Preliminary engineering for in situ in vivo bioprinting: a novel micro bioprinting platform for in situ in vivo bioprinting at a gastric wound site.

We first proposed the concept of in situ in vivo bioprinting in order to address the existing deficiencies in conventional bioprinting. Herein we verified this concept taking the case of the treatment for gastric wall injury and presented this work as a preliminary step towards a new method in the field of bioprinting. In this study, a micro bioprinting platform which can be installed to an endoscope was developed to enter the human body and process bioprinting. Printed circuit micro-electro-mechanical-system techniques were used in the design and fabrication of the platform. Control system with high accuracy was developed and performance tests were carried out to verify the feasibility of the platform. The 2-layer tissue scaffolds were printed in a stomach model. Gelatin-alginate hydrogels with human gastric epithelial cells and human gastric smooth muscle cells were used as bioinks to mimic the anatomical structure of a stomach. A 10 d cell culture showed that printed cells remained a high viability and a steady proliferation, which indicated good biological function of cells in printed tissue scaffolds. This work presents an innovative advance not only in the field of bioprinting but also in the clinical sciences.