Fabrication and in vivo characterization of FRESH-based 3D printed chitosan construct for small intestine regeneration.

This study demonstrates the implantation of a 3D-printed small intestine construct using chitosan bioink and freeform reversible embedding of suspended hydrogels (FRESH) bioprinting technology. The research addresses the significant clinical challenges posed by inflammatory bowel disease (IBD) and short bowel syndrome (SBS), which often require surgical interventions leading to substantial loss of small intestine (SI) surface area. High costs, side effects, and donor shortages limit traditional treatments such as total parenteral nutrition and small bowel transplantation. Therefore, developing an engineered artificial intestine represents a critical need. The study employed a natural biopolymer, i.e., chitosan, known for its biocompatibility and blood compatibility, as the primary material for the bioink. The 3D-bioprinted constructs were evaluated through mechanical characterization, blood biocompatibility tests, and antibacterial assays. The mechanical properties indicated the constructs' ability to withstand significant deformation, while the blood compatibility tests showed minimal hemolysis, supporting the material's suitability for implantation. Antibacterial tests revealed that the constructs could inhibit bacterial growth, reducing the risk of implant-associated infections. Following the implantation of the prepared constructs in rats, the post-implantation analysis indicated successful integration and biocompatibility with no significant adverse reactions. The biochemical parameters, like inflammatory markers, were found to be slightly higher than the normal range. All other parameters, like bilirubin and albumins, etc, were in the normal range. This study highlights the potential of 3D-bioprinted chitosan-based constructs in organ regeneration and presents a promising solution for treating SBS and IBD. The findings support further exploration of the fabricated 3D printed biocompatible materials for medical applications in regenerative medicine and tissue engineering. .