Cell sheets have previously shown greater efficacy for tissue repair than injections of single stem cells.

New research conducted by scientists at the Los Angeles Biomedical Research Institute and Emmaus Life Sciences, Inc. (both CA, USA) has demonstrated the possibility of producing scaffold-free engineered cell sheets. These cell ‘patches’ could enable better organ repair follow injury or disease.

Injection of stem cells to effect reversal of disease has been proven in the field of bone marrow transplantation for the immune system. However, in the case of organ repair, where stem cells are injected directly into the organ, their uncontrollable migration and low survival rates decreases the efficacy of this therapeutic technique. Cell sheets produced on natural and synthetic scaffolds can overcome the problem of cell migration, but can also lead to unwanted differentiation due to the scaffold movement.

In this study, human adipose-derived stem cells (hADSC) were seeded and grown into a multilayer cell sheet by allowing for extra growth once the hADSCs had reached confluence. The hADSCs in the multilayered sheet were differentiated into adipocytes before the sheet was harvested and identity confirmed via immunohistostaining.

“Our group has developed an easy and efficient method to engineer and harvest hADSC multilayer cell sheets (undifferentiated, adipocyte, osteogenic and chondrogenic), with the possibility of grafting an entire multilayer cell sheets on targeted organs or support”, commented the author in their paper.

Further study is required to learn to control the number of layers forming the cell sheet and understand the influence of the number of layers on the cell sheet therapeutic properties. The functionality of the sheet must also be confirmed in an animal model before it can be translated to the clinic. However, this “easy method to engineer graftable, scaffold-free cell sheets” shows promise to address this unmet need in the shortage of organs for transplantation.