Advances in thermoplastic polymers for 3D-printed medical devices: Balancing mechanical performance and biocompatibility

This study offers a systematic review of the methodology surrounding the use of thermoplastics in three-dimensional (3D) printing for medical applications. Despite 3D printing not being extensively adopted for the creation of clinical medical devices due to safety and legal concerns, recent developments in materials, printing technology, and professional skills have broadened its clinical uses. The use of thermoplastics in 3D printing allows for the creation of economical components with diverse properties and potential applications. For example, literature consistently reports that while PLA-based structures typically exhibit tensile strengths in the range of 50–65 MPa, PEEK-based printed components achieve substantially higher strengths of 90–100 MPa, alongside superior fatigue resistance and long-term biocompatibility, making PEEK more suitable for load-bearing orthopedic applications. By employing design tactics such as thermoplastic layering, it is possible to reconcile competing demands, such as the mechanical strength and biological compatibility required for tissue structures. Consequently, this review summarizes the research efforts aimed at identifying appropriate thermoplastics, including polylactic acid (PLA), polypropylene (PP), polycarbonate (PC), polyurethane (PU), Acrylonitrile Butadiene Styrene (ABS), polyetheretherketone (PEEK), and polyvinyl alcohol (PVA), for the production of biomedical parts through 3D printing. It covers a range of produced items, including bones, high-quality prosthetics, intervertebral discs, medical devices, heart valves, and tissues containing blood vessels. Additionally, this review examines various 3D printing techniques, the challenges faced, and the future prospects for thermoplastic biomedical components.