A Broad Palette for Biological Drug Delivery

Nanoparticles are the center of many drug-delivery specialists' attention because they can form the basis of mechanisms that provide targeted and controlled drug delivery. Because nanoparticles also enhance drug stability and reduce immunogenicity, they provide a particularly advantageous solution for biological drugs. But they are not the only option on the table.

One common approach to delivering protein drugs is to attach polyethylene glycol (PEG) molecules to their amine groups. This process is called PEGylation. Anjan Nan, research assistant professor at the University of Maryland School of Pharmacy (Baltimore, MD), says that this technique has several advantages.

First, PEGylation reduces the protein's net amount of available amine groups, thus decreasing its net charge. "As a result, the whole formulation is less immunogenic because the body doesn't react to that excessive charge," Nan explains. "This is an easy and efficient strategy to make immunogenic molecules nonimmunogenic."