A study of Q-switched Nd:YAG laser irradiation and paracrine function in human skin cells

Efficacy of isobutylamido thiazolyl resorcinol for prevention of laser-induced post-inflammatory hyperpigmentation: A randomized, controlled trial

BACKGROUND

Q-switched (QS) Nd: YAG laser is one of the treatment options for solar lentigines (SLs). However, the incidence of post-inflammatory hyperpigmentation (PIH) is a common complication, especially in dark-complexioned skin. Isobutylamido thiazolyl resorcinol (ITR) has been reported as a preventive modality for ultraviolet B (UVB)-induced hyperpigmentation.

AIMS

This study aims to evaluate the efficacy and safety of ITR for the prevention of laser-induced PIH.

PATIENTS/METHODS

A randomized, evaluator-blinded study including 24 subjects with SLs was conducted. Three SLs of each patient were randomized into three groups, which were to apply ITR twice daily, once daily, and no application for 2 weeks. Thereafter, 532-nm QS Nd: YAG laser was performed. Incidence of laser-induced PIH, relative melanin index (RMI), mean luminance score (L*), hyperpigmentation score, and adverse events were recorded for 2 months post-laser.

RESULTS

The incidence of PIH at the 4th week after laser treatment was significantly lower in the ITR twice-daily group compared to the no-application group (20.83% vs. 50%, p = 0.028). There was no statistically significant difference in RMI, mean L*, and hyperpigmentation score between treatments at all visits. No serious adverse events were reported regarding ITR application and laser treatment.

CONCLUSION

Two-week application of ITR prior to QS: Nd YAG laser treatment may potentially reduce the incidence of PIH. A longer duration of application, including after the laser procedure, may be more beneficial for the prevention of laser-induced PIH.

Dermal Fibroblasts as the Main Target for Skin Anti-Age Correction Using a Combination of Regenerative Medicine Methods

This article includes the data from current studies regarding the pathophysiological mechanisms of skin aging and the regenerative processes occurring in the epidermis and dermis at the molecular and cellular level, mainly, the key role of dermal fibroblasts in skin regeneration. Analyzing these data, the authors proposed the concept of skin anti-age therapy that is based on the correction of age-related skin changes by stimulating regenerative processes at the molecular and cellular level. The main target of the skin anti-age therapy is dermal fibroblasts (DFs). A variant of the cosmetological anti-age program using the combination of laser and cellular methods of regenerative medicine is presented in the paper. The program includes three stages of implementation and defines the tasks and methods of each stage. Thus, laser technologies allow one to remodel the collagen matrix and create favorable conditions for DFs functions, whereas the cultivated autologous dermal fibroblasts replenish the pool of mature DFs decreasing with age and are responsible for the synthesis of components of the dermal extracellular matrix. Finally, the use of autological platelet-rich plasma (PRP) enables to maintenance of the achieved results by stimulating DF function. It has been shown that growth factors/cytokines contained in α-granules of platelets injected into the skin bind to the corresponding transmembrane receptors on the surface of DFs and stimulate their synthetic activity. Thus, the consecutive, step-by-step application of the described methods of regenerative medicine amplifies the effect on the molecular and cellular aging processes and thereby allows one to optimize and prolong the clinical results of skin rejuvenation.

Platelet rich plasma versus Carboxytherapy in the treatment of Periorbital dark circles: A split-face study

BACKGROUND

Periorbital hyperpigmentation is a recurrent problem in dermatologic clinics that affect the patients' quality of life and their psychological status. Platelet-rich plasma (PRP) may serve as a source of different growth factors which may reduce the pigmentation in this problem. Carboxytherapy is carbon dioxide infusion into human tissue for therapeutic purposes.

OBJECTIVE

to evaluate and compare the clinical efficacy of PRP and carboxytherapy in the treatment of periorbital dark circles (PODC). Histopathological evaluation was also done.

PATIENTS AND METHODS

Split-face study of 23 patients with PODC treated with PRP at the right side and carboxytherapy at the left side. Patients received four sessions; one session/week. Final follow-up evaluation was done 3 months after the last session by clinical and histopathological assessment.

RESULTS

PRP showed significant better response (p=0.002), shorter downtime and tolerable side effects than caboxytherapy. Reduction in area percent of melanin after PRP injections showed 46.6% improvement, while after carboxytherapy, it showed only 14.3% improvement.

CONCLUSION

The present study had showed that PRP is more effective and tolerable than caboxytherapy in the treatment of PODC.

The effects of recombinant human epidermal growth factor containing ointment on wound healing and post inflammatory hyperpigmentation prevention after fractional ablative skin resurfacing: A split-face randomized controlled study

BACKGROUND

Epidermal growth factor (EGF) is one of the important peptides in wound healing process. The effects of EGF have been increasingly studied in various types of ulcers. However, data on postablative laser resurfacing wound is still limited.

