Though many mono and multi-activated PEGs are commercially available in R & D grade, GMP-grade PEGs or PEGs that are functionally optimized to the intended application are less common and require customized synthesis. Biosynth GmbH is capable to meet your needs for activated PEGs.
Principles of PEG and activated PEGs
Polyethylene glycols (PEGs) are made from ethylene oxide by polymerization in thousands of tons per year. The molecular weight of PEGs ranges from 300 to 60.000 Da. PEGs are “linear by nature” but branched PEGs have been synthesized using suitable polyols as starters. Pharmaceutical grade PEGs are used as formulation additives for drug delivery or for PEGylation of biologics. Predominantly, maleimide, aldehyde or NHS ester are used as active groups in activated PEGs. PEGs for PEGylation are typically activated on one end of the chain (so-called mPEGs). PEGs for crosslinking or multimerization are bi or multi-activated. These PEGs are used in conjugate pharmaceuticals such as antibody drug conjugates (ADCs) or in medicinal products, e.g., hydrogels for the incorporation of living cells, among others.
Mono, bi and multi-activated PEGs
Structures of activated PEGs
PEGs are used in numerous applications ranging from as additives for concrete to excipients for pharmaceuticals. The broad spectrum of opportunities also reflects the structural variability of activated PEGs. As mentioned, many activated PEGs contain one active group but other functional PEGs, containing two or even more active groups, have been developed and are in use as well (see the different PEG structures displayed in the figure). Such homo and heterofunctional, multi-activated PEGs have been developed as crosslinker between two or more proteins or between proteins and small-molecules. Possible applications for such multi-activated PEGs are the construction of protein multimers and antibody drug conjugates (ADCs), among others.