A 78-year-old man was referred to clinic due to a 5-year history of weight loss, lethargy, and pathology showing hyponatremia. In the year prior, he had a hospital admission for symptomatic hyponatremia. MRI brain during that admission showed a 1-2 mm pituitary lesion of unknown significance.
View Article and Find Full Text PDFImplantation of insulin-secreting cells has been trialed as a treatment for Type 1 diabetes mellitus; however, the host immunogenic response limits their effectiveness. The authors developed a core-shell nanostructure of upconversion nanoparticle-mesoporous silica for controlled local delivery of an immunomodulatory agent, MCC950, using near-infrared light and validated it in models of fibrosis. The individual components of the nanosystem did not affect the proliferation of insulin-secreting cells, unlike fibroblast proliferation (p < 0.
View Article and Find Full Text PDFDrug-delivery vehicles have garnered immense interest in recent years due to unparalleled progress made in material science and nanomedicine. However, the development of stimuli-responsive devices with controllable drug-release systems (DRSs) is still in its nascent stage. In this paper, we designed a two-way controlled drug-release system that can be promoted and prolonged, using the external stimulation of near-infrared light (NIR) and protein coating.
View Article and Find Full Text PDFType 1 diabetes (T1D) is a chronic, lifelong metabolic disease. It is characterised by the autoimmune-mediated loss of insulin-producing pancreatic β cells in the islets of Langerhans (β-islets), resulting in disrupted glucose homeostasis. Administration of exogenous insulin is the most common management method for T1D, but this requires lifelong reliance on insulin injections and invasive blood glucose monitoring.
View Article and Find Full Text PDFImmunoprotection and oxygen supply are vital in implementing a cell therapy for type 1 diabetes (T1D). Without these features, the transplanted islet cell clusters will be rejected by the host immune system, and necrosis will occur due to hypoxia. The use of anti-rejection drugs can help protect the transplanted cells from the immune system; yet, they also may have severe side effects.
View Article and Find Full Text PDFIntroduction: Delirium is one of the most common conditions diagnosed in hospitalised older people and is associated with numerous adverse outcomes, yet there are no proven pharmacological treatments. Recent research has identified cerebral glucose hypometabolism as a pathophysiological mechanism offering a therapeutic target in delirium. Insulin, delivered via the intranasal route, acts directly on the central nervous system and has been shown to enhance cerebral metabolism and improve cognition in patients with mild cognitive impairment and dementia.
View Article and Find Full Text PDFReplacement of pancreatic β-cells is one of the most promising treatment options for treatment of type 1 diabetes (T1D), even though, toxic immunosuppressive drugs are required. In this study, we aim to deliver allogeneic β-cell therapies without antirejection drugs using a bioengineered hybrid device that contains microencapsulated β-cells inside 3D polycaprolactone (PCL) scaffolds printed using melt electrospin writing (MEW). Mouse β-cell (MIN6) pseudoislets and QS mouse islets are encapsulated in alginate microcapsules, without affecting viability and insulin secretion.
View Article and Find Full Text PDFType 1 diabetes, characterized by autoimmune destruction of pancreatic beta cells, affects 41 million people worldwide. Beta cell replacement therapies have immense potential as a treatment option because pancreatic progenitors derived from human pluripotent stem cells can provide a near limitless supply of transplantable tissue. The key limitation of this approach is the need for lifelong use of immunosuppressive drugs that have undesirable side effects.
View Article and Find Full Text PDFNew and more efficient methods of gene editing have intensified the ethical and legal issues associated with editing germlines. Yet no research has separated the impact of hereditary concern on public attitudes from moral concern. This research compares the impact these two concerns have on public attitudes across five applications including, the prevention of human disease, human and animal research, animals for the use of human food and the enhancement of human appearance.
View Article and Find Full Text PDFTechnology is now available which facilitates gene editing and has recently been applied internationally to embryos in the laboratory. A 2002 law in Australia prohibits making heritable changes in embryos, regardless of whether the treated embryo is discarded thereafter. We sought to begin to understand public opinion in Australia about this matter, using a questionnaire given to the audience attending a Q and A panel of experts.
View Article and Find Full Text PDFHost reactivity to biocompatible immunoisolation devices is a major challenge for cellular therapies, and a human screening model would be of great value. We designed new types of surface modified barium alginate microspheres, and evaluated their inflammatory properties using human whole blood, and the intraperitoneal response after three weeks in Wistar rats. Microspheres were modified using proprietary polyallylamine (PAV) and coupled with macromolecular heparin conjugates (Corline Heparin Conjugate, CHC).
