4D Hydrogels: Fabrication Strategies, Stimulation Mechanisms, and Biomedical Applications
【Abstract】
Shape-morphing hydrogels have emerged as a promising biomaterial due to their ability to mimic anisotropic tissue composition by creating an out-of-plane and in-plane gradient due to differences in local swelling behavior. Shape deformations occur due to the non-uniform distribution of internal stresses, asymmetrical swelling, and shrinking of different parts of the same hydrogel. This article discusses four-dimensional (4D) fabrication techniques (extrusion-based printing, dynamic light processing, and solvent casting) to prepare shape-shifting hydrogels. The important distinction between mono–and dual-component hydrogel systems, the capabilities of 3D constructs to undergo uni- and bi-directional shape changes, and the advantages of composite hydrogels over pristine are made. Discussion on various types of actuators, such as moisture, light, temperature, pH, and magnetic field, and their role in achieving desired and pre-determined shapes are presented. Such 4D gels have shown remarkable potential as a dynamic tissue scaffold for regenerative engineering and drug delivery applications. The review article closes with futuristic insights into integrating piezoelectric biopolymers and sensors to harvest mechanical energy from motions during shape transformations to develop self-powered biodevices. The capabilities of data science to create imaginative tools based on artificial intelligence and deep-learning algorithms can widen the field of biorobotics.
【Author】
Amit Nain, Srishti Chakraborty, Nipun Jain, Saswat Choudhury, Suravi Chattopadhyay, Kaushik Chatterjee, Souvik Debnath
【Journal】
Biomaterials Science(IF：5.3) Time：2024-04-26
