0000000000471268

AUTHOR

Heiko Zimmermann

0000-0001-8595-1304

showing 4 related works from this author

Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.

2012

Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs expe…

endocrine systemendocrine system diseasesSiloxanesCell Survivalmedicine.medical_treatmentImmunologyTransplantation HeterologousIslets of Langerhans TransplantationNanoparticleCell CountCell SeparationFerric CompoundsIslets of LangerhansMagneticsmedicineGlucose homeostasisAnimalsHumansViability assayRats WistarTransplantationIslet cell transplantationgeographygeography.geographical_feature_categoryChemistryHeparinDextransIsletMagnetic Resonance ImagingRatsTransplantationToxicityBiophysicsNanoparticlesPreclinical imagingXenotransplantation
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Encapsulation of Langerhans' islets: Microtechnological developments for transplantation

2011

There is an increasing trend to apply microsystems and microfluidics to solve medical and biomedical tasks. Microfluidic modules are used to modify and manipulate cells and cell clusters for therapeutic applications. Specifically, a method and technical system for encapsulation of Langerhans' islets as an option for the future treatment of diabetes mellitus is described. Type-1 diabetes patients suffer from an absolute lack of the hormone insulin caused by an autoimmune process destroying the Langerhans' islets. One way to restore glucose-dependent insulin secretion is the transplantation of human pancreatic islet cells (85% beta cells) from cadaveric donors. However, to prevent the rejecti…

geographyEnvironmental Engineeringgeography.geographical_feature_categorybusiness.industryInsulinmedicine.medical_treatmentCellBioengineeringIsletmedicine.diseaseRegenerative medicineTransplantationmedicine.anatomical_structureImmune systemAutoimmune ProcessDiabetes mellitusImmunologyMedicinebusinessBiotechnologyEngineering in Life Sciences
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Long-term graft function of adult rat and human islets encapsulated in novel alginate-based microcapsules after transplantation in immunocompetent di…

2005

We describe the results of the first study to show that adult rat and human islets can be protected against xenogenic rejection in immunocompetent diabetic mice by encapsulating them in a novel alginate-based microcapsule system with no additional permselective membrane. Nonencapsulated islets lost function within 4–8 days after being transplanted into diabetic Balb/c mice, whereas transplanted encapsulated adult rat or human islets resulted in normoglycemia for >7 months. When rat islet grafts were removed 10 and 36 weeks after transplantation, the mice became immediately hyperglycemic, thus demonstrating the efficacy of the encapsulated islets. The explanted capsules showed only a …

AdultBlood GlucoseMaleendocrine systemmedicine.medical_specialtyTime FactorsRatónAlginatesEndocrinology Diabetes and Metabolismmedicine.medical_treatmentIslets of Langerhans TransplantationCapsulesGraft functionIslets of LangerhansMiceGlucuronic AcidDiabetes mellitusInternal medicineInsulin SecretionInternal MedicineDiabetes MellitusMedicineAnimalsHumansInsulinInsulin secretiongeographyMice Inbred BALB Cgeography.geographical_feature_categorybusiness.industryHexuronic AcidsGraft SurvivalImmunosuppressionDiabetic mousemedicine.diseaseIsletRatsTransplantationEndocrinologybusinessDiabetes
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Alginate encapsulation improves viability and integrity of cryopreserved pancreatic islets and multicellular spheroids: combined fluorescence, scanni…

2007

Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007

medicine.anatomical_structureScanning electron microscopeChemistryPancreatic isletsAlginate encapsulationBlock facemedicineBiophysicsAnalytical chemistryMulticellular spheroidInstrumentationFluorescenceCryopreservationMicroscopy and Microanalysis
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