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Selected Publication:
Stiegler, Ph.
Cellulose sulfate (NaCS) for microencapsulation of pancratic ß-cells
[ Dissertation ] Medical University Graz
Department of Surgery, Div. of Transplantation Surgery; 2004. pp.182.
- Authors Med Uni Graz:
- Stiegler Philipp
- Advisor:
- Baumann Gabriele
- Iberer Florian
- Altmetrics:
- Abstract:
- Indroduction. At the moment more than 150 million people suffer from diabetes mellitus worldwide. Although there is a wide range of possibilities to treat diabetes, it became apparent that the late complications cannot be prevented totally by exogenous insulin therapy. Islet transplantation may be a therapeutic option. As there is a lack of human donor organs, therefore, immunoisolation is needed to protect the cells from the host immune system. In this work a novel material for micoencapsulation of pancreatic islets is tested. Methods: An insulin producing cell line (HIT-T15) is established in our laboratory and the insulin secretion dependent on the glucose concentration in the nutrient solution is measured by using ELISA. Antibody-stains are used to show that HIT-T15 cells form islet-like clusters. Cells are encapsulated with sodium cellulose sulphate (NaCS) in co-operation with Austrianova, Vienna, and the insulin produced by these cells is detected in media with different amounts of glucose. A MTT cell proliferation test is used to estimate the cell number and the growth is observed by photo documentation. Moreover, insulin-producing cells are located by using an insulin-antibody-staining considering that the microcapsule is three-dimensional. The diffusion of the glucose through the microcapsules is observed with flouroescence maked glucose. Differences in the reaction time of encapsulated and non-encapsulated cells on a glucose stimulus are compared and lactate production as a sign for anaerobic metabolism is measured. Results: HIT-T15 cells show glucose dependent insulin secretion. Cells form islet-like clusters and never build a monolayer. Cell growth and mitose rate are relying on the glucose concentration in the medium. Encapsulation with NaCS is feasible and neither cell growth nor mitose rate are influenced. Insulin production dependent on the glucose concentration in the nutrient solution works in a proper way. Transport of the nutrients and of insulin through the membrane is not inhibited. Cell growth of encapsulated cells is still dependant on the glucose concentration in the medium. Reaction time of encapsulated cells on the glucose stimulus is only delayed about five min compared to non-encapsulated cells can be frozen an thawed according to the needs. Conclusions: HIT-t15 cells show insulin production relying on the amount of glucose in the nutrient solution. Encapsulation with NaCS is feasible and it is shown that the material is permeable for nutrients and that is why cell growth and cell division are guaranteed.