Insertion of DNA or RNA (a gene) into a cell is usually referred to as Gene Therapy. The new gene will add or delete a function.

Skin is a desirable target organ for gene therapy. Skin is a large and accessible tissue, and the site of gene delivery can be monitored. Potential complications, such as infection and neoplasia, may be diagnosed and treated. Skin cells can produce various proteins that are therapeutic both locally and systemically. Antigen-presenting cells in the skin are effective for genetic immunization (DNA vaccination).

Skin Cells

Cells cultured in the wound chamber can be genetically modified. The genetic engineering can be done in the laboratory, or directly in the patient. If the cells were not covered by the wound chamber, most of them would desiccate and die. The chamber seals the wound from the outside, eliminating the spread of genetic material and vectors to places outside the wound. At the same time, the chamber prevents the accidental introduction of undesired contamination into the wound.

The use of the wound chamber system for gene transfer also allows non-invasive assessment of the success of the transfer by assaying for the presence of the expressed protein in wound fluid, in contrast to the prior art use of invasive techniques, such as biopsies, in order to achieve the same assessment of early expression. 

We increase the yield of genetically engineered cells by targeting epidermal stem cells for gene transfer. The epidermis is a continuously renewing tissue from which cells are sloughed into the environment. The benefits of gene transfer are short lived as the cells are lost. Epidermal stem cells, however, remain for the lifetime of the epidermis. Gene transfer to these cells results in a longer lasting gene therapy. Our patent for this technology is the only patent issued to date with respect to gene delivery to epidermal stem cells.

Microseeding

Microseeding™ uses repeated injection from solid microneedles to deliver genetic material directly into an external or internal target. Our primary targets are skin cells and periosteal cells. Other tissue and organs, such as muscle, heart, stomach, and bowel are also treatable. Microseeding™ can be used with naked DNA or in combination with any viral or chemical vector. 

Microseeding™ has many advantages

• Effective, efficient, versatile
• Works with almost any vector or formulation
• Potentiates most vectors
• High level of safety, predictability, and reproducibility 
• Economical, practical, and customizable to the patient

The following chart indicates the efficiency of in vivo gene transfer to skin and partial-thickness wounds by Microseeding™ as compared to delivery by single needle injection and particle bombardment (gene gun). Each delivery method was used to deliver a DNA plasmid expressing human epidermal growth factor (EGF).