Epidermolysis bullosa (“EB”) is a group of rare genetic disorders that manifests as blistering or erosion of the skin in response to little or no apparent trauma. There are many genetic and symptomatic variations of EB. EB is always painful, often pervasive and debilitating, and is in some cases lethal before the age of 30. EB affects both genders and every racial and ethnic background equally. The most severe forms of EB require meticulous care similar to that given to burn patients. Standard treatment for EB patients is daily wound care, bandaging and pain management. There is no treatment or cure for EB.

Dystrophic epidermolysis bullosa (DEB) is one of the major forms of EB. The severity of symptoms in DEB patients varies widely among those affected. In more mild cases, patients suffer blistering primarily of the hands, feet, knees, and elbows. The most severe cases of DEB involve widespread blistering that can lead to vision loss, disfigurement, and Aegle’s Platform serious medical problems. Blistering of the skin is present in almost all forms of DEB. As the blisters heal, they can result in severe scarring. Additional complications of progressive scarring can include fusion of the fingers and toes, loss of fingernails and toenails, joint deformities (contractures) that restrict movement, and eye inflammation leading to vision loss. Additionally, young adults with chronic wounds have a very high risk of developing a form of skin cancer called squamous cell carcinoma, which tends to be unusually aggressive and is often life-threatening. While there are several subtypes of DEB, they share the majority of symptoms and they are all caused by mutations in the same gene, COL7A1.

COL7A1 is a gene that is responsible for producing type VII collagen. Type VII collagen is a protein that plays an important role in strengthening and stabilizing the skin. The body uses type VII collagen to make structures called anchoring fibrils, which anchor the top layer of skin, called the epidermis, to an underlying layer called the dermis. COL7A1 mutations alter the structure or disrupt the production of type VII collagen, which prevents the establishment of the necessary connection of the epidermis to the dermis. When type VII collagen is abnormal or missing, minor friction or trauma can cause the skin separate which leads to the formation of blisters and extensive scarring.

Aegle’s extracellular vesicles including exosomes (“EVs”) contain and transport cargo, including proteins and genetic material. In a recent publication entitled Dual mechanism of type VII collagen transfer by bone marrow mesenchymal stem cell extracellular vesicles to recessive dystrophic epidermolysis bullosa fibroblasts (Biochimie, 2018), Aegle researchers demonstrated that EVs transport and deliver type VII collagen protein as well as COL7A1 mRNA to diseased RDEB fibroblasts. Additionally, the EVs were shown to fuse into recessive DEB fibroblasts, stimulating the diseased cells to produce their own type VII collagen. EVs have significant potential to treat DEB and, due to their regenerative healing characteristics, all forms of EB as well.