PEG Quantitation Using Reversed-Phase High-Performance Liquid Chromatography and Charged Aerosol Detection
This chapter describes a method for the quantitation of polyethylene glycol (PEG) in PEGylated colloidal gold nanoparticles using a reversed-phase high-performance liquid chromatography (RP-HPLC) with charged aerosol detection. The method can be used to calculate the total PEG on the nanoparticle, as well as the bound and free unbound PEG fractions after a simple centrifugation step. This is a significant distinction as the bound PEG fraction affects biocompatibility, circulation time, and overall nanoparticle efficacy. PEG quantitation can be achieved through two methods, one involving the dissolution of colloidal gold nanoparticles by potassium cyanide (KCN) and the other by displacement of PEG by dithiothreitol (DTT). The methods outlined herein were applied to 30 nm colloidal gold grafted with 20 kDa PEG, but they can be easily adapted to any size colloidal gold nanoparticle and PEG chain length.
Key wordsPolyethylene glycol (PEG) Surface characterization Charged aerosol detector Gold nanoparticles Stability Displacement Dissolution
This project has been funded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.