Deciphering the In Vivo Metabolism of Polyethylene Glycol by a Polymeromics Approach

Area of Science:

• Polymer Chemistry
• Pharmacokinetics
• Analytical Chemistry

Background:

• Polyethylene glycols (PEGs) are widely used in pharmaceuticals but have potential adverse effects.
• PEG polydispersity complicates the study of their in vivo metabolism.
• Understanding PEG metabolism is crucial for developing safer PEGylated drugs.

Purpose of the Study:

• To introduce and validate "polymeromics" for elucidating PEG metabolism.
• To characterize the in vivo metabolism of methoxy polyethylene glycol 2000 (mPEG2000).
• To investigate the kinetics, distribution, and excretion of mPEG2000 and its metabolites.

Main Methods:

• Development of a polymeromics approach using liquid chromatography and high-resolution mass spectrometry.
• Application of clustering analysis for molecular weight profiling.
• In vivo studies using mPEG2000 as a model polymer.

Main Results:

• Comprehensive molecular-weight-resolved characterization of mPEG2000 in vivo metabolism.
• Identification of various mPEG2000 metabolites.
• Demonstration of midchain scission mediated by hydroxyl radicals.

Conclusions:

• Polymeromics provides a powerful platform for studying PEG metabolism.
• Midchain scission is a key metabolic pathway for mPEG2000 in vivo.
• Findings offer insights into the biological fate of PEGs, informing safer drug development.