DNA vaccine delivery program at NCI
Posted by Jim H on March 18, 2008
I was reading an interesting bit this morning about a collaboration between scientists at NCI-Ft Detrick and Inovio Biomedical Corp. of San Diego, CA. The program, initiated in July 2007, is being conducted under a Cooperative Research and Development Agreement (CRADA) and will assess novel HIV constructs in non-human primates, cytokine genes as vaccine adjuvants (immune system stimulants), and possibly anticancer therapies delivered using Inovio’s electroporation-mediated DNA delivery technology. The work is being performed in collaboration with Drs. George Pavlakis and Barbara Felber at the Fort.
The method of electroporation is a “needle-less” vaccine, introducing the vaccine via electronic pulses through the skin or soft tissue. There are some analogies for BioElectronics mechanisms, as well as standard electroporation methods used in recombinant DNA technology like electro-competent cells.
Here’s a little more from Inovio’s web site:
In all of these applications, the purpose of electroporation is to assist the uptake of useful molecules such as DNA vaccine into a cell. The biological material is first injected into or applied to the surface of the target tissue and followed by the application of brief, controlled electrical pulses directed to that tissue. As shown in the pictures below, electroporation’s millisecond electrical pulses temporarily create enhanced permeability of pores in the cell membrane. After a short period of time the pores reseal, leaving the cells undamaged. During the period that these pores exist, a significant quantity of the previously injected biomolecules are taken up and then trapped in the cell, enabling them to then perform their intended function.
How does the electroporation process work?
The following illustration depicts the process of administering a DNA vaccine using electroporation:
Inovio’s electroporation technology can increase the cellular uptake (also termed transfection) of an agent by 1,000 times or more. When used to deliver DNA vaccines, Inovio’s systems can increase levels of gene expression (i.e. production of the coded protein) by 100 times or more compared to plasmid DNA delivered without other delivery enhancements.