Poly(ethylene glycol) (PEG) is a highly biocompatible and water‐soluble polymer that is widely utilized for biomedical applications. Unfortunately, the immunogenicity and antigenicity of PEG severely restrict the biomedical efficacy of pegylated therapeutics. As emerging PEG alternatives, biodegradable zwitterionic polymers (ZPs) have attracted significant interest in recent years. Biodegradable ZPs generally are not only water‐soluble and immunologically inert, but also possess a range of favorable biomedically relevant properties, without causing long‐term side effects for in vivo biomedical applications. This review presents a systematic overview of recent studies on biodegradable ZPs. Their structural designs and synthetic strategies by integrating biodegradable base polymers with zwitterions are addressed. Their applications in the delivery of small molecule drugs (as mono‐drugs or multi‐drugs) and proteins are highlighted.

中文翻译：

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可生物降解的两性离子聚合物作为药物输送的 PEG 替代品

聚乙二醇（PEG）是一种高度生物相容性和水溶性聚合物，广泛用于生物医学应用。不幸的是，PEG的免疫原性和抗原性严重限制了聚乙二醇化疗法的生物医学功效。作为新兴的 PEG 替代品，可生物降解的两性离子聚合物（ZP）近年来引起了人们的极大兴趣。可生物降解的 ZP 通常不仅是水溶性和免疫惰性的，而且还具有一系列有利的生物医学相关特性，不会对体内生物医学应用造成长期副作用。本综述对可生物降解 ZP 的最新研究进行了系统概述。通过将可生物降解的基础聚合物与两性离子结合来解决它们的结构设计和合成策略。它们在小分子药物（作为单一药物或多药物）和蛋白质输送方面的应用受到了重视。