An in vitro evaluation of the biocompatibility of proline‐alanine‐serine peptides compared with polyethylene glycol and polyglycerol

Abstract PASylation has been recently reported as a feasible alternative to PEGylation, which in essence is using polypeptides constituted of a combination of proline, alanine and serine for the hydrophilic modification of pharmaceuticals. In this work, we focused on the biocompatibility evaluation of two PAS peptides, (PAS) 8 and (PA 3 ) 7 as well as the more frequently used polymers polyethylene glycol (PEG) and polyglycerol (PG). It has been verified in this study that (PAS) 8 and (PA 3 ) 7 both exhibited low cell toxicity against HUVEC and RAW 264.7 cell lines. They also showed negligible RBC hemolysis and agglutination, which demonstrated adequate hemocompatibility. Their potential interactions with bovine serum albumin have also been investigated, and the results indicated little hydrophobic interactions between the polymers and protein. In conclusion, (PAS) 8 and (PA 3 ) 7 as well as PEG and PG all showed considerable compatibility and safety in these studies, suggesting that (PAS) 8 and (PA 3 ) 7 could be considered as potential candidates for PEG replacement in future studies.