Assessment of the Reproducibility of Alginate Encapsulation of Pancreatic Islets Using the MTT Colorimetric Assay
| Autor: | T.R. Jay, K.A. Heald, R. Downing |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: |
Graft Rejection
0301 basic medicine endocrine system Lysis Alginates Swine Islets of Langerhans Transplantation Biomedical Engineering lcsh:Medicine Complement Hemolytic Activity Assay Islets of Langerhans 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine medicine Animals Humans Polylysine MTT assay Cytotoxicity Transplantation geography geography.geographical_feature_category Pancreatic islets lcsh:R Antibody-Dependent Cell Cytotoxicity Membranes Artificial Cell Biology Islet Molecular biology 030104 developmental biology medicine.anatomical_structure chemistry Colorimetry Formazan 030217 neurology & neurosurgery |
| Zdroj: | Cell Transplantation, Vol 3 (1994) |
| ISSN: | 1555-3892 0963-6897 |
| Popis: | Radioisotope diffusion experiments demonstrate that alginate/polyaminoacid encapsulation can prevent antibody and cytotoxic cell contact in vitro. The unpredictable outcome of xenotransplantation of encapsulated islets may reflect incomplete encapsulation. We have assessed a cytotoxic/MTT (tetrazolium) assay to test antibody permeability of capsules. Samples of free porcine islet tissue, and islet tissue encapsulated in alginate/poly-l-lysine/alginate microspheres were incubated with fresh autologous pig serum or normal human serum overnight. Cell metabolism was assessed by the MTT assay. Data from eight experiments (10 replicates/experiment) were analyzed using the Mann-Whitney U-test. Values were deemed significant when p < 0.05. Free islets cultured in human serum showed a significant reduction in metabolism when compared with islets cultured in pig serum: percentage reduction 52 ± 23% (mean ± SD). The differences in formazan production were significant in all experiments (p < 0.05). Alginate encapsulation of islets or removal of xeno-reactive antibodies in human serum by adsorption was shown to prevent the effects of complement-mediated lysis. However, in one of the eight experiments, there was a significant reduction in islet metabolism after exposure of encapsulated porcine islets to human serum. In conclusion, it has been shown that alginate encapsulation can prevent complement-mediated lysis. However, the encapsulation process employed was imperfect and did not prevent complement-mediated lysis of porcine islets in all experiments. The cytotoxicity/MTT assay allows investigation of the permeability of capsules to serum antibodies and could be performed to determine the viability of the islets and the integrity of microcapsules prior to transplantation. |
| Databáze: | OpenAIRE |
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