A hydrogel-based stem cell delivery system to treat retinal degenerative diseases

Regenerative strategies for retinal degenerative diseases are limited by poor cellular survival, distribution and integration after transplantation to the sub-retinal space. To overcome this limitations a stem cell delivery system was developed, taking advantage of the minimally-invasive, injectable and biodegradable properties of a blend of hyaluronan and methylcellulose (HAMC). The physical and biological properties of this unique HAMC formulation were studied. HAMC supported retinal stem-progenitor cell (RSPC) survival and proliferation in vitro. The blend was a viscous solution, exhibiting properties ideal for delivery to the sub-retinal space. In vivo transplantation studies in mice were carried out to investigate both the biodegradability of HAMC in the sub-retinal space over 7 days and the potential of HAMC as a cell delivery vehicle. RSPCs delivered in HAMC were more evenly distributed in the sub-retinal space than those delivered in traditional saline solutions, suggesting that HAMC is a promising vehicle for cellular delivery to the degenerating retina overcoming previously reported barriers to tissue integration in the retina such as cellular aggregation and non-contiguous distribution.