Chapter 8 - Polyurethane-based structures obtained by additive manufacturing technologies

Abstract

In the past few years, research and the development of biomedical polymers and processing technologies for biomedical applications have received growing attention. Among the most attractive technologies, additive manufacturing (commonly known as three-dimensional printing) is highly suitable for producing sophisticated and tailor-made scaffolds for biomedical applications due its inherent advantages of customizability and the ability to create complex shapes with precision. Moreover, this is a time-saving approach, being far more reproducible than conventional techniques to obtain scaffolds. Additive manufacturing (AM) includes a wide variety of manufacturing techniques and it is being used in personalized prosthetic/implant devices for otorhinolaryngology, dentistry, orthopedics, and craniofacial reconstruction, among others. Tissue engineering and controlled drug-release systems are also important research fields which use AM as a tool for designing accurate, structured, and tailored functional structures. However, there are some limitations for processing new materials using AM techniques. Furthermore, there is an increasing need for new biocompatible and/or bioresorbable materials with different mechanical properties, degradation rates, and surface requirements to be processed for a broad range of applications. In the past years, biocompatible and biodegradable segmented polyurethanes (SPUs) have been investigated for their applications in tissue engineering, controlled drug-release systems, wound dressings, and many biomedical devices. SPU and their composites with poly(ethylene glycol), cellulose, starch, gelatin, alginate, fibrinogen, and collagen, among others, have been explored through different AM techniques for biomedical applications. This chapter aims to review the use of novel AM as microfabrication tools for bioresorbable SPU elastomers and SPU composites. Current advances in 3D printing of SPU are described and commented on. Advantages and shortcomings of the current approaches, as well as future perspectives are outlined. Finally, a vision for future research on this topic is presented.