Most studied focused on the transplantation of stem cells in the central nervous system have demonstrated a cell survival of 2%–8%. Because of such poor viability, biomaterial and scaffold-based approaches have become attractive in recent years.
However, the selection of biomaterial is critical for successful cell transplantation. We have previously discussed the importance of selection of biomaterial for scaffold development, and a new study takes these concepts further by testing biomaterial-specific transplantation of cells into multiple tissues of injured mice.
Authored by the lab of Dr. Molly Shoichet at the Department of Chemical Engineering and Applied Chemistry at the University of Toronto, a new study describes an injectable hydrogel based on hyaluronan (HA) and methylcellulose (MC), which is known to be minimally swelling, bioresorbable, and fast gelling for improved stem cell transplantation. Two types of cells – neural stem cells and progenitor cells – were used for that purpose, and they were injected in stroke injured brains and retinas of target mice, respectively.
The paper, titled A Hyaluronan-Based Injectable Hydrogel Improves the Survival and Integration of Stem Cell Progeny following Transplantation, was published in Stem Cell Reports last week.
The authors used a previously developed hyaluronan (HA) and methylcellulose (MC) (HAMC) hydrogel, which they injected, alongside target cells as a blend, into the brain or sub-retinal space of adult CD10 mice.
Immunocytochemical analysis of euthanized mice was carried out to evaluate differentiation of transplanted cells. Evaluation of the number of animals with surviving cells was carried out via anti-GFP to identify the transplanted cells. They observed improved cell distribution and NSC differentiation toward GFAP-positive cells, which they postulate was at least partially caused by the positive transplantation environment.
They further reported that the HAMC-based transplantation approach resulted in the greatest absolute number of adult stem cell-derived rods integrated into neural retina to date.
The authors did not postulate about any of the mechanisms underprinning differentiation of their transplanted cells, leaving it as something to be followed up on alongside additional work related to further development of this biomaterial-based delivery system.
This remains, nonetheless, a valuable study that elucidated a significant advance in the difficult area of CNS cell transplantation.