laxity and facial rhytides.

Materials and methods. Twenty patients (skin phototypes I–III) with mild to moderate rhytides and skin laxity received three treatments at 3‐week intervals with a combined radiofrequency and diode laser system (Polaris WR^TM, Syneron Medical Ltd, Israel). Clinical improvement was determined through masked assessments by the treating investigator and two independent assessors after each treatment session, and at 3 and 6 months after the final treatment using a quartile grading scale (1<25%; 2?=?25–50%; 3?=?51–75%; 4>75% improvement). Patient satisfaction surveys were also obtained at end‐study.

Results. Modest improvement in facial rhytides was observed in the majority of patients as evidenced by investigator and independent assessor evaluations. Patient satisfaction surveys reflected the clinical improvements observed. Side effects were mild and limited to transient erythema and edema. No scarring or pigmentary alteration was seen.

Conclusions. The Polaris WR^TM, which sequentially delivers radiofrequency and diode laser energy, is safe and effective for treatment of mild to moderate facial rhytides and skin laxity. Multiple treatment sessions and laser passes were well tolerated by patients due to the minimization of individual optical and radiofrequency energies used.     

The lamellar peel: A sequential nonablative and ablative laser treatment for facial skin rejuvenation

Objectives. Ablative and nonablative laser treatments have established themselves independently in the rejuvenation of aging skin. This study was designed to determine the effects of sequential nonablative and ablative laser treatments on facial skin.

Materials and methods. Twelve patients, ages 32–56 years, with skin phototypes I‐IV, received three treatments spaced six weeks apart. Each treatment consisted of one pass with 1319‐nm Nd:YAG laser at 16 J/cm², 50 ms pulse duration. This was immediately followed by one pass of 2940‐nm Er:YAG laser at 5 J/cm². Photographs and biopsies were taken prior to the first treatment and following the third treatment.

Results. Clinical improvements in facial skin tone and texture, acne scarring and dyschromia were noted in all patients. Histologic changes included a more compact epidermal granular layer and lamellar collagen formation with decreased solar elastosis in the dermis. Compared to controls, treated skin had a thicker, more homogeneous papillary dermis.

Conclusion. The sequential use of nonablative and superficial ablative laser treatments clinically and histologically improved photodamaged and chronologically aged skin. This occurred with minimal recovery and little morbidity, demonstrating this laser application to be a safe and effective method for facial rejuvenation.     

Soybean-fragmented proteoglycans against skin aging

Objective: The majority of age-dependent skin changes happen in the dermis layer inducing changes in skin collagen and in the proteoglycans. The main aim of this work is to study the efficacy of a Proteum serum, containing soybean-fragmented proteoglycans, against skin aging. Materials and methods: In vitro tests were performed to evaluate the Proteum serum ability on activating the production of collagen and proteoglycans. An in vivo long-term study was performed to determine the efficacy of the Proteum serum when applied on skin. Protection of healthy skin against detergent-induced dermatitis and the antioxidant properties of the applied Proteum serum were also studied. Results and discussion: The in vitro tests demonstrated that the Proteum serum was able to elevate the production of molecules which are essential for supporting the dermal extracellular matrix organization. These results were correlated by the in vivo measurements where a clear trend on improving the measured skin parameters due to the Proteum serum application was found. Conclusions: A beneficial effect of the Proteum serum was demonstrated with an improvement in the skin roughness and a reinforcement of the skin barrier function. Moreover, a significant protector effect on human stratum corneum against lipids peroxides (LPO) was demonstrated.     

