Department of Biomechanical Engineering, Faculty of Mechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft, 2628 CD, The Netherlands.
Department of Precision and Microsystems Engineering, Faculty of Mechanical Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft, 2628 CD, The Netherlands.
Adv Mater. 2024 Aug;36(31):e2402301. doi: 10.1002/adma.202402301. Epub 2024 May 28.
4D (bio-)printing endows 3D printed (bio-)materials with multiple functionalities and dynamic properties. 4D printed materials have been recently used in biomedical engineering for the design and fabrication of biomedical devices, such as stents, occluders, microneedles, smart 3D-cell engineered microenvironments, drug delivery systems, wound closures, and implantable medical devices. However, the success of 4D printing relies on the rational design of 4D printed objects, the selection of smart materials, and the availability of appropriate types of external (multi-)stimuli. Here, this work first highlights the different types of smart materials, external stimuli, and design strategies used in 4D (bio-)printing. Then, it presents a critical review of the biomedical applications of 4D printing and discusses the future directions of biomedical research in this exciting area, including in vivo tissue regeneration studies, the implementation of multiple materials with reversible shape memory behaviors, the creation of fast shape-transformation responses, the ability to operate at the microscale, untethered activation and control, and the application of (machine learning-based) modeling approaches to predict the structure-property and design-shape transformation relationships of 4D (bio)printed constructs.
4D（生物）打印赋予了 3D 打印（生物）材料多种功能和动态特性。4D 打印材料最近已被用于生物医学工程，用于设计和制造生物医学设备，如支架、封堵器、微针、智能 3D 细胞工程微环境、药物输送系统、伤口闭合和可植入医疗设备。然而，4D 打印的成功依赖于 4D 打印物体的合理设计、智能材料的选择以及适当类型的外部（多）刺激的可用性。在这里，这项工作首先强调了 4D（生物）打印中使用的不同类型的智能材料、外部刺激和设计策略。然后，它对 4D 打印的生物医学应用进行了批判性的回顾，并讨论了这一令人兴奋领域的生物医学研究的未来方向，包括体内组织再生研究、具有可逆形状记忆行为的多种材料的实施、快速形状转变响应的创建、在微尺度上的操作能力、无约束的激活和控制，以及（基于机器学习的）建模方法在预测 4D（生物）打印结构-性能和设计-形状转变关系中的应用。
