<i>In situ</i> bioprinting: bioprinting methods, bioinks, cell sources &amp; advanced bioprinting strategies

Bioprinting is a tissue engineering approach which has great potential to devise regenerative therapies and alleviate tissue/organ shortage.<i>In situ</i>bioprinting, allowing the direct creation of functional 3D tissues/organs at the defect site in the patient body, has attracted significant attention of surgeons and researchers. However, it is challenging to design adequate combinations of manufacturing devices, bioinks and cells to meet the<i>in situ</i>bioprinting requirements of medical functions, complex human body environment and clinical applications. This review highlights current state-of-art bioprinting technologies, summarising their advantages and challenges for<i>in situ</i>applications from four perspectives: bioprinting methods, bioinks, cell sources and advanced bioprinting strategies.