Laser assisted drug delivery: a review of an evolving technology.

BACKGROUND: Topically applied drugs have a relatively low cutaneous bioavailability. OBJECTIVE: This article reviews the existing applications of laser assisted drug delivery, a means by which the permeation of topically applied agents can be enhanced into the skin. RESULTS: The existing literature suggests that lasers are a safe and effective means of enhancing the delivery of topically applied agents through the skin. The types of lasers most commonly studied in regards to drug delivery are the carbon dioxide (CO2 ) and erbium:yttrium-aluminum-garnet (Er:YAG) lasers. Both conventional ablative and fractional ablative modalities have been utilized and are summarized herein. LIMITATIONS: The majority of the existing studies on laser assisted drug delivery have been performed on animal models and additional human studies are needed. CONCLUSIONS: Laser assisted drug delivery is an evolving technology with potentially broad clinical applications. Multiple studies demonstrate that laser pretreatment of the skin can increase the permeability and depth of penetration of topically applied drug molecules for both local cutaneous and systemic applications.

A pathogenic role for IgE in autoimmunity: bullous pemphigoid IgE reproduces the early phase of lesion development in human skin grafted to nu/nu mice.

Bullous pemphigoid (BP) is an autoimmune disease characterized by subepidermal blistering. Based on previous work, IgG autoantibodies directed against BP180 are thought to be the primary pathogenic agent in BP. In addition to these IgG autoantibodies, however, most BP patients produce IgE class autoantibodies that also react with BP180, and total IgE levels are often elevated in this disease. To directly test whether BP IgE is pathogenic, 6 ng of total IgE isolated from two BP and two normal sera were injected into human skin grafted onto athymic, nude mice. Twenty-four hours after injection, erythematous, elevated plaques were observed in all human skin grafts receiving BP IgE (n=11), but not control IgE (n=9). Histologic and ultrastructural examination of the lesions showed engorgement of blood vessels and a dermal infiltrate composed of neutrophils, eosinophils, and mast cells, many of which were degranulated. At a higher dose of BP IgE (47 ng), histological separation of the epidermis from the dermis was observed in two of the three grafts. The BP IgE-induced erythematous plaques were reminiscent of those clinically seen in BP. This provides early evidence of a direct demonstration of a pathogenic role for IgE class autoantibodies in a human autoimmune disease.