Functional polymers find broad application in the biomedical field. Inter alia, research and application in drug, protein and gene delivery systems self-assembled polymers , nanoreactors , bioimaging contrast agent carriers , anti-biofouling coatings , sensors , tissue engineering requires specifically designed polymers with suitable functionalities for appropriate bioconjugation and further biomedical application . Among the plethora of synthetic polymers, poly(ethylene glycol) (PEG) remains the commercially available "gold standard "for biomedical application due to its high hydrophilicity combined with good solubility in organic solvents , low toxicity , and stealth behavior . In addition, structural varieties such as star-PEG and a considerable diversity of endgroup functionalization are commercially available. Despite PEG being generally regarded safe, antibodies against PEG and some other limitations such as toxic side products , hypersensitivity , vacuolization and accumulation in the body were reported. Several studies reported on already pre-existing antibodies in several patients during clinical trials with PEGylated therapeutic agents. demonstrate that depending on PEG concentration and molar mass, unexpected anaphylaxis in some sensitive individual animals could occur after administration with medicines containing a high concentration of PEGylated carriers. Zhang and later Zhao et al. reported on the toxic influence of PEG-modified particles. Accordingly, the search for alternatives has been a going research topic in the chemistry community. Especially, safe alternatives are again of particular interest in the current COVID-19 pandemic considering the allergic reaction and/or anaphylaxis after vaccination with currently developed vaccines . These side effects have been associated with any of the vaccine components, including PEG and PEG derivatives . Among some other polypeptides, polypeptoids, and poly(2oxazoline)s, have been suggested as excellent candidates to substitute PEG .