Epidermolysis Bullosa (EB ) is a genetic skin disease where blistering occurs on the skin and on internal linings such as the mouth and the intestines. It is believed to occur in an estimated one out of every 50,000 births worldwide. Those affected are often described as ‘butterfly children’ as their skin is as fragile as a butterfly’s wings.
EB can occur in varying degrees of severity, so while one patient may have very slight blistering in restricted areas, another may have extensive blistering over their entire body. Recessive Dystrophic Epidermolysis Bullosa, or RDEB, is a particularly severe form of EB. RDEB is caused by mutations in the Type VII collagen gene. Type VII collagen is responsible for the formation of the anchoring fibrils in the skin. The anchoring fibrils help to keep the layers of the skin intact so when these fibrils are not formed correctly as in RDEB, the skin layers are more fragile and blisters form.
A goal of researchers in the Network of Excellence for Functional Biomaterials (NFB ) at NUI Galway is to develop a biomaterial based device in which genes or drugs can be delivered to different targets throughout the human body.
In my work, the focus is on a method to deliver the normal type VII collagen gene to a cell found in the skin called keratinocytes. An average keratinocyte in the human body is about 10-30µm, or roughly one tenth the size of a grain of salt! If we want to deliver something into this cell it must be much smaller than this. As a result, we focus on nano-systems.
Nanoscience is a fast emerging field of scientific research. It refers to the study of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometres or smaller. One nanometre is a millionth of a millimetre – this cannot be seen by the naked eye, but can be viewed using very high powered microscopes in the lab.
The nanosystem we propose to use are called nanospheres. The nanospheres are formed using different biodegradable materials made from natural and synthetic polymers which render them biocompatible and absorbable. The gene of interest, in this case the Type VII collagen gene, is encapsulated in the hollow core of the nanosphere.
The outer surface of the sphere is then modified using a dendrimer which allows small molecules to be added to the surface of the sphere in order to improve its function. For this project, I add a fluorescent probe to the nanosphere which allows me to easily track the nano-system when viewed through the microscope.
Also added is a special homing molecule that allows the nanosystem to be delivered directly to the keratinocytes. Our goal is to deliver the completed nanosystem to the RDEB keratinocytes, which will release the gene and encourage type VII collagen to be produced normally again, correcting the disorder.
The best part of my work is the fact that we are working towards an important goal; a gene therapy approach to treat RDEB. While a cure will not be found overnight, I do expect to see clinical translation in the next 5-6 years.
Each promising result in the lab leads the field a step closer to an effective treatment. My research is funded by DEBRA (Dystrophic Epidermolysis Bullosa Research Association ) which is a charity that relies on donations from the general public to fund research. This drives home the fact that what I do in the laboratory is ultimately going to benefit those affected by this disease and hopefully in the future it will no longer be incurable.
