469 Using human pancreatic islets as a bioink for 3D bioprinting for bioengineering an artificial pancreas - preliminary report
Tuesday November 17, 2015 from 11:00 to 12:30
Room 110

Michal Wszola, Poland

associate professor

Department of General and Transplantation Surgery

Warsaw Medical University


Using human pancreatic islets as a bioink for 3D bioprinting for bioengineering an artificial pancreas - preliminary report

Michał Wszoła1, Marco Constantini2, Andrzej Berman1, Joanna Idaszek2, Łukasz Górski1, Agata Ostaszewska1, Marta Serwańska-Świętek1, Agnieszka Perkowska-Ptasińska1, Andrzej Chmura1, Wojciech Swięszkowski2, Artur Kwiatkowski1.

1Departament of General Surgery and Transplant, Warszaw Medical University, Warsaw, Poland; 2Department of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland

Islets transplantation has emerged as a mini-invasive procedure for treatment of diabetic complications. Since publishing Edmonton Protocol in 2000, many new centers undertaking islets transplantation have been established. Unfortunately number of islets transplantation is still low which does not meet demands for transplantation in diabetic patients. One of the problems is IBMIR reaction and another is lost of Extracellular matrix during isolation, which may start apoptosis. IBMIR might be limited if anti-inflammatory drugs will be used or if one decides to use extra-hepatic site like gastric submucosa. There has been no solution established for Extracellular matrix loss during isolation. Possible solution might be bioengenering artificial pancreas with use of islets as a bioink together with extracellular matrix. The aim of this study was to analyze whether islets can be used as a bioink and if they survive 3Dprinting process.
Material and Methods: Islets were isolated from human donors for transplantation. If insufficient islets yield was obtained, which excluded human transplantation, islets were suspended in CMRL and immediately sent for printing process in 3Dprinter. In printing facility were re-suspended in a customized bioink for 3Dprinting. The chemical composition of the bioink was 4% w/w alginate and 6% w/w gelatin-methacrylamide in buffer. The composition of the bioink was developed to achieve both a very high resolution in 3Dprinting and a high cell viability:alginate allows easy 3Dprinting of fine hydrogel fibers thanks to the fast gelation in presence of calcium ions while the UV-photopolimerization of the second polymer gives a major chemical stability to the 3Dprinted construct. The islet-laden beads were first extruded into a CaCl2 bath and then cross-linked using UV-light. Subsequently, the beads were washed with 25mM HEPES/10%FBS to remove the excess of the CaCl2 and cultured in RPMI1640medium supplemented with 10%FBS and 1% of penicillin-streptomycin solution for 10 days after printing process. Culture of fresh “unprinted” islets was a control.  Islet viability was assessed using live-dead assay just after printing process and, 2,3,5,10 days post printing. The samples were incubated for 15 min and analyzed using fluorescence microscope and filter sets corresponding to the fluorescence of interest. Additionally, the islets viability was investigated by means of a colorimetric MTS assay, in which the MTS tetrazolium salt is reduced by metabolically active cells to a water-soluble formazan. The islet-laden gelatin beads were transferred to RPMI1640w/oFBS and incubated with MTS at 37°C for 4 hours. The absorbance was measured using microplate reader. After culturing  printed artificial pancreas were suspended in formaline and analyzed under microscope.
Results: Sheets of artificial pancreas of 3x3x2mm were 3Dprinted. Viable cells were obtained just after printing process and up to 10th day of culture. Viable islets after bioprinting were as often seen as islets in control culture. On the 10th day of culture in both control and bioprinted sheets death cells were more often seen then viable cells. Fully integrated islets were seen under microscope in 3Dbioprinted pancreatic sheets.
Conclusion: Bioprinted islets survive process of bioprinting and might be used as a bioink. 3Dbioprinting of a pancreas is feasible and might be solution for extracellular matrix loss during isolation process.

© 2018 Melbourne2015