3D Liver Tissue Model with Branched Vascular Networks by Multimaterial Bioprinting.

Complicated vessels pervade almost all body tissues and influence the pathophysiology of the human body significantly. However, current fabrication strategies have limited success at multiscale vascular biofabrication. This study reports a methodology to fabricate soft vascularized tissue at centimeter scale using multimaterial bioprinting by a customized multistage-temperature-control printer. The printed constructs can be perfused via the branched endothelialized vasculatures to support the well-formed 3D capillary networks, which ensure cellular activities with sufficient nutrient supply and then mimic a mature and functional liver tissue in terms of synthesis of liver-specific proteins. Moreover, an inner and external pressure-bearing layer is printed to support the direct surgical anastomosis of the carotid artery to the jugular vein. In summary, a versatile platform to recapitulate the vasculature network is presented, in which case sustaining the optimal cellularization in engineered tissues is achievable.

Reconstruction of functional uterine tissues through recellularizing the decellularized rat uterine scaffolds by MSCs in vivo and in vitro.

Infertile people who suffered from loss of uterine structures and/or functions can be treated through gestational surrogacy or uterus transplantation, which remains challenging due to the ethical and social issues, the lack of donor organs as well as technical and safety risks. One promising solution is to regenerate and reconstruct a bioartificial uterus for transplantation through the engineering of uterine architecture and appropriate cellular constituents. Here, we developed a well-defined system to regenerate a functional rat uterine through recellularization of the decellularized uterine matrix (DUM) patches reseeded with human mesenchymal stem cells (hMSCs). Engraftment of the recellularized DUMs on the partially excised uteri yielded a functional rat uterus with a pregnancy rate and number of fetuses per uterine horn comparable to that of the control group with an intact uterus. Particularly, the recellularized DUMs enhanced the regeneration of traumatic uterine in vivo because of MSC regulation. The established system here will shed light on the treatment of uterine infertility with heterogeneous DUMs/cell resources through tissue engineering in the future.