Office of Technology Transfer – University of Michigan

Controlling PEG Chain Density on Gold Nanoparticles: A Living PEGylation

Technology #5387

PEGylated nanoparticles for biological and pharmaceutical applications Nanoparticles are gaining prominence in the development of new in vitro assays, imaging applications, drug delivery technologies, and therapeutics. A key feature of nanoparticle agents is their multifunctionality; the ability to append ligands, antibodies, imaging labels, drugs, or other molecules to nanoparticles enables targeted molecular imaging and therapy. Gold nanoparticles (AuNPs) serve as an excellent platform to attach these functional moieties, often via PEGylation of the colloidal gold. While advances have been made in the development of functionalized gold nanoparticles, current synthesis approaches lack the ability to control PEG chain density and therefore the density and stability of the functional groups coating the AuNP.

Controlled PEGylation of gold nanoparticles enhances synthesis of functionalized AuNPs Researchers at the University of Michigan have developed technology which facilitates the synthesis of functionalized gold nanoparticles. This technology, termed “living PEGylation,” is a unique process in which polyethylene glycol chains are added in sequential steps to gold nanoparticles, allowing control of PEG chain density on the nanoparticles. This PEGylation process facilitates the synthesis of multifunctional nanoparticles, with implications for both therapeutic and diagnostic nanoparticle development. Moreover, the process increases stability of the colloidal gold particles.

Applications • new process for synthesis of multifunctional diagnostic probes • new synthesis method for targeted therapeutic nanoparticles

Advantages • allows control of PEG chain density • improves specificity of nanoparticle targeting • enhances stability of gold nanoparticles • enables generation of multifunctional nanoparticles