Which area can PEGylation be effective in?

Question

Common limits for therapeutic application of peptides and proteins are their chemical instability, their short circulation time in blood and their tendency to promote immunological response. Linking one or more PEG (polyethylene glycol) molecules to these peptides and proteins (PEGylation) have been proven to be a possible solution for these problems. This is achieved due to the combination of increased molecular weight and coverage of epitopes or blockage of sequences prone to enzymatic degradation.