Phenotypic and Functional Characterization of Müller Glia Isolated from Induced Pluripotent Stem Cell-Derived Retinal Organoids: Improvement of Retinal Ganglion Cell Function upon Transplantation.

Glaucoma is one of the leading causes of blindness, and there is an ongoing need for new therapies. Recent studies indicate that cell transplantation using Müller glia may be beneficial, but there is a need for novel sources of cells to provide therapeutic benefit. In this study, we have isolated Müller glia from retinal organoids formed by human induced pluripotent stem cells (hiPSCs) in vitro and have shown their ability to partially restore visual function in rats depleted of retinal ganglion cells by NMDA. Based on the present results, we suggest that Müller glia derived from retinal organoids formed by hiPSC may provide an attractive source of cells for human retinal therapies, to prevent and treat vision loss caused by retinal degenerative conditions. Stem Cells Translational Medicine 2019;8:775&784.

The Effect of Hypothermic and Cryogenic Preservation on Engineered Neural Tissue.

This study explored different approaches to preserve engineered neural tissue (EngNT), a stabilized, cellular collagen hydrogel containing columns of aligned Schwann cells for nervous system repair. The ability to preserve EngNT without disrupting cellular and extracellular components and structures is important for clinical translation and commercialization. Stabilized cellular gels and EngNT constructs were preserved under various conditions and cell survival assessed using live/dead microscopy and metabolic assay. Optimal survival was recorded in hypothermic (4°C) conditions for 2-3 days using Hibernate®-A media and, for longer-term cryogenic storage (liquid nitrogen), using a mixture of 60% Dulbecco's modified Eagle's medium, 30% fetal bovine serum, and 10% dimethyl sulfoxide. Functionality and structure of preserved EngNT were assessed in coculture with dorsal root ganglion neurons, which indicated that alignment of Schwann cells and the ability of EngNT to support and guide neuronal regeneration were not disrupted. The identification of conditions that preserve EngNT will inform development of storage and transport methodologies to support clinical and commercial translation of this technology and other therapies based on cellular hydrogels.

Three-dimensional alignment of schwann cells using hydrolysable microfiber scaffolds: strategies for peripheral nerve repair.

Injuries to the peripheral nervous system affect 1 in 1,000 individuals each year. The implication of sustaining such an injury is considerable with loss of sensory and/or motor function. The economic implications too are extensive running into millions of pounds (or dollars) annually for provision and support. The natural regrowth of peripheral nerves is possible for small gap injuries (of approximately 1-2 mm). However, patients with larger gap injuries require surgical intervention. The "gold standard" for repairing gap injuries is autografting; however, there are problems associated with this approach, and so, the use of nerve guidance conduits (NGC) is a realistic alternative. We outline in this chapter the development of an NGC that incorporates aligned poly-L-lactide fibres for supporting the growth of organised Schwann cells within a three-dimensional scaffold in vitro. A closed loop bioreactor for growing cells within NGC scaffolds is described together with a method of plasma deposition for modifying the microfibre surface chemistry (which improves the ability of Schwann cells to attach) and confocal microscopy for measuring cell viability and alignment within 3D constructs.