PEGylated Dendrimers: A Novel Mechanism of Drug Delivery

Researchers have developed a new way to deliver medications by using PEGylated polylysine dendrimers. These are 5-10 nm drug delivery systems whose properties can be altered by changing the peripheral sites surrounding their core. The new technique shows particular promise in fighting certain metastatic cancers, HIV, and other diseases which are spread by the lymphatic system.

The dendrimer itself consists of an inner core surrounded by layers of polymer. These layers provide each dendrimer with surfaces for drug attachment as well as polyethylene glycol (PEG) attachment. PEG attachments are important in increasing the amount of time that the delivery system can exist in the body before breaking down. The interesting finding is that the body’s decision to place these systems depends on the length of attached PEG chains. A longer PEG chain seems to have an easier time entering into the lymphatic system, while shorter chain systems are quickly absorbed into the blood. Early observations indicate the possibility that a dendrimer system can be tailored based on the medical application to reach target sites.

This article caught my attention primarily because it is similar in spirit to last semester’s device design project. Researchers are actually developing devices on the nanoscale that target specific sites and areas in the body. These researchers utilized PEG layers in precisely the same manner that many of us did. That is, to disguise the system from the body’s defense mechanisms. It wasn’t until after many tests were performed that the special properties of these devices were realized though, which would have been the next step for us as well.


http://www.sciencedaily.com/releases/2010/03/100311101612.htm