Efficacy of Paracrine Factors from Mesenchymal Stem Cells for Treating Biofilm-Infected Wounds in a Murine Model

Abstract

Background: Chronic wounds are a serious medical condition affecting over 6 million people in the United States. Biofilms, which alter the host immune response and establish a microenvironment that prevents wound healing, are intimately associated with the development of chronic wounds. Current treatment options do not specifically target the underlying molecular mechanisms of biofilm pathology. Paracrine factors secreted by mesenchymal stem cells (MSCs) have been demonstrated to play an important role in wound healing. The objective of this study was to examine the effects of the paracrine factors secreted from MSCs on reducing infection and accelerating wound closure in biofilm-infected wounds.Methods: MSCs were cultured by seeding on an extracellular matrix (ECM). The supernatant from MSCs containing paracrine factors were applied to mature <i>Pseudomonas aeruginosa</i> biofilms <i>in vitro</i> and the number of viable bacteria were quantitated. BALB/cJ mice were wounded and infected with <i>P. aeruginosa</i> biofilms and the paracrine factors from reprogrammed MSCs were applied topically. The wound surface area and colony forming units counts of the treatment group were compared to control (culture media) and biofilm (untreated) groups. Results: The paracrine factors from MSCs grown on ECM were found to reduce <i>P. aeruginosa</i> biofilm growth significantly (P<0.01). Wounds in the treatment group had lower bacterial counts and an increased rate of wound closure compared to non-treated mice wounds. Conclusion: The results indicate that paracrine factors from reprogrammed MSCs accelerated wound healing and reduced the bacterial burden in biofilm-infected wounds. Future studies are needed to further characterize this phenomenon.