The polar regions of the lipid rearrange around the drug in such a manner that the apolar regions bind with the drug so that a three-dimensional cage is formed around the drug. The liposomes are then injected into the blood, travel to the target organ and keep the drug safe from blood enzymes that might inactivate it prior to getting to the target organ, tissue or tumor. There has been some success with this in the lab. Tight Junctions, Gap Junctions or Desmosomes. Figure 4 illustrates each type of connection.
Tight junctions occur by fusing membranes.
These are commonly found in the intestine and blood-brain barrier. It is this kind of connection in the central nervous system that makes it so difficult to get drugs to cross the blood-brain barrier and, hence, to treat disorders of the nervous system. These are common in the nervous system. By definition, diffusion is the net movement of solute from a region of higher solute concentration to a region of lower solute concentration. The difference between the two regions is called the Concentration Gradient.