Hamelink, T.L. (Tim) (2019) Cryoperfusion of porcine kidneys – A novel approach towards organ banking. thesis, Medicine.
Full text available on request.Abstract
Introduction: Nowadays, kidneys are preserved using hypothermic machine perfusion (HMP) to conserve organ viability prior to transplantation. As the current preservation strategies lack the ability to preserve kidneys for longer than a few hours, a method has to be established to preserve organs for longer periods. Cryopreservation could be a possible solution to store organs for longer periods or even indefinitely. This study aimed to generate the first pilot data on cryopreservation of porcine kidneys using a combination of the principles of cryopreservation and machine perfusion. A perfusion solution that remained liquid at -20°C and was not cytotoxic had to be developed. Methods: The freezing point of two possible perfusion solutions was assessed (DMSO/DMEM and PEG35/UW). The most suitable perfusion solution was tested on cytotoxicity on HEK293 AD- and HUVEC cells. After performing these two experiments, a cryoperfusion setup was realised. Porcine kidneys were retrieved at a local slaughterhouse and subjected to 20 minutes of warm ischaemia. Kidneys were preserved using HMP for 2 hours. Thereafter, kidneys were perfused for 4 hours at -20°C with 3 different protocols (n=3 per group). Histology was assessed before and after cryoperfusion to score morphological differences induced by cryopreservation. Results: The perfusion solution containing DMSO showed an increasing freezing point depression as the DMSO concentration increased. Cytotoxicity of increasing concentrations of DMSO was examined and showed acceptable survival until 35% volume/volume DMSO/DMEM. During perfusion, slow cooling of the kidney proved technically feasible but rewarming remained difficult. Biopsies before and after cryopreservation showed no substantial tissue injury as a result of this novel method. Conclusion: The developed perfusion solution with DMSO was of acceptable cytotoxicity until a concentration of 35%. Cooling of kidneys to -20°C without the formation of ice crystals was possible and machine perfusion is a promising technique for cryopreservation of whole organs. Further research is needed to improve the rewarming technique and investigate long term influences of cryopreservation.
Item Type: | Thesis (Thesis) |
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Supervisor name: | Faculty supervisor: and Leuvenink, prof. dr. H.G.D. and Daily supervisor: and Moers, dr. C. and Department of Surgery – Surgical Research Laboratory Univers |
Faculty: | Medical Sciences |
Date Deposited: | 25 Jun 2020 10:51 |
Last Modified: | 25 Jun 2020 10:51 |
URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/1252 |
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