When a scar does not resolve, uncontrolled chronic inflammation can persist and elicits excessive scarring that leads to a range of abnormal phenotypes, such as hypertrophic and keloid scars. These pathologies result in significant impairment of quality of life over a long period of time. Existing treatment options are generally unsatisfactory, and there is mounting interest in innovative cell-based therapies. Despite the interest in mesenchymal stem cells (MSCs), there is yet to be a human clinical trial that investigates the potential of MSCs in treating abnormal scarring. A synthesis of existing evidence of animal studies may therefore provide insight into the barriers to human application.

The goal of a new study published in Cell and Tissue Research was to evaluate the effectiveness of MSC transplantation in the treatment of hypertrophic and keloid scars in in vivo models.

In this PRISMA systematic review, 11 case-control studies were identified that treated 156 subjects with MSCs or MSC-conditioned media. Ten studies assessed hypertrophic scars while one looked at keloid scars. All studies evaluated scars in terms of macroscopic and histological appearances and most incorporated immunohistochemistry.

All included studies found improvements in the above outcomes with MSC or MSC-conditioned media without complications

Hence, the findings support a role for MSC therapy in treating scars that needs further exploration.

Source: Cell and Tissue Research.2021 Jan 2. doi: 10.1007/s00441-020-03361-z.