In situ bioprinting: intraoperative implementation of regenerative medicine.

Bioprinting has emerged as a strong tool for devising regenerative therapies to address unmet medical needs. However, the translation of conventional in vitro bioprinting approaches is partially hindered due to challenges associated with the fabrication and implantation of irregularly shaped scaffolds and their limited accessibility for immediate treatment by healthcare providers. An alternative strategy that has recently drawn significant attention is to directly print the bioink into the patient's body, so-called 'in situ bioprinting'. The bioprinting strategy and the associated bioink need to be specifically designed for in situ bioprinting to meet the particular requirements of direct deposition in vivo. In this review, we discuss the developed in situ bioprinting strategies, their advantages, challenges, and possible future improvements.