Laser skin rejuvenation: epidermal changes and collagen remodeling evaluated by in vivo confocal microscopy

Stem Cell-Derived Extracellular Vesicle-Bearing Injectable Hydrogel for Collagen Generation in Dermis

Despite the remarkable advances of dermal fillers that reduce wrinkles caused by dermis thickness reduction, they still lack effective hydrogel systems that stimulate collagen generation along with injection convenience. Here, we develop a stem cell-derived extracellular vesicle (EV)-bearing thermosensitive hydrogel (EVTS-Gel) for effective in vivo collagen generation. The TS-Gel undergoes sol-gel transition at 32.6 °C, as demonstrated by the storage and loss moduli crossover. Moreover, the TS-Gel and the EVTS-Gel have comparable rheological properties. Both hydrogels are injected in a sol state; hence, they require lower injection forces than conventional hydrogel-based dermal fillers. When locally administered to mouse skin, the TS-Gel extends the retention time of EVs by 2.23 times. Based on the nature of the controlled EV release, the EVTS-Gel significantly inhibits the dermis thickness reduction caused by aging compared to the bare EV treatment for 24 weeks. After a single treatment, the collagen layer thickness of the EVTS-Gel-treated dermis becomes 2.64-fold thicker than that of the bare EV-treated dermis. Notably, the collagen generation efficacy of the bare EV is poorer than that of the EVTS-Gel of a 10× lesser dose. Overall, the EVTS-Gel shows potential as an antiaging dermal filler for in vivo collagen generation.

Fractional CO2 Laser for Vulvar Tissue Rejuvenation: A Prospective Study

Objective: Aging and changes in hormone levels influence the appearance of the vulva, including the texture, pigmentation, and other manifestations, all of which may largely affect the physical and mental health of women. This study aimed to evaluate the efficacy and safety of fractional carbon dioxide (CO2) laser treatment for vulvar rejuvenation in Chinese women. Background: The limited options currently available for vulvar rejuvenation raise concerns. There is insufficient evidence to determine whether the fractional CO2 laser can safely and effectively rejuvenate the vulvar area for women of various ages and races. Methods: The study included 17 patients (mean age = 36.4 years) treated three times by continuous fractional CO2 laser with an interval of 1 month between each session. The primary outcomes were changes in vulva texture and pigmentation. Treatment was evaluated using images of the patients. Baseline and posttreatment images were collected and evaluated using a scoring system from 0 to 3 to grade the vulvar texture and pigmentation changes. In addition, patients rated their degree of vaginal rejuvenation after the treatment using a scoring system from 0 to 3. Results: Fractional CO2 laser treatment effectively and significantly increased vulvar texture and decreased vulvar pigmentation after three sessions (p < 0.05). Patients also self-reported noticeable improvement. There were no adverse reactions during the treatment and follow-up. Conclusions: Fractional CO2 laser treatment is a safe and effective method for vulvar rejuvenation in women.

Laser Therapy for Vulvar Lichen Sclerosus, a Systematic Review

Lichen sclerosus (LS) is a chronic inflammatory disease that mainly affects the anogenital area, with a higher incidence in post-menopausal women. In the long term, it can lead to loss of vulvar architecture or progress to squamous cell carcinoma. The evidence-based treatment involves high-potency topical corticosteroids in long regimens. However, second-line treatments are not well-established, including laser therapy. This current study aims to assess the level of evidence supporting this therapy. We conducted a search for primary-level studies published before April 2023 through MEDLINE/PubMed, Embase, Web of Science, Scopus, and CENTRAL, with no restrictions on the publication language or date. The methodological quality and risk of bias of the included studies were evaluated using the updated Cochrane Collaboration's tool for assessing risk of bias (RoB-2). Six studies (177 patients) met our eligibility criteria. Laser therapy was compared to topical corticosteroid treatment in five out of six studies. No significant histological differences were found, except for an increase in collagen production in the laser group. A greater reduction in itching, pain, and dyspareunia at 1 and 3 months of treatment in the laser group, as well as in the Skindex-29 at 6 months, was reported. Patient satisfaction was significantly higher among those who received laser therapy. Tolerability was excellent. No significant differences were observed in any of the previous aspects in the study compared to the placebo. In conclusion, there is not enough evidence to recommend laser therapy as a standalone treatment.

The Effectiveness of Using CO2 Fractional Laser and Mebo Burn Ointment Together in Treating Scars on the Face after Surgery

Background

This study aimed to investigate the efficacy and safety of CO2 fractional laser combined with Mebo burn ointment in treating facial postoperative scars.

Methods

Sixty patients with facial postoperative scars in the department of plastic surgery of Sun Yat-sen Memorial Hospital from January 2020 to June 2022 were divided into a control group (30 cases) and a study group (30 cases). Both groups received CO2 fractional laser treatment, but the study group also received Mebo burn ointment application.

Results

The study found that both methods resulted in a significant decrease in Sawada score and a significant increase in Investigator Global Assessment score after treatment (P < 0.05), with the study group showing a more significant improvement and higher patient satisfaction (P < 0.05). All patients experienced varying degrees of bleeding, swelling, and erythema immediately after treatment, with two cases of pigmentation and two cases of persistent erythema in the control group, and one case of pigmentation and one case of persistent erythema in the study group. Adverse reactions were minimal, with the study group showing better tolerance.

Conclusions

The study suggests that CO2 fractional laser combined with Mebo burn ointment is an effective and safe treatment for facial postoperative scars.

Radiofrequency energy in the treatment of erectile dysfunction-a novel cohort pilot study on safety, applicability, and short-term efficacy

