Melanocyte Transfer Research Articles

Melanocytes and Keratinocytes Transfer Using Sandpaper Technique Combined with Dermabrasion for Stable Vitiligo

Surgery is currently the most successful approach for difficult cases of vitiligo. The efficacy of epidermal surface removal (dermabrasion) is near 50%, and the efficacy of grafts is 70%. To evaluate the efficacy and safety of a combined approach using dermabrasion and grafting for unresponsive vitiligo. Eleven patients with stable vitiligo each underwent two different procedures on different body areas: transfer of melanocytes and epidermal cells obtained using the "sandpaper method" combined with dermabrasion of the receptor area or simple dermabrasion. Micropunch testing was used to evaluate the activity of vitiligo. Only patients without activity were treated. Subjects were followed for 3 months, and digital pictures were analyzed to estimate the percentage of repigmentation. Transfer delivered visible results in the first month, and dermabrasion showed results in the second month. The quality of pigmentation was superior with the transfer technique, especially in the short term, although at the end of treatment, both techniques showed similar results. Transfer of melanocytes and keratinocytes with the sandpaper method is feasible, safe, and effective as treatment for stable vitiligo, although simple dermabrasion is as effective in the long term.

Lectins modulate multi-walled carbon nanotubes cellular uptake in human epidermal keratinocytes

The development of nanomaterials for biomedical applications has attracted a great deal of attention. Carbon nanotubes may interact and cross cell membranes and serve as potential carriers for drug delivery studies. The reflection mode in the confocal laser scanning microscope was used to image multi-walled carbon nanotubes (MWCNT) in human neonatal epidermal keratinocytes (HEK) stained with the cytoskeleton protein F-actin. Scanning electron microscopy depicted tight binding of MWCNT on the plasma membrane of HEK, while some MWCNT were located in the cell. Since keratinocytes normally engulf melanosomes, we hypothesized that the melanocyte transfer pathway could be a potential route of entry into keratinocytes. Lectins are inhibitors of the melanosome transfer pathway was used to study the uptake of MWCNT in keratinocytes, to see if they played a role in reducing the cellular uptake of MWCNT in HEK. Three different lectins, Pisum sativum (PS), Lycopersicon esculentum (LE), and Tetragonolobus purpureas (TP) were used as a cocktail. The maximal concentrations of lectins that would be non-toxic to the HEK was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay. These studies confirmed that lectin cocktails (PS 5 μg/ml, LE 25 μg/ml and TP 25 μg/ml) decreased MWCNT interaction at the cell surface and uptake. F-actin, a cytoskeleton protein, was used to visualize how the MWCNT interacted with the cytoskeleton in the cells. MWCNT traversed through the cells’ cytoskeleton and the plasma membrane into adjacent keratinocytes.

La couleur de la peau humaine : de la recherche à l’esthétique

Skin color is controlled by pigmentary genes that regulate constitutive skin pigmentation and by environmental factors, the most obvious of them being solar U.V. At this time, more than 130 distinct pigmentary genes are known. They affect embryogenesis and survival of the melanocyte system, mélanosome biogenesis, melanogenesis, mélanosome transport and transfer, eumelanins/pheomelanins ratio and epidermal mélanosome turn-over and elimination. The pigmentary disorders of the skin are common and represent an important part of dermatologist activity. They concern at the same time the general dermatology and the aesthetic dermatology.

Transplantation of Melanocytes Into Iris: Method for Iris Repigmentation

Transplantation of Melanocytes Into Iris: Method for Iris Repigmentation

Identification of a Keratin 4 Mutation in a Chemically Induced Mouse Mutant that Models White Sponge Nevus

With the goal of increasing the number of genetic entry points for studying physiologic processes and human disease, large-scale, systematic, chemical mutagenesis projects in mice have been initiated in several different centers. We have been studying mouse mutants that exhibit dominantly inherited defects in either skin and/or hair color. Here, we describe a bright coat color mutant, Bright coat color 1 (Bcc1), which develops light-colored hair at 4 weeks of age, and when homozygous exhibits oral leukoplakia and blistering, and growth retardation. We identified a missense mutation in mutant animals that predicts an N154S amino-acid substitution in the 1A domain of Keratin 4 (encoded by the Krt2-4 gene), a region known to be mutated in human patients with white sponge nevus (WSN). Bcc1 recapitulates the gross pathologic, histologic, and genetic aspects of the human disorder, WSN.

