Mesenchymal stromal cell therapy for scarring: A systematic review of clinical and preclinical studies

Background: Mesenchymal stromal/stem cell (MSC) transplantation has emerged as a promising therapeutic strategy for managing cutaneous scarring, an issue associated with significant aesthetic and functional morbidity. This systematic review evaluates the potential of MSCs to modulate scarring, highlighting their efficacy and distinct mechanisms from traditional scar treatments. 

Materials and Methods: The review adheres to the PRISMA guidelines. We followed a prospectively registered protocol and conducted comprehensive searches in the PubMed and EMBASE databases. Eleven studies, including preclinical and clinical trials, met the inclusion criteria. Study quality was assessed using the ROBINS-I and Cochrane Risk of Bias 2 tools. 

Discussion: MSC and MSC-conditioned medium therapies derived from adipose tissue, bone marrow, or the umbilical cord demonstrated significant improvements in scar appearance, reductions in thickness and volume, and beneficial remodeling of collagen structures. MSC treatment positively influenced inflammatory and immunomodulatory responses, as reflected by the regulation of cytokines and fibrotic biomarkers. However, the heterogeneity in methodologies, MSC sources, and administration routes limits the ability to make conclusive statements. Furthermore, insufficient transparency in MSC preparation challenges clinical reproducibility and application. 

Conclusion: MSC therapy is becoming increasingly important in regenerative medicine. Based on our findings, MSC therapy demonstrates potential in scar remodeling through antifibrotic and immunomodulatory effects. However, robust randomized controlled trials and standardized product reporting are essential to confirm long-term efficacy and safety, improve reproducibility, and facilitate clinical translation. Advancements in these areas will define the future role of MSC therapies in managing scarring.