The Combined Effects of Hyaluronic Acid and Retinol on the Formation of Hypertrophic Scar Tissue in Wounds Modeled by Bacillus subtilis

In the past decade, there has been a high demand for safe, transparent, and ethically sourced ingredients in cosmetic products. However, about 30-40% of these products and their ingredients are not ethically sourced. Hyaluronic acid (HA) has gained attention for its skin benefits, particularly in healing damaged areas. Retinol, despite its long-standing popularity, is known to potentially irritate the skin. This study aimed to investigate how effectively HA inhibits hypertrophic and regular scarring in wounds using a model with B. subtilis. It is hypothesized that the higher the molar concentrations of HA and retinol, the increase in scar tissue growth, modeled by the zone of inhibition (ZOI) formed in the Petri dishes. Three solutions were prepared, including a control group with no chemical combination administered. 30 discs were soaked in each solution and placed in the center of each quadrant of 30 tryptic soy agar plates and incubated for 24 hours, forming zones of inhibition for most of the quadrants in the 30 plates, with the sizes of the zones of inhibition increasing consistently from the one molarity group to the three molarity group. The results indicated that HA and retinol are associated with worsening scarring. The increasing sizes of the ZOI, which showed a lack of bacterial growth, suggest a deficiency in cells needed for wound healing, leading to the conclusion that HA and retinol may hinder the healing process in wounds.