Programmable hydrogels are defined as hydrogels that are able to change their properties and functions periodically, reversibly and/or sequentially on demand. They are different from those responsive hydrogels whose changes are passive or cannot be stopped or reversed once started and vice versa. The purpose of this review is to summarize major progress in developing programmable hydrogels from the viewpoints of principles, functions and biomedical applications. The principles are first introduced in three categories including biological, chemical and physical stimulation. With the stimulation, programmable hydrogels can undergo functional changes in dimension, mechanical support, cell attachment and molecular sequestration, which are introduced in the middle of this review. The last section is focused on the introduction and discussion of four biomedical applications including mechanistic studies in mechanobiology, tissue engineering, cell separation and protein delivery.

可编程水凝胶定义为能够根据需要周期性地，可逆地和/或顺序地改变其性质和功能的水凝胶。它们不同于那些响应性水凝胶，后者的变化是被动的，一旦启动就不能停止或逆转，反之亦然。这篇综述的目的是从原理，功能和生物医学应用的角度总结开发可编程水凝胶的主要进展。原则首先在三个类别中介绍，包括生物，化学和物理刺激。通过刺激，可编程水凝胶可能会发生尺寸变化，机械支撑，细胞附着和分子螯合的功能变化，这些变化将在本文的中间进行介绍。