View Article and Find Full Text PDFPericapsular fibrotic overgrowth (PFO) is associated with poor survival of encapsulated islets. A strategy to combat PFO is the use of mesenchymal stem cells (MSC). MSC have anti-inflammatory properties and their potential can be enhanced by stimulation with proinflammatory cytokines.
View Article and Find Full Text PDFMitochondrial deoxyribonucleic acid (mtDNA) copy number is tightly regulated during pluripotency and differentiation. There is increased demand of cellular adenosine triphosphate (ATP) during differentiation for energy-intensive cell types such as hepatocytes and neurons to meet the cell's functional requirements. During hepatocyte differentiation, mtDNA copy number should be synchronously increased to generate sufficient ATP through oxidative phosphorylation.
View Article and Find Full Text PDFTransplantation of pancreatic islets encapsulated within immuno-protective microcapsules is a strategy that has the potential to overcome graft rejection without the need for toxic immunosuppressive medication. However, despite promising preclinical studies, clinical trials using encapsulated islets have lacked long-term efficacy, and although generally considered clinically safe, have not been encouraging overall. One of the major factors limiting the long-term function of encapsulated islets is the host's immunological reaction to the transplanted graft which is often manifested as pericapsular fibrotic overgrowth (PFO).
View Article and Find Full Text PDFMicroencapsulated islets are usually injected free-floating into the peritoneal cavity, so the position of the grafts remains elusive after transplantation. This study aims to assess magnetic resonance imaging (MRI) as a noninvasive means to track microencapsulated insulin producing cells following transplantation. Encapsulated insulin producing cells (MIN6 and human islets) were labelled with magnetic microspheres (MM), assessed for viability and insulin secretion, and imaged in vitro using a clinical grade 3 T MRI and in vivo using both clinical grade 3 T and research grade 11.
View Article and Find Full Text PDFPericapsular fibrotic overgrowth (PFO) is a problem that thwarts full implementation of cellular replacement therapies involving encapsulation in an immunoprotective material, such as for the treatment of diabetes. Mesenchymal stem cells (MSCs) have inherent anti-inflammatory properties. We postulated that coencapsulation of MSCs with the target cells would reduce PFO.
View Article and Find Full Text PDFType 2 diabetes is a growing problem, with 387 million people currently affected, and 592 million by 2035. Whilst diet and exercise are the corner stones of treatment, oral hypoglycaemic agents are often needed to achieve glycaemic control, thereby reducing the chance of long term diabetic complications. Biguanides and sulfonylureas have been the standard tablets used for this disorder, until 2005-7 when glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP4) inhibitors became available.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2014
Embryonic/pluripotent stem cells offer the possibility of an unlimited source of cells to be differentiated into beta cells. This requires differentiating the stem cells into pancreatic progenitors by tissue culture, and then transplanting into recipients for the final stages of development into mature beta-cells. Exposing embryonic stem cells seeded onto laminin coated PLGA scaffolds to biochemical cues resulted in enhanced expression of definitive endoderm markers compared to those differentiated on 2D monolayers.
View Article and Find Full Text PDFPlacenta derived human amniotic epithelial cells (hAEC) are an attractive source of stem cells for the generation of hepatocyte-like cells (HLC) for therapeutic applications to treat liver diseases. During hAEC differentiation into HLC, they become increasingly immunogenic, which may result in immune cell-mediated rejection upon transplantation into allogeneic recipients. Placing cells within devices such as alginate microcapsules can prevent immune cell-mediated rejection.
View Article and Find Full Text PDFPericapsular fibrotic overgrowth (PFO) is associated with poor survival of encapsulated pancreatic islets. Modification of the microcapsule membrane aimed at preventing PFO should improve graft survival. This study investigated the effect of macromolecular Corline Heparin Conjugate (CHC) binding on intrinsic properties of alginate microcapsules and assessed the anti-fibrotic potential of this strategy both in vitro and in vivo.
View Article and Find Full Text PDFXenotransplantation of microencapsulated fetal pig islet-like cell clusters (FP ICCs) offers a potential cellular therapy for type 1 diabetes. Although microcapsules prevent direct contact of the host immune system with the xenografted tissue, poor graft survival is still an issue. This study aimed to characterise the nature of the host immune cells present on the engrafted microcapsules and effects on encapsulated FP ICCs that were transplanted into immunocompetent mice.
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