Ex vivo gene therapy cures a blistering skin disease

Ultrasound mediated transdermal drug delivery

Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injections. However, the stratum corneum serves as a barrier that limits the penetration of substances to the skin. Application of ultrasound (US) irradiation to the skin increases its permeability (sonophoresis) and enables the delivery of various substances into and through the skin. This review presents the main findings in the field of sonophoresis in transdermal drug delivery as well as transdermal monitoring and the mathematical models associated with this field. Particular attention is paid to the proposed enhancement mechanisms and future trends in the fields of cutaneous vaccination and gene therapy.

Epidermolysis bullosa: prospects for cell-based therapies

Heritable forms of epidermolysis bullosa (EB) are characterized by chronic, lifelong blistering and erosions due to mutations in 10 distinct genes expressed at the cutaneous basement membrane zone. No specific treatment for this group of intractable diseases is currently available. Recent progress in molecular therapies has indicated that cell-based approaches may potentially offer amelioration--and perhaps even cure--for afflicted individuals. In this issue, Wong et al. (2008) demonstrate the feasibility of direct intradermal injection of allogeneic fibroblasts to the lesional skin of patients with recessive dystrophic EB, with improvement in skin fragility.

Therapeutic potential of stem cells in skin repair and regeneration

Stem cells are defined by their capacity of self-renewal and multilineage differentiation, which make them uniquely situated to treat a broad spectrum of human diseases. Based on a series of remarkable studies in several fields of regenerative medicine, their application is not too far from the clinical practice. Full-thickness burns and severe traumas can injure skin and its appendages, which protect animals from water loss, temperature change, radiation, trauma and infection. In adults, the normal outcome of repair of massive full-thickness burns is fibrosis and scarring without any appendages, such as hair follicles, sweat and sebaceous glands. Perfect skin regeneration has been considered impossible due to the limited regenerative capacity of epidermal keratinocytes, which are generally thought to be the key source of the epidermis and skin appendages. Currently, researches on stem cells, such as epidermal stem cells, dermal stem cells, mesenchymal stem cells from bone marrow, and embryonic stem cells, bring promise to functional repair of skin after severe burn injury, namely, complete regeneration of skin and its appendages. In this study, we present an overview of the most recent advances in skin repair and regeneration by using stem cells.

Protein therapeutics for junctional epidermolysis bullosa: incorporation of recombinant beta3 chain into laminin 332 in beta3-/- keratinocytes in vitro

Junctional epidermolysis bullosa (JEB) is an inherited mechanobullous disease characterized by reduced adherence of the epidermal keratinocytes to the underlying dermis, and is often caused by the absence of functional laminin 332 due to the lack or dysfunction of its beta3 chain. As there are no specific therapies for JEB, we tested whether a protein replacement strategy could be applicable for the restoration of the laminin 332 assembly and reversion of the JEB phenotype in human keratinocytes that lack beta3 subunit. Here, we developed the protocol for production and purification of the biologically active recombinant beta3 chain. Next, we demonstrated that delivery of recombinant beta3 polypeptide into the endoplasmic reticulum of the immortalized beta3-null keratinocytes led to the restoration of the laminin 332 assembly, secretion, and deposition into the basement membrane zone, as confirmed by Western blot analysis, confocal immunofluorescent microscopy in vitro, and on cultured organotypic human JEB skin reconstructs. Although the amount of laminin 332 produced by protein-treated beta3-null keratinocytes is lower than that in normal human keratinocytes, our results demonstrate the applicability of the recombinant proteins for JEB treatment and open new perspectives for the development of novel therapeutics for this inherited, currently intractable, skin disorder.