Autologous Melanocyte Transplantation Research Articles

Enhanced cell survival of melanocyte spheroids in serum starvation condition

Autologous melanocyte transplantation for vitiligo treatment by use of melanocyte suspension has drawbacks including cell damage in cell preparation and transportation, difficult manipulation and low engraftment rate in acral vitiligious lesions. We have proposed the concept of cellular patch as an alternative solution. In the development of melanocyte patches, we have shown that chitosan membrane supports the growth and phenotype expression of melanocytes. Surprisingly, melanocytes spontaneously grow into three-dimensional spheroids on chitosan-coated surface. In this work, we demonstrate that, compared with monolayered melanocytes, melanocyte spheroids show a better survival in growth factor and serum-deprived condition. Survival of melanocytes is further ameliorated when a greater portion of melanocytes is precultured into spheroidal morphology. Melanocyte spheroids disintegrate and the cells return to a physiological dendritic morphology after they are reinoculated on collagen I-coated surface. Our results show that melanocytes are morphologically transformable depending on the substratum used and spheroidal melanocytes have a superior survival to that of monolayered dendritic melanocytes in stringent conditions. Preculturing melanocytes into spheroids can provide melanocytes a survival advantage. Chitosan-based melanocyte patch can be a promising method to enhance the engraftment rate and facilitate the cell preparation and transplantation procedures in melanocyte transplantation for vitiligo treatment.

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.

Formation of melanocyte spheroids on the chitosan-coated surface

The search for biocompatible materials that can maintain function of melanocytes as the cellular patch is a feasible alternative for use in the autologous melanocyte transplantation for vitiligo. In this study, we demonstrated that the surface of chitosan-coated polystyrene wells supported the growth and phenotype expression of melanocytes. Depending on the seeding density and culture time, melanocytes were monolayered or spheroidal in morphology. At seeding densities above 10×10 3 cells/cm 2, human melanocytes started to aggregate on the surface of chitosan after 2 days in culture. These aggregates grew into compact melanocyte spheroids on day 3 and more melanocyte spheroids were observed when a higher seeding density was used. Cells remained viable in the spheroids and grew into dendritic melanocytes when they were reinoculated on polystyrene wells. Conversely, the time for the formation of melanocyte spheroids needed a longer period at lower seeding density. For example, melanocytes at as low as 1.25×10 3 cells/cm 2 did not aggregate until the 20th day of culture. In order to interpret the phenomenon further, we proposed the formation of melanocyte spheroids on the chitosan is mediated by a balance between two competing forces: the interactions of cell–chitosan and cell–cell.

Hypopigmentary skin disorders: current treatment options and future directions.

Alterations of skin and hair pigmentation are important features that have warranted treatment from ancient history on up to modern time. In some cultures, even today patients with vitiligo are regarded as social outcasts and are affected considerably both emotionally and physically. This article presents current options and future directions for the treatment of hypopigmentary disorders. Whereas with congenital disorders, such as albinism and phenylketonuria, no causal therapy has been established up to now, several treatment options for acquired hypopigmentary disorders have been investigated. In particular, in vitiligo, one of the most prevalent hypopigmentary disorders, a number of treatment modalities have been employed in the past 30 years. However, most of them are only able to palliate, not cure, the disease. Depending on the distribution of the hypopigmented lesions (localised or generalised) and the state of the disease (active or stable), several therapeutic options, for example phototherapy, surgical skin grafts, autologous melanocyte transplantation and immunomodulators, can be applied alone or in combination. For phototherapy, because of unfavourable results and adverse effects, ultraviolet (UV) A has been largely replaced by narrow-band UVB for repigmentation of generalised vitiligo. Although immunomodulators, such as corticosteroids, have been used both topically and systemically over the past 3 decades for the treatment of disseminated vitiligo, they are only suitable for the treatment of acrofacial and localised forms because of adverse effects. Hence, new immunomodulatory agents, such as calcineurin antagonists, have recently been introduced as new promising tools to treat acquired hypopigmentary disorders. However, all therapeutic approaches are hampered by the fact that the pathophysiology of hypopigmentary disorders is still poorly understood.

Autologous grafting with noncultured melanocytes: A simplified method for treatment of depigmented lesions

Achromic lesions on the trunk and the extremities often do not respond to treatment and little improvement is obtained in cases of segmental vitiligo. Transplantation of autologous noncultured melanocytes was performed to obtain a successful repigmentation. The grafting method is carried out in two steps: production of blisters on the depigmented lesions by freezing with liquid nitrogen and injection in each blister of a suspension of epidermal cells (mainly keratinocytes and melanocytes). The cellular suspension was obtained from samples of skin of the hair scalp after trypsinization. Repigmentation was evident within 25 to 30 days. Coalescence of the pigmented areas was spontaneously observed or obtained after UVA stimulation. Patients with two types of leukoderma-vitiligo or nevus depigmentosus had successful repigmentation after transplantation of autologous noncultured melanocytes. This technique appears to be an effective and simple method for treating patients with achromic areas lacking melanocytes.

Melanocyte autologous grafting for treatment of leukoderma

Patients with three types of leukoderma--vitiligo, idiopathic guttate hypomelanosis, and postinflammatory leukoderma--had successful repigmentation after transplantation of autologous melanocytes. The procedure was performed easily by producing blisters on normal skin and on depigmented lesions. Blisters were produced by suction or by freezing with liquid nitrogen. The roof of the blister from donor skin was grafted to the raw surface of the recipient site. Repigmentation was visible within 7 to 14 days. Direct immunofluorescence staining with bullous pemphigoid antibodies suggested that the separation of the epidermis from the dermis occurs within the lamina lucida. Histochemical studies confirmed the absence of dopa-positive cells in the areas of leukoderma prior to grafting. Melanocytes were present in the successful grafts.