Introduction: 3D bioprinting using living cells is the latest technique in the field of biomedical engineering. One of the most important points of the procedure is to preserve the cells and leave them fully functional in the resulting bioconstruction. In the case of bioprinting of bionic tissue, it is important to provide cells with access to nutrients and gas exchange. These are the first results of printed bionic petals and the first studies on a mouse model.

Material: The research was carried out on 60 mice (SCID). Diabetes induction was not undertaken in small animal studies because T1D is difficult to achieve in a mouse model. The mice were divided into 3 groups: a control; the IsletTx in which porcine pancreatic islets were transplanted under the renal capsule; 3D Bioprint in which the 3D bioink petals consisted of bioink A and porcine islets. The petals were transplanted into the dorsal part of the muscles under the skin. Daily glucose measurement was performed and the level of C-peptide was tested every 7 days.

Results: The results obtained in mice initially showed no differences in the concentration of peptide-C and glucose between the groups. However, as early as 7 days after transplantation, both parameters analyzed in the fasting state were significantly lower in the IsletsTx and 3Dbioprinted groups compared to the control group. On day 14, decreased values ​​of C-peptide and glucose were observed only in the group with petals transplants. 

Conclusion: Transplantation of bionic petals in mice resulted in a decrease in mean glucose levels. The mice showed a reduced concentration of their own C-peptide, which can indicate relief in mice's owns islets function. None of the animals died due to postoperative complications or the lack of biocompatibility with the bionic structure. The positive effect of transplantation was maintained throughout the experiment, which proves the optimal selection of the composition of the bioink and the bioprinting parameters.