Pain inhibition in Q‐switched laser tattoo removal with pneumatic skin flattening (PSF): A pilot study

Background: Tattoo removal with a Q‐switched laser is often a painful procedure. The sensation of pain associated with the treatment is immediate and acute. Application of topical anesthesia to the treated area of the skin is time‐consuming, with only very moderate pain relief. Objective: To determine the efficacy of pneumatic skin‐flattening (PSF) technology which utilizes an evacuation chamber that generates skin compression and activates tactile neural receptors in the skin, resulting in afferent inhibition of pain transmission in the dorsal horn (the ‘gate theory’). Methods: Eleven young patients aged 17–25 years old (nine females, two males) who were treated for tattoo removal were enrolled in the study. The patients were treated by a Q‐switched Nd:YAG laser. Acute pain evaluation was performed on all 11 patients: one to two sites per patient with PSF and one to two control sites without PSF. When patients were treated with PSF, they knew they were being treated with a device that might reduce pain. This may have influenced patients' perception of pain. The evaluation was based on a modified McGill pain questionnaire. Results: All 11 patients completed the study. A lower pain score with PSF was observed in all but one patient (10/11 or 91%). The average reduction of pain is by two levels: from very painful to very mild pain. The energy transmission of the PSF window is 95%, resulting in essentially identical efficacy of the PSF treatment and the regular non‐PSF treatment. Conclusion: This pilot study indicates that PSF technology may reduce pain in tattoo removal with medium energy density Q‐switched lasers (3–5?J/cm²).     

Acyclovir skin depot characterization following in vivo iontophoretic delivery

Background/purpose: Current Herpes labialis infection treatment by oral, parenteral or topical routes is inefficient. The objective of this study was to investigate the use of iontophoresis for improved topical delivery of acyclovir (ACV) in vivo in hairless rat. Methods: Iontophoresis was performed for 10 min using a 5% ACV gel formulation. Tape stripping and skin extractions were performed at different time points following treatment for drug quantification in stratum corneum (SC) and underlying skin, respectively. Results: Fourfold more ACV was detected in the SC immediately following 10‐min iontophoresis as compared with passive delivery. Similarly, high ACV levels (29.27±3.52 μg/cm²) were achieved in the underlying skin following a single 10‐min iontophoretic treatment while no drug detected following passive delivery (P<0.05). At 24‐h post‐iontophoresis, ACV levels in the SC decreased with a corresponding increase in the underlying skin due to drug migration. After 24‐h post‐iontophoresis, drug levels gradually decreased in both skin compartments until no ACV was detected at 72‐h post‐iontophoresis. Conclusion: Iontophoretic delivery of ACV resulted in high drug levels in skin layers to form a drug depot, which persisted over 2–3 days.     

Right–left comparison study of hydrogel pad versus transparent fluid gel in patients with dermo‐cosmetic lesions undergoing non‐ablative laser therapy

Objective: The aim of this study was to compare the cooling properties of a transparent hydrogel pad and a fluid gel in patients with dermo‐cosmetic lesions undergoing non‐ablative laser therapy. Methods: Patients enrolled in this prospective, open, randomized study had vascular or pigmented lesions in the face, v‐neck or hands. The assigned test product was applied to the skin on the left side of the lesion whereas the other product was applied to the opposite side. Primary endpoints were the maximal pain intensity during laser treatment and the number of blisters and crusts after laser treatment. Results: Twenty‐one patients were enrolled and underwent laser procedures using a hydrogel pad and fluid gel (16 patients with vascular and five with pigmented lesions). Maximal local pain severity was lower in all 21 patients on the side where the transparent hydrogel pad was applied (p<0.001); the transparent hydrogel pad was associated with a more cooling effect (p<0.001) and less erythema (p = 0.027). The number of crusts was similar for both test products. Conclusion: Overall, laser therapy was more convenient for the patients on the side where the transparent hydrogel pad was applied. The transparent hydrogel pad offers an alternative skin cooling method worth considering for non‐ablative laser therapy.     

