Encapcelrapy

Differentiation and Encapsulation of β-like cells for the treatment of Type 1 Diabetes Mellitus

 T1DM is an autoimmune disease that leads to the destruction of pancreatic β-cells and thus hampers an effective glycaemia regulation. Because of the induced insulin deficiency, the development of efficient and long lasting bioartificial organs as new treatment is now a therapeutic option to better control and regulate glycaemia within physiological concentrations. It is an absolute requirement as untreated and persistent hyperglycemia can lead to severe health problems affecting eyes, kidneys, nerves and heart, largely caused, at the molecular level, by protein glycation and oxidative stress. Current treatments such as insulin-based therapies or pancreas and β-cell/organ transplantation present major disadvantages such as the regular need for insulin injections or the administration of immunosuppressant drugs and a shortage of donor organs, respectively. While many efforts and research activity are invested in developing encapsulated beta-cells to restore or compensate for Langerhans beta-cell destruction, several challenges remain to achieve the ultimate therapeutic goal.

This proposal aims to develop innovative capsules containing beta-like cells derived from iPSCs that could correct and regulate glycemia. The research programme is divided into 5 interconnected workpackages :1) Differentiation of hiPSCs into insulin secreting β-like cells, 2) Design of a hybrid capsule with a core/shell structure, 3) Microcapsules synthesis via an innovative droplet-based microfluidic approach, 4) In vitro cell viability and metabolic activity and 5) In vivo biocompatibility and glycaemia regulation.

We will develop a new approach for the replacement of the deficient β-cells by new stem cell-derived beta-cells and their encapsulation within immune-protective microcapsules. With such engineered devices, the lack of insulin production caused by endogenous beta-cell death will be counterbalanced and rejection by the immune system will be prevented without the use of immunosuppressive drugs. The combined expertise of the Cell and Molecular Biological laboratories (Prof. Arnould) and the chemistry and materials (Prof. Su) will be combined to select appropriate stem cells (induced pluripotent stem cells or iPSCs: HEL115.6) for their differentiation in 2D and 3D culture conditions and to develop the matrix for the synthesis of the capsules and the encapsulation of differentiated stem cells via an innovative microfluid device (= microfluidic droplet-based double emulsion synthesis).

In order to protect the therapeutic cells from the host immune cell responders and cytokines, the strategy will be to develop cell capsules based on the design of a “core-shell silica-alginate-titania matrix” hybrid material surrounding a Matrigel component for β-cell encapsulation that display a good chemical and mechanical resistances, appropriate porosity and good bio-compatibility combined with a protective/adaptive stiffness gel matrix. The first goal of this project is to use differentiated human iPSCs (hiPSCs). The long differentiation protocol will be optimized in order to obtain glucose-responsive, insulin-secreting β-like cells with the highest possible efficiency rate. The second main objective will be to generate and optimize a core-shell hybrid material that allows the full immune protection of the encapsulated cells. The third objective will be to encapsulate the beta-like cells will be performed by droplet-based microfluidic approach: w/w/o double emulsion system keeping cell biology properties and tunable porosity with good diffusion properties for nutrients, metabolites and hormones compatible overtime and stable after implantation to rat animal models. Functional and metabolic activities will be addressed. The cell viability of differentiated and encapsulated cells will be evaluated by measuring their oxygen consumption over time (oximetry with a Clark electrode) and cell biological activity and function, will be assessed by glucose-sensitivity and insulin release. In vivo assays in rats with chemically induced T1DM (streptozotocin or alloxan) will allow to evaluate the adequacy of the hybrid material in terms of stability, biocompatibility, glucose-sensitivity and insulin secretion to correct altered glycemia.