Encapsulation of Thymol in Gelatin Methacryloyl (GelMa)-Based Nanoniosome Enables Enhanced Antibiofilm Activity and Wound Healing

Abstract

Non-healing wounds impose huge cost on patients, healthcare, and society, which are further fortified by biofilm formation and antimicrobial resistance (AMR) problems. Here, Thymol, an herbal antimicrobial agent, is utilized to combat AMR. For efficient delivery of Thymol gelatin methacryloyl (GelMa), a hydrophilic polymeric hydrogel with excellent biocompatibility combined with niosome was used to encapsulate Thymol. After optimization of the niosomal Thymol (Nio–Thymol) in the company of GelMa (Nio–Thymol@GelMa) to achieve maximum entrapment efficiency, minimum size, and low polydispersity index, the Thymol release peaked at 60% and 42% from Nio–Thymol@GelMa in medium with pH values of 6.5 and 7.4 after 72 h, respectively. Furthermore, Nio–Thymol@GelMa demonstrated higher antibacterial and anti-biofilm activity than Nio–Thymol and free Thymol against both Gram-negative and Gram-positive bacteria. Interestingly, compared with other obtained formulations, Nio–Thymol@GelMa also led to greater enhancement of migration of human dermal fibroblasts in vitro, and higher upregulation of the expression of certain growth factors such as FGF-1, and matrix metalloproteinases such as MMP-2 and MMP-13. These results suggest that Nio–Thymol@GelMa can represent a potential drug preparation for Thymol to enhance the wound healing process and antibacterial efficacy.