Instant trachea reconstruction using 3D-bioprinted C-shape biomimetic trachea based on tissue-specific matrix hydrogels

Currently,3D-bioprinting technique has emerged as a promising strategy to offer native-like tracheal substitutes for segmental trachea reconstruction.However,there has been very limited breakthrough in tracheal repair using 3D-bioprinted biomimetic trachea owing to the lack of ideal bioinks,the requirement for precise structural biomimicking,and the complexity of multi-step surgical procedures by mean of intramuscular pre-implantation.Herein,we propose a one-step surgical technique,namely direct end-to-end anastomosis using C-shape 3D-bioprinted biomimetic trachea,for segmental trachea defect repair.First,two types of tissue-specific matrix hydrogels were exploited to provide mechanical and biological microenvironment conducive to the specific growth ways of cartilage and fibrous tissue respectively.In contrast to our previous O-shape tracheal design,the tubular structure of alternating C-shape cartilage rings and connecting vascularized-fibrous-tissue rings was meticulously designed for rapid 3D-bioprinting of tracheal constructs with optimal printing paths and models.Furthermore,in vivo trachea regeneration in nude mice showed satisfactory mechanical adaptability and efficient physiological regeneration.Finally,in situ segmental trachea reconstruction by direct end-to-end anastomosis in rabbits was successfully achieved using 3D-bioprinted C-shape biomimetic trachea.This study demonstrates the potential of advanced 3D-bioprinting for instant and efficient repair of segmental trachea defects.