Purpose: Tissue engineering is an interdisciplinary field involving activities based on two interrelated areas: developing new methods to repair, regenerate and replace damaged tissues and organs. Currently, the most suitable materials for bioprinting of living constructs are biomaterials based on decellularized extracellular matrix (ECM). In this researches, we made two independent hypotheses: (1) that bioinks based on ECM obtained from pancreatic organs should provide structural elements that improve the functionality of pancreatic islets in vitro and (2) the produced bioink should be biocompatible and safe for living organisms, which must be tested on animals.
Methods: The bioinks used in this study were: 3% alginate, 3% alginate with the addition of gelatin, 3% alginate with the addition of proteins from the extracellular matrix of the pancreas, commercially available bioink with cellulose nanofibrils and our proprietary pancreatic dECM bioink. The islets were subjected to the bioprinting process in each of the above-mentioned bioinks. The petals and islets of the control group were then grown on the inserts immersed in the growth medium for 7 days. After the 7th day of testing, both the petals and the control islets were stained with FDA/Pi and GSIS to demonstrate their viability. Surface and transmission electron microscope was preformed. Bio ink was bioprinted and transplanted into BALB/c mice and observation period was one year.
Results: There were no statistical difference in GSIS results after bioprinting procedure and control islets after 3Dbioprinting of islets. On the 7-th day post 3Dbioprinitng GSIS was significantly higher in islets bioprinted in our dECM bioink in comparison to control group and other bioinks and was respectively in high glucose: 30 uU/ml vs 5 in control and 4 in other groups.
Conclusions: The bioink produced by the authors allows for bioprinting of complex tissue systems together with pancreatic cells and islets, while improving their functionality by recreating the natural environment of the pancreas.