The erectile mechanism depends, in part on the intactness of the collagen components in the penis. As such, impaired collagen may have a deleterious effect on erectile function. Radiofrequency energy has been shown to renew and restore spatial structural arrangement of collagen fibers; therefore, treatment of erectile dysfunction with radiofrequency could lead to anatomical and physiological changes at the penile tissue level and could lead to improvement in the erectile mechanism. We conducted this study to assess the effect of radiofrequency treatment on erection quality. We evaluated the safety, applicability, and efficacy of a self-applied, handheld, low-intensity radiofrequency device (Vertica®) in men with moderate and mild-to-moderate organic erectile dysfunction. The treatment protocol consisted of 12 treatments (twice a week during the 1st month, and once a week during the 2nd month), and each participant treated himself individually. Treatment outcomes were evaluated using the International Index of Erectile Function, Erection Hardness Scale, Erectile Dysfunction Index of Treatment Satisfaction, Benefit, Satisfaction & Willingness to continue, Quality of Erection Questionnaire, Sexual Quality of Life questionnaires and specific questions addressing side effects and ease of use. Twenty-eight out of 32 men (mean age 59.5 ± 9.8, range: 41-78 years) completed a one-month follow-up after treatment. Mean International Index of Erectile Function (43.7. ± 7.8 vs. 60.9 ± 10.8, p < 0.01), International Index of Erectile Function -Erection Function domain (16.8 ± 3.1 vs. 24.4 ± 4.4, p < 0.001), and Erection Hardness Scores (2.2 ± 0.8 vs. 3.2 ± 0.5, p = 0.01) were all significantly improved. Fifty percent of patients achieved normal erectile function parameters according to the International Index of Erectile Function -Erection Function domain score >25. High mean scores were achieved in the Erectile Dysfunction Index of Treatment Satisfaction (76.8 ± 20.3), Benefit, Satisfaction & Willingness to continue (4.83 ± 1.1), Quality of Erection Questionnaire (73.4 ± 23.8), and Sexual Quality of Life (67 ± 29.4) questionnaires. No side effects were reported and participants rated the device as very comfortable, simple, and easy to operate.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Laser Treatment Monitoring with Reflectance Confocal Microscopy

Laser treatments have become popular in Dermatology. In parallel to technologic development enabling the availability of different laser wavelengths, non-invasive skin imaging techniques, such as reflectance confocal microscopy (RCM), have been used to explore morphologic and qualitative skin characteristics. Specifically, RCM can be applied to cosmetically sensitive skin areas such as the face, without the need for skin biopsies. For these reasons, apart from its current use in skin cancer diagnosis, our systematic review reveals how RCM can be employed in the field of laser treatment monitoring, being particularly suitable for the evaluation of variations in epidermis and dermis, and pigmentary and vascular characteristics of the skin. This systematic review article aims to provide an overview on current applications of RCM laser treatment monitoring, while describing RCM features identified for different applications. Studies on human subjects treated with laser treatments, monitored with RCM, were included in the current systematic review. Five groups of treatments were identified and described: skin rejuvenation, scar tissue, pigmentary disorders, vascular disorders and other. Interestingly, RCM can assist treatments with lasers targeting all chromophores in the skin and exploiting laser induced optical breakdown. Treatment monitoring encompasses assessment at baseline and examination of changes after treatment, therefore revealing details in morphologic alterations underlying different skin conditions and mechanisms of actions of laser therapy, as well as objectify results after treatment.

Can Microneedle Fractional Radiofrequency System Treatment Impair the Skin Barrier Function in Chinese Patients? A Prospective Clinical Trial

Introduction

Facial cosmetic conditions can manifest as post-inflammatory erythema, scars, pigmentation, enlarged pores, skin laxity, and photoaging. The microneedle fractional radiofrequency system (MFRS) is a new device that combines radiofrequency and microneedles and has been widely used for skin rejuvenation. Since MFRS is an invasive technique, this study aimed to evaluate whether the skin barrier functions might be impaired by this treatment, revealed by skin sensitivity and exacerbation of melasma.

Methods

Twenty patients with Fitzpatrick grades III–IV facial conditions (skin laxity with melasma, n = 9; post-inflammatory erythema and scars, n = 5; and enlarged pores, n = 6) and treated with MFRS were enrolled. Transepidermal water loss (TEWL, using Ultrascan UC22), skin sensitivity (ten-item Sensitive Scale, SS-10), melanin index (MI), melasma area and severity index (MASI), red areas (VISIA), and thickness and density of the epidermis and dermis on ultrasonography were compared between baseline and 6 months after all treatment sessions.

Results

Twenty patients completed a 6-month follow-up after two MFRS treatments. During days 1–3 post-treatment, the TEWL values gradually increased to the peak and decreased to baseline levels (BD) on day 7. There was no significant difference in TEWL compared with baseline in month (M) 1, M3, and M6. There were no significant changes in the thickness and density of the epidermis. Although the thickness and density of the dermis increased, there was no significant difference compared to baseline. There was no significant difference in the MI, MASI, and SS-10 score before and after MFRS treatment. After treatment with MFRS, the red area and scarring reduced significantly (p < .01), and no significant difference was observed in other patients.

Conclusions

MFRS is a safe and effective treatment for facial cosmetic conditions. The skin barrier function is not impaired by MFRS treatment, since it does not cause skin sensitivity or melasma exacerbation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13555-022-00807-w.

Application of a Reflectance Confocal Microscopy Imaging Analysis Score for the Evaluation of Non-Melanogenic Changes in Male Photoaged Skin

The photoaging process is characterized by skin changes due to ultraviolet radiation exposure and is the principal environmental factor affecting skin aging. Reflectance confocal microscopy permits noninvasive skin imaging to understand how the photoaging process may change skin. Since men do not habitually use a sunscreen, the application of skin imaging techniques is important to understand the influence of sunlight on their skin health. The aim of this study was to develop a score based on RCM imaging analyses to evaluate the morphological and structural changes of the photoaged skin according to literature data. The score was applied in order to determine possible correlations between chronological aging and sunscreen use behavior among men. Thus, 40 men aged 18 to 50 years were recruited, images from the frontal region of their skin were obtained and the score was applied. It was observed that habits are more important than age for the skin photoaging process. Men with photoprotection habits showed overall better skin morphological and structural characteristics regardless of age, demonstrating that sun protection behavior is a major key factor in the understanding of photoaging, so that men should be encouraged to start the use of cosmetic products and to perform selfcare.

Transcriptomic analysis of human skin wound healing and rejuvenation following ablative fractional laser treatment

Ablative fractional laser treatment is considered the gold standard for skin rejuvenation. In order to understand how fractional laser works to rejuvenate skin, we performed microarray profiling on skin biopsies to identify temporal and dose-response changes in gene expression following fractional laser treatment. The backs of 14 women were treated with ablative fractional laser (Fraxel®) and 4 mm punch biopsies were collected from an untreated site and at the treated sites 1, 3, 7, 14, 21 and 28 days after the single treatment. In addition, in order to understand the effect that multiple fractional laser treatments have on skin rejuvenation, several sites were treated sequentially with either 1, 2, 3, or 4 treatments (with 28 days between treatments) followed by the collection of 4 mm punch biopsies. RNA was extracted from the biopsies, analyzed using Affymetrix U219 chips and gene expression was compared between untreated and treated sites. We observed dramatic changes in gene expression as early as 1 day after fractional laser treatment with changes remaining elevated even after 1 month. Analysis of individual genes demonstrated significant and time related changes in inflammatory, epidermal, and dermal genes, with dermal genes linked to extracellular matrix formation changing at later time points following fractional laser treatment. When comparing the age-related changes in skin gene expression to those induced by fractional laser, it was observed that fractional laser treatment reverses many of the changes in the aging gene expression. Finally, multiple fractional laser treatments, which cover different regions of a treatment area, resulted in a sustained or increased dermal remodeling response, with many genes either differentially regulated or continuously upregulated, supporting previous observations that maximal skin rejuvenation requires multiple fractional laser treatments. In conclusion, fractional laser treatment of human skin activates a number of biological processes involved in wound healing and tissue regeneration.

