Non-isocyanate polyurethanes: perspectives as biomaterials

Polyurethanes (PUs) are used in many applications, including in the medical sector (e.g., breast implants, vascular access and cardiac assist devices) due to their remarkable mechanical performances combined with proven in vivo biocompatibility. However, their industrial synthesis from toxic isocyanate precursors poses environmental and health concerns. With regulations increasingly restricting the isocyanate use, exploring greener alternatives has become imperative. Extensive research of health-friendlier synthesis processes triggered the emergence of a new family of PUs called Non-Isocyanate Polyurethanes (NIPUs). Recent developments have shown that NIPUs are already competitive with PUs, for example in the adhesives and coatings field, and new opportunities emerged in biomedical applications. This review highlights recent breakthroughs regarding NIPUs development, emphasizing their appealing properties for biomedical applications as well as their biocompatibility. By shedding light on the close relationship between their peculiar structure and specific properties, we highlight the potential of NIPUs to engineer biomaterials and we position them as unprecedented options for the design of future medical devices.