Autologous melanocyte transfer via epidermal grafts for lip vitiligo

Vitiligo of the lips is a common concern of great psychologic consequence. Medical therapies are often ineffective due mainly to the absence of hair follicles. The transfer of melanocytes or melanocyte-bearing skin by a surgical procedure may repigment this condition. Only a few surgical modalities have been successful in this "difficult to treat" site. To assess the effectiveness of autologous melanocyte transfer by epidermal grafts for lip vitiligo and to review the literature on the surgical correction of lip vitiligo. Twenty-six vitiligo patients (20 women and six men; age range, 13-43 years; mean, 26.8 years) having 31 affected lips with stable disease were included in the study. The suction blisters were raised using our own modified device on the lateral aspect of the thigh. The roofs of the blisters were transferred to the dermabraded recipient area. The dressing, together with the grafts, was removed on day 8. Patients were given photochemotherapy for 6 weeks. In addition, meta-analysis of the published literature on the surgical management of lip vitiligo was also performed. Complete repigmentation was observed in 27 of the 31 lip areas (87%) in 23 of 25 patients (92%) in whom a follow-up for 6 months or more was available. Complications observed were persistent hyperpigmentation in 12 lips and reactivation of herpes in one patient. Minimal hyperpigmentation was seen in most of the remaining lips. The results of the meta-analysis revealed that the success rate varies from 32.5% to 100% with various surgical procedures. Autologous melanocyte transfer is an effective and safe therapeutic option for stable vitiligo of the lips. It is cosmetically more acceptable, as there is no abnormal keratinization, which is a problem associated with dermo-epidermal grafts.

A study of autologous melanocyte transfer in treatment of stable vitiligo

Replenishing melanocytes selectively in vitiliginous macules by autologous melanocytes is a promising treatment. With expertise in culturing melanocytes, it has now become possible to treat larger recipient areas with smaller skin samples. To study the extent of repigmentation after autologous melanocyte transplantation in patients with stable vitiligo. The melanocytes were harvested as an autologous melanocyte rich cell suspension from a donor split thickness graft. Melanocyte culture was performed in selected cases where the melanocyte cell count was insufficient to meet the requirement of the recipient area. These cells were then transplanted to the recipient area that had been superficially dermabraded. An excellent response was seen in 52.17% cases with the autologous melanocyte rich cell suspension (AMRCS) technique and in 50% with the melanocyte culture (MC) technique. Autologous melanocyte transplantation can be an effective form of surgical treatment in stable but recalcitrant lesions of vitiligo.

Punch Grafting for Lip Leucoderma

Background: Lip leucoderma (LL) is a common concern of great psychological scarring. The condition is often resistant to medical management due mainly to the absence of hair follicles. Melanocyte transfer, therefore, by any surgical procedure may repigment this condition. Objective: To repigment LL by punch graft (PG) and to estimate and evaluate the degree of repigmentation and its complications. Methods: One hundred and eight cases of stable and resistant LL of various causes were studied. They were followed up to a maximum of 5 years. Results: Graft take was achieved in 98 cases (91%) whereas all the grafts were rejected in 8 cases of herpes-labialis-induced LL (HlLL). Two cases (1.5%) showed depigmentation of grafts. Cobblestoning was the most common complication and was observed in 32 cases (30%). Complete repigmentation was achieved in 78 cases (72%). Conclusion: PG is a simple office procedure to treat LL. The procedure should exclude HILL.

Melanocyte transfer via epidermal grafts for vitiligo of labial mucosa.

Physiologic pigmentation of labial mucosa is seen regularly in dark-skinned races. Vitiligo of nonkeratinized labial mucosa is often visible while talking and is a cosmetic problem. Medical therapies are not effective, and surgical therapies have not been tried for this site. To study the efficacy of melanocyte transfer through contact of intact epidermal grafts with abraded labial mucosa. Seven patients (five females and two males, age range from 17 to 29) with vitiligo of labial mucosa with or without involvement of vermilion were included in the study. Affected labial mucosa was dermabraded, and suction blister grafts were transferred over these areas. After 7 days, both dressing and grafts were removed, and photochemotherapy was started. Excellent color match and repigmentation were seen in all patients after 4 to 6 weeks. The proposed modification in a well-established procedure of epidermal grafting is safe and effective. It is less time consuming and simpler than melanocyte culture, although the results are equivalent. There is no actual trans-plantation of keratinized skin, as it was removed.

Melanocyte Transfer via Epidermal Grafts for Vitiligo of Labial Mucosa

Melanocyte Transfer via Epidermal Grafts for Vitiligo of Labial Mucosa

Flip-top pigment transplantation: a novel transplantation procedure for the treatment of depigmentation.

Cutaneous depigmentation afflicts millions of people worldwide. For example, vitiligo affects an estimated 1% of Americans' and 0.38% to 1.13% of individuals worldwide. 2 Although some patients may respond to treatment with topical corticosteroids or topical or oral psoralen plus UV-A (PUVA), 5 many do not, and therefore, they seek additional therapy. Several surgical procedures have been devised to repigment depigmented skin. 6 These include the transfer of autologous melanocytes derived from split-thickness skin grafts, 7 full-thickness skin grafts,8 punch grafts,9 pinch grafts, 10 or suction-induced blister roofs. 11 Autologous melanocytes have also been obtained from tissue cultures of melanocytes alone'2 or melanocytes plus keratinocytes. 13 Recipient sites may be prepared in a number of ways, including dermabrasion, 14 suction blisters, 15 liquid nitrogen-induced blisters, PUVA-induced blisters,'6 laser ablation, 17 or by removal of skin with a dermatome. 7 Some of these methods leave undesirable scarring (eg, cobblestoning), are time intensive, and/or require special equipment.

