In situ 3D bioprinting: The future of regenerative medicine

3D bioprinting is utilized to design and construct scaffolds with scalable forms and physicochemical properties. Recently, this technology has been extensively studied in the field of biology and has achieved promising results in tissue and organ repair. However, challenges such as shape mismatch, unstable adhesion, and contamination arise during the transition from externally printed scaffolds to their internal transplantation, thereby limiting clinical applications. Compared to traditional 3D bioprinting, in situ 3D bioprinting offers enhanced tissue integration and surface construction capabilities, demonstrating greater clinical potential. Nevertheless, it places higher demands on printing technology and bio-ink. This article summarizes the methods and characteristics of in situ 3D bioprinting, and introduces research on the composition and reactivity of bio-inks. The latest progress in tissue repair using in situ bioprinting is highlighted. Further research in 3D bioprinting for tissue engineering, encompassing defect model scanning, printing platform construction, printing techniques, ink combinations, and large tissue printing, is ongoing. In situ 3D bioprinting holds promise as a novel and effective treatment method for future clinical applications.