A novel treatment option for photoaged skin

Background DNA damage as a result of ultraviolet (UV) exposure plays an important role in the progression of cutaneous aging. Both folic acid and creatine have been linked to the process of DNA protection and repair. Aims This study aims to investigate the effects of a commercially available folic acid– and creatine‐containing formulation to fight the clinical signs of premature skin aging. Patients/methods Both in vitro and in vivo home‐in‐use studies using a folic acid– and creatine‐containing formulation were performed aiming to elucidate the efficacy in terms of improvement of skin regeneration, protection from UV‐induced DNA damage (Comet assay), reduction of wrinkle volume, and skin visco‐elasticity. Furthermore, clinical evaluation and photography were carried out to determine the improvement of clinically graded parameters after treatment. Results Cultured full‐thickness epidermal skin models supplemented with folic acid and creatine after epithelial perturbation showed an accelerated skin regeneration compared to untreated control models. Similarly, application of a folic acid– and creatine‐containing formulation significantly improved epidermal turnover in vivo as evidenced by smaller corneocytes derived from the treated sites relative to the vehicle‐treated sides. In addition, topical in vivo application of this formulation significantly protected from UV‐induced DNA lesions, increased skin firmness, and reduced wrinkle volume compared to untreated control areas. Expert grading confirmed a significant decrease of fine and coarse wrinkles in the periocular region as well as overall wrinkles, tactile roughness, and laxity. Conclusions Taken together, these results show that the combination of folic acid and creatine significantly accelerates epidermal skin regeneration in vitro and in vivo. Together with the finding of improved biomechanical skin properties, we conclude that the described topical formulation provides an effective treatment option for (photo)‐aged skin.     

Effect of ultraviolet adaptation on the ultraviolet absorption spectra of human skin in vivo

Background: The absorption spectrum of human skin provides a basis for the estimation of the possible photobiological impact of ultraviolet (UV) radiation. The optical properties of human skin in the UV spectral range have so far mainly been measured ex vivo due to a lack of an appropriate in vivo technique and the change of optical properties during the course of adaptation to higher UV doses has hardly been addressed. Methods: We have determined the absorption spectra of human skin in vivo in the wavelength range from 290 to 341 nm in 3 nm steps using laser optoacoustics. In this technique, optical properties are derived from the pressure profile generated by absorbed light energy in the sample. Spectra from the volar and dorsal aspects of the forearm of 20 subjects were compared, i.e. sites with native and various facultative pigmentation. Results: UV adaptation shows as an increase in absorption coefficients over the entire measured UV range and especially in short‐range UVB. Subject groups with high vs. low UV exposure can be discriminated by analyzing the difference absorption spectra between dorsal and volar aspects of the forearm. No dependence on the subject's phototype was seen in the degree of adaptation. Conclusion: The difference between native and facultative pigmentation may be explained by the absorption properties of the two prime chromophores responsible for adaptation to higher UV exposure: melanin and keratin. Stronger pigmentation, i.e. a higher melanin concentration, is found as an increase of absorption coefficients over the entire UVA‐II/UVB range. The thickening of the horny layer and accordingly, a higher influence of keratin on the absorption spectra is prominent especially in the UVB region.     

A Chinese experience of fractional Ultrapulsed CO2 laser for skin rejuvenation

Abstract

Background and objectives: The ablative fractional CO₂ laser has been successfully used in treating photoaged skin in the Caucasian population. However, its application in Asian skin has not been widely reported. The purpose of this study is to observe the efficacy and safety of the protocol ‘ActiveFX’ for photodamaged facial skin in Chinese patients. Methods: A non-sequential fractional ultrapulsed CO₂ laser with specific settings is used in addition to a new computer pattern generator (CPG). Twenty patients received a single-session, single-pass, ablative fractional treatment on a split face. The patients were evaluated at baseline, and 1 and 3 months (M1, M3) after the treatment using a quartile grading scale. They were also asked to assess their overall satisfaction using a 4-point scale. The improvement of the coarse wrinkles was also quantitatively analyzed with a 3D in vivo imaging system. Results: At M1 and M3, the blinded investigator rated global improvement as 2.8 ± 0.95 and 3.00 ± 0.73, which was consistent with the patients' assessment (2.55 ± 0.83 at M1 and 3.15 ± 0.88 at M3). The roughness analysis (Rz) demonstrated a significant decrease in periorbital wrinkles (p < 0.0001). Minimal and reversible adverse side effects and rapid healing were noted. Conclusions: Non-sequential fractional ultrapulsed CO₂ laser resurfacing (ActiveFX) is considered an excellent treatment modality for photodamaged Chinese facial skin.