Potential cosmetic applications of reconstructed epidermis

Various models of reconstructed epidermis already provide useful tools for safety and efficacy assessment of cosmetic products. However, the majority of these in vitro models are composed of keratinocytes only. Recently, the introduction of melanocytes into epidermal reconstructs has considerably enlarged their field of application. Depending on the melanocyte donor, the different phototypes (I-VI) as well as the racial specific pigmentation, caucasian, Asiatic or black epidermis can be reproduced in vitro. The reconstructed pigmented epidermis allows the evaluation of modulators of melanogenesis such as the depigmenting agent kojic acid. In contrast to conventional melanocyte cultures, the pigmented reconstructed epidermis is air-exposed and covered, as in vivo, with a stratum corneum. This allowed us to evaluate the effect of UV-irradiations on the epidermis and its protection by topically applied sunscreens. The introduction of resident epidermal Langerhans cells into the reconstructed epidermis remained an important challenge. We succeeded by seeding blood derived CD34+ hematopoietic progenitors onto a reconstructing epidermis composed of keratinocytes and melanocytes. The resulting pigmented epidermis shows melanocytes in the basal layer and resident epidermal Langerhans cells suprabasally. As in normal skin, the melanocytes transfer melanin to the neighboring keratinocytes, and the Langerhans cells express major histocompatibility complex class II molecules, CD1a antigen and Birbeck granules. This reconstructed epidermis, comprising for the first time the three major epidermal cell types, has the potential to serve in the near future as a predictive model for immuno-pharmaco-toxicological in vitro studies.

Tuberous sclerosis and guttate leukodermas.

The clinical, histopathologic, and electron microscopic features of guttate leukodermas are reviewed, including the hypomelanoses of the skin and hair observed in the tuberous sclerosis complex (TSC). The hypopigmentation seen in patients with TSC is related primarily to a decrease in the function of epidermal and follicular melanocytes; the density of active melanocytes is normal. Poorly developed dendritic processes are observed frequently as are melanosomes that are smaller in size and less melanized than those in melanocytes of uninvolved skin and hair. There is also a decreased number of melanosomes within the melanocytes, but in the absence of abnormal autophagic aggregation. These hypofunctioning melanocytes transfer fewer melanosomes to surround keratinocytes, and therefore the overall melanin content in the affected skin and hair is decreased. Two loci for TSC have been clearly identified, and one gene on chromosome 16p 13.3 (TSC-2) has been cloned. The protein product of the TSC-2 gene, tuberin, is involved in the regulation of cellular growth. The second gene is an chromosome 9q34 (TSC-1) near the locus for dopamine-o-hydroxylase, an enzyme involved in the synthesis of catecholamine neurotransmitters. The differential diagnosis of the guttate leukoderma of TSC includes several clinical entities such as idiopathic guttate hypomelanosis, disseminated hypopigmented keratoses, and dyschromic amyloidosis.

Human melanocytes transfer pigment to epidermal keratinocytes after grafting of a cultured skin substitute to athymic mice

Melanocytes are pigment-synthesizing cells intercalated among the basal keratinocytes along the dermal-epidermal junction of the skin. Through production of melanin, melanocytes generate skin pigmentation that provides the ultraviolet barrier in the epidermis. Melanosomes are very electron-dense, membrane-bound organelles that package and transfer pigment throughout the epidermis. Melanocytes transfer melanosomes to nearby keratinocytes in the basal layer of the epidermis. The mechanism of pigment transfer may involve either the fusion and breakdown of plasma membranes of both melanocyte and keratinocyte, establishing cytoplasmic communication, or phagocytosis of melanosome containing dendritic processes by the keratinocyte. Most melanosomes within keratinocytes are degraded by lysosomal enzymes as the cells differentiate and move upward. However, some keratinocytes retain melanosomes into the stratum corneum. Melanocytes are identified in light micrographs by their palely staining cytoplasm, ovoid nucleus, and cytoplasmic granules (Figs. 1,3) and in electron micrographs by the absence of keratin filaments and presence of melanosomes (Figs. 2,4,5,6).

Tattooing for the management of white patches.

Although biologically more or less inert, a white patch is a social taboo in India. When a white patch is localized and remains static in spite of conservative treatment, it can be dealt with by tattooing as a camouflage procedure. Inert pigments of skin color match are impregnated into the intradermal plane. The procedure is simpler than melanocyte transfer and serves the purpose of hiding a white patch. In the present study, histology of the tattooed skin was studied to confirm the retention of the pigments into the intradermal plane. The patient remains pain-free in the postoperative period. The procedure does not keep the patient away from work, nor does it require hospitalization or general anaesthesia. It can be dealt with as an office procedure, making it relatively inexpensive.