Evaluation of the efficacy and safety of plasma exeresis in periorbital rejuvenation using the Reviscometer®

BACKGROUND

Periorbital rejuvenation is performed through various methods. Recently, plasma exeresis has been suggested for the treatment of dermatochalasis and periorbital wrinkles.

AIMS

To evaluate the clinical efficacy and safety of plasma exeresis in periorbital rejuvenation and palpebral laxity and assess its effectiveness using the Reviscometer^® .

PATIENTS/METHODS

Fifty-six women with mild-to-severe dermatochalasis and periorbital wrinkles volunteered to participate in this clinical trial. They received plasma exeresis thrice at one-month intervals. The efficacy of the intervention was evaluated according to the Cutaneous Resonance Running Time (CRRT) value changes, photographic changes, patients' satisfaction, and clinical side effects.

RESULTS

This study showed significant clinical improvements in dermatochalasis and palpebral laxity after treatment compared with the baseline (p < 0.001). Most of the participants had relative satisfaction, and no significant or permanent side effects were observed.

CONCLUSION

The findings of this study suggest that plasma exeresis is a safe and effective nonsurgical method for periorbital rejuvenation. Furthermore, the procedure has no serious adverse effects if performed correctly and for the right patient.

Assessing Light and Energy-Based Therapy by Optical Coherence Tomography and Reflectance Confocal Microscopy: A Randomized Trial of Photoaged Skin

BACKGROUND AND OBJECTIVES

Image-guided quantitative and semi-quantitative assessment of skin can potentially evaluate treatment efficacy. Optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) are ideal for this purpose. This study assessed clinically relevant statistical changes in RCM and OCT features in photoaged skin after light and energy-based therapy.

METHODS

Novel statistical analyses were performed using OCT and RCM data collected during a previously published trial: a 12-week study of female décolleté skin randomized to four areas treated with thulium laser (L), photodynamic therapy (PDT), combined L-PDT, and control. Eight semi-quantitative RCM scores of photodamage and OCT measurements of skin roughness, blood flow, and epidermal thickness (ET) were evaluated and compared to dermoscopy and clinical skin scores. In statistical analysis, estimated treatment difference (ETD) was calculated.

RESULTS

Twelve women with moderate to severe photodamage were included. RCM and OCT data demonstrated a trend towards rejuvenation of epidermis with increased ET, changes in skin surface, and improved honeycomb pattern in RCM. In angiographic OCT, non-significant changes towards more regular capillary meshes were shown, which matched a decline in appearance of gross telangiectasias in dermoscopy. Improved skin tone after laser and L-PDT was identified in RCM, showing less edged papillae in 36% and 45%, and lentigo number declined in 55% of patients after treatments in dermoscopy. Based on clinical scores, L-PDT provided the greatest clinical improvement, which corresponded to superior ETD outcomes in ET and edged papillae shown in OCT and RCM, respectively.

CONCLUSION

Objective OCT and RCM assessment of skin rejuvenation was demonstrated in this study. Importantly, image-based improvements corresponded to favorable clinical skin scores and fewer photoaging characteristics in dermoscopy. Importantly, most changes did not reach statistical significance, prompting further studies and emphasizing the modest value of non-randomized, non-blinded anti-aging trials.

Longitudinal Label-Free Two-Photon Microscopy of Cellular Healing Processes in Non-Ablative Fractional Laser Wounds

BACKGROUND AND OBJECTIVES

Wound healing is an important biomedical problem with various associated complications. Although cutaneous wound healing has been studied in vivo extensively using various optical imaging methods, early-stage cellular healing processes were difficult to study due to scab formation. The objective of this study is to demonstrate that minimal laser wounds and optical microscopy can access the detailed cellular healing processes of cutaneous wounds from the early stage.

STUDY DESIGN/MATERIALS AND METHODS

A non-ablative fractional laser (NAFL) and label-free two-photon microscopy (TPM) were used to induce minimal cutaneous wounds and to image the wounds in three-dimension. Sixteen hairless mice and a single human volunteer were used. NAFL wounds were induced in the hindlimb skin of the mice and in the forearm skin of the human subject. The NAFL wounds were longitudinally imaged during the healing period, starting from an hour post wound induction in the earliest and until 21 days. Cells in the wound and surrounding normal skin were visualized based on two-photon excited auto-fluorescence (TPAF), and cellular changes were tracked by analyzing longitudinal TPM images both qualitatively and quantitatively. Damage and recovery in the skin dermis were tracked by using the second harmonic generation (SHG) signal of collagen. Immunofluorescence and hematoxylin and eosin histology analysis were conducted to validate the TPM results of the murine skin.

RESULTS

Cellular healing processes in NAFL wounds and surroundings could be observed by longitudinal TPM. In the case of murine skin, various healing phases including inflammation, re-epithelization, granulation tissue formation, and late remodeling phase including collagen regeneration were observed in the same wounds owing to minimal or no scab formation. The re-epithelization process was analyzed quantitatively by measuring cell density and thickness of the epithelium in the wound surroundings. In the case of the human skin, the access inside the wound was blocked for a few days post wound induction due to scabs but the cellular changes in the wound surroundings were observed from the early stage. Cellular healing processes in the NAFL wound of the human skin were similar to those in murine skin.

CONCLUSIONS

The minimal NAFL wound model and label-free TPM demonstrated the cell level assessment of wound healing processes with applicability to human subjects. © 2021 Wiley Periodicals LLC.

Reflectance Confocal Microscopy of Aging Skin and Skin Cancer

Skin aging is a complex process that causes morphologic variations. Some of these variations have been hypothesized to be involved in skin cancer development. This paper reviews current knowledge of the features of aged skin as seen with reflectance confocal microscopy (RCM). Basic principles of the technique are described, and the RCM features of healthy skin and skin cancer are briefly discussed. Moreover, the RCM features at different layers of young and elderly skin are described, as are the variations that occur with passing years and in relation to sun exposure that contribute to photoaging and the development of skin cancer. RCM enables the noninvasive evaluation, at quasi-histologic resolution, of aging-related skin changes, some of which are shared with skin cancer; this ability helps avoid skin biopsy. Further research is needed to understand the relation between skin aging and skin cancer development.

