We investigated the ability of human processed lipoaspirate-derived (PLA) cells to regenerate corneal stroma in experimental animals. In a first set of experiments, we tested the biosafety and immunogenicity of human PLA stem cells transplanted into the corneal stroma of rabbits. No immune response was elicited even though we used immunecompetent animals. PLA cells survived up to 10 weeks post-transplant, maintained their shape and remained intermingled between the stroma without disrupting its histological pattern. Interestingly, transparency was preserved even 10 weeks after the transplant, when PLA cells formed a discontinuous layer in the stroma. In a second set of experiments, regeneration of the corneal stroma by PLA cells was assessed, creating a niche by partial ablation of the stroma. After 12 weeks, human cells were disposed following a multilayered pattern, and differentiated into functional keratocytes, as assessed by the expression of aldehyde-3-dehydrogenase and cornea-specific proteoglycan keratocan.

Based on our results, we believe that adipose-derived adult stem cells can be a cell source for stromal regeneration and repopulation in diseased corneas. The low health impact of the surgical procedure performed to obtain the PLA cells provides this cell source with an additional beneficial feature for their possible future autologous use in human patients.