The Molecular Mechanisms Involved in the Hypertrophic Scars Post-Burn Injury

Abstract

Scar formation is a normal response to skin injuries. During the scar-remodeling phase, scar tissue is usually replaced with normal, functional tissue. However, after deep burn injuries, the scar tissue may persist and lead to contractures around joints, a condition known as hypertrophic scar tissue. Unfortunately, current treatment options for hypertrophic scars, such as surgery and pressure garments, often fail to prevent their reappearance. One of the primary challenges in treating hypertrophic scars is a lack of knowledge about the molecular mechanisms underlying their formation. In this review, we critically analyze studies that have attempted to uncover the molecular mechanisms behind hypertrophic scar formation after severe burn injuries, as well as clinical trials conducted to treat post-burn hypertrophic scars. We found that most clinical trials used pressure garments, laser treatments, steroids, and proliferative inhibitors for hypertrophic scars, with outcomes measured using subjective scar scales. However, fundamental research using human burn injury biopsies has shown that pathways such as Transforming Growth factor β (TGFβ), Phosphatase and tensin homolog (PTEN), and Toll-like receptors (TLRs) could be potentially regulated to reduce scarring. Therefore, we conclude that more testing is necessary to determine the efficacy of these molecular targets in reducing hypertrophic scarring. Specifically, double-blinded clinical trials are needed, where the outcomes can be measured with more robust quantitative molecular parameters.