OBJECTIVES

To evaluate the effects of the topical EGF ointment on wound healing process and postinflammatory hyperpigmentation (PIH) prevention after fractional ablative laser resurfacing.

MATERIALS AND METHODS

This is a randomized split-face study. Nineteen healthy subjects were enrolled and completed follow up protocol. Patients received single treatment of fractional carbon dioxide laser on both cheeks. After randomization, each patient was assigned to apply one side of the face with topical EGF ointment and another side with petrolatum. Wound healing was evaluated by duration of scab shedding, duration of postlaser erythema, erythema index, and transepidermal water loss on the daily follow up period of seven days after treatment. PIH was evaluated at 2, 3 weeks and 1, 2 months follow up by photographs and melanin index.

RESULTS

Most of patients were female with Fitzpatrick skin phototype III to V. Comparing with control (petrolatum), EGF treated side showed no significant difference in duration of scab shedding, duration of postlaser erythema, erythema index, and transepidermal water loss (P-value = .58, .22, .78, and .51, respectively). Incidence of PIH was 52.6% on EGF side and 57.9% on petrolatum side, however, it was not statistically different (P = .56). The melanin index was also not different as well (P = .96).

CONCLUSION

Topical EGF might provide significant wound healing stimulation for chronic wound more than acute wound. Further studies, especially in post laser wound or other cosmetic purposes are needed.

The convergence theory for vitiligo: A reappraisal

Vitiligo is characterized by progressive loss of skin pigmentation. The search for aetiologic factors has led to the biochemical, the neurologic and the autoimmune theory. The convergence theory was then proposed several years ago to incorporate existing theories of vitiligo development into a single overview of vitiligo aetiology. The viewpoint that vitiligo is not caused only by predisposing mutations, or only by melanocytes responding to chemical/radiation exposure, or only by hyperreactive T cells, but rather results from a combination of aetiologic factors that impact melanocyte viability, has certainly stood the test of time. New findings have since informed the description of progressive depigmentation. Understanding the relative importance of such aetiologic factors combined with a careful selection of the most targetable pathways will continue to drive the next phase in vitiligo research: the development of effective therapeutics. In that arena, it is likewise important to acknowledge that pathways affected in some patients may not be altered in others. Taken together, the convergence theory continues to provide a comprehensive viewpoint of vitiligo aetiology. The theory serves to intertwine aetiologic pathways and will help to define pathways amenable to disease intervention in individual patients.

Tranexamic Acid Diminishes Laser-Induced Melanogenesis

Background

The treatment of post-inflammatory hyperpigmentation (PIH) remains challenging. Tranexamic acid, a well-known anti-fibrinolytic drug, has recently demonstrated a curative effect towards melasma and ultraviolet-induced PIH in Asian countries. However, the precise mechanism of its inhibitory effect on melanogenesis is not fully understood.

Objective

In order to clarify the inhibitory effect of tranexamic acid on PIH, we investigated its effects on mouse melanocytes (i.e., melan-a cells) and human melanocytes.

Methods

Melan-a cells and human melanocytes were cultured with fractional CO₂ laser-treated keratinocyte-conditioned media. Melanin content and tyrosinase activity were evaluated in cells treated with or without tranexamic acid. Protein levels of tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 were evaluated in melan-a cells. Signaling pathway molecules involved in melanogenesis in melanoma cells were also investigated.

Results

Tranexamic acid-treated melanocytes exhibited reduced melanin content and tyrosinase activity. Tranexamic acid also decreased tyrosinase, TRP-1, and TRP-2 protein levels. This inhibitory effect on melanogenesis was considered to be involved in extracellular signal-regulated kinase signaling pathways and subsequently microphthalmia-associated transcription factor degradation.

Conclusion

Tranexamic acid may be an attractive candidate for the treatment of PIH.

Autologous platelet rich plasma: topical versus intradermal after fractional ablative carbon dioxide laser treatment of atrophic acne scars

BACKGROUND

A proposal has recently been made regarding the potential adjuvant use of platelet-rich plasma (PRP) with fractional carbon dioxide laser (FCL) for the correction of acne scars.

OBJECTIVE

To compare the efficacy and safety of two administration modes of autologous PRP (intradermal injection (ID) and topical application) after FCL with that of FCL alone in the treatment of atrophic acne scars.

PATIENTS AND METHODS

Thirty patients were randomly divided into two groups. Both underwent split-face therapy. Group 1 was administered FCL followed by ID PRP on one side and FCL followed by ID saline on the other. In group 2, one cheek was treated with FCL followed by ID PRP, and the other received FCL followed by topical PRP. Each patient received 3 monthly sessions. The final assessment took place at 6 months.

RESULTS

Combined PRP- and FCL-treated areas had a significantly better response (p = .03), fewer side effects, and shorter downtime (p = .02) than FCL-treated areas, but there were no significant differences in ID- and topical PRP-treated areas in degree of response and downtime (p = .10); topically treated areas had significantly lower pain scores.

