The 308-nm excimer laser treatment does not increase the risk of skin cancer in patients with vitiligo: A population-based retrospective cohort study

Nanotechnology strategies to address challenges in topical and cellular delivery of siRNAs in skin disease therapy

Gene therapy is one of the most advanced therapies in current medicine. In particular, interference RNA-based therapy by small interfering RNA (siRNA) has gained attention in recent years as it is a highly versatile, selective and specific therapy. In dermatological conditions, topical delivery of siRNA offers numerous therapeutic advantages, mainly by inhibiting the expression of target transcripts directly in the skin. However, crossing the stratum corneum and overcoming intracellular barriers is an inherent challenge. Substantial efforts by scientists have moved towards the use of multimodal and multifunctional nanoparticles to overcome these barriers and achieve greater bioavailability in their site of action, the cytoplasm. In this review the most innovative strategies based on nanoparticle and physical methods are presented, as well as the design principles and the main factors that contribute to the performance of these systems. This review also highlights the synergistic contributions of medicine, nanotechnology, and molecular biology to advancing translational research into siRNA-based therapeutics for skin diseases.

Vitiligo Treatments: Review of Current Therapeutic Modalities and JAK Inhibitors

Vitiligo is a chronic autoimmune disease characterized by loss of pigment of the skin, affecting 0.5-2% of the population worldwide. It can have a significant impact on patients' quality of life. In recent years, there has been significant progress in our understanding of the pathogenesis of vitiligo. It is believed that vitiligo develops due to a complex combination of genetics, oxidative stress, inflammation, and environmental triggers. Conventional treatments include camouflage, topical corticosteroids, topical calcineurin inhibitors, oral corticosteroids, phototherapy, and surgical procedures, with the treatment regimen dependent on the patient's preferences and characteristics. With increased understanding of the importance of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway in the pathogenesis of vitiligo, treatment has expanded to include the first US FDA-approved cream to repigment patients with vitiligo. This review summarizes our understanding of the major mechanisms involved in the pathogenesis of vitiligo and its most common available treatments.

UV Exposure and the Risk of Keratinocyte Carcinoma in Skin of Color: A Systematic Review

Importance

Ultraviolet radiation exposure is an important modifiable risk factor for keratinocyte carcinoma (KC) in fair-skinned non-Hispanic White populations; however, the evidence for this relationship in darker-skinned populations is less certain.

Objective

To assess and synthesize the published data concerning the association between UV exposure and the risk of KC in individuals with skin of color.

Evidence Review

PubMed, Cochrane, and Web of Science databases were searched from database origin through January 2022. Studies deemed eligible included UV exposure as a risk factor for KC in individuals with skin of color, defined as any race other than non-Hispanic White, Fitzpatrick skin types IV to VI, or tanning ability of rarely or never burns. The UV index, irradiance, latitude, history of phototherapy, history of sunburn, or occupational exposure were used as measures of exposure. The Oxford Centre for Evidence-Based Medicine guidelines were used to assess evidence quality.

Findings

A total of 72 716 articles appeared in the search. After duplicate removal, 29 393 database records were screened, 454 full-text articles were assessed, a forward and reverse citation search was performed, and 12 articles, with clinical data spanning the years 1990 to 2019, met inclusion criteria. More than 32 970 KCs in individuals with skin of color were included. Eight studies found no association between UV exposure and KC, while 4 studies showed a positive association. Study types included 1 ecological study, 9 cohort studies, and 2 case-control studies. The quality of the studies was rated from moderate to low (2b to 4).

Conclusions and Relevance

Results of this systematic review show that the evidence assessing the association of UV exposure with KC is of moderate to low quality. The studies that found no association were among patients receiving phototherapy. Studies assessing nonphototherapy-related UV exposure, such as geographic location or occupation, found small positive associations in primarily East Asian individuals. There were no studies performed in the US, no studies among Black individuals, and only 1 study among a Hispanic population. Further research is required to better assess whether these associations exist across populations of patients with darker skin types.

Non-surgical treatment of vitiligo

Vitiligo is an acquired depigmenting skin disorder that affects 0.5% to 2% of the population. Skin lesions from vitiligo, white macules and patches on the skin, can pose a substantial psychological burdencan, causing a significant decrease in one’s quality of life. Recent basic and clinical studies have found that vitiligo is an autoimmune disorder, mediated by CD8+ T-cell and interferon-γ-mediated cytokine/chemokines. Although no treatment modality presents a complete cure for vitiligo, current treatment modalities have a modest effect on vitiligo by reversing the disease’s progression, inducing its stabilization, and promoting melanocyte regeneration. Current non-surgical treatment modalities include topical corticosteroids, topical calcineurin inhibitors, systemic corticosteroids, and phototherapy such as narrowband ultraviolet B phototherapy and excimer laser. In addition, clinicians have used and combined non-surgical treatment modalities based on the activity and extent of vitiligo. Moreover, considering the high risk of vitiligo relapse, maintenance therapy for re-pigmented lesions has also been introduced. Lastly, based on the results of recent translational research, new and emerging treatment modalities have been introduced, such as Janus kinase inhibitors. This review presents an overview of the current non-surgical treatment modalities for vitiligo and discusses emerging treatments.

In vitro proliferation of human epidermal melanocytes biopsied from multiple anatomical sites

BACKGROUND

Vitiligo is an acquired disease that involves low pigment variation in the skin. The use of cultured melanocytes for treatment of recalcitrant vitiligo has become a well-established treatment modality. In vitro cultured melanocytes present an effective autologous transplantation treatment modality for vitiligo. The present study investigated the in vitro culture of epidermal melanocytes sampled from multiple body parts, as well as the differences in total propagation time.

METHODS

Skin specimens were collected from 30 participants (14 males and 16 females) who supplied normal colored skin sections from various regions of their body, including the face, chest, abdomen, buttock, and extremities. Subsequently, all of these specimens were treated with an identical melanocyte purification and culturing process.

RESULTS

Melanocytes from the face demonstrated the most rapid growth and longest total propagation time. Melanocytes from the buttock, abdomen, and extremities displayed similar results to one another, and melanocytes from the chest and back had the slowest growth and shortest total propagation time.

CONCLUSION

Selecting the most favorable site to obtain epidermal melanocytes will reduce the required quantity of skin and culturing time, and maximize the growth and total propagation time of melanocytes. Therefore, care should be exercised when selecting the region of skin when culturing epidermal melanocytes.