The pursuit of medications that work more effectively with less side effects has led to tremendous interest in nanocarrier delivery systems. Polyetheylene glycol (PEG) is one such nanocarrier shown to extend the circulation time of medication and repel immune responses to its carrier medication. A significant drawback of PEG, however, is that studies have shown that as high as 40% of the population has anti-PEG antibodies, likely due to the prevalence of PEG in cosmetics and healthcare products. These antibodies not only accelerate the clearance of PEGylated therapeutics and reduce their efficacies but may also cause severe side effects.
In the search for alternatives to PEG, zwitterionic polymers have attracted the most attention. These polymers have equal numbers of positively and negatively charged ion groups along their molecular chains, which makes them extremely hydrophilic and antifouling. Hao Cheng, PhD, associate professor of materials science and engineering, has received a two-year NIH grant for his project “Zwitterionic polyethylene glycol for therapeutic delivery” which seeks to develop a zwitterionic PEG (ZPEG) that combines the advantageous properties of both PEG and conventional zwitterionic polymers that will be superior in extending the circulation of therapeutics and minimizing the generation of antibodies. Because of the broad application of PEG, successfully creating a replacement will generate tremendous societal impact. This project will pave the way to replace PEG with ZPEG in therapeutic delivery for minimized side effects and consistent efficacy.