Isolation, banking, encapsulation and transplantation of different types of Langerhans islets

Antosiak-Iwańska, Magdalena; Sitarek, E; Sabat, M; Godlewska, Ewa; Kinasiewicz, Joanna; Weryński, Andrzej

doi:10.20452/pamw.681

Cited by 10 publications

(5 citation statements)

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“…Immunoisolation does not require the use of immunosuppressive agents and, theoretically, allows for transplantation of islets from nonhuman sources, thereby solving the donor shortage problem. The principle applicability of immunoisolation was previously shown in experimental systems (1,12,14,24) and in pilot clinical trials (17). However, encapsulated islets have a limited graft survival time that has been attributed to lack of sufficient supply of oxygen (13,21).…”

Section: Introductionmentioning

confidence: 87%

Enhanced Oxygen Supply Improves Islet Viability in a New Bioartificial Pancreas

et al. 2013

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The current epidemic of diabetes with its overwhelming burden on our healthcare system requires better therapeutic strategies. Here we present a promising novel approach for a curative strategy that may be accessible for all insulin-dependent diabetes patients. We designed a subcutaneous implantable bioartificial pancreas (BAP)-the "b-Air"-that is able to overcome critical challenges in current clinical islet transplantation protocols: adequate oxygen supply to the graft and protection of donor islets against the host immune system. The system consists of islets of Langerhans immobilized in an alginate hydrogel, a gas chamber, a gas permeable membrane, an external membrane, and a mechanical support. The minimally invasive implantable device, refueled with oxygen via subdermally implanted access ports, completely normalized diabetic indicators of glycemic control (blood glucose intravenous glucose tolerance test and HbA1c) in streptozotocin-induced diabetic rats for periods up to 6 months. The functionality of the device was dependent on oxygen supply to the device as the grafts failed when oxygen supply was ceased. In addition, we showed that the device is immunoprotective as it allowed for survival of not only isografts but also of allografts. Histological examination of the explanted devices demonstrated morphologically and functionally intact islets; the surrounding tissue was without signs of inflammation and showed visual evidence of vasculature at the site of implantation. Further increase in islets loading density will justify the translation of the system to clinical trials, opening up the potential for a novel approach in diabetes therapy.

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Section: Introductionmentioning

confidence: 87%

Enhanced Oxygen Supply Improves Islet Viability in a New Bioartificial Pancreas

et al. 2013

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“…These biomaterials are designed to isolate surrounding tissues, thereby making transplanted cells inaccessible to host immune system and increasing the probability of xenograft survival. By enclosing a transplant with a semipermeable barrier, an ‘artificial immunoprivileged site’ could be created to shield engraft from destruction of host immune system (Paul et al, 2009 ; Antosiak-Iwanska et al, 2009 ). Such protective strategy for cells/tissues transplantation has been demonstrated efficient in pathological reversal of many diseases, such as central nervous system diseases, diabetes mellitus, hepatic diseases, amyotrophic lateral sclerosis, hemophilia, hypothyroidism, and cardiovascular diseases (Zhang et al, 2008 ; Grandoso et al, 2007 ; Colton, 1995 ; Desai et al, 2000 ; Sellitto et al, 1995 ).…”

Section: Biomaterials As Barriersmentioning

confidence: 99%

Biomaterials as carrier, barrier and reactor for cell-based regenerative medicine

et al. 2015

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Cell therapy has achieved tremendous success in regenerative medicine in the past several decades. However, challenges such as cell loss, death and immune-rejection after transplantation still persist. Biomaterials have been designed as carriers to deliver cells to desirable region for local tissue regeneration; as barriers to protect transplanted cells from host immune attack; or as reactors to stimulate host cell recruitment, homing and differentiation. With the assistance of biomaterials, improvement in treatment efficiency has been demonstrated in numerous animal models of degenerative diseases compared with routine free cell-based therapy. Emerging clinical applications of biomaterial assisted cell therapies further highlight their great promise in regenerative therapy and even cure for complex diseases, which have been failed to realize by conventional therapeutic approaches.

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“…In one of the pharmaceutical applications of alginate capsules, components can be masked from the immune system. There have been, for instance, efforts for encapsulating Langerhans islets in alginate composite capsules in order to produce insulin for the treatment of diabetes [6]. In this case, the donor cells were not recognized by the immune system because they were surrounded by thin membranes of calcium alginate [6].…”

Section: Introductionmentioning

confidence: 99%

Production, deformation and mechanical investigation of magnetic alginate capsules

Zwar

Kemna

Richter

et al. 2018

J. Phys.: Condens. Matter

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In this article we investigated the deformation of alginate capsules in magnetic fields. The sensitivity to magnetic forces was realised by encapsulating an oil in water emulsion, where the oil droplets contained dispersed magnetic nanoparticles. We solved calcium ions in the aqueous emulsion phase, which act as crosslinking compounds for forming thin layers of alginate membranes. This encapsulating technique allows the production of flexible capsules with an emulsion as the capsule core. It is important to mention that the magnetic nanoparticles were stable and dispersed throughout the complete process, which is an important difference to most magnetic alginate-based materials. In a series of experiments, we used spinning drop techniques, capsule squeezing experiments and interfacial shear rheology in order to determine the surface Young moduli, the surface Poisson ratios and the surface shear moduli of the magnetically sensitive alginate capsules. In additional experiments, we analysed the capsule deformation in magnetic fields. In spinning drop and capsule squeezing experiments, water droplets were pressed out of the capsules at elevated values of the mechanical load. This phenomenon might be used for the mechanically triggered release of water-soluble ingredients. After drying the emulsion-filled capsules, we produced capsules, which only contained a homogeneous oil phase with stable suspended magnetic nanoparticles (organic ferrofluid). In the dried state, the thin alginate membranes of these particles were rather rigid. These dehydrated capsules could be stored at ambient conditions for several months without changing their properties. After exposure to water, the alginate membranes rehydrated and became flexible and deformable again. During this swelling process, water diffused back in the capsule. This long-term stability and rehydration offers a great spectrum of different applications as sensors, soft actuators, artificial muscles or drug delivery systems.

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Isolation, banking, encapsulation and transplantation of different types of Langerhans islets

Cited by 10 publications

References 0 publications

Enhanced Oxygen Supply Improves Islet Viability in a New Bioartificial Pancreas

Enhanced Oxygen Supply Improves Islet Viability in a New Bioartificial Pancreas

Biomaterials as carrier, barrier and reactor for cell-based regenerative medicine

Production, deformation and mechanical investigation of magnetic alginate capsules

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