A review of stimuli-responsive materials in 4D bioprinting for biomedical applications

Abstract

Four-dimensional (4D) bioprinting has been increasingly explored due to the potential to create dynamic, tunable structures that can respond to external stimuli. The fusion of the dynamic stimuli-responsive material with conventional three-dimensional printing technologies forms the foundation of 4D bioprinting and has the potential to revolutionise tissue engineering. 4D bioprinting involves the printing of structures which have the ability to alter their shape, function, or properties as a function of time in response to environmental stimulus. Critical to 4D bioprinting is the development of smart biomaterials that respond to different stimuli such as temperature, pH, light, and biochemical signals. This review article explores various stimuli-responsive materials used in 4D bioprinting for biomedical applications. Further, the review provides an overview of material properties and categorizes them according to responsiveness to external stimuli. Additionally, the review identifies current trends in material design, cell compatibility, and possible applications in tissue regeneration, drug delivery, and personalized medicine.