Ultrapulsed CO2 Resurfacing of Photodamaged Facial Skin in Vegan and Omnivore Patients: A Multicentric Study

BACKGROUND AND OBJECTIVES

Skin photoaging is related to extrinsic environmental exposures, mainly represented by ultraviolet radiation. One of the treatment options is laser resurfacing. As nutritional status is involved in cutaneous photodamage, we evaluated whether dietary patterns can also influence the response to facial resurfacing. Our prospective multicentric study involves three dermatologic centers specialized in laser therapy in northern Italy. The study aims to compare the outcome of a CO₂ ablative laser therapy between omnivore and vegan patients.

STUDY DESIGN/MATERIALS AND METHODS

Fifty-three omnivore and fifty-three vegan women undergoing ultrapulsed CO₂ resurfacing for photodamaged facial skin were enrolled in this study. Clinical improvement was evaluated 3 and 6 months after the treatment using the modified Dover score.

RESULTS

After laser treatment, vegans showed slower complete re-epithelialization (P < 0.001*) and disappearance of the erythema (P < 0.001*). After 3 and 6 months, vegans showed worse outcomes in terms of fine lines (P < 0.001* and P < 0.001*, respectively) and tactile roughness (P = 0.003* and ​​​​P = 0.002*, respectively) compared with omnivores, while they did not differ in mottled pigmentation.

CONCLUSIONS

The present study suggests that diet influences the clinical outcome of fractioned CO₂ laser treatment. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

Fractional 1064 nm picosecond laser and skin photoaging: in vivo evaluation of treatment effects with reflectance confocal microscopy

Few studies showed the role of picosecond laser (PLS) in the treatment of skin photoaging signs. However, no studies have explored the microscopic effects of PSL in photoaging. The aim of this study is to preliminarily identify clinical variations induced by a 1,064 nm Nd:YAG PSL on the décolleté area, then to apply the treatment protocol to treat facial photoaging and estimate the clinical and microscopic outcomes. A total of 10 consecutive patients with cutaneous photoaging were enrolled. Patients were treated 3 times at monthly intervals with the fractionated 1,064 nm Nd:YAG PSL. In a preliminary phase, PSL treatment was performed on the décolleté to establish its efficacy and safety. Then, the same treatment protocol was applied to all the face and clinical and reflectance confocal microscopy (RCM) were analyzed, comparing baseline (T0) pictures and 4 months after the treatment (T1) ones. On the face, a reduction of dyschromia and wrinkles was observed at T1. Furthermore, the underlying RCM variations were revealed at different skin levels. Our results show the clinical and microscopic effectiveness and safety of the 1,064-nm Nd:YAG PSL in the treatment of skin photoaging signs.

Low-fluence and low-density CO2 laser: histological analysis of collagen fiber changes in skin and its clinical repercussions in photorejuvenation

This study refers to clinical and histologic analysis of effects on photorejuvenation after one single treatment of fractional CO2 laser with low fluence and low density. To analyze histologically the quantitative variation of collagen fibers type I and III, elastic fibers, and epidermal thickness on D84, besides clinical evaluation of amount, length, thickness, and depth of periocular wrinkles during the same period. This is an open, prospective, interventional study. There were 40 healthy female with age between 35 and 65 years. Twenty-six participants were randomly selected for D0 and D84 biopsy. A single session of fractional CO2 laser was done in the hole face, using a 800-µm tip, 5% density, and 10 mJ fluence with a single pass. On D0, D42, and D84, a clinical comparative analysis of amount, length, depth, and thickness of periocular wrinkles has been done. On histological analysis, a comparative quantitative evaluation of collagen fibers type I and III, elastic fibers, and epidermal thickness has been done on D0 and D84. The results of this study denoted a significant clinical improvement of amount (- 32.17%; p < 0.0001), thickness (- 33%; p < 0.0001), lenght (- 35.84%; p < 0.0001), and depth of periocular wrinkles (- 32.46%; p < 0.0001). A significant increase in the amount of collagen fibers type III was observed on D84 (+ 60.67%; p = 0.0013). Collagen fibers type I and elastic fibers did not have the same result, with a nonsignificant increase (+ 8.31%; p = 0.3820) and a decrease (- 12.4%; p = 0.0585) respectively. Epidermal thickness has a tendency to significant variation (p = 0.05553). The results demonstrate that fractional CO2 laser with low fluence and low density is a safe and efficient option for photorejuvenation of the face.

A plea for standardization of confocal microscopy and optical coherence tomography parameters to evaluate physiological and para-physiological skin conditions in cosmetic science

Non-invasive reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have been extended to the dermo-cosmetic field, for skin pathophysiology understanding and therapeutics monitoring. However, standardized methodology and parameters to interpret structures and changes in these settings are still lacking. Present study aimed to propose a validated standard methodology and a list of defined parameters for objective non-pathological skin assessments in the cosmetically sensitive cheekbone area of the face. OCT and RCM quantitative, semi-quantitative and qualitative features were considered for assessments. Validation process included 50 sets of images divided into two age groups. Inter-rater reliability was explored to assess the influence of the proposed methodology. Quantitative OCT parameters of "epidermal thickness," "density and attenuation coefficients" and "vascular density" were considered and calculated. Severity scales were developed for semi-quantitative OCT features of "disruption of collagen" and "vascular asset," while extent scales were produced for semi-quantitative RCM "irregular honeycomb," "mottled pigmentation" and "polycyclic papillary contours." Qualitative assessment was obtained for RCM type of collagen, and comparison between age groups was performed for all features considered. Severity visual scales assistance proved excellent inter-rater agreement across all semi-quantitative and qualitative domains. The assistance of shareable software systems allows for objective OCT quantitative parameters measurement. The use of standard reference scales, within a defined assessment methodology, offers high inter-rater reliability and thus reproducibility for semi-quantitative and qualitative OCT and RCM parameters. Taken together, our results may represent a starting point for a standardized application of RCM and OCT in dermo-cosmetic research and practice.

Effects of the lower energy and pulse stacking in carbon dioxide laser skin treatment: an objective analysis using second harmonic generation

PURPOSE

To evaluate the effect of fractional carbon dioxide (CO2) laser treatment using lower power associated with pulse stacking within collagen fibers, using second harmonic generation microscopy and computerized image analysis.