CONCLUSION

The current study introduces the combination of topical PRP and FCL as an effective, safe modality in the treatment of atrophic acne scars with shorter downtime than FCL alone and better tolerability than FCL combined with ID PRP.

Low-Level Laser Therapy Effectiveness for Reducing Pain after Breast Augmentation

Introduction:

The purpose of this Institutional Review Board (IRB)-approved, placebo-controlled, randomized, double-blinded parallel-grouped, multicenter trial was to determine the effectiveness of low-level laser therapy (LLLT) in decreasing patients' postoperative pain 24 hours post breast augmentation surgery.

Materials and Methods:

The Erchonia EML, 630–640 nm, (Erchonia Medicial, Inc., McKinney, Texas) with 2 7-mw laser-emitting diodes was used within 10 minutes of the start of the procedure over each breast for 4 minutes at a distance of 6 inches. This was repeated within 10 minutes of completion of the procedure with the same methodology. One hundred and four (104) patients participated in the study, 50 test subjects and 54 controls. Primary investigator and patient were blinded with respect to treatment group.

Results:

The success criteria for this study using the standardized Visual Analogue Scale (VAS) was a self-reported degree-of-pain rating of less than 30 at 24 hours after the implant procedure. At this time the patient had not taken pain medication for 4 hours. Overall study success criteria were defined as at least 30% difference between treatment groups with respect to proportion of successes. At the 24-hour time interval 37 (74%) of the test subjects and 20 (37%) of the control subjects met the success criteria, a difference of 37% (p<.0002). The amount of pain medication used over the first 7 days post operatively was measured as a covariant. The test subjects used less medication 848 versus 932 total doses (p<.01).

Conclusion:

Low-level laser therapy is effective at significantly decreasing postoperative pain and the amount of pain medication needed after breast augmentation at 1 day and 1 week respectfully. All other covariants studied including, implant type, implant size, incision size, implant location, test site location, amount of swelling measurements, hydration level, and adverse events were found to be neglible.

Low-level laser irradiation promotes the recovery of atrophied gastrocnemius skeletal muscle in rats

Low-level laser (LLL) irradiation promotes proliferation of muscle satellite cells, angiogenesis and expression of growth factors. Satellite cells, angiogenesis and growth factors play important roles in the regeneration of muscle. The objective of this study was to examine the effect of LLL irradiation on rat gastrocnemius muscle recovering from disuse muscle atrophy. Eight-week-old rats were subjected to hindlimb suspension for 2 weeks, after which they were released and recovered. During the recovery period, rats underwent daily LLL irradiation (Ga-Al-As laser; 830 nm; 60 mW; total, 180 s) to the right gastrocnemius muscle through the skin. The untreated left gastrocnemius muscle served as the control. In conjunction with LLL irradiation, 5-bromo-2-deoxyuridine (BrdU) was injected subcutaneously to label the nuclei of proliferating cells. After 2 weeks, myofibre diameters of irradiated muscle increased in comparison with those of untreated muscle, but did not recover back to normal levels. Additionally, in the superficial region of the irradiated muscle, the number of capillaries and fibroblast growth factor levels exhibited significant elevation relative to those of untreated muscle. In the deep region of irradiated muscle, BrdU-positive nuclei of satellite cells and/or myofibres increased significantly relative to those of the untreated muscle. The results of this study suggest that LLL irradiation can promote recovery from disuse muscle atrophy in association with proliferation of satellite cells and angiogenesis.

Efficacy and adverse effects of Q-switched ruby laser on solar lentigines: a prospective study of 91 patients with Fitzpatrick skin type II, III, and IV

BACKGROUND

Laser-induced postinflammatory hyperpigmentation could be a limiting factor for selecting patients appropriate for the use of ruby laser in the treatment of lentigenes, especially in dark-skinned individuals.

OBJECTIVE

To evaluate the efficacy and adverse effects of Q-switched ruby laser light (694 nm) on solar lentigines in patients with Fitzpatrick skin type II, III, and IV.

METHODS AND MATERIALS

Controlled comparison study in a university-based laser clinic center. Ninety-one solar lentigines in patients with skin type II, III, and IV were enrolled. All patients were followed for 6 months for frequency of side effects. Before-and-after photographs and images from all follow-up sessions were taken and then assessed by a blinded dermatologist for the evaluation of side effects.

RESULTS

Complete clearance was achieved in all patients. Postinflammatory dyspigmentation occurred in 7.8% patients with Fitzpatrick skin type II, 9.8% patients with type III, and 16.6 patients with type IV (p=.67); all improved over a 6-month follow-up period.

CONCLUSION

Q-switched ruby laser treatment is a safe procedure for the treatment of solar lentigines even in dark-skinned individuals. Considering routine factors in addition to melanin content alone is required for minimizing side effects, especially postinflammatory hyperpigmentation in darker skin.