Poly(2-oxazoline)-based stimulus-responsive (Co)polymers: An overview of their design, solution properties, surface-chemistries and applications

Pseudopeptidic poly(2-oxazoline)s are a special class of bio-inspired polymers with multiple applications, especially in the field of polymer therapeutics. Unsurprisingly, poly(2-oxazoline) has been extensively studied in recent decades, and pioneering studies on these polymers have shown that non-ionic, hydrophilic and thermo-responsive poly(2-oxazoline)s are comparable to and sometimes even more advantageous than poly(ethylene glycol) for biomedical applications. Considering their applications in the biomedical field, stimuli-responsive polymer materials open new opportunities for in vivo applications such as on-demand drug delivery, tissue repairing, biosensing and smart coatings, among others. In this context, this article is a comprehensive review of recent advances in stimuli-responsive polymers/interfaces consisting of poly(2-oxazoline)-based “smart” homopolymer and (co)polymer materials responsive to different single stimulus or to multiple stimuli. In particular, we focus on the synthesis (design strategies), “smart” solution properties (tuning of cloud points), self-assembly (tuning of nanostructures), surface chemistry (surface grafting strategies, antifouling properties, responsive behaviors) and possible biomedical applications of different stimulus-responsive materials based on functionalized poly(2-oxazoline). Accordingly, this review can be used as a benchmark for biopolymer researchers, thereby helping them design innovative functional poly(2-oxazoline)-based “smart” bio-inspired materials for novel applications by highlighting key research gaps and future research avenues in this dynamic and highly relevant field of research.