METHODS

Twenty male Wistar rats aging eight weeks were used. Each treatment area received a single-pass CO2 fractional laser with different parameters. The 20 animals were divided into two groups and euthanized after 30 and 60 days. Second harmonic generation images were obtained and program ImageJ was utilized to evaluate the collagen organization within all areas. Collagen anisotropy, entropy and optical density were quantified.

RESULTS

Increased anisotropy over time was observed in all four areas, but only reached statistical significance (p = 0.0305) when the mildest parameters were used (area four). Entropy decreased over time in all areas, but without significance(p = 0.1779) in area four. Density showed an overtime increase only in area four, but no statistical significance was reached (p = 0.6534).

CONCLUSIONS

When combined, the results obtained in this study regarding anisotropy, entropy and density tend to demonstrate that it is possible to achieve collagen remodeling with the use of lower power levels associated with stacked pulses.

Clinical Applications of In Vivo and Ex Vivo Confocal Microscopy

Confocal laser scanning microscopy (CLSM) has been introduced in clinical settings as a tool enabling a quasi-histologic view of a given tissue, without performing a biopsy. It has been applied to many fields of medicine mainly to the skin and to the analysis of skin cancers for both in vivo and ex vivo CLSM. In vivo CLSM involves reflectance mode, which is based on refractive index of cell structures serving as endogenous chromophores, reaching a depth of exploration of 200 μm. It has been proven to increase the diagnostic accuracy of skin cancers, both melanoma and non-melanoma. While histopathologic examination is the gold standard for diagnosis, in vivo CLSM alone and in addition to dermoscopy, contributes to the reduction of the number of excised lesions to exclude a melanoma, and to improve margin recognition in lentigo maligna, enabling tissue sparing for excisions. Ex vivo CLSM can be performed in reflectance and fluorescent mode. Fluorescence confocal microscopy is applied for “real-time” pathological examination of freshly excised specimens for diagnostic purposes and for the evaluation of margin clearance after excision in Mohs surgery. Further prospective interventional studies using CLSM might contribute to increase the knowledge about its application, reproducing real-life settings.

Reflectance confocal microscopy for striae distansae treatment monitoring after CO2 fractional laser

The aim of this study is to describe the efficacy and safety of CO₂ fractional laser to treat striae distensae (SD), before (T0) and 1 month after the last laser session (T1), in patients following different protocols based on the number of laser sessions, ≤4 and > 4. Efficacy was estimated with global assessment improvement scale (GAIS) performed by both physicians and patients, reflectance confocal microscopy (RCM), dermatology life quality index (DLQI). Safety was evaluated through pain assessment and adverse events. Eighteen patients with SD were enrolled. Clinical improvement of SD was observed in all patients at T1, as compared to T0. Furthermore, a reduction of RCM features of SD was observed at T1, above all in patients receiving >4 treatments, as compared to T0. Interestingly, we describe herein a new RCM feature of SD, the "neat-wall", corresponding to a distortion of the normal dermo-epidermal junction (DEJ), with a well-demarcated margin. A significant improvement of DLQI (P-value = .007) was also registered after SD treatment. Adverse events included temporary erythema and edema. In conclusion, the current study confirms the efficacy and safety of fractional CO₂ laser, proposing RCM features, such as parallel collagen fibers and the neat-wall, as potential markers of SD treatment response.

Noninvasive skin imaging in esthetic medicine-Why do we need useful tools for evaluation of the esthetic procedures

BACKGROUND

Despite the constant development of aesthetic medicine, there is still a lack of objective methods to assess the effectiveness of antiaging treatments and their impact on the skin. Histopathological examination of the skin section provides most of the key information about the condition of the skin, but it is an invasive procedure that requires a skin biopsy, which may be associated with the formation of a scar that is considered to be an aesthetic defect. Non-invasive imaging methods of the skin like dermoscopy, skin ultrasonography and reflectance confocal microscopy may be a useful solution.

AIMS AND METHODS

In this systematic review, we present the possible application of noninvasive skin imaging methods in esthetic medicine. The literature search was conducted via medical database (PubMed, Google Scholar).

RESULTS

The research suggests the use of dermoscopy during laser therapy, for the targeted treatment of vascular lesions and appropriate adjustment of laser parameters. Skin ultrasonography, especially high-frequency ultrasonography, has been widely used in aesthetic medicine-during and after volumetric treatments and in the assessment of the effects of anti-cellulite therapies, treatments that correct discolorations and improve skin quality. Publications also highlight the importance of reflexive confocal microscopy in the evaluation of the results of anti-aging treatments using the fractional laser, moisturizing preparations or micro puncturing combined with hyaluronic acid injections.

CONCLUSION

Non-invasive skin imaging methods are useful tools for pre- and postoperative assessment in aesthetic medicine and their wide application may help to objectively assess the impact of anti-aging procedures on the skin.

CO2 Fractional Laser Combined with 5-Fluorouracil Ethosomal Gel Treatment of Hypertrophic Scar Macro-, Microscopic, and Molecular Mechanism of Action in a Rabbit Animal Model

The treatment of hypertrophic scar (HS) has thus far been a clinical challenge. We evaluated the therapeutic effect of CO₂ fractional laser combined with 5-fluorouracil ethosomal gel (5-FU EG) in rabbit HS model. HS model was established as standardized scars on the ventral surface of rabbit ears, divided into four groups: control (no intervention), EG treatment, laser treatment, and combined treatment group (laser plus 5-FU EG). Clinical macroscopic and H&E-stained microscopic observations were conducted to assess HS improvement. The mRNA levels of types I and III collagen, transforming growth factor-β1 (TGF-β1), and interleukin-6 (IL-6) were detected by real-time PCR. After 14 days, H&E staining shows that the thickness of HS in treatment groups was significantly lower compared with the control group, and the thickness in laser treatment group and combined treatment group was significantly lower compared with the EG treatment group. The mRNA levels of types I and III collagen, TGF-β1 were significantly low in all treatment groups, whereas IL-6 was highest in the laser treatment group at day 14. The macro- and microscopic effects of the combined and CO₂ fractional laser treatment were better compared with 5-FU EG only. Inhibition of types I and III collagen, TGF-β1 are the possible underlying mechanism of action, whereas the function of IL-6 remains to be further studied. Our study suggests that the effect of combined 5-FU EG and laser, as well as laser-only treatment are superior to 5-FU EG monotreatment. The mechanism of HS improvement is related to reduction of collagen I/III and the inhibition of TGF-β1 expression.

