Kim Jinku, D A Gouripriya, Debnath Poonam, Saha Prosenjit
Department of Biological and Chemical Engineering, Hongik University, Sejong 30016, Republic of Korea.
Center for Interdisciplinary Science (CIS), JIS Institute of Advanced Studies and Research (JISIASR), JIS University, Kolkata 700091, India.
Biomimetics (Basel). 2024 Aug 11;9(8):484. doi: 10.3390/biomimetics9080484.
The emergence of 4D printing has become a pivotal tool to produce complex structures in biomedical applications such as tissue engineering and regenerative medicine. This chapter provides a concise overview of the current state of the field and its immense potential to better understand the involved technologies to build sophisticated 4D-printed structures. These structures have the capability to sense and respond to a diverse range of stimuli, which include changes in temperature, humidity, or electricity/magnetics. First, we describe 4D printing technologies, which include extrusion-based inkjet printing, and light-based and droplet-based methods including selective laser sintering (SLS). Several types of biomaterials for 4D printing, which can undergo structural changes in various external stimuli over time were also presented. These structures hold the promise of revolutionizing fields that require adaptable and intelligent materials. Moreover, biomedical applications of 4D-printed smart structures were highlighted, spanning a wide spectrum of intended applications from drug delivery to regenerative medicine. Finally, we address a number of challenges associated with current technologies, touching upon ethical and regulatory aspects of the technologies, along with the need for standardized protocols in both in vitro as well as in vivo testing of 4D-printed structures, which are crucial steps toward eventual clinical realization.
4D打印的出现已成为在生物医学应用（如组织工程和再生医学）中制造复杂结构的关键工具。本章简要概述了该领域的现状及其巨大潜力，以便更好地理解构建复杂4D打印结构所涉及的技术。这些结构能够感知并响应各种刺激，包括温度、湿度或电/磁的变化。首先，我们描述了4D打印技术，包括基于挤出的喷墨打印以及基于光和液滴的方法，如选择性激光烧结（SLS）。还介绍了几种用于4D打印的生物材料，这些材料会随着时间在各种外部刺激下发生结构变化。这些结构有望变革那些需要适应性和智能材料的领域。此外，还强调了4D打印智能结构的生物医学应用，涵盖了从药物递送到再生医学的广泛预期应用。最后，我们讨论了与当前技术相关的一些挑战，涉及技术的伦理和监管方面，以及在4D打印结构的体外和体内测试中对标准化方案的需求，这些都是最终实现临床应用的关键步骤。
