Abstract <p>Tissue engineering, a critical branch of biomedical engineering, plays a pivotal role in regenerative medicine by integrating cells, biomaterials, and biochemical cues to repair or replace damaged tissues and organs. Among recent innovations, three-dimensional (3D) bioprinting has emerged as a transformative tool, enabling the fabrication of complex, static biological structures for applications such as organ printing and targeted drug delivery. However, 3D bio-printed constructs lack the ability to replicate the dynamic behavior of native tissues, such as growth, adaptation, and self-repair. To overcome these limitations, four-dimensional (4D) bioprinting introduces time as an additional functional element, utilizing smart, stimuli-responsive bio-inks capable of altering shape or function in response to environmental triggers like temperature, pH, or magnetic fields. Key real-world applications of 4D bioprinting include self-morphing vascular grafts, adaptive implants, dynamic drug testing platforms, and intelligent wound dressings. While 4D bioprinting offers exciting possibilities, significant challenges remain—such as the limited availability of responsive, biocompatible materials, complexity in mimicking native tissue microenvironments, and technical constraints in current printing platforms. Advancements in smart biomaterial design, multi-material printing systems, and computational modeling are essential for progressing toward clinical adoption. Despite these challenges, 4D bioprinting holds immense potential to revolutionize regenerative medicine by enabling the development of dynamic, patient-specific, and functionally responsive tissue constructs. This review systematically examines the literature on 3D and 4D bioprinting, focusing on their applications, current limitations, and future prospects. </p> Lay Summary <p>Tissue engineering is the concept by which damaged tissues or organs may be restored such that life can go on forever, especially for our loved ones. The process, however, is very complex and challenging, as there are so many coordinated events orchestrated in the process of development, and the mechanism behind every event is still not clear. The basic requirements for tissue engineering are the stem cells, growth factors, and the biomaterials for making the scaffold. The scaffolds provide the framework or support for the tissue being developed. Initially, 2D scaffolds were used, but they were soon replaced by 3D scaffolds, as they mimic the organ or tissue more effectively. Recently, the concept of 4D tissue bioprinting has been developed to produce a tissue or organ with better functional responsiveness to changes in stimuli. 4D tissue bioprinting holds promise for better healing of damaged tissues to save lives and also for managing the paucity of organ donation to some extent.</p>