Amino Functionalized Poly(2-oxazoline)s: Synthesis and Specific Applications in Biology and Medicine

This article reviews the recent advancements in amino-functionalized poly(2-oxazoline)s (POxs), an area that has seen significant growth in recent years. Incorporating amino groups into the POx structure imparts a positive charge to the macromolecules, facilitating interactions with negatively charged biological targets. Depending on their protonation state, amino-functionalized POxs can also exhibit pH sensitivity in aqueous environments, making them promising candidates for sensing and drug delivery applications. Additionally, the presence of amino groups allows for further functionalization of the polymers with drugs, chelators, or other active molecules. To avoid cytotoxic effects, it is essential to carefully control the number, distribution, spatial arrangement, and accessibility of amino groups. The review highlights major synthetic strategies for introducing amino functionalities into POxs, including chain-end quenching, polymerization of protected monomers, post-polymerization modifications, and partial hydrolysis. It also discusses the key applications of amino-functionalized POxs as antibacterial agents and gene delivery vectors, emphasizing how the type and structure of the amino groups influence performance. Finally, the article outlines future directions for the development of functional POx-based materials. We hope that this work will serve as a guide for the syntheses of amino-functionalized poly(2-oxazoline)s and the design of new polymer-based materials for various applications in biology and medicine.