In situ 3D bioprinting: A promising technique in advanced biofabrication strategies

3D bioprinting is a potential technique for developing functional 3D tissues for tissue engineering and regenerative medicine applications. Recently, the direct formation of 3D tissues on defect sites, known as in situ 3D bioprinting, has gained increasing attention to fulfill unmet needs. In situ 3D bioprinting has shown the capability of addressing problems, such as the need for invasive operations for transplantation and fabrication of sophisticated, irregularly shaped constructs, demonstrating its advantages over conventional methods. This review summarizes the two main approaches used for in situ bioprinting, namely robotic and handheld bioprinting. Besides, the latest advances in organ regeneration using this approach are discussed. Furthermore, some natural and synthetic materials used for in situ bioprinting are briefly presented.