Researchers Hongpeng Zhang, et. al., investigated the treatment effect of different administrations of human umbilical cord-derived stem cells on hypertrophic scars on rabbit ears, and confirmed their hypothesis that stem cells can be used to treat hypertrophic scars. They published these findings in Lasers in Surgery and Medicine (January 2022).
The study included 30 New Zealand, female white rabbits. The researchers injected phospate buffered saline (PBS) into the scars on the right ear of each group as a control variable, and administered human umbilical cord-derived stem cells or conditioned medium of human umbilical cord-derived stem cells to the left ear through subcutaneous injection or fractional laser-assisted administration.
The researchers evaluated the ears using the scar elevation index (SEI). Calculation and sampling were performed five weeks after administration. The study also used H&E and Masson staining analysis and expression level detections of α-SMA, Collagen I, TGF-β1, IL-1β, and IL-6.
The severity of hyperplasia was lower in the treatment group. H&E and Masson staining results showed that inflammation in scars was greatly alleviated and the degree of fibrosis reduced post treatment in the stem cell- and conditioned medium-treated scars. There was no significant difference in the therapeutic effect between subcutaneous injection or fractional laser-assisted administration.
The results showed that both stem cells and conditioned medium can down-regulate SEI and factors expression levels in scars, but the stem cells had a greater therapeutic effect than the conditioned medium.