Integration of polarized spatial frequency domain imaging (pSFDI) with a biaxial mechanical testing system for quantification of load-dependent collagen architecture in soft collagenous tissues

Collagen fiber networks provide the structural strength of tissues, such as tendons, skin and arteries. Quantifying the fiber architecture in response to mechanical loads is essential towards a better understanding of the tissue-level mechanical behaviors, especially in assessing disease-driven functional changes. To enable novel investigations into these load-dependent fiber structures, a polarized spatial frequency domain imaging (pSFDI) device was developed and, for the first time, integrated with a biaxial mechanical testing system. The integrated instrument is capable of a wide-field quantification of the fiber orientation and the degree of optical anisotropy (DOA), representing the local degree of fiber alignment. The opto-mechanical instrument''s performance was assessed through uniaxial loading on tendon tissues with known collagen fiber microstructures. Our results revealed that the bulk fiber orientation angle of the tendon tissue changed minimally with loading (median ± 0.5*IQR of 52.7° ± 3.3° and 51.9° ± 3.3° under 0 and 3% longitudinal strains, respectively), whereas on a micro-scale, the fibers became better aligned with the direction of loading: the DOA (mean ± SD) increased from 0.149 ± 0.032 to 0.198 ± 0.056 under 0 and 3% longitudinal strains, respectively, p < 0.001. The integrated instrument was further applied to study two representative mitral valve anterior leaflet (MVAL) tissues subjected to various biaxial loads. The fiber orientations within these representative MVAL tissue specimens demonstrated noticeable heterogeneity, with the local fiber orientations dependent upon the sample, the spatial and transmural locations, and the applied loading. Our results also showed that fibers were generally better aligned under equibiaxial (DOA = 0.089 ± 0.036) and circumferentially-dominant loading (DOA = 0.086 ± 0.037) than under the radially-dominant loading (DOA = 0.077 ± 0.034), indicating circumferential predisposition. These novel findings exemplify a deeper understanding of the load-dependent collagen fiber microstructures obtained through the use of the integrated opto-mechanical instrument. STATEMENT OF SIGNIFICANCE: In this study, a novel quantitative opto-mechanical system was developed by combining a polarized Spatial Frequency Domain Imaging (pSFDI) device with a biaxial mechanical tester. The integrated system was used to quantify the load-dependent collagen fiber microstructures in representative tendon and mitral valve anterior leaflet (MVAL) tissues. Our results revealed that MVAL's fiber architectures exhibited load-dependent spatial and transmural heterogeneities, suggesting further microstructural complexity than previously reported in heart valve tissues. These novel findings were possible through the system's ability to, for the first time, capture the load-dependent collagen architecture in the mitral valve anterior leaflet tissue over a wide field of view (e.g., 10 × 10 mm for the MVAL tissue specimens). Such capabilities afford unique future opportunities to improve patient outcomes through concurrent mechanical and microstructural assessments of healthy and diseased tissues in conditions such as heart valve regurgitation and calcification.

Application of reflectance confocal microscopy to investigate the non-ablative, micro-ablative, and ablative effects of CO2 fractional laser irradiation on skin

CO₂ fractional laser, as an ablative fractional laser, is commonly used in cosmetic treatment. We applied CO₂ fractional laser irradiation to skin in vitro and used reflectance confocal microscopy (RCM) to image and detect the presence of any non-ablative, micro-ablative and ablative effects, in order to better understand the features of a CO₂ fractional laser. In vitro irradiation of foreskin was performed using a CO₂ fractional laser. Foreskin specimens were divided into 4 groups that received different amounts of irradiation energy, based on the number of irradiation passes they received: 5, 10, 15, and 20 passes, respectively. This corresponds to fluence energy of 16.3, 32.6, 48.9, 65.3 J/cm². Immediately after irradiation, digital microscopy (DM), RCM, and histopathology were performed to observe whether the non-ablative, micro-ablative, and ablative phenomenon occurred, and the injury features of MTZs. Immediately after CO₂ fractional laser irradiation, RCM and DM showed that when the numbers of passes were 5 and 10, a micro-ablative column (MAC) could not be observed or was very small. We mainly observed a thicker thermal coagulation zone (TCZ), representing non-ablative or micro-ablative effects. When the number of passes were increased to 15 and 20, the MAC was significantly enlarged and surrounded by a TCZ of medium thickness, representing ablative effects. For the first time, this study used RCM and DM to demonstrate that a CO₂ fractional laser could achieve non-ablative, micro-ablative, and ablative effects on irradiated skin via different energy levels.

Changes in Dermal Thickness in Biopsy Study of Histologic Findings After a Single Injection of Polycaprolactone-Based Filler into the Dermis

BACKGROUND

During aging, facial skin thins, atrophies, and loses elasticity. Subdermal filler injections can volumize and treat wrinkles but cannot directly change dermal thickness. Polycaprolactone (PCL) fillers can improve skin texture and quality through dermal thickening and inducing neocollagenesis. Through biopsy study, evidence of neocollagenesis will be introduced.

OBJECTIVES

In this single-clinic prospective study, 13 patients received a single injection of diluted 0.5 cc of PCL filler in the facial dermis except the right temple area for intra-individual control study.

METHODS

A biopsy was performed from temple skin at 1 year for all patients. An additional biopsy was performed at 2 weeks and 4 years posttreatment for 3 patients. Dermal thickness was measured with sonography after 1 year.

RESULTS

On average, the mean rate of temporal skin thickness in biopsy specimens (n = 117 points in 13 patients) at 1 year posttreatment increased by 26.74% ± 9.26% from 1412.41 μm ± 69 μm to 1781.11 μm ± 110 μm (P < 0.001). On average, the mean thickness of facial skin (n = 39 points in 13 patients) measured by ultrasound at 1 year increased by 21.31% ± 4.34%. Around PCL particles, many fibroblasts, giant cells, new capillaries, new collagen, and elastic fibers were found in various stains.

CONCLUSIONS

Facial dermal thickness increased after intradermal injection of PCL filler by neocollagenesis to treat skin atrophy. PCL filler may last more than 4 years in the dermis.

LEVEL OF EVIDENCE: 4

Will Repeated Ablative Er:YAG Laser Treatment Sessions Cause Facial Skin Sensitivity? Results of a 12-Month, Prospective, Randomized Split-Face Study

Whether multiple laser irradiations affect skin sensitivity is still elusive. We aimed to investigate if repeated ablative erbium:yttrium-aluminum-garnet (Er:YAG) laser therapy could cause or increase skin sensitivity in the treatment areas. Nineteen healthy females received three sessions of a randomized, split-face, Er:YAG laser treatment in a scanning ablative mode (MicroLaserPeel™), with a 6-mm spot size, 8-μm ablative depths, and 30% of pulse overlap first. The next round was conducted in the fractional mode (ProFractional™) at depths ranging from 100 to 150 μm, with one pass by at coverage of 11% in the coagulation mode. Objective biophysical parameters, including transepidermal water loss (TEWL), skin glossiness, epidermal and dermal thickness and density, sensory nerve current perception threshold (CPT), and local blood flow, were measured before and after treatment. Quantitative evaluation of the Er:YAG laser treatment's effect on skin sensitivity is presented. Seventeen volunteers completed a follow-up of 12 months. On days 1 and 3, skin TEWL and epidermal thickness increased, while glossiness decreased. On day 7, there was no significant difference in the skin barrier function between the treated and the control side. Similarly, there was no significant difference in CPT values or local microvascular blood flow between sides at any time point before or after treatment, except that the local microvascular blood flow on the treated side was higher on the first day post-treatment. Er:YAG laser treatment does not influence skin sensitivity in healthy subjects in a long-term follow-up.

Second-harmonic patterned polarization-analyzed reflection confocal microscope

We introduce the second-harmonic patterned polarization-analyzed reflection confocal (SPPARC) microscope-a multimodal imaging platform that integrates Mueller matrix polarimetry with reflection confocal and second-harmonic generation (SHG) microscopy. SPPARC microscopy provides label-free three-dimensional (3-D), SHG-patterned confocal images that lend themselves to spatially dependent, linear polarimetric analysis for extraction of rich polarization information based on the Mueller calculus. To demonstrate its capabilities, we use SPPARC microscopy to analyze both porcine tendon and ligament samples and find differences in both circular degree-of-polarization and depolarization parameters. Moreover, using the collagen-generated SHG signal as an endogenous counterstain, we show that the technique can be used to provide 3-D polarimetric information of the surrounding extrafibrillar matrix plus cells or EFMC region. The unique characteristics of SPPARC microscopy holds strong potential for it to more accurately and quantitatively describe microstructural changes in collagen-rich samples in three spatial dimensions.

Evaluation of Laser-Assisted Trans-Nail Drug Delivery with Optical Coherence Tomography

The nail provides a functional protection to the fingertips and surrounding tissue from external injuries. The nail plate consists of three layers including dorsal, intermediate, and ventral layers. The dorsal layer consists of compact, hard keratins, limiting topical drug delivery through the nail. In this study, we investigate the application of fractional CO₂ laser that produces arrays of microthermal ablation zones (MAZs) to facilitate drug delivery in the nails. We utilized optical coherence tomography (OCT) for real-time monitoring of the laser-skin tissue interaction, sparing the patient from an invasive surgical sampling procedure. The time-dependent OCT intensity variance was used to observe drug diffusion through an induced MAZ array. Subsequently, nails were treated with cream and liquid topical drugs to investigate the feasibility and diffusion efficacy of laser-assisted drug delivery. Our results show that fractional CO₂ laser improves the effectiveness of topical drug delivery in the nail plate and that OCT could potentially be used for in vivo monitoring of the depth of laser penetration as well as real-time observations of drug delivery.

The Clinical Efficacy of Autologous Platelet-Rich Plasma Combined with Ultra-Pulsed Fractional CO2 Laser Therapy for Facial Rejuvenation

Ultra-pulsed fractional CO₂ laser is an efficient, precise, and safe therapeutic intervention for skin refreshing, although accompanied with prolonged edema and erythema. In recent years, autologous platelet-rich plasma (PRP) has been proven to promote wound and soft tissue healing and collagen regeneration. To investigate whether the combination of PRP and ultra-pulsed fractional CO₂ laser had a synergistic effect on therapy for facial rejuvenation. Totally, 13 facial aging females were treated with ultra-pulsed fractional CO₂ laser. One side of the face was randomly selected as experimental group and injected with PRP, the other side acted as the control group and was injected with physiological saline at the same dose. Comprehensive assessment of clinical efficacy was performed by satisfaction scores, dermatologists' double-blind evaluation and the VISIA skin analysis system. After treatment for 3 months, subjective scores of facial wrinkles, skin texture, and skin elasticity were higher than that in the control group. Similarly, improvement of skin wrinkles, texture, and tightness in the experimental group was better compared with the control group. Additionally, the total duration of erythema, edema, and crusting was decreased, in the experimental group compared with the control group. PRP combined with ultra-pulsed fractional CO₂ laser had a synergistic effect on facial rejuvenation, shortening duration of side effects, and promoting better therapeutic effect.

Skin healing and collagen changes of rats after fractional erbium:yttrium aluminum garnet laser: observation by reflectance confocal microscopy with confirmed histological evidence

The fractional erbium:yttrium aluminum garnet (Er:YAG) laser is widely applied. Microstructural changes after laser treatment have been observed with histopathology. Epidermal and dermal microstructures have also been analyzed using reflectance confocal microscopy (RCM). However, no studies have compared these two types of microstructural changes in the same subject at multiple time points after irradiation, and it is unclear if these two types of changes are consistent. We use RCM to observe the effect of different laser energies on skin healing and collagen changes in the skin of Sprague-Dawley rats that had been irradiated by fractional Er:YAG lasering at different energies. RCM was used to observe skin healing and detect collagen changes at different time points. Collagen changes were observed using hematoxylin and eosin (H&E) staining and quantitatively analyzed by western blot. RCM showed that, irrespective of laser energy, microscopic treatment zones (MTZs) were larger at 1 day after irradiation. The MTZs then reduced in size from 3 to 7 days after irradiation. The higher the energy, the larger the MTZ area. The amount of collagen also increased with time from 1 day to 8 weeks. However, the increase in the collagen amount on both RCM and H&E staining was not influenced by the laser energy. Western blotting confirmed that the amount of type I and type III collagens increased over time, but there were no significant differences between the different energy groups (p > 0.05). In conclusion, RCM is a reliable technique for observing and evaluating skin healing and collagen expression after laser irradiation.

Hsa-miR-520d converts fibroblasts into CD105+ populations

BACKGROUND

We have previously shown that hsa-miR-520d-5p can convert cancer cells into induced pluripotent stem cells (iPSCs) or mesenchymal stem cells (MSCs) via a dedifferentiation by a demethylation mechanism.

METHODS

We tested the effect of miR-520d-5p on human fibroblasts to determine whether it could be safely used in normal cells for future clinical therapeutic applications. After we transfected the microRNA into fibroblasts, we analyzed the phenotypic changes, gene expression levels, and stemness induction in vitro, and we evaluated tumor formation in an in vivo xenograft model.

RESULTS

The transfected fibroblasts turned into CD105+ cell populations, survived approximately 24 weeks, and exhibited increases in both the collagen-producing ability and in differentiation. Combinatorial transfection of small interfering RNAs for miR-520d-5p target genes (ELAVL2, GATAD2B, and TEAD1) produced similar results to miR-520d-5p transfection. These molecules converted normal cells into MSCs and not iPSCs.

CONCLUSIONS

In vitro data indicate the potent usefulness of this small molecule as a therapeutic biomaterial in normal cells and cancer cells because CD105+ cells never converted to iPSCs despite repeated transfections and all types of transfectants lost their tumorigenicity. This maintenance of a benign state following miR-520d-5p transfection appears to be caused by p53 upregulation. We conclude that miR-520d-5p may be a useful biomaterial at an in vitro level.

Vulvo-vaginal atrophy: a new treatment modality using thermo-ablative fractional CO2 laser

OBJECTIVE

To evaluate the efficacy and feasibility of thermo-ablative fractional CO2 laser for the treatment of symptoms related to vulvo-vaginal atrophy (VVA) in post-menopausal women.

METHODS

From April 2013 to December 2013, post-menopausal patients who complained of one or more VVA-related symptoms and who underwent vaginal treatment with fractional CO2 laser were enrolled in the study. At baseline (T0) and 30 days post-treatment (T1), vaginal status of the women was evaluated using the Vaginal Health Index (VHI), and subjective intensity of VVA symptoms was evaluated using a visual analog scale (VAS). At T1, treatment satisfaction was evaluated using a 5-point Likert scale.

RESULTS

During the study period, a total of 48 patients were enrolled. Data indicated a significant improvement in VVA symptoms (vaginal dryness, burning, itching and dyspareunia) (P<0.0001) in patients who had undergone 3 sessions of vaginal fractional CO2 laser treatment. Moreover, VHI scores were significantly higher at T1 (P<0.0001). Overall, 91.7% of patients were satisfied or very satisfied with the procedure and experienced considerable improvement in quality of life (QoL). No adverse events due to fractional CO2 laser treatment occurred.

CONCLUSION

Thermo-ablative fractional CO2 laser could be a safe, effective and feasible option for the treatment of VVA symptoms in post-menopausal women.

Sexual function after fractional microablative CO₂ laser in women with vulvovaginal atrophy

OBJECTIVE

To investigate the effects of fractional microablative CO2 laser on sexual function and overall satisfaction with sexual life in postmenopausal women with vulvovaginal atrophy (VVA).

METHOD

This prospective study included 77 postmenopausal women (mean age 60.6 ± 6.2 years) treated for VVA symptoms with the fractional microablative CO2 laser system (SmartXide(2) V(2)LR, Monalisa Touch, DEKA, Florence, Italy). Sexual function and quality of life were evaluated with the Female Sexual Function Index (FSFI) and the Short Form 12 (SF-12), respectively, both at baseline and at 12-week follow-up. A 10-mm visual analog scale was used to measure the overall satisfaction with sexual life and the intensity of VVA symptoms (vaginal burning, vaginal itching, vaginal dryness, dyspareunia and dysuria) before and after the study period.

RESULTS

We observed a significant improvement in the total score and the scores in each specific domain of the FSFI at 12-week follow-up compared to baseline (p < 0.001). After concluding the laser treatment, the overall satisfaction with sexual life significantly improved (p < 0.001). Seventeen (85%) out of 20 (26%) women, not sexually active because of VVA severity at baseline, regained a normal sexual life at the 12-week follow-up. Finally, we also found a significant improvement in each VVA symptom (p < 0.001) and in quality-of-life evaluation, both for the scores in the physical (p = 0.013) and mental (p = 0.002) domains.

CONCLUSIONS

Fractional microablative CO2 laser treatment is associated with a significant improvement of sexual function and satisfaction with sexual life in postmenopausal women with VVA symptoms.

The melanogenesis-inhibitory effect and the percutaneous formulation of ginsenoside Rb1

Ginsenoside Rb1 (Rb1) is the most predominant ginsenoside isolated from the roots of ginseng (Panax ginseng C. A. Meyer). This compound is active in various human biological pathways that are involved in human collagen synthesis and inhibition of cell apoptosis. In this study, the skin-whitening effects of Rb1 were investigated in B16 melanoma cells. Our results showed that Rb1 inhibited melanogenesis in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16 cells in a dose-dependent manner, which collectively indicated that Rb1 may have skin-whitening effects and may be formulated into skin-whitening products for skin care. Accordingly, a ginsenoside collagen transdermal patch was developed as a vehicle to topically deliver Rb1 into pig skin. The percutaneous permeation, retention within skin, and release in vitro of Rb1 from seven transdermal patch formulas were studied. It was determined that the best formula for ginsenoside collagen transdermal patch is made of protein collagen hydrolysate powder (PCHP) 2.0% (w/w), methyl cellulose (MC) 0.5% (w/w), polyethyleneglycol 6000 (PEG6000) 0.5% (w/w), ginsenoside 0.036% (w/w), azone 0.4% (v/w), menthol 0.20% (w/w), and water.

Observation of in vivo morphologic changes after carbon dioxide ablative fractional laser in a mouse model using noninvasive imaging modalities and comparison with histologic examination

Ablative fractional carbon dioxide (CO2) lasers have been widely used for several types of cosmetic dermatosis. A number of previous studies have evaluated this technique in animals or human beings by observing morphologic changes using an invasive modality such as skin biopsy. In this study, we assessed in vivo skin changes after CO2 ablative fractional laser treatment in a mouse model using noninvasive imaging modalities (Folliscope(®) and Visioscan 98(®)), and each results was compared with data from histologic examination. An ablative fractional CO2 laser was applied with different pulse energy between 7 to 35 mJ/microspot. As results of above methods, we also confirmed that the CO2 ablative fractional laser generated injuries with increasing width and depth with increasing pulse energy. Although numerous papers have described application of this laser in vivo skin specimens, our study evaluated the feasibility of using relative noninvasive imaging modalities for assessing the outcome of laser ablation. Based on our data, we suggest that these technologies may be useful alternative modalities for assessing laser ablation that are easier to perform and less